阅读说明：本技术 非水电解质二次电池和非水电解质二次电池的制造方法 (Nonaqueous electrolyte secondary battery and method for manufacturing nonaqueous electrolyte secondary battery ) 是由 中村利一 于 2018-05-17 设计创作，主要内容包括：本发明提供一种具有优异的电池特性和优异的可靠性的非水电解质二次电池。该非水电解质二次电池至少具备：包含负极合剂的非水电解质二次电池用负极、非水电解质二次电池用正极以及包含电解质和溶剂的电解液,其中,该负极合剂包含负极活性物质粉体,该负极活性物质粉体包含碳系材料和硅系材料,该碳系材料与该硅系材料的混合比(碳系材料(质量％)/硅系材料(质量％))为90质量％/10质量％～0质量％/100质量％,在达到电池电压0V的电流速率0.001ltA的深放电中,电池电压0V地点处的负极电位为3.2Vvs(Li/Li<Sup>+</Sup>)以下,该负极合剂中的电解质浓度大于除该负极合剂以外的该非水电解质二次电池中所存在的该电解液中的电解质浓度。(The present invention provides a nonaqueous electrolyte secondary battery having excellent battery characteristics and excellent reliability. The nonaqueous electrolyte secondary battery includes at least: a negative electrode for a nonaqueous electrolyte secondary battery comprising a negative electrode mixture, a positive electrode for a nonaqueous electrolyte secondary battery, and an electrolytic solution comprising an electrolyte and a solvent, wherein the negative electrode mixture comprises a negative electrode active material powder, the negative electrode active material powder comprises a carbon-based material and a silicon-based material, the mixing ratio of the carbon-based material to the silicon-based material (carbon-based material (% by mass)/silicon-based material (% by mass) is 90% by mass/10% by mass/0% by mass/100% by mass, and the negative electrode potential at a point of a battery voltage of 0V is 3.2Vvs (Li/Li) in deep discharge at a current rate of 0.001ltA at which the battery voltage reaches 0V + ) Hereinafter, the electrolyte concentration in the negative electrode mixture is greater than the electrolyte concentration in the electrolytic solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture.)

1. A nonaqueous electrolyte secondary battery includes at least:

a negative electrode for a nonaqueous electrolyte secondary battery, comprising a negative electrode mixture;

a positive electrode for a nonaqueous electrolyte secondary battery; and

an electrolyte solution comprising an electrolyte and a solvent,

the negative electrode mixture contains a negative electrode active material powder,

the negative electrode active material powder contains a carbon-based material and a silicon-based material,

the mixing ratio of the carbon-based material to the silicon-based material, i.e., the mass percentage of the carbon-based material/the mass percentage of the silicon-based material, is 90 mass%/10 mass% to 0 mass%/100 mass%,

in a deep discharge at a current rate of 0.001ltA to reach a battery voltage of 0V, the negative electrode potential at the battery voltage 0V site is 3.2Vvs (Li/Li)⁺) In the following, the following description is given,

the electrolyte concentration in the negative electrode mixture is greater than the electrolyte concentration in the electrolytic solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture.

2. The nonaqueous electrolyte secondary battery according to claim 1,

in the deep discharge at a current rate of 0.001ltA to a battery voltage of 0V, the negative electrode potential at the battery voltage 0V site is 3.15Vvs (Li/Li)⁺) The following.

3. The nonaqueous electrolyte secondary battery according to claim 1 or 2,

the nonaqueous electrolyte secondary battery includes a battery can having a base material containing iron and nickel-plated,

in the discharge curve obtained by deep discharge at a current rate of 0.001ltA to reach a battery voltage of 0V, there is no elliptic or plateau-like peak in the region where the battery voltage is 0.5 to 0V.

4. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 3,

the silicon-based material contains at least one compound selected from the group consisting of metal silicon, silicon oxide, silicon fluoride, silicon alloy, and lithium silicon fluoride.

5. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 4,

the negative electrode active material powder contains fibrous carbon and/or highly conductive powdery carbon.

6. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 5,

the electrolyte contains at least lithium hexafluorophosphate.

7. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 6, wherein the electrolyte contains at least a boron-containing lithium electrolyte salt.

8. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 7, wherein the negative electrode mixture contains at least polyvinylidene fluoride.

9. The nonaqueous electrolyte secondary battery according to any one of claims 1 to 8,

the ratio of the electrolyte concentration in the negative electrode mixture to the electrolyte concentration in an electrolyte solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture, namely "electrolyte concentration in the negative electrode mixture"/"electrolyte concentration in an electrolyte solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture" is greater than 1 and 2.5 or less.

10. A method for manufacturing a nonaqueous electrolyte secondary battery, the nonaqueous electrolyte secondary battery comprising at least: a negative electrode for a nonaqueous electrolyte secondary battery, a positive electrode for a nonaqueous electrolyte secondary battery, and an electrolytic solution, each containing a negative electrode active material powder, wherein the method for producing the nonaqueous electrolyte secondary battery comprises:

the method for producing a negative electrode for a nonaqueous electrolyte secondary battery comprises predoping lithium ions to a negative electrode active material powder by electrochemical treatment in a liquid containing an electrolyte, and mixing at least the predoped negative electrode active material powder with a binder; and

the nonaqueous electrolyte secondary battery is assembled by using the negative electrode for nonaqueous electrolyte secondary battery, the positive electrode for nonaqueous electrolyte secondary battery, and the electrolytic solution.

11. The method for manufacturing a nonaqueous electrolyte secondary battery according to claim 10,

the method for manufacturing the negative electrode for the nonaqueous electrolyte secondary battery includes:

coating at least the pre-doped negative electrode active material powder and a binder with a nonaqueous solvent to obtain a negative electrode coating material; and

the negative electrode coating material is applied to a current collector and dried and press-molded to form an electrode plate.

12. A battery pack is provided with:

the nonaqueous electrolyte secondary battery according to any one of claims 1 to 9;

a control unit that controls the use state of the nonaqueous electrolyte secondary battery; and

and an opening/closing unit that switches the use state of the nonaqueous electrolyte secondary battery in accordance with the instruction of the control unit.

13. A vehicle is provided with:

the nonaqueous electrolyte secondary battery according to any one of claims 1 to 9;

a driving force conversion device that receives the supply of electric power from the nonaqueous electrolyte secondary battery and converts the electric power into driving force of the vehicle; and

and a driving unit that drives the motor based on the driving force.

14. An electricity storage system is provided with:

an electricity storage device having the nonaqueous electrolyte secondary battery according to any one of claims 1 to 9;

a power consumption device to which power is supplied from the nonaqueous electrolyte secondary battery;

a control device that controls supply of electric power from the nonaqueous electrolyte secondary battery to the electric power consumption device; and

and a power generation device for charging the nonaqueous electrolyte secondary battery.

15. An electric power tool is provided with:

the nonaqueous electrolyte secondary battery according to any one of claims 1 to 9; and

and a movable part to which electric power is supplied from the nonaqueous electrolyte secondary battery.

16. An electronic device comprising the nonaqueous electrolyte secondary battery according to any one of claims 1 to 9, and receiving supply of electric power from the nonaqueous electrolyte secondary battery.

Technical Field

The present technology relates to a nonaqueous electrolyte secondary battery and a method for manufacturing the nonaqueous electrolyte secondary battery, and more particularly to a nonaqueous electrolyte secondary battery and a method for manufacturing the nonaqueous electrolyte secondary battery, and a battery pack, a vehicle, an electricity storage system, an electric power tool, and an electronic apparatus.

Background

In recent years, in the technical fields of electronic devices such as Personal Computers (PCs) and mobile communication terminals, automobiles such as electric automobiles, and new energy systems such as wind power generation, the demand for batteries, particularly nonaqueous electrolyte secondary batteries, has been rapidly expanding.

For example, a nonaqueous secondary battery has been proposed, which is characterized in that, in a nonaqueous secondary battery comprising a positive electrode, a negative electrode and a nonaqueous electrolyte, the positive electrode is capable of electrochemically occluding and releasing lithiumWherein the negative electrode contains SiOx (0.3. ltoreq. x.ltoreq.1.6) formed with a binder, and the electrode unit is pressurized to 3Kgf/cm during charge and discharge²As described above (see patent document 1), there has been proposed a lithium secondary battery comprising a negative electrode having a negative electrode active material and a negative electrode current collector, a positive electrode, and a nonaqueous electrolyte, wherein the negative electrode active material is a material that is alloyed with lithium during charging and increases in volume, the negative electrode active material is provided on the negative electrode current collector so as to be in direct contact with the negative electrode current collector, and the negative electrode active material contains lithium in a state in which lithium is not contained in the negative electrode active material and lithium having a total capacity of 8% or more in a lithium-free state is contained in the negative electrode active material in a state in which discharge is terminated (see patent document 2).

In addition, for example, there has been proposed a method for predoping lithium, in which a material capable of doping lithium and a lithium metal are mixed in the presence of a solvent (see patent document 3), and a method for manufacturing a predoping electrode, comprising: a pre-doping and slurry adjusting step of mixing a material capable of doping lithium and a lithium metal in the presence of a solvent to adjust a slurry capable of coating; a coating step of coating the slurry on a current collector; and a drying step of drying the slurry coated on the current collector (see patent document 4).

Further, for example, a nonaqueous electrolyte electricity storage element is proposed, which is characterized by comprising: a nonaqueous electrolyte electricity storage device has been proposed which comprises a positive electrode containing a positive electrode active material capable of inserting or releasing anions, a negative electrode containing a negative electrode active material capable of occluding or releasing at least one of metal lithium and lithium ions, a first separator between the positive electrode and the negative electrode, and a nonaqueous electrolyte formed by dissolving a lithium salt in a nonaqueous solvent, wherein the nonaqueous electrolyte electricity storage device contains a solid lithium salt at a discharge voltage of 4.0V and 25 ℃, and has an ion exchange membrane between the first separator and at least one of the positive electrode and the negative electrode (see patent document 5), and which comprises: the present invention provides a lithium secondary battery including a positive electrode containing a positive electrode active material capable of inserting or releasing anions, a negative electrode containing a negative electrode active material capable of occluding or releasing at least one of metal lithium and lithium ions, a nonaqueous electrolytic solution formed by dissolving a lithium salt in a nonaqueous solvent, and a first separator between the positive electrode and the negative electrode, wherein at least one of the positive electrode, the negative electrode, and the separator contains a solid lithium salt, and the solubility of the lithium salt in the nonaqueous solvent is not more than the saturation solubility (see patent document 6).

Disclosure of Invention

Technical problem to be solved by the invention

However, the nonaqueous electrolyte secondary batteries (secondary batteries) according to the techniques proposed in patent documents 1 to 6 may not be able to further improve battery characteristics and reliability. Therefore, the present situation is that a nonaqueous electrolyte secondary battery is desired in which battery characteristics and reliability are further improved.

Therefore, the present technology has been made in view of such circumstances, and a main object thereof is to provide a nonaqueous electrolyte secondary battery having excellent battery characteristics and excellent reliability, and a method for manufacturing the nonaqueous electrolyte secondary battery. In addition, a main object of the present technology is to provide a battery pack, a vehicle, a power storage system, an electric power tool, and an electronic device, each of which includes a nonaqueous electrolyte secondary battery having excellent battery characteristics and excellent reliability.

Means for solving the technical problem

The present inventors have conducted intensive studies to solve the above-mentioned object, and as a result, succeeded in developing a nonaqueous electrolyte secondary battery having excellent battery characteristics and excellent reliability, and a method for manufacturing the nonaqueous electrolyte secondary battery, and have completed the present technology.

That is, the present technology provides a nonaqueous electrolyte secondary battery including at least: a negative electrode for a nonaqueous electrolyte secondary battery, comprising a negative electrode mixture; a positive electrode for a nonaqueous electrolyte secondary battery; and an electrolyte solution containing an electrolyte and a solvent, wherein the negative electrode mixture contains a negative electrode active material powder containing a carbon-based material and a silicon-based material, the mixing ratio of the carbon-based material to the silicon-based material (carbon-based material (% by mass)/silicon-based material (% by mass) is 90% by mass/10% by mass/0% by mass/100% by mass, and the negative electrode potential at a 0V point of the battery voltage is 3.2Vvs (Li/Li) in deep discharge at a current rate of 0.001ltA at which the battery voltage reaches 0V⁺) Hereinafter, the electrolyte concentration in the negative electrode mixture is greater than the electrolyte concentration in the electrolytic solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture.

With the nonaqueous electrolyte secondary battery according to the present technology, in the deep discharge at a current rate of 0.001ltA to a battery voltage of 0V, the negative electrode potential at the battery voltage 0V site may be 3.15Vvs (Li/Li)⁺) The following.

The nonaqueous electrolyte secondary battery according to the present technology may include a battery can including a base material containing iron and nickel-plated on the base material, and in the nonaqueous electrolyte secondary battery according to the present technology, in a discharge curve obtained by deep discharge at a current rate of 0.001ltA that reaches a battery voltage of 0V, an elliptical or plateau-shaped peak may not be present in a region where the battery voltage is 0.5 to 0V.

In the nonaqueous electrolyte secondary battery according to the present technology, the silicon-based material may include at least one compound selected from the group consisting of metal silicon, silicon oxide, silicon fluoride, a silicon alloy, and lithium silicofluoride.

In the nonaqueous electrolyte secondary battery according to the present technology, the negative electrode active material powder may contain fibrous carbon and/or highly conductive powdery carbon.

In the nonaqueous electrolyte secondary battery according to the present technology, the electrolyte may contain at least lithium hexafluorophosphate.

In the nonaqueous electrolyte secondary battery according to the present technology, the electrolyte may contain at least a boron-containing lithium electrolyte salt.

In the nonaqueous electrolyte secondary battery according to the present technology, the negative electrode mixture may contain at least polyvinylidene fluoride.

In the nonaqueous electrolyte secondary battery according to the present technology, a ratio of the electrolyte concentration in the negative electrode mixture to the electrolyte concentration in an electrolytic solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture ("electrolyte concentration in negative electrode mixture"/"electrolyte concentration in an electrolytic solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture") may be more than 1 and 2.5 or less.

In addition, the present technology provides a method for manufacturing a nonaqueous electrolyte secondary battery including at least: a negative electrode for a nonaqueous electrolyte secondary battery, a positive electrode for a nonaqueous electrolyte secondary battery, and an electrolytic solution, each containing a negative electrode active material powder, wherein the production method comprises: the method for producing a negative electrode for a nonaqueous electrolyte secondary battery comprises predoping lithium ions to the negative electrode active material powder by electrochemical treatment in a liquid containing an electrolyte, and mixing at least the predoped negative electrode active material powder with a binder.

In the method of manufacturing a nonaqueous electrolyte secondary battery according to the present technology, the method of manufacturing a negative electrode for a nonaqueous electrolyte secondary battery may include: coating at least the pre-doped negative electrode active material powder and a binder with a nonaqueous solvent to obtain a negative electrode coating material; and coating the negative electrode coating material on a current collector, drying and forming an electrode plate by press (roll) forming.

Further, in the present technology,

provided is a battery pack, which is provided with: a nonaqueous electrolyte secondary battery according to the present technology; a control unit that controls the use state of the nonaqueous electrolyte secondary battery; and a switch unit for switching the use state of the nonaqueous electrolyte secondary battery according to the instruction from the control unit,

provided is a vehicle provided with: a nonaqueous electrolyte secondary battery according to the present technology; a driving force conversion device that receives the supply of electric power from the nonaqueous electrolyte secondary battery and converts the electric power into driving force of the vehicle; and a driving section for driving the motor in accordance with the driving force,

provided is an electricity storage system provided with: an electricity storage device having the nonaqueous electrolyte secondary battery according to the present technology; a power consumption device to which power is supplied from the nonaqueous electrolyte secondary battery; a control device that controls supply of electric power from the nonaqueous electrolyte secondary battery to the electric power consumption device; and a power generation device for charging the nonaqueous electrolyte secondary battery,

provided is an electric power tool, which is provided with: a nonaqueous electrolyte secondary battery according to the present technology; and a movable portion to which electric power is supplied from the nonaqueous electrolyte secondary battery,

provided is an electronic device which is provided with the nonaqueous electrolyte secondary battery according to the present technology and receives power supply from the nonaqueous electrolyte secondary battery.

Effects of the invention

According to the present technology, battery characteristics and reliability can be improved. Further, the effects described herein are not necessarily limited thereto, and may be any of the effects described in the present disclosure or different effects from these effects.

Drawings

Fig. 1 is a graph showing the discharge results of example 1 and comparative example 1 according to the present technology.

Fig. 2 is a diagram showing a pre-doping unit 1 of lithium ions.

Fig. 3 is a diagram illustrating the pre-doping unit 2 of lithium ions.

Fig. 4 is a graph showing the discharge results of example 1 and comparative example 1 according to the present technology.

Fig. 5 is a graph showing the discharge results of example 1 and comparative example 4 according to the present technology.

Fig. 6 is a block diagram showing a configuration of an application example (an example of a battery pack) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 7 is a block diagram showing a configuration of an application example (an example of a vehicle) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 8 is a block diagram showing a configuration of an application example (an example of a power storage system) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 9 is a block diagram showing a configuration of an application example (an example of an electric power tool) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 10 is a block diagram showing a configuration of an application example (an example of an electronic device) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 11 is a block diagram showing a configuration of application example 1 (an example of a printed circuit board) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 12 is a diagram showing an example of the structure of application example 2 (example of a universal credit card) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 13 is a diagram showing an example of the configuration of application example 3 (an example of a wrist-worn activity meter) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 14 is a diagram showing an example of the configuration of application example 3 (an example of a wrist-worn activity meter) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 15 is a diagram showing a configuration of application example 3 (an example of a wrist-worn electronic device) of a nonaqueous electrolyte secondary battery according to the present technology.

Fig. 16 is an exploded perspective view showing the structure of application example 4 (example of a smart watch) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 17 is a diagram showing a part of the internal structure of application example 4 (an example of a tape-type electronic device) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 18 is a block diagram showing a circuit configuration of application example 4 (an example of a tape-type electronic device) of the nonaqueous electrolyte secondary battery according to the present technology.

Fig. 19 is a diagram showing a specific example of the structure of application example 5 (an example of a glasses-type terminal) of the nonaqueous electrolyte secondary battery according to the present technology.

Detailed Description

Preferred embodiments for carrying out the present technology are described below. The embodiments described below show an example of a representative embodiment of the present technology, and do not narrowly explain the scope of the present technology.

The following description is made in order.

1. Summary of the present technology

2. First embodiment (example of nonaqueous electrolyte Secondary Battery)

3. Second embodiment (example of method for manufacturing nonaqueous electrolyte secondary battery)

4. Use of nonaqueous electrolyte secondary battery

4-1. outline of use of nonaqueous electrolyte Secondary Battery

Third embodiment (example of Battery pack)

4-3 fourth embodiment (example of vehicle)

Fifth embodiment (example of Electrical storage System)

4-5 sixth embodiment (example of electric tool)

4-6 seventh embodiment (example of electronic device)

<1 > summary of the present technology

First, an outline of the present technology will be described.

When a negative electrode is formed by adding a silicon-based material to a carbon-based material as an active material used in a nonaqueous electrolyte secondary battery having an active material capable of occluding or releasing lithium ions, the following two problems may occur as the ratio of the silicon-based material becomes larger.

The first problem is deterioration (capacity reduction), can cracking, or battery swelling caused by a reduction in current collecting performance. As the ratio of the silicon-based material becomes larger, the expansion of the mixture layer accompanying charging becomes larger, and deterioration (capacity reduction) accompanying the charge-discharge cycle process such as electrical isolation of the silicon-based material in the mixture layer due to charge-discharge expansion and contraction or reduction in current collecting performance due to separation of the mixture layer from the current collecting foil occurs. In both the cylindrical battery and the laminate battery, deterioration due to reduction in current collecting performance occurs, and there are also problems that the can is broken in the cylindrical battery and the battery swells in the laminate battery.

The second problem is deterioration (capacity reduction) due to the generation of irreversible capacity after charging. The irreversible capacity caused by charge and discharge of the silicon-based material is larger than that of the active material of the carbon-based material, and does not completely converge even after the cycle has elapsed, and therefore, this causes a problem as a cause of capacity reduction accompanying the charge and discharge cycle.

In order to solve the first problem, there are the following methods: the adhesive strength between the mixture layers or the collector foils is improved by using a polyimide/amide resin binder having high adhesive strength or by heat treatment of the negative electrode plate in a CMC-SBR-based electrode or the like to improve the adhesive strength by thermal hardening modification of the binder.

In order to solve the second problem, there are the following methods: li ions are occluded (pre-doped) by sticking Li metal or the like on the negative electrode plate before assembling the battery, so as to replenish the amount of the irreversible capacity loss portion in the negative electrode before forming the battery.

As a first technique, a battery has been proposed in which a polyimide/amide binder is used to enhance adhesion and Li ions are doped into a negative electrode or a negative electrode active material SiOx after the battery is manufactured. The pre-doping method is a method for utilizing an internal battery reaction caused by adhesion of Li metal to the manufactured negative electrode plate. As a second technique, a lithium secondary battery has been proposed, which is characterized in that 8% or more of lithium in the negative electrode active material in a discharge-terminated state is pre-doped into the negative electrode active material before charge and discharge. The pre-doping method is a method for utilizing an internal battery reaction caused by adhesion of Li metal to the manufactured negative electrode plate.

In both of the above techniques, after a negative electrode plate is produced by painting, coating, and press-molding an uncharged negative electrode active material, metal lithium or the like is stuck to the negative electrode plate before assembling the battery, and thereby pre-doping treatment of lithium ions is performed while the battery is left to stand after an electrolyte is injected. That is, a method of pre-doping lithium ions by utilizing a so-called internal battery reaction has been proposed, in which since the natural potential of the negative electrode active material is a high potential much higher than the redox potential of metal lithium, metal lithium is immediately dissolved after charging, and electrons are transferred to the current collector (note that, in the present disclosure, the current collector may be used by replacing the current collector with a current collector foil substrate or a current collector foil). However, since the negative electrode plate is obtained by press-molding a mixture layer composed of a negative electrode active material in an uncharged and unexpanded form, the negative electrode plate cannot sufficiently improve the current collecting performance and the cycle characteristics of the negative electrode plate, which are caused by separation of the mixture layer from a current collecting foil core body due to expansion and contraction of the negative electrode active material caused by charge and discharge, regardless of the presence or absence of the lithium ion predoping. In particular, in a system having a high content of the Si-containing negative electrode active material, the above problem is more significant.

The lithium ion pre-doping into the negative electrode as described above does not contribute to the long-term cycle process such as 500 cycles, and is insufficient in the effect of improving deterioration due to the reduction in current collecting performance under stress accompanying the change in the thickness of the negative electrode due to the charge expansion and discharge shrinkage of the active material as described above.

In addition, there is a technique of mixing carbon with lithium metal having an oxidation-reduction potential at a potential lower than the natural potential of carbon only and mixing the carbon with LiPF-free lithium metal₆Mixing the electrolytes with a specific solvent to realize pre-doping in the carbon powderHetero Li ions. It is preferable to use the particulate metallic lithium having a reduced surface area, but in actual confirmation, a clear pre-doping effect of lithium ions cannot be exerted.

The natural potential of carbon itself is about 3.6V relative to Li, even if it comes into contact with metallic lithium as 6C + xLi + nxe^-→C6Li_x(A) It is also necessary to transfer sufficient electrons to the respective active materials, and if lithium metal is pasted to a negative plate roll-formed on a current collecting foil, Li → Li⁺+e^-(B) The generated electrons are transferred to the next active material through the Cu foil, and thus the (a) reaction is continuously generated using the electrons and occlusion of Li ions, that is, pre-doping is generated.

However, in a system in which the respective active material particles move in a separated state, such as the above-described "kneading", the effect cannot be actually confirmed.

Based on the above situation, the present technology can improve and maintain the battery characteristics and reliability of the nonaqueous electrolyte secondary battery. More specifically, according to the present technology, in a nonaqueous electrolyte secondary battery manufactured by press-molding a negative electrode using an active material powder that has been expanded by charging (Li ion pre-doping) and using the negative electrode plate, even in a system in which the ratio of a silicon material in the composition (mixing ratio) of a carbon material/silicon material active material is greatly increased, the adverse effect on the current collecting property with a current collecting foil due to expansion and contraction during charging and discharging can be reduced, and a nonaqueous electrolyte secondary battery exhibiting good charge and discharge cycle characteristics can be obtained.

The nonaqueous electrolyte secondary battery according to the present technology is, for example, a cylindrical or rectangular lithium ion secondary battery or a laminated film type lithium ion secondary battery, and is suitably used for a battery pack, a vehicle, an electric storage system, an electric power tool, an electronic device, and the like.

<2 > first embodiment (example of nonaqueous electrolyte Secondary Battery) >

A nonaqueous electrolyte secondary battery according to a first embodiment (an example of a nonaqueous electrolyte secondary battery) of the present technology includes at least: negative electrode for nonaqueous electrolyte secondary battery comprising negative electrode mixture, positive electrode for nonaqueous electrolyte secondary battery, and battery,And an electrolytic solution containing an electrolyte and a solvent, wherein the negative electrode mixture contains a negative electrode active material powder containing a carbon-based material and a silicon-based material, the mixing ratio of the carbon-based material to the silicon-based material (carbon-based material (% by mass)/silicon-based material (% by mass) is 90% by mass/10% by mass/0% by mass/100% by mass, and the negative electrode potential at a 0V point of the battery voltage is 3.2Vvs (Li/Li) in deep discharge at a current rate of 0.001ltA at which the battery voltage reaches 0V⁺) Hereinafter, the electrolyte concentration in the negative electrode mixture is greater than the electrolyte concentration in the electrolytic solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture.

According to the nonaqueous electrolyte secondary battery of the first embodiment according to the present technology, the battery characteristics and reliability can be improved and maintained, and more specifically, the adverse effect on the current collecting property with the current collecting foil due to expansion and contraction during charge and discharge can be reduced, and favorable charge and discharge cycle characteristics can be obtained.

Regarding the nonaqueous electrolyte secondary battery of the first embodiment relating to the present technology, it is preferable that the negative electrode potential at the battery voltage 0V point is 3.15Vvs (Li/Li) in deep discharge at a current rate of 0.001ltA to reach the battery voltage 0V⁺) The following. According to the preferred embodiment, the battery characteristics and reliability of the nonaqueous electrolyte secondary battery can be further improved and maintained.

In the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, by using the negative electrode active material powder in which 10 to 100%, preferably 30 to 100%, of charging is performed in advance and charging expansion is generated in advance, and by forming the electrode mixture layer as the negative electrode plate by painting, coating, and press forming, even if expansion and contraction of the active material occur due to charging and discharging of the battery, the change in thickness of the negative electrode can be suppressed to a very small degree, and therefore, the negative electrode plate for a nonaqueous electrolyte secondary battery including a carbon-based material and a silicon-based material, which is excellent in current collecting performance such as suppression of separation of the mixture from the current collector due to the influence of expansion and contraction of the active material due to charging and discharging of the battery, and which has excellent cycle characteristics, or the nonaqueous electrolyte secondary battery including the negative electrode plate can be obtained.

In the case of packaging a battery as a charged negative electrode plate, the opposite positive electrode may be previously adjusted to a charged state and packaged in the same manner as the negative electrode plate, for example, by a method of charging an electrode in an electrolytic bath. The reason is that the charging rates of the positive electrode and the negative electrode before assembly are arbitrary, but when the battery is initially charged as an assembled battery, lithium ions extracted from the positive electrode are stored, that is, charged to the pre-doped negative electrode, and therefore, the capacity of the negative electrode is greatly exceeded by the combination of the charging rates before assembly of the positive electrode and the negative electrode, and the capacity degradation is promoted.

Therefore, in the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, when the assembled battery is fully charged after the initial charge, the degree (%) of the negative electrode capacity corresponding to the irreversible capacity at the initial charge can be adjusted so as to be added to the full charge capacity at the initial charge of the battery, and a battery that is not overcharged can be manufactured.

For example, when the charge rate of the pre-doped negative electrode is 100% of the negative electrode capacity and L% is a portion corresponding to the irreversible capacity at the time of initial charging of the negative electrode, the positive electrode is adjusted in advance to a charge amount of 100-L% by electrode charging or the like, and the battery is assembled using these. After assembly, if the initial charge of L% is performed for full charge, the charging rate is 100% for the positive electrode and 100+ L% for the negative electrode. However, since the negative electrode irreversible capacity is partially lost when the second full charge is performed after the discharge, the charge rate at the second full charge is 100% of the positive electrode and 100% of the negative electrode, and a battery that does not become an overcharged battery can be produced.

(method of calculating irreversible Capacity portion at initial charging of negative electrode)

A negative electrode plate is produced by coating an active material obtained by mixing a carbon-based material or a silicon-based material such as SiO with a predetermined composition, a binder, a predetermined conductive agent typified by fibrous carbon such as vapor-grown carbon, and a predetermined solvent for coating, applying the resultant coating to a current collecting foil, and pressing the resultant coating, and is punched out into a predetermined size after drying, and a LiCoO is used as a counter electrode₂The positive electrode was prepared by the same method as the negative electrode, such as the positive electrode active material, binder, conductive agent, and the like, and the separator was inserted, and the electrolyte was injected to assemble a coin-type cell.

Charging: current 0.1ltA voltage 4.2V CCCV Charge stop Current 0.001ltA

Discharge: the current is 0.1ltA, the CC discharge termination voltage is 2.5V

The obtained initial charge capacity is several percent larger than the discharge capacity, and the difference in charge-discharge capacity in the second charge is a small difference of less than 0.5%. In the initial charge, lithium ions corresponding to the irreversible capacity of the negative electrode active material are consumed, and thus such a result is obtained.

Irreversible capacity at initial charging of negative electrode L (%)

{ (initial charge capacity) — (initial discharge capacity) }/(initial charge capacity) × 100 (%)

As for the method for manufacturing the negative electrode plate by precharging and predoping the negative electrode active material powder, which is used in the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, for example, the following two methods can be cited.

(method 1) negative electrode charging, lithium ion pre-doping charging in a liquid bath containing an electrolyte

Fig. 2 is a diagram illustrating pre-doping of lithium ions (method 1). Method 1 will be described with reference to fig. 2.

After the coated and dried electrode winding tape is provided with a wiring made of a copper wire or the like and immersed in a liquid containing an electrolyte, the counter electrode is made of metallic lithium, and the metallic lithium is dissolved by a charging operation or the like to occlude, i.e., predope, lithium ions into the negative electrode. Then, the electrode mixture is dried, peeled off and pulverized to obtain active material powder in which the active material powder is charged (expanded) and is pre-occluded, i.e., pre-doped with lithium ions. Then, the charged powder is coated with a nonaqueous solvent to form a coating, and the coating is applied to a current collector foil core, followed by drying, press molding, and electrode plate formation, thereby obtaining a negative electrode plate in which a mixture layer is press-molded from the active material powder having been charged and expanded.

(method 2) lithium ion pre-doping charging of negative electrode active material powder in liquid bath containing electrolyte

Fig. 3 is a diagram illustrating pre-doping of lithium ions (method 2). Method 2 will be described with reference to fig. 3.

After a liquid containing an electrolyte is sufficiently impregnated with an active material in a liquid tank, the liquid is pressed against a conductive metal container (conductive folder) having a shape that allows lithium ions to pass through, so that metal lithium is used as a counter electrode, and the metal lithium is dissolved by a charging operation or the like, thereby obtaining a charged (expanded) active material powder that is pre-occluded, i.e., pre-doped with lithium ions. Then, the charged powder is coated with a nonaqueous solvent to form a coating, and the coating is applied to a current collector foil core, followed by drying, press molding, and electrode plate formation, thereby obtaining a negative electrode plate in which a mixture layer is press-molded from the active material powder having been charged and expanded.

In the production of any one of the negative electrode plates described above (method 1) and (method 2), the negative electrode plate is formed by immersing the negative electrode plate in a liquid bath containing an electrolyte in a first stage, charging the negative electrode plate or the negative electrode plate in a powder state, drying the negative electrode plate in a second stage, drying the negative electrode plate to obtain a primary dried powder, painting the primary dried powder with a solution of PVDF binder in NMP, coating the primary dried powder on a current collector foil, and pressing the collector foil.

Therefore, as a result of intensive studies on the negative electrode plate of the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, when the electrolyte concentration is "in the negative electrode mixture" > "in the electrolyte present in the battery other than the negative electrode" in a state in which the battery is in operation, particularly when the ratio of "in the negative electrode mixture"/"in the electrolyte present in the battery other than the negative electrode" is greater than 1 and 2.5 or less, the first nonaqueous electrolyte secondary battery according to the present technology, in which the charge-discharge cycle characteristics are further improved, can be obtained more preferably. In addition, when the ratio of "in the negative electrode mixture"/"in the electrolyte present in the battery other than the negative electrode" is 1.2 or more and 2.0 or less, the first nonaqueous electrolyte secondary battery according to the present technology, in which the charge-discharge cycle characteristics are further improved, can be obtained more preferably.

The electrolyte concentration in the negative electrode mixture can be calculated from the above two results by analyzing and quantifying the elements constituting the electrolyte present in the negative electrode mixture by ICP or the like, and measuring the void volume (mL or mL/g) in the negative electrode mixture layer by mercury porosimeter or the like.

The electrolyte concentration (mol/L) contained in the negative electrode mixture can be calculated by analyzing and quantifying the elements constituting the electrolyte in the electrolyte solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture by ICP or the like with respect to the electrolyte concentration in the electrolyte solution present in the nonaqueous electrolyte secondary battery other than the negative electrode mixture.

The electrolyte of the electrolyte-containing liquid (methods 1 and 2) may be the same as or different from the electrolyte contained in the electrolyte solution injected at the time of battery assembly, and the nonaqueous solvent of the electrolyte-containing liquid may be the same as or different from the nonaqueous solvent contained in the electrolyte solution injected at the time of battery assembly.

For example, the electrolyte contained in the electrolyte-containing liquid is LiPF₆In the case of (3), the electrolyte contained in the electrolytic solution may be LiPF₆、LiBF₄At least one of LiBOB and LiSI.

For example, when the nonaqueous solvent contained in the electrolyte-containing liquid may be at least one of EC (ethylene carbonate), EMC (ethyl methyl carbonate), DMC (dimethyl carbonate), DEC (diethyl carbonate), MP (methyl propionate), PE (ethyl propionate), PP (propyl propionate), PB (butyl propionate), and PC (propylene carbonate), the nonaqueous solvent contained in the electrolytic solution may be at least one of EC (ethylene carbonate), EMC (ethyl methyl carbonate), DMC (dimethyl carbonate), DEC (diethyl carbonate), MP (methyl propionate), PE (ethyl propionate), PP (propyl propionate), PB (butyl propionate), and PC (propylene carbonate).

Further, the nonaqueous solvent contained in the electrolyte-containing liquid and the nonaqueous solvent contained in the electrolytic solution may contain an additive. When both the nonaqueous solvent contained in the electrolyte-containing liquid and the nonaqueous solvent contained in the electrolytic solution contain the additive, the additive may be contained in the same kind or different kinds. Examples of the additive include VC (vinylene carbonate), FEC (4-fluoroethyl carbonate), ES (ethylene sulfide), PS (propane sultone), BS (butane sultone), CHB (cyclohexylbenzene), and the like.

In addition, (method 3) is a method in which after the negative electrode plate obtained by coating, and press-molding the above-described uncharged negative electrode active material is produced, metallic lithium or the like is attached to the negative electrode plate before the battery is assembled, and a preliminary doping treatment of lithium ions is performed after the battery is charged.

In the double carbon capacitor, there is a case where a separator or a positive electrode, a negative electrode and a separator are mixed with LiPF in advance₆The technique of (1). When LiPF₆Is separated from the anion and PF₆ ^-Is occluded with Li by the positive electrode⁺When occluded by the negative electrode, by compensating for Li generated at the electrode interface⁺Or PF₆ ^-The ion concentration is reduced, and the cycle characteristics can be improved. However, the present invention relates to an improvement effect mainly focusing on various problems of the formation of the negative electrode carbon film. This technique is not a system for separating and occluding anions and cations as shown in the above technique, but Li⁺The lithium ion secondary battery of (1) is different from the above-described technical contents. The negative electrode active material (powder) in the present technology may be a mixed active material of a certain carbon-based material and SiO, or may be a mixed active material with another carbon-based material or another silicon-based material.

[ negative electrode for nonaqueous electrolyte Secondary Battery ]

The nonaqueous electrolyte secondary battery according to the first embodiment of the present technology includes a negative electrode for a nonaqueous electrolyte secondary battery including a negative electrode mixture. For example, the negative electrode for a nonaqueous electrolyte secondary battery may have a negative electrode mixture on one or both surfaces of a negative electrode current collector. The negative electrode current collector may be formed in a foil shape, for example, and may be formed of any one or two or more kinds of conductive materials such as copper, nickel, and stainless steel.

[ negative electrode mixture ]

The negative electrode mixture provided in the negative electrode for a nonaqueous electrolyte secondary battery contains at least a powder of a negative electrode active material, and may further contain a binder (binder) and a conductive agent. In addition, in addition to containing pre-doped lithium, at least an electrolyte may be contained, including examples of the above electrolyte species.

The negative electrode active material powder includes a carbon-based material and a silicon-based material. The carbon-based material and the silicon-based material will be described in detail below.

[ carbon-based Material ]

Since the carbon-based material has a very small change in crystal structure during Li occlusion and release, a high energy density and excellent cycle characteristics can be obtained. The carbon-based material can function as a conductive agent for the negative electrode. The carbon-based material may be, for example, graphitizable carbon, graphite, or the like. However, it is preferable that the surface spacing of the (002) plane in the non-graphitizable carbon is 0.37nm or more and the surface spacing of the (002) plane in the graphite is 0.34nm or less. More specifically, the carbon includes pyrolytic carbons, cokes, glassy carbon fibers, calcined organic polymer compounds, activated carbon, carbon blacks and the like. The coke includes pitch coke, needle coke, petroleum coke, and the like. The calcined organic polymer compound is obtained by calcining (carbonizing) a polymer compound such as a phenol resin or a furan resin at an appropriate temperature. In addition, the carbon-based material may be low crystalline carbon heat-treated at a temperature of about 1000 ℃ or lower, or may be amorphous carbon. The shape of the carbon-based material may be any of fibrous, spherical, granular and scaly.

[ silicon-based Material ]

The silicon-based material may be any of a simple substance, an alloy, and a compound of Si (silicon) (silicon oxide, silicon fluoride, lithium silicon fluoride, and the like), two or more of them, or a material having at least a part of one or two or more phases of them. It should be noted that the term "simple substance" merely means a simple substance in a general sense (a small amount of impurities may be contained), and does not necessarily mean a simple substance having a purity of 100%.

The Si alloy contains, for example, one or two or more elements selected from Sn, Ni, Cu, Fe, Co, Mn, Zn, In, Ag, Ti, Ge, Bi, Sb, and Cr, as constituent elements other than Si. The Si compound contains any one or two or more of C, O, F and the like as a constituent element other than Si, for example. The Si compound may contain, for example, any one or two or more of the elements described for the Si alloy as constituent elements other than Si.

Alloys and compounds of Si, e.g. SiB₄、SiB₆、Li₂SiF₆、Mg₂Si、Ni₂Si、TiSi₂、MoSi₂、CoSi₂、NiSi₂、CaSi₂、CrSi₂、Cu₅Si、FeSi₂、MnSi₂、NbSi₂、TaSi₂、VSi₂、WSi₂、ZnSi₂、SiC、Si₃N₄、Si₂N₂O、SiO_v(0<v is less than or equal to 2), LiSiO and the like. It is noted that SiO_vV in (3) may be 0.2<v<1.4。

[ mixing ratio of carbon-based material and silicon-based material ]

The mixing ratio (mass% ratio) of the carbon-based material to the silicon-based material is a mixing ratio (carbon-based material (% by mass)/silicon-based material (% by mass)) of the carbon-based material to the silicon-based material, and is 90 mass%/10 mass%/0 mass%/100 mass%, and preferably 90 mass%/10 mass%/50 mass%. According to this preferred embodiment, the battery characteristics and reliability of the nonaqueous electrolyte secondary battery can be further improved and maintained.

The negative electrode active material powder may contain, in addition to the carbon-based material and the silicon-based material, a material containing either one or both of a metal element and a semimetal element as a constituent element. This is because a high energy density can be obtained. The metal material may be any of a simple substance, an alloy, and a compound, two or more of them, or a material having at least one or two or more phases of them in part. Further, the alloy includes a material containing one or more metal elements and one or more semimetal elements, in addition to a material composed of two or more metal elements. In addition, the alloy may contain a non-metallic element. The structure thereof includes a solid solution, a eutectic crystal (eutectic mixture), an intermetallic compound, and a coexisting substance of two or more of them.

The metal element and the semimetal element are, for example, any one or two or more of metal elements and semimetal elements capable of forming an alloy with Li. Specifically, examples thereof include Mg, B, Al, Ga, In, Ge, Sn, Pb, Bi, Cd, Ag, Zn, Hf, Zr, Y, Pd and Pt.

The binder is not particularly limited, and includes, for example, one or two or more of synthetic rubber, polymer material, and the like.

Examples of the synthetic rubber include styrene butadiene rubber, fluorine rubber, ethylene propylene diene, and the like, and examples of the polymer material include polyvinylidene fluoride, polyimide, and the like, and preferably polyvinylidene fluoride.

The coating solvent used for preparing the negative electrode mixture may be any solvent as long as it is a solvent capable of kneading the negative electrode active material, the binder, the conductive agent, and the like into a paste, but the negative electrode active material predoped in the above (methods 1 and 2) contains predoped lithium and may be deactivated by reaction with water, and therefore, a nonaqueous solvent is preferable, and N-methylpyrrolidone (NMP) is more preferable. In addition to NMP, for example, PC (propylene carbonate), THF (tetrahydrofuran), and the like can be considered, but NMP is preferable in view of compatibility with a binder such as PVDF (polyvinylidene fluoride).

[ electrolyte ]

The nonaqueous electrolyte secondary battery according to the first embodiment of the present technology includes an electrolytic solution containing an electrolyte and a solvent. The electrolyte may further contain other materials such as the above-mentioned additives.

[ electrolyte ]

The electrolyte (electrolyte salt) contained in the electrolytic solution contains, for example, one or two or more kinds of salts such as lithium salts. However, the electrolyte may contain, for example, a salt other than a lithium salt. The other salt may be, for example, a light metal salt other than a lithium salt.

The lithium salt is, for example, lithium hexafluorophosphate (LiPF)₆) Lithium tetrafluoroborate (LiBF)₄) Lithium bis (oxalato) borate (LiBOB), lithium fluorooxalato borate (LiFOB), lithium difluoro (oxalato) borate (lidob), lithium bis (fluorosulfonyl) imide (LiFSI), lithium hexafluoroarsenate (LiAsF)₆) Lithium tetraphenylborate (LiB (C)₆H₅)₄) Lithium methanesulfonate (LiCH)₃SO₃) Lithium trifluoromethanesulfonate (LiCF)₃SO₃) Lithium aluminum tetrachloride (LiAlCl)₄) Dilithium hexafluorosilicate (Li)₂SiF₆) Lithium chloride (LiCl), lithium bromide (LiBr), and the like. This is because excellent battery capacity, cycle characteristics, storage characteristics, and the like can be obtained.

Among them, LiPF is preferable₆、LiBF₄More preferably LiPF₆. This is because a higher effect can be obtained because the internal resistance is reduced. However, the electrolyte is not limited to the above series of materials, and may be another material.

The content of the electrolyte is not particularly limited, but is preferably 0.3 to 3.0mol/kg relative to the solvent. This is because high ion conductivity can be obtained.

[ solvent ]

The solvent includes one or more kinds of non-aqueous solvents such as organic solvents. Examples of the nonaqueous solvent include cyclic carbonates, chain carbonates, lactones, chain carboxylates, and nitriles. This is because excellent battery capacity, cycle characteristics, storage characteristics, and the like can be obtained. Examples of the cyclic carbonate include ethylene carbonate, propylene carbonate, and butylene carbonate, and examples of the chain carbonate include dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and propyl methyl carbonate. The lactone is, for example, γ -butyrolactone, γ -valerolactone, and the like. The carboxylic acid ester is, for example, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, methyl isobutyrate, methyl pivalate, ethyl pivalate or the like. The nitrile is, for example, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropionitrile or the like.

In addition, the nonaqueous solvent may be, for example, 1, 2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1, 3-dioxolane, 4-methyl-1, 3-dioxolane, 1, 3-dioxane, 1, 4-dioxane, N-dimethylformamide, N-methylpyrrolidone, N-methyloxazolidinone, N' -dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethylsulfoxide, or the like. Since the same advantages can be obtained.

Among them, any one or two or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are preferable. This is because more excellent battery capacity, cycle characteristics, storage characteristics, and the like can be obtained. In this case, a combination of a high-viscosity (high dielectric constant) solvent (e.g., a relative dielectric constant. epsilon. 30) such as ethylene carbonate and propylene carbonate and a low-viscosity solvent (e.g., a viscosity of 1 mPas or less) such as dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate is more preferable. This is because the dissociation property of the electrolyte salt and the mobility of the ion are improved.

In particular, the solvent may contain one or more of unsaturated cyclic carbonate, halogenated carbonate, sultone (cyclic sulfonate) and acid anhydride. This is because the chemical stability of the electrolyte is improved. The unsaturated cyclic carbonate refers to a cyclic carbonate having one or more unsaturated bonds (carbon-carbon double bonds), and examples thereof include vinylene carbonate, vinyl ethylene carbonate, and methylene ethylene carbonate. The halogenated carbonate refers to a cyclic or chain carbonate containing one or two or more halogens as constituent elements. Examples of the cyclic halogenated carbonates include 4-fluoro-1, 3-dioxolan-2-one and 4, 5-difluoro-1, 3-dioxolan-2-one. Examples of the chain halogenated carbonates include fluoromethyl methyl carbonate, bis (fluoromethyl) carbonate, and difluoromethyl methyl carbonate. Examples of the sultone include propane sultone and propene sultone. Examples of the acid anhydride include succinic anhydride, ethanedisulfonic anhydride, and sulfobenzoic anhydride. However, the solvent is not limited to the above series of materials, and may be other materials.

[ Positive electrode for nonaqueous electrolyte Secondary Battery ]

The nonaqueous electrolyte secondary battery according to the first embodiment of the present technology includes a positive electrode for a nonaqueous electrolyte secondary battery.

The positive electrode for a nonaqueous electrolyte secondary battery may have a positive electrode active material on one or both surfaces of the positive electrode current collector. Further, the positive electrode for a nonaqueous electrolyte secondary battery may include one or two or more of other materials such as a binder and a conductive agent. The positive electrode current collector is, for example, in the form of a foil, and may be formed of any one or two or more kinds of conductive materials such as aluminum, nickel, and stainless steel.

The positive electrode active material includes any one or two or more of materials capable of occluding and releasing lithium.

The positive electrode active material is preferably a lithium-containing compound, and more specifically, is preferably one or both of a lithium-containing composite oxide and a lithium-containing phosphoric acid compound. This is because a high energy density can be obtained.

The "lithium-containing composite oxide" refers to an oxide containing lithium and one or two or more elements (hereinafter referred to as "other elements" excluding lithium (Li)) as constituent elements, and has a layered rock-salt type crystal structure or a spinel type crystal structure. The "lithium-containing phosphoric acid compound" refers to a phosphoric acid compound containing lithium and one or two or more other elements as constituent elements, and has an olivine-type crystal structure.

The kind of the other element is not particularly limited, and is any one or two or more kinds of any elements. Among them, the other elements are preferably any one or two or more of elements belonging to groups 2 to 15 of the long period periodic table. More specifically, the other element is more preferably one or two or more metal elements selected from nickel (Ni), cobalt (Co), manganese (Mn), iron (Fe), and the like. This is because a high voltage can be obtained.

Among them, the lithium-containing composite oxide having a layered rock-salt type crystal structure is preferably any one or two or more compounds represented by formulae (21) to (23), respectively.

Li_aMn_(1-b-c)Ni_bM11_cO_(2-d)F_e……(21)

(M11 represents at least one of cobalt (Co), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), zirconium (Zr), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W). a to e satisfy the conditions of 0.8. ltoreq. a.ltoreq.1.2, 0. ltoreq. b.ltoreq.0.5, 0. ltoreq. c.ltoreq.0.5, (B + c) <1, -0.1. ltoreq. d.ltoreq.0.2 and 0. ltoreq. e.ltoreq.0.1, wherein the composition of lithium differs depending on the charge-discharge state, a is a value in the fully discharged state.)

Li_aNi_(1-b)M12_bO_(2-c)F_d……(22)

(M12 represents at least one of cobalt (Co), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W). a to d satisfy the conditions of 0.8. ltoreq. a.ltoreq.1.2, 0.005. ltoreq. b.ltoreq.0.5, -0.1. ltoreq. c.ltoreq.0.2 and 0. ltoreq. d.ltoreq.0.1, wherein the composition of lithium differs depending on the charge-discharge state, and a represents a value in the complete discharge state.)

Li_aCo_(1-b)M13_bO_(2-c)F_d……(23)

(M13 represents at least one of nickel (Ni), manganese (Mn), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W). A to d satisfy the conditions of 0.8. ltoreq. a.ltoreq.1.2, 0. ltoreq. b.ltoreq.0.5, -0.1. ltoreq. c.ltoreq.0.2 and 0. ltoreq. d.ltoreq.0.1, wherein the composition of lithium differs depending on the charge-discharge state, and a represents a value in the complete discharge state.)

A specific example of the lithium-containing composite oxide having a layered rock-salt type crystal structure is LiNiO₂、LiCoO₂、LiCo_0.98Al_0.01Mg_0.01O₂、LiNi_0.5Co_0.2Mn_0.3O₂、LiNi_0.8Co_0.15Al_0.05O₂、LiNi_0.33Co_0.33Mn_0.33O₂、Li_1.2Mn_0.52Co_0.175Ni_0.1O₂And Li_1.15(Mn_0.65Ni_0.22Co_0.13)O₂And the like.

The lithium-containing composite oxide having a spinel-type crystal structure is preferably any one or two or more of the compounds represented by formula (24).

Li_aMn_(2-b)M14_bO_cF_d……(24)

(M14 represents at least one of cobalt (Co), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), molybdenum (Mo), tin (Sn), calcium (Ca), strontium (Sr) and tungsten (W). A-d satisfy the conditions that a is 0.9-1.1, B is 0-0.6, c is 3.7-4.1 and d is 0-0.1, wherein the composition of lithium varies depending on the charge and discharge state, and a is a value in a complete discharge state.)

A specific example of the lithium-containing composite oxide having a spinel-type crystal structure is LiMn₂O₄And the like.

The lithium-containing phosphoric acid compound having an olivine-type crystal structure is preferably any one or two or more of the compounds represented by formula (25).

Li_aM15PO₄……(25)

(M15 represents at least one of cobalt (Co), manganese (Mn), iron (Fe), nickel (Ni), magnesium (Mg), aluminum (Al), boron (B), titanium (Ti), vanadium (V), niobium (Nb), copper (Cu), zinc (Zn), molybdenum (Mo), calcium (Ca), strontium (Sr), tungsten (W) and zirconium (Zr). a satisfies 0.9. ltoreq. a.ltoreq.1.1. wherein the composition of lithium varies depending on the state of charge and discharge, and a represents a value in the state of complete discharge.)

A specific example of a lithium-containing phosphate compound having an olivine-type crystal structure is LiFePO₄、LiMnPO₄、LiFe_0.5Mn_0.5PO₄And LiFe_0.3Mn_0.7PO₄And the like.

The lithium-containing composite oxide may be any one of the compounds represented by formula (26), or two or more thereof.

(Li₂MnO₃)_x(LiMnO₂)_1-x……(26)

(x satisfies 0. ltoreq. x. ltoreq.1, where the composition of lithium differs depending on the charge and discharge state, and x is a value in a completely discharged state.)

The binder for the positive electrode includes, for example, one or two or more of synthetic rubber and a polymer material. Examples of the synthetic rubber include fluororubbers and ethylene propylene diene. Examples of the polymer material include polyvinylidene fluoride and polytetrafluoroethylene, a copolymer of vinylidene fluoride and hexafluoropropylene, polyacrylonitrile, and polyacrylic polymer polyimide.

The positive electrode conductive agent includes, for example, any one or two or more of carbon materials and the like. Examples of the carbon material include graphite, carbon black, acetylene black, ketjen black, and the like. The positive electrode conductive agent may be a metal material, a conductive polymer, or the like, as long as it is a material having conductivity.

In addition, the positive electrode material may be any one or two or more of an oxide, a disulfide, a chalcogenide, a conductive polymer, and the like. Examples of the oxide include titanium oxide, vanadium oxide, manganese dioxide, and the like. Examples of the disulfide include titanium disulfide, molybdenum sulfide and the like. The chalcogenide is, for example, niobium selenide or the like. Examples of the conductive polymer include sulfur, polyaniline, and polythiophene. However, the positive electrode material is not limited to the above-described series of materials, and may be another material.

[ spacers ]

The nonaqueous electrolyte secondary battery according to the first embodiment of the present technology may include a separator. The separator separates the positive electrode for a nonaqueous electrolyte secondary battery from the negative electrode for a nonaqueous electrolyte secondary battery, thereby preventing a short circuit of current due to contact between the two electrodes and allowing lithium ions to pass therethrough. The separator may be a porous film made of, for example, a synthetic resin, a ceramic, or the like, or a laminated film in which two or more kinds of porous films are laminated. Examples of the synthetic resin include polytetrafluoroethylene, polypropylene, and polyethylene.

<3. second embodiment (example of method for manufacturing nonaqueous electrolyte secondary battery) >

A method for manufacturing a nonaqueous electrolyte secondary battery according to a second embodiment (an example of a method for manufacturing a nonaqueous electrolyte secondary battery) related to the present technology is a method for manufacturing a nonaqueous electrolyte secondary battery including at least a negative electrode for a nonaqueous electrolyte secondary battery containing a negative electrode active material powder, a positive electrode for a nonaqueous electrolyte secondary battery, and an electrolytic solution, the method including: a method for producing a negative electrode for a nonaqueous electrolyte secondary battery, which comprises predoping lithium ions to a negative electrode active material powder by electrochemical treatment in a liquid containing an electrolyte, and mixing at least the predoped negative electrode active material powder with a binder, and a nonaqueous electrolyte secondary battery assembled using the negative electrode for a nonaqueous electrolyte secondary battery, a positive electrode for a nonaqueous electrolyte secondary battery, and an electrolytic solution.

The nonaqueous electrolyte secondary battery obtained by the method for manufacturing a nonaqueous electrolyte secondary battery according to the second embodiment of the present technology can improve and maintain battery characteristics and reliability, and more specifically, can reduce adverse effects on current collection from the current collecting foil due to expansion and contraction during charge and discharge, and can obtain good charge and discharge cycle characteristics.

The method of manufacturing a negative electrode for a nonaqueous electrolyte secondary battery preferably includes: coating at least the pre-doped negative electrode active material powder and the binder with a nonaqueous solvent to obtain a negative electrode coating material; the negative electrode coating is coated on a current collector, dried, and formed into an electrode plate by press (roll) forming.

Specific examples of the method for producing the negative electrode for a nonaqueous electrolyte secondary battery, which is the preliminary doping method, and the method for producing the negative electrode plate include the above-described (method 1) and (method 2). Further, the electrochemical treatment in the electrolyte-containing liquid for preliminary doping refers to a treatment utilizing an electrochemical reaction.

The positive electrode for a nonaqueous electrolyte secondary battery can be produced by the same production method as the method after the coating by the negative electrode production method.

The case of assembling a nonaqueous electrolyte secondary battery, for example, a cylindrical lithium ion secondary battery, using a negative electrode for a nonaqueous electrolyte secondary battery, a positive electrode for a nonaqueous electrolyte secondary battery, and an electrolytic solution is as follows.

(Battery Assembly)

First, a positive electrode lead is attached to a positive electrode current collector by welding or the like, and a negative electrode lead is attached to a negative electrode current collector by welding or the like. Subsequently, the positive electrode and the negative electrode were stacked with a separator interposed therebetween, and then wound to produce a wound electrode body, and a center pin was inserted into the winding center. Subsequently, the wound electrode assembly is housed inside the battery can while being sandwiched between a pair of insulating plates. In this case, the leading end portion of the positive electrode lead is attached to the safety valve mechanism by welding or the like, and the leading end portion of the negative electrode lead is attached to the battery can by welding or the like. Subsequently, an electrolytic solution in which an electrolyte is dispersed in a nonaqueous solvent is injected into the battery can and impregnated into the separator. Subsequently, the battery cover, the safety valve mechanism, and the thermistor element are crimped to the opening end portion of the battery can via the gasket.

<4. use of nonaqueous electrolyte Secondary Battery >

Hereinafter, the use of the nonaqueous electrolyte secondary battery will be described in detail.

<4-1. brief summary of the use of nonaqueous electrolyte Secondary Battery >

The application of the nonaqueous electrolyte secondary battery is not particularly limited, and any machine, equipment, appliance, device, system (an assembly of a plurality of pieces of equipment and the like) or the like that can use the nonaqueous electrolyte secondary battery as a driving power source, a power storage source for power storage and the like may be used. The nonaqueous electrolyte secondary battery used as a power source may be a main power source (power source to be preferentially used) or an auxiliary power source (power source used instead of or after switching from the main power source). When a nonaqueous electrolyte secondary battery is used as the auxiliary power supply, the type of the main power supply is not limited to the nonaqueous electrolyte secondary battery.

The nonaqueous electrolyte secondary battery is used, for example, as follows. Electronic devices (including portable electronic devices) such as notebook Personal computers, tablet Personal computers, mobile phones (e.g., smart phones, etc.), Personal Digital Assistants (PDAs), image pickup apparatuses (e.g., Digital still cameras, Digital video cameras, etc.), audio devices (e.g., portable audio players), game machines, cordless telephone handsets, electronic books, electronic dictionaries, radios, headsets, navigation systems, memory cards, pacemakers, hearing aids, lighting devices, toys, medical devices, robots, etc. Portable life appliances such as electric shavers. A backup power supply, and a storage device such as a memory card. Electric tools such as electric drills and electric saws. A battery pack used as a detachable power source for a notebook personal computer and the like. Medical electronic devices such as pacemakers and hearing aids. Vehicles such as electric vehicles (including hybrid vehicles). And a power storage system such as a household battery system for storing electric power in advance in preparation for an emergency or the like. Of course, the use of the nonaqueous electrolyte secondary battery may be other than the above.

Among them, the nonaqueous electrolyte secondary battery is effectively applicable to battery packs, vehicles, power storage systems, electric tools, electronic devices, and the like. This is because, since excellent battery characteristics are required, performance can be effectively improved by using the nonaqueous electrolyte secondary battery of the present technology. The battery pack is a power source using a nonaqueous electrolyte secondary battery, a so-called assembled battery, or the like. The vehicle is a vehicle that runs (travels) using the nonaqueous electrolyte secondary battery as a driving power source, and as described above, may be a vehicle (such as a hybrid vehicle) that is provided with a driving source other than the nonaqueous electrolyte secondary battery. The power storage system is, for example, a residential power storage system, and is a system using a nonaqueous electrolyte secondary battery as a power storage source. In the electricity storage system, electric power is stored in a nonaqueous electrolyte secondary battery that is an electric power storage source, and therefore, an electric power consumption device such as a household electrical appliance can be used using the electric power. The electric power tool is a tool in which a movable portion (for example, a drill) is movable using a nonaqueous electrolyte secondary battery as a driving power source. An electronic device is a device that exhibits various functions using a nonaqueous electrolyte secondary battery as a driving power source (power supply source).

Here, several application examples of the nonaqueous electrolyte secondary battery are specifically described. Note that the configurations of the application examples described below are merely exemplary, and thus the configurations of the application examples can be appropriately changed.

<4-2. third embodiment (example of Battery Package) >

A battery pack according to a third embodiment of the present technology includes: the present technology relates to a nonaqueous electrolyte secondary battery of a first embodiment, a control unit that controls a use state of the nonaqueous electrolyte secondary battery, and a battery pack including a switch unit that switches the use state of the nonaqueous electrolyte secondary battery in accordance with an instruction from the control unit. The battery pack according to the third embodiment of the present technology includes the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, which has excellent battery characteristics and excellent reliability, and therefore, the performance and reliability of the battery pack can be improved.

Hereinafter, a battery pack according to a third embodiment of the present technology will be described with reference to the drawings.

Fig. 6 shows a frame structure of the battery pack. The battery pack includes a control unit 61, a power supply 62, a switch unit 63, a current measuring unit 64, a temperature detecting unit 65, a voltage detecting unit 66, a switch control unit 67, a memory 68, a temperature detecting element 69, a current detecting resistor 70, a positive electrode terminal 71, and a negative electrode terminal 72, for example, in a case 60 formed of a plastic material or the like.

The control unit 61 controls the operation of the entire battery pack (including the use state of the power source 62), and includes, for example, a Central Processing Unit (CPU). The power source 62 includes one or more nonaqueous electrolyte secondary batteries (not shown). The power source 62 is, for example, a battery pack including two or more nonaqueous electrolyte secondary batteries, and the nonaqueous electrolyte secondary batteries may be connected in series, in parallel, or in a hybrid type. As an example, the power source 62 includes six nonaqueous electrolyte secondary batteries connected in series 2 in parallel 3.

The switch 63 switches the use state of the power source 62 (whether or not the power source 62 is connected to an external device) in accordance with an instruction from the control unit 61. The switch unit 63 includes, for example, a charge control switch, a discharge control switch, a charge diode, a discharge diode (both not shown), and the like. The charge control switch and the discharge control switch are semiconductor switches such as field effect transistors (MOSFETs) using metal oxide semiconductors, for example.

The current measuring unit 64 measures a current using the current detection resistor 70, and outputs the measurement result to the control unit 61. The temperature detector 65 measures the temperature using the temperature detection element 69, and outputs the measurement result to the controller 61. The temperature measurement results are used, for example, in the following cases: the control unit 61 performs charge/discharge control during abnormal heat generation, and the control unit 61 performs correction processing when calculating the remaining capacity. The voltage detection unit 66 measures the voltage of the nonaqueous electrolyte secondary battery in the power supply 62, converts the measured voltage into analog and digital, and supplies the converted voltage to the control unit 61.

The switch control unit 67 controls the operation of the switch unit 63 based on signals input from the current measuring unit 64 and the voltage detecting unit 66.

For example, when the battery voltage reaches the overcharge detection voltage, the switch control unit 67 turns off the switch unit 63 (charge control switch) and controls the charging current not to flow through the current path of the power supply 62. Thus, only the discharge diode can discharge the power source 62. For example, when a large current flows during charging, the switching control unit 67 blocks the charging current.

For example, when the battery voltage reaches the overdischarge detection voltage, the switch control unit 67 turns off the switch unit 63 (discharge control switch) and controls the current path through which the discharge current does not flow through the power supply 62. Thus, the power source 62 can be charged only by the charging diode. For example, when a large current flows during discharging, the switching control unit 67 blocks the discharging current.

In addition, in the nonaqueous electrolyte secondary battery, for example, the overcharge detection voltage is 4.2V ± 0.05V, and the overdischarge detection voltage is 2.4V ± 0.1V.

The memory 68 is, for example, an EEPROM or the like which is a nonvolatile memory. The memory 68 stores, for example, a numerical value calculated by the control unit 61, information (for example, internal resistance in an initial state) of the nonaqueous electrolyte secondary battery measured at the stage of the manufacturing process, and the like. Further, if the memory 68 is made to store the full charge capacity of the nonaqueous electrolyte secondary battery, the control section 61 can grasp information such as the remaining capacity.

The temperature detection element 69 measures the temperature of the power source 62 and outputs the measurement result to the control unit 61, and the temperature detection element 69 is, for example, a thermistor or the like.

The positive electrode terminal 71 and the negative electrode terminal 72 are terminals to which an external device (e.g., a notebook personal computer or the like) operated using the battery pack, an external device (e.g., a charger or the like) for charging the battery pack, and the like are connected. The power source 62 is charged and discharged through the positive electrode terminal 71 and the negative electrode terminal 72.

<4-3. fourth embodiment (example of vehicle) >

A vehicle according to a fourth embodiment of the present technology includes: a nonaqueous electrolyte secondary battery according to a first embodiment of the present technology, a driving force conversion device that converts electric power supplied from the nonaqueous electrolyte secondary battery into driving force, a driving unit that drives in accordance with the driving force, and a vehicle control device. The vehicle according to the fourth embodiment of the present technology has the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology having excellent battery characteristics and excellent reliability, and therefore, the performance and reliability of the vehicle can be improved.

A vehicle according to a fourth embodiment of the present technology will be described below with reference to fig. 7.

Fig. 7 schematically shows an example of the structure of a hybrid vehicle employing a series hybrid system to which the present technology is applied. A series hybrid system is a vehicle that runs by an electric power drive force conversion device using electric power generated by a generator driven by an engine or electric power temporarily stored in a battery.

This hybrid vehicle 7200 is mounted with an engine 7201, a generator 7202, an electric-power driving-force conversion device 7203, driving wheels 7204a, driving wheels 7204b, wheels 7205a, wheels 7205b, a battery 7208, a vehicle control device 7209, various sensors 7210, and a charging port 7211. The power storage device (not shown) is applied to the battery 7208.

Hybrid vehicle 7200 runs using electric-power drive force conversion device 7203 as a power source. One example of the electric power drive force conversion device 7203 is an electric motor. The electric power-drive force conversion device 7203 is operated by the electric power of the battery 7208, and the rotational force of the electric power-drive force conversion device 7203 is transmitted to the drive wheels 7204a, 7204 b. Further, the electric power driving force conversion device 7203 may be applied to an alternating current motor and a direct current motor by using direct current-alternating current (DC-AC) or reverse conversion (AC-DC conversion) where necessary. The various sensors 7210 control the engine speed via the vehicle control device 7209 and control the opening degree of a throttle valve (throttle opening degree), not shown. The various sensors 7210 include a speed sensor, an acceleration sensor, an engine speed sensor, and the like.

The rotational force of the engine 7201 is transmitted to the generator 7202, and electric power generated by the generator 7202 by the rotational force can be stored in the battery 7208.

When the hybrid vehicle is decelerated by a brake mechanism, not shown, resistance at the time of deceleration is applied as rotational force to the electric-drive-force conversion device 7203, and regenerative electric power generated by the electric-drive-force conversion device 7203 by the rotational force is stored in the battery 7208.

Battery 7208 is connected to an external power supply of the hybrid vehicle, and can receive electric power supply from the external power supply with charging port 211 as an input port and store the received electric power.

Although not shown, an information processing device that performs information processing related to vehicle control based on information related to the nonaqueous electrolyte secondary battery may be provided. As such an information processing apparatus, there is an information processing apparatus that displays the remaining battery amount based on information on the remaining battery amount, for example.

In addition, the series hybrid vehicle that runs by the electric motor using the electric power generated by the generator driven by the engine or the electric power temporarily stored in the battery has been described above as an example. However, the present disclosure can also be effectively applied to a parallel hybrid vehicle in which both the outputs of the engine and the motor are drive sources, and the three manners of running only with the engine, running only with the motor, and running with the engine and the motor are switched and used as appropriate. Further, the present technology can also be effectively applied to a so-called electric vehicle that travels only by driving of a drive motor without using an engine.

<4-4. fifth embodiment (example of Power storage System) >

A power storage system according to a fifth embodiment of the present technology includes: an electricity storage system including the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, an electric power consumption device that supplies electric power from the nonaqueous electrolyte secondary battery, a control device that controls the supply of electric power from the nonaqueous electrolyte secondary battery to the electric power consumption device, and a power generation device that charges the nonaqueous electrolyte secondary battery. The power storage system according to the fifth embodiment of the present technology includes the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology having excellent battery characteristics and excellent reliability, and therefore, the performance and reliability of the power storage system can be improved.

A residential power storage system as an example of a power storage system according to a fifth embodiment of the present technology will be described below with reference to fig. 8.

For example, in power storage system 9100 for house 9001, electric power is supplied from concentrated power system 9002 such as thermal power generation 9002a, nuclear power generation 9002b, and hydroelectric power generation 9002c to power storage device 9003 via power grid 9009, information grid 9012, smart meter 9007, and power hub 9008. At the same time, power is supplied to power storage device 9003 from an independent power supply such as in-home power generation device 9004. The electric power supplied to power storage device 9003 is stored. Power storage device 9003 is used to supply electric power used in house 9001. The same power storage system may be used for a building, not limited to the house 9001.

A home power generation device 9004, a power consumption device 9005, a power storage device 9003, a control device 9010 that controls each device, a smart meter 9007, and a sensor 9011 that acquires various information are provided in the house 9001. Each device is connected to the information network 9012 through the power grid 9009. As the in-home power generation device 9004, a solar cell, a fuel cell, or the like is used, and generated electric power is supplied to the power consumption device 9005 and/or the power storage device 9003. The power consumption devices 9005 are a refrigerator 9005a, an air conditioner 9005b, a television receiver 9005c, a bathroom 9005d, and the like. Further, the power consumption device 9005 includes an electric vehicle 9006. The electric vehicle 9006 is an electric vehicle 9006a, a hybrid vehicle 9006b, and an electric motorcycle 9006 c.

The nonaqueous electrolyte secondary battery (battery cell) of the present technology described above is applied to the power storage device 9003. Power storage device 9003 is formed of a nonaqueous electrolyte secondary battery or a capacitor. For example, a lithium ion secondary battery. The lithium ion secondary battery may be a stationary type, or may be used in an electric vehicle 9006. The smart meter 9007 has a function of measuring the amount of commercial power used and transmitting the measured amount of commercial power to the electric power company. The power grid 9009 may combine any one or more of dc power, ac power, and contactless power.

The various sensors 9011 are, for example, a human body sensor, an illuminance sensor, an object detection sensor, a power consumption sensor, a vibration sensor, a contact sensor, a temperature sensor, an infrared sensor, and the like. Information obtained by the various sensors 9011 is transmitted to the control device 9010. From the information from the sensor 9011, it is possible to grasp weather conditions, human conditions, and the like and automatically control the power consumption device 9005 to minimize energy consumption. Further, control device 9010 may transmit information regarding house 9001 to an external power company or the like via the internet.

The power line branching, dc/ac conversion, and other processes are performed by the power hub 9008. As a communication method of the information network 9012 connected to the control device 9010, there are a method of using a communication interface such as UART (Universal Asynchronous Receiver-Transmitter: Asynchronous serial communication transceiver circuit) and a method of using a sensor network based on a wireless communication standard such as bluetooth (registered trademark), ZigBee, Wi-Fi. The bluetooth (registered trademark) system is applicable to multimedia communication and performs one-to-many connection communication. ZigBee uses the physical layer of IEEE (Institute of Electrical and electronics Engineers) 802.15.4. Ieee802.15.4 is the name of a short-range Wireless Network standard called PAN (Personal Area Network) or W (Wireless) PAN.

The control device 9010 is connected to an external server 9013. The server 9013 may be managed by any one of the house 9001, an electric power company, and a service provider. The information transmitted and received by the server 9013 is, for example, power consumption information, life pattern information, electricity charges, weather information, natural disaster information, and information related to power transactions. These pieces of information may be transmitted and received from a power consumption device (e.g., a television receiver) inside the home, or may be transmitted and received from a device (e.g., a mobile phone) outside the home. Such information may be displayed on a device having a display function, for example, a television receiver, a mobile phone, a portable information terminal (PDA), or the like.

The control device 9010 for controlling each unit is configured by a CPU, a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and is accommodated in the power storage device 9003 in this example. The control device 9010 is connected to the power storage device 9003, the home power generation device 9004, the power consumption device 9005, various sensors 9011, and the server 9013 via the information network 9012, and has a function of adjusting the amount of commercial power used and the amount of power generated, for example. In addition, a function of trading electric power in the electric power market may be provided.

As described above, not only the electric power of the centralized power system 9002 such as the thermal power generation 9002a, the nuclear power generation 9002b, and the hydroelectric power generation 9002c, but also the generated electric power of the in-home power generation facility 9004 (solar power generation, wind power generation) can be stored in the power storage facility 9003. Therefore, even if the generated power of the in-home power generation device 9004 changes, it is possible to perform control to make the amount of power transmitted to the outside constant or only to require discharge. For example, the following method of use may be performed: the electric power obtained by solar power generation is stored in the power storage device 9003, the midnight electric power which is inexpensive at night is stored in the power storage device 9003, and the electric power stored in the power storage device 9003 is released and used in a time zone which is expensive in daytime.

In this example, although the example in which the control device 9010 is housed in the power storage device 9003 is described, the control device 9010 may be housed in the smart meter 9007 or may be configured separately. Further, power storage system 9100 may be used for a plurality of households in a multi-family house, or may be used for a plurality of individual houses.

<4-5. sixth embodiment (example of electric tool) >

An electric power tool according to a sixth embodiment of the present technology is an electric power tool including the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology and a movable portion to which electric power is supplied from the nonaqueous electrolyte secondary battery. The electric power tool according to the sixth embodiment of the present technology has the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology having excellent battery characteristics and excellent reliability, and therefore, the performance and reliability of the electric power tool can be improved.

An electric power tool according to a sixth embodiment of the present technology will be described below with reference to fig. 9.

Fig. 9 shows a frame structure of the electric power tool. The electric power tool is, for example, an electric drill, and includes a control unit 99 and a power supply 100 inside a tool body 98 formed of a plastic material or the like. A drill 101 as a movable portion is mounted to the tool body 98 so as to be operable (rotatable), for example.

The control unit 99 controls the operation of the entire electric power tool (including the use state of the power supply 100), and includes, for example, a CPU. The power supply 100 includes one or more nonaqueous electrolyte secondary batteries (not shown). The controller 99 supplies power from the power source 100 to the drill 101 in response to an operation of an operation switch, not shown.

<4-6. seventh embodiment (example of electronic apparatus) >

An electronic device according to a seventh embodiment of the present technology is an electronic device that includes the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology and receives power supply from the nonaqueous electrolyte secondary battery. As described above, the electronic device according to the seventh embodiment of the present technology is a device that exhibits various functions using a nonaqueous electrolyte secondary battery as a driving power source (power supply source). The electronic device according to the seventh embodiment of the present technology includes the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology, which has excellent battery characteristics and excellent reliability, and therefore, the performance and reliability of the electronic device can be improved.

An electronic device according to a seventh embodiment of the present technology will be described below with reference to fig. 10.

An example of the configuration of the electronic device 400 according to the seventh embodiment of the present technology will be described. The electronic device 400 includes an electronic circuit 401 of an electronic device main body and a battery pack 300. The battery pack 300 is electrically connected to the electronic circuit 401 via the positive terminal 331a and the negative terminal 331 b. The electronic apparatus 400 has a structure in which the battery pack 300 can be freely attached and detached by a user, for example. Note that the structure of the electronic apparatus 400 is not limited to this, and the battery pack 300 may be built into the electronic apparatus 400 so that the user cannot detach the battery pack 300 from the electronic apparatus 400.

When the battery pack 300 is charged, the positive terminal 331a and the negative terminal 331b of the battery pack 300 are connected to a positive terminal and a negative terminal of a charger (not shown), respectively. On the other hand, when the battery pack 300 is discharged (when the electronic device 400 is used), the positive terminal 331a and the negative terminal 331b of the battery pack 300 are connected to the positive terminal and the negative terminal of the electronic circuit 401, respectively.

Examples of the electronic device 400 include, but are not limited to, a notebook personal computer, a tablet personal computer, a mobile phone (e.g., a smartphone), a portable information terminal (PDA), an imaging device (e.g., a digital still camera, a digital video camera, etc.), an audio device (e.g., a portable audio player), a game machine, a cordless telephone handset, an electronic book, an electronic dictionary, a radio receiver, a headset, a navigation system, a memory card, a pacemaker, a hearing aid, a lighting device, a toy, a medical device, and a robot. As a specific example, a head-mounted display including an image display device, a wearing device for wearing the image display device on the head of an observer, and a mounting member for mounting the image display device on the wearing device, and an electronic apparatus using the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology as a driving power source, and a tape-type electronic apparatus including a plurality of segments connected in a tape shape, a plurality of electronic components arranged in the plurality of segments, and a flexible circuit board connecting the plurality of electronic components in the plurality of segments and arranged in at least one segment in a bent shape, for example, the nonaqueous electrolyte secondary battery according to the first embodiment of the present technology is an electronic apparatus arranged in the segments described above, will be described.

The electronic circuit 401 includes, for example, a CPU, a peripheral logic unit, an interface unit, a storage unit, and the like, and controls the entire electronic apparatus 400.

The battery pack 300 includes a battery pack 301 and a charge/discharge circuit 302. The assembled battery 301 is configured by connecting a plurality of nonaqueous electrolyte secondary batteries 301a in series and/or in parallel. The plurality of nonaqueous electrolyte secondary batteries 301a are connected in n parallel m series (n and m are positive integers), for example. Fig. 10 shows an example in which six nonaqueous electrolyte secondary batteries 301a are connected in 2 parallel and 3 series (2P 3S). As the nonaqueous electrolyte secondary battery 301a, the nonaqueous electrolyte secondary battery of the first embodiment is used.

At the time of charging, the charge-discharge circuit 302 controls charging of the battery pack 301. On the other hand, at the time of discharge (i.e., when the electronic device 400 is used), the charge and discharge circuit 302 controls discharge to the electronic device 400.