阅读说明：本技术 正极混合物、包含其的正极和锂二次电池 (Cathode mix, anode and lithium secondary battery comprising it ) 是由 宋周容 金锡九 金忍哲 金珠利 于 2018-11-27 设计创作，主要内容包括：本发明涉及一种正极混合物、包含该正极混合物的正极和锂二次电池。具体而言,该正极混合物包含过氧化锂(Li<Sub>2</Sub>O<Sub>2</Sub>)和铂(Pt),从而有效地抵消两个电极之间的不可逆容量失衡,并进一步增加正极的初始充电容量。(Anode and lithium secondary battery the present invention relates to a kind of cathode mix, comprising the cathode mix.Specifically, the cathode mix includes lithium peroxide (Li 2 O 2 ) and platinum (Pt), so that the irreversible capacity effectively canceled out between two electrodes is unbalance, and further increase the initial charge capacity of anode.)

1. a kind of cathode mix comprising:

Positive electrode active materials；

Conductive material；With

Include lithium peroxide (Li₂O₂) and platinum additive, wherein amount to 100 weight % platinum and the conductive material in, The content of platinum is 7 weight % up to 20 weight % or less.

2. cathode mix as described in claim 1, wherein the weight ratio of lithium peroxide and platinum is 100:7 to 100:20 (Li₂O₂:Pt)。

3. cathode mix as described in claim 1 is comprising lithium peroxide (Li₂O₂) and platinum the additive in institute Stating content shared in the total weight i.e. 100 weight % of cathode mix is 5 weight % to 10 weight %.

4. cathode mix as described in claim 1, wherein the conductive material is in the total weight of the cathode mix Shared content is 0.1 weight % to 10 weight % in 100 weight %.

5. cathode mix as described in claim 1, wherein the conductive material includes selected from by natural graphite, artificial stone One in group that ink, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, metallic fiber and polyphenylene derivatives form Kind is a variety of.

6. cathode mix as described in claim 1, wherein gross weight of the positive electrode active materials in the cathode mix Amount is that content shared in 100 weight % is 86 weight % to 88 weight %.

7. cathode mix as described in claim 1, wherein the positive electrode active materials include in cobalt, manganese, nickel or combinations thereof Metal and lithium one or more composite oxides.

8. cathode mix as described in claim 1 further includes adhesive.

9. a kind of anode, it includes cathode mixes described in claim 1.

10. a kind of lithium secondary battery, it includes anode, cathode and electrolyte as claimed in claim 9.

11. lithium secondary battery as claimed in claim 10, wherein when the lithium secondary battery once charges at room temperature 2.5V to 4.25V is (relative to Li/Li⁺) when, the charging capacity of the anode is 600mAh/g or more.

12. lithium secondary battery as claimed in claim 10, wherein the cathode includes in the group being made of following material One or more negative electrode active materials: carbon based negative electrodes active material, lithium metal, lithium metal alloy, Si, SiO_x(0<x<2)、 Si-C compound, Si-Q alloy (wherein Q be alkali metal, alkaline-earth metal, 13 races to 16 race's elements, transition metal, rare earth element or Person's their combination does not include Si), Sn, SnO₂, Sn-C compound and Sn-R (wherein R be alkali metal, alkaline-earth metal, 13 races extremely 16 race's elements, transition metal, rare earth element or their combination, do not include Sn).

Technical field

Cross reference to related applications

The application is based on following patent application and requires its priority: respectively on November 27th, 2017 and in November, 2018 The South Korea patent application No.10-2017-0159733 and No.10-2018-0148220 submitted for 27, the disclosure of which is by drawing Be integrally incorporated herein.

Anode and lithium secondary battery this application involves a kind of cathode mix, comprising the cathode mix.

Background technique

As cathode and anode and make lithium by using insertion/deintercalation electrode active material that lithium ion can be made reversible Ion is mobile via electrolyte, and lithium secondary battery is produced electricl energy by the oxidation/reduction reaction of electrode.

However, can not will be kept away respectively during initial charge/electric discharge (the 1st charge-discharge cycles) of lithium secondary battery It generates with exempting from insertion cathode (battery charging) lithium ion of deintercalation (battery discharge) and by positive deintercalation (battery charging) afterwards It is not embedded in the lithium ion of (battery discharge) again afterwards.This is related with the irreversible capacity of two electrodes.

When the difference between the irreversible capacity of two electrodes is larger, positive starting efficiency be may be decreased, and battery Energy density during work may gradually decrease, and the service life of battery is caused to reduce.

Summary of the invention

Technical problem

An embodiment of the invention provides a kind of cathode mix, it includes during the initial charge of battery not Reversibly discharge lithium ion (Li⁺) to compensate the lithium peroxide (Li of the irreversible capacity of cathode₂O₂), and as improving Lithium ion (Li⁺) release reaction efficiency catalyst platinum (Pt).

Specifically, the cathode mix of an embodiment includes additive, positive electrode active materials and conductive material, described Additive includes lithium peroxide (Li₂O₂) and platinum；Wherein, the content of platinum is controlled in 7 weight % with below up to 20 weight % It measures (total weight of platinum and conductive material is considered as 100 weight %).Therefore, the present invention can effectively offset between electrode can not Inverse capacity is unbalance, and can dramatically increase in terms of the initial charge capacity of anode that there are critical meanings.

Technical solution

The advantages of embodiments of the present invention and feature and realize that their method will be from the implementation being described below in detail It is become apparent in mode.However, the present invention can be embodied in many different forms, and should not be construed as being limited to herein The embodiment of elaboration.On the contrary, these embodiments are provided so that the disclosure is thorough and complete, and by model of the invention It encloses and is fully conveyed to those skilled in the art in the invention.The present invention is limited solely by the scope of the following claims.

Unless otherwise defined, otherwise technical and scientific terms used herein has and technology people of the art The identical meaning of the normally understood meaning of member.In addition, will omit to routine techniques construction and the technical construction that is equal of measure and The repeated explanation of measure.

Throughout the specification, when referring to that an element ' attach ' to another element, which is arrived Another element is arrived in another element or " electrical connection ", is inserted into one or more intermediary elements therebetween.

Throughout the specification, when referring to a component at another component "upper", a component can be with another Component is adjacent, or may exist intermediate member therebetween.

Throughout the specification, when a certain element of element " comprising ", it means that may further include other element Rather than exclude other element, unless specifically described opposite content.

Throughout the specification, term " about " or the numerical value or model that " substantially " are intended to have specified close to allowable error The meaning enclosed, and be intended to prevent to understand the disclosure and disclosed accurate or absolute figure is illegal by any non-bona fide third party Or it partially uses.

Throughout the specification, term " ... the step of " does not mean that " the step of being used for ... ".

It throughout the specification, include that term " combination " in the description of Markush type refers to the mixed of one or more components Object or combination are closed, described group is selected from the group that the group as described in Markush type is grouped as, and this means that the present invention includes Selected from one of group being grouped as by described group or a variety of.

Throughout the specification, the phrase of " A and/or B " form indicates " A or B ", or " A and B ".

Cathode mix

Based on experimental result, the cathode mix of an embodiment of the invention includes: positive electrode active materials；Conduction material Material；With include lithium peroxide (Li₂O₂) and platinum (Pt) additive, wherein amount to 100 weight % platinum and conductive material in, It is 7 weight % up to 20 weight % or less by the content control of platinum.

According to experimental fact, such as in the cathode mix of an embodiment, when the platinum and conduction for amounting to 100 weight % In material platinum content control specially 7 weight % with up to 20 weight % or less, more specifically 8 weight % up to 17 weights Measure % or less, even more for 10 weight % with up to 15 weight % or less when, critical meaning be obtain anode just Beginning charging capacity is 600mAh/g or more, and more specifically 650mAh/g or more is even more 690mAh/g or more.

It has had been pointed out during initial charge/electric discharge (the 1st charge-discharge cycles) of lithium secondary battery inevitably There is the irreversible capacity of two electrodes.When the difference between the irreversible capacity of two electrodes is larger, positive starting efficiency It reduces, the service life of battery is caused to deteriorate.

For example, being greater than while to anode application identical positive electrode active materials to cathode application theoretical capacity carbon-based negative When the silicon-based anode active material of pole active material, unbalance between the irreversible capacity of two electrodes be can increase, and initially be filled Positive charging capacity may be decreased after electricity/electric discharge.

Due to recognizing that the above problem, an embodiment of the invention provide a kind of cathode mix, can support The irreversible capacity to disappear between two electrodes is unbalance, and increases the starting efficiency of anode.

The cathode mix of one embodiment may include the (Li containing lithium peroxide₂O₂) and platinum (Pt) additive, to have The irreversible capacity that effect ground is offset between two electrodes is unbalance, and further increases the initial charge capacity of anode.

1) specifically, in anode additive, compared with the common positive electrode active materials comprising about 1 mole of lithium, peroxidating Lithium (Li₂O₂) it may include a large amount of lithium, to discharge a large amount of lithium.

More specifically, lithium peroxide (Li₂O₂) it can irreversibly discharge lithium ion and oxygen.Reaction is following reaction process 1 Oxygen evolution reaction (OER), wherein can be by 1 mole of lithium peroxide (Li₂O₂) irreversibly discharge 1 mole oxygen and 2 moles of lithium ions.

[reaction process 1] Li₂O₂→2Li⁺+O₂

Therefore, comprising being added to lithium peroxide (Li₂O₂) anode lithium secondary battery can during initial charge/electric discharge The irreversible capacity for showing cathode reduces, so that the irreversible capacity offset between cathode and anode is unbalance, and increases anode Starting efficiency.

2) however, lithium peroxide (Li ought be applied only₂O₂) when, in such as 2.5V to 4.25V (vs.Li/Li⁺) initially fill Under piezoelectric voltage, the efficiency of reaction process 1 is poor.In this regard, according to experimental result described below, when in cathode mix Lithium peroxide (Li is used only during preparation₂O₂) without the use of Pt (comparative example 1) when, find anode initial charge capacity be only 180mAh/g。

Therefore, in one embodiment, platinum (Pt) application is the catalyst for improving the efficiency of reaction process 1.It changes Yan Zhi, when lithium peroxide is added to anode together with platinum, compared in anode using only lithium peroxide, reaction process 1 Efficiency can increase.

This is because platinum is by lithium peroxide (Li₂O₂) carry out reaction process 1 oxygen evolution reaction (OER) in be used as catalysis Agent, to help to improve the reaction efficiency of reaction process 1.

3) however, even if adding lithium peroxide (Li simultaneously to anode₂O₂) and when platinum, positive initial charge capacity characteristic It can be significantly changed according to the relative quantity of platinum and conductive material.

In this regard, according to experimental result described below, when by the inclusion of conductive material and containing lithium peroxide (Li₂O₂) and platinum (Pt) additive (wherein amount to platinum in the platinum and conductive material of 100 weight % content control be 5 weights Amount %) when preparing cathode mix (comparative example 2), compared with the cathode mix (comparative example 1) without Pt, find anode just Beginning charging capacity increases, but initial charge capacity is only about 315mAh/g.

In contrast, when the content control of platinum in the platinum and conductive material for amount to 100% is 7 weight % up to 20 weights Measure % or less, more specifically 8 weight % with up to 17 weight % or less, even more for 10 weight % with up to 15 weight % with Under (Examples 1 and 2) when, compared with the anode (comparative example 2) for using the platinum of 5 weight % to prepare, positive initial charge capacity It increases more than twice.

In experiments described below, in order to confirm additive to the effect of battery initial performance, not as extreme case Blend positive electrode active materials.In order to improve the initial performance of battery in the case where ensuring long term life characteristic, according to required Battery behavior can be blended positive electrode active materials and the anode additive of an embodiment with Blend proportion appropriate.

Therefore, when by the inclusion of positive electrode active materials, conductive material and the (Li containing lithium peroxide₂O₂) and platinum (Pt) add Add agent (wherein amount to platinum in the platinum and conductive material of 100 weight % content control be 7 weight % with up to 20 weight % with Under, more specifically 8 weight % are up to 17 weight % or less) when preparing cathode mix, positive initial charge is held according to inferring Amount can significantly improve.

The blending of additive and the cathode mix comprising additive

In the blending of additive and the cathode mix comprising the additive, it is contemplated that the weight ratio of lithium peroxide and platinum And conductive material accounts for the content of the total weight of cathode mix.

In additive, the weight ratio of lithium peroxide and platinum can be 100:0.1 to 100:50, such as 100:0.5 is extremely 100:20,100:1 are to 100:10 or 100:7 to 100:20.When weight ratio meets the range, said effect can be improved, but not It is limited to this.

Meanwhile relative to the total weight of cathode mix (100 weight %), the content of conductive material can in cathode mix In the range of 0.1 weight % to 10 weight % commonly used in the art, such as 0.5 weight % to 3 weight %.

In view of the weight ratio and conductive material of all platinum/conductive material weight ratios, lithium peroxide and platinum account for just The content of the total weight of pole mixture, relative to the total weight (100 weight %) of cathode mix, conduction material in cathode mix The content of material can control in 0.1 weight % to 10 weight %, such as 0.5 weight % to 3 weight %；Relative to 100 weight % Platinum and conductive material, the content of platinum can be controlled in 7 weight % with up to 20 weight % hereinafter, more specifically 8 weight % or more To 17 weight % hereinafter, being even more 10 weight % up to 15 weight % or less；Include platinum (Pt) and lithium peroxide (Li₂O₂) the total amount of anode additive may be controlled to 1 weight % to 20 weight %, such as 1 weight % to 10 weight % or 5 Weight % to 10 weight %.When each content is met the above range, it can further improve the initial charge capacity of anode, but this hair It is bright without being limited thereto.

The method for preparing additive

The raw material of additive and the method for preparing additive are not specifically limited.

For example, using platinum (Pt) and lithium peroxide (Li₂O₂) respective powder is as raw material, by these powder dry-mixings, and And anode additive of this powder being simply mixed as an embodiment can be used.When the anode of an embodiment adds When agent being added to be embodied as the powder being simply mixed, in embodiment as be described below, platinum (Pt) and lithium peroxide (Li₂O₂) respectively Powder can be dry-mixed with the other components of cathode mix (such as positive electrode active materials, conductive material and/or adhesive) immediately It closes.Alternatively, platinum (Pt) and lithium peroxide (Li₂O₂) respective powder can dry-mixing first, then with cathode mix its His component dry-mixing.

Alternatively, various powder are dissolved in nmp solvent, and using the devices such as paste mixer by acquired solution that This wet mixing is closed.Then, it is heat-treated at 40 DEG C to 150 DEG C, or omits heat treatment, the baking by gains at 40 DEG C to 150 DEG C It dries in case to obtain spheric granules, can be used as additive.

There is no limit for the condition of each method for preparing anode additive exemplified here.Other than exemplary method, it can make The anode additive of an embodiment is prepared with method known in this field.

The type of conductive material

The type of conductive material is not specifically limited.For example, conductive material is used to provide conductibility to electrode, and do not have Concrete restriction, as long as its is conductive and do not cause chemical change in the battery.The example may include natural graphite, people Graphite, carbon black, acetylene black, Ketjen black, carbon fiber, the metal powder or metallic fiber of copper, nickel, aluminium, silver etc. are made, and is such as gathered The conductive materials such as crystalline 1,2-phenylene derivatives can be used alone or be used with the mixture of one or more of them.

The type of active material and its content in cathode mix

In addition, the type of positive electrode active materials is not specifically limited in the cathode mix of an embodiment, as long as It includes one or more composite oxides of cobalt, manganese, nickel or combinations thereof and lithium and can make the reversible insertion/deintercalation of lithium ion .For example, positive electrode active materials may include one or more composite oxides of cobalt, manganese, nickel or combinations thereof with lithium.

More specifically, the compound of any expression in following below formula: Li can be used as positive electrode active materials_aA_{1- b}R_bD₂(wherein 0.90≤a≤1.8 and 0≤b≤0.5)；Li_aE_1-bR_bO_2-cD_c(wherein 0.90≤a≤1.8,0≤b≤0.5 and 0 ≤c≤0.05)；LiE_2-bR_bO_4-cD_c(wherein 0≤b≤0.5 and 0≤c≤0.05)；Li_aNi_1-b-cCo_bR_cD_α(wherein 0.90≤a ≤ 1.8,0≤b≤0.5,0≤c≤0.05 and 0 < α≤2)；Li_aNi_1-b-cCo_bR_cO_2-αZ_α(wherein 0.90≤a≤1.8,0≤b≤ 0.5,0≤c≤0.05 and 0 < α < 2)；Li_aNi_1-b-cCo_bR_cO_2-αZ₂(wherein 0.90≤a≤1.8,0≤b≤0.5,0≤c≤ 0.05 and 0 < α < 2)；Li_aNi_1-b-cMn_bR_cD_α(wherein 0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05 and 0 < α≤2)； Li_aNi_1-b-cMn_bR_cO_2-αZ_α(wherein 0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05 and 0 < α < 2)；Li_aNi_{1-b- c}Mn_bR_cO_2-αZ₂(wherein 0.90≤a≤1.8,0≤b≤0.5,0≤c≤0.05 and 0 < α < 2)；Li_aNi_bE_cG_dO₂(wherein 0.90 ≤ a≤1.8,0≤b≤0.9,0≤c≤0.5 and 0.001≤d≤0.1)；Li_aNi_bCo_cMn_dGeO₂(wherein 0.90≤a≤1.8, 0≤b≤0.9,0≤c≤0.5,0≤d≤0.5 and 0.001≤e≤0.1)；Li_aNiG_bO₂(wherein 0.90≤a≤1.8 and 0.001≤b≤0.1)；Li_aCoG_bO₂(wherein 0.90≤a≤1.8 and 0.001≤b≤0.1)；Li_aMnG_bO₂(wherein 0.90≤a ≤ 1.8 and 0.001≤b≤0.1)；Li_aMn₂G_bO₄(wherein 0.90≤a≤1.8 and 0.001≤b≤0.1)；QO₂；QS₂； LiQS₂；V₂O₅；LiV₂O₅；LiTO₂；LiNiVO₄；Li_(3-f)J₂(PO₄)₃(wherein 0≤f≤2)；Li_(3-f)Fe₂(PO₄)₃(wherein 0≤ f≤2)；And LiFePO₄。

In above-mentioned chemical formula, A is Ni, Co, Mn or combinations thereof；R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth Element or combinations thereof；D is O, F, S, P or combinations thereof；E is Co, Mn or combinations thereof；Z is F, S, P or combinations thereof；G be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or combinations thereof；Q is Ti, Mo, Mn or combinations thereof；T is Cr, V, Fe, Sc, Y or combinations thereof；J be V, Cr, Mn, Co, Ni, Cu or combinations thereof.

It may be used on the surface of above compound and forms cated compound or usable above compound and shape At the mixture of cated compound.Coating may include the oxide or hydrogen-oxygen of the coating element as coating element compound Compound, the oxyhydroxide for being coated with element, the oxygroup carbonic ester for being coated with element or the hydroxy polycarbonates for being coated with element.Constitute these The compound of coating can be amorphous or crystallization.The coating element for including in coating can be Mg, Al, Co, K, Na, Ca, Or mixtures thereof Si, Ti, V, Sn, Ge, Ga, B, As, Zr.The formation process of coating can be any coating method, as long as the party Method (such as spray coating method, dip coating etc.) will not negatively affect positive-active when above-mentioned element to be used in compound The physical property of material.Since those skilled in the art are appreciated that its explanation, omit it.

Regardless of the type of positive electrode active materials, total weight (100 weights of the positive electrode active materials in cathode mix Amount %) in content can be 80 weight % to 99.5 weight %, only allow for blending amount commonly used in the art Range, but not limited to this.

Adhesive

Meanwhile the cathode mix of an embodiment also may include adhesive.

Adhesive is used to improve the viscous of adherency between positive electrode active materials particle and positive electrode active materials and collector It is attached.Its representative example may include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polychlorostyrene second Alkene, carboxylated polyvinylchloride, polyvinyl fluoride, the polymer containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethyl-ne Alkene, polyvinylidene fluoride, polyethylene, polypropylene, SBR styrene butadiene rubbers, propylene are acidified SBR styrene butadiene rubbers, ring Oxygen resin, nylon etc., but not limited to this.

The cathode mix of one embodiment can be prepared by methods known in the art, by description is omitted.

Anode and lithium secondary battery

Another embodiment of the invention provides the anode comprising above-mentioned cathode mix, and includes the anode Lithium secondary battery.

The lithium secondary battery of one embodiment is the lithium secondary battery that above-mentioned anode additive is applied to anode, and By inhibit operation during energy density reduce, the lithium secondary battery can show cathode initial irreversible capacity reduce, The starting efficiency of anode increases and excellent life characteristic.

Specifically, when lithium secondary battery once charges to 2.5V to 4.25V (vs.Li/Li at room temperature⁺) when, it is positive Charging capacity can be 600mAh/g or more, especially 690mAh/g.It is illustrated and same as described above.

The lithium secondary battery of one embodiment can be manufactured according to method well known in the art, the difference is that using upper The anode additive and cathode mix stated.

It hereinafter, will simply propose those of known in this field, but these are for illustration purposes only, and an embodiment party The cathode mix of formula is without being limited thereto.

The anode of one embodiment may include plus plate current-collecting body and be arranged on plus plate current-collecting body and including above-mentioned The positive-electrode mixture layer of cathode mix.

Specifically, the anode of an embodiment can be manufactured in the following manner: by cathode mix, conductive material, just The electrode mixture of pole active material and/or adhesive is applied on plus plate current-collecting body, is then dried.It when necessary can be into one Step adds filler to mixture.

Plus plate current-collecting body can be fabricated to the thickness with 3 μm to 500 μm.Plus plate current-collecting body is not specifically limited, as long as It is with high conductivity and does not cause chemical change in the battery.It is, for example, possible to use stainless steel, aluminium, nickel, titanium, calcinings Carbon and with carbon, nickel, titanium or the processed aluminium of silver surface or stainless steel.It is subtle coarse by being formed on the surface of collector Object can increase the adhesiveness of positive electrode active materials, and collector can use in a variety of manners, such as film, piece, foil, net, more Porous materials, foamed material, nonwoven cloth material etc..

Relative to total weight of the mixture containing a positive electrode active material, the additive amount of conductive material be usually 1 weight % extremely 50 weight %.Conductive material is not specifically limited, as long as its is conductive and do not cause chemical change in the battery.Example Such as, as conductive material, graphite, such as natural or artificial graphite can be used；Carbon black, such as carbon black, acetylene black, section's qin Black, channel black, furnace black, lampblack, ardent method carbon black etc.；Conductive fiber, such as carbon fiber, metallic fiber etc.；Metal powder, such as fluorine Carbon compound, aluminium, nickel by powder etc.；Conductive whiskers, such as ZnOw, potassium titanate crystal whisker etc.；Conductive metal oxide, such as Titanium dioxide etc.；With polyphenylene derivatives etc..

Meanwhile flexible graphite type material can be used as conductive material, and can be used together with above-mentioned material.

Adhesive helps to improve between adherency and active material and collector between active material and conductive material Adherency.Relative to total weight of the mixture containing a positive electrode active material, the additive amount of adhesive is usually 1 weight % to 50 weights Measure %.Its specific example include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, Regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethene, polyethylene, polypropylene, Ethylene-Propylene-Diene polymer (EPDM), Sulfonated epdm, SBR styrene butadiene rubbers, fluorubber or various copolymers.

Filler is optionally for the component for inhibiting positive electrode expansion.Filler is not specifically limited, as long as it is fibrous material And do not cause chemical change in the battery.It is, for example, possible to use olefin polymers such as polyethylene, polypropylene and all Such as glass fibre, carbon fiber fibrous material.

Cathode may include the anode active material layer of collector and formation on a current collector, wherein anode active material layer Include negative electrode active material.

Negative electrode active material can be selected from by carbon based negative electrodes active material, lithium metal, lithium metal alloy, Si, SiO_x(0< X < 2), Si-C compound, (wherein Q is alkali metal, alkaline-earth metal, 13 races to 16 race's elements, transition metal, rare earth to Si-Q alloy Element or their combination do not include Si), Sn, SnO₂, (wherein R is alkali metal, alkaline earth gold by Sn-C compound and Sn-R Belong to, 13 races are to 16 race's elements, transition metal, rare earth element or their combination, do not include Sn) one of the group of composition or A variety of negative electrode active materials.

Negative current collector can usually be fabricated to the thickness with 3 μm to 500 μm.Negative current collector is not specifically limited, As long as it is with high conductivity and does not cause chemical change in the battery.It is, for example, possible to use copper, stainless steel, aluminium, nickel, Titanium calcines carbon, perhaps with carbon, nickel, titanium or the processed copper of silver surface or stainless steel or aluminium cadmium alloy.In addition, collecting with anode Fluid is the same, by forming subtle dietary fibres on the surface of collector, can increase the adhesiveness of negative electrode active material.Afflux Body can use in a variety of manners, such as film, piece, foil, net, porous material, foamed material, nonwoven cloth material etc..

According to the type of electrolyte and/or the type of diaphragm, the lithium secondary battery of an embodiment can be lithium ion Battery, lithium ion polymer battery or lithium polymer battery.

When the lithium secondary battery of an embodiment is the lithium ion battery for applying liquid electrolyte, immerse wherein Liquid electrolyte can be applied after diaphragm.Diaphragm is between anode and cathode.As diaphragm, using with high ion permeability and The insulation film of mechanical strength.Diaphragm generally has 0.01 μm to 10 μm of aperture and 5 μm to 300 μm of thickness.As diaphragm, Such as it is made using by olefin polymer (such as with chemical resistance and hydrophobic polypropylene etc.), glass fibre or polyethylene Sheet material or non-woven fabrics.When using solid electrolytes such as polymer as electrolyte, solid electrolyte can be functioned simultaneously as Diaphragm and electrolyte.

Liquid electrolyte can be the non-aqueous electrolyte containing lithium salts.Non-aqueous electrolyte containing lithium salt is by non-aqueous electricity Solve matter and lithium salts composition.As non-aqueous electrolyte, Non-aqueous Organic Solvents, organic solid electrolyte or inoganic solids can be used Electrolyte.However, non-aqueous electrolyte is without being limited thereto.

For example, Non-aqueous Organic Solvents can be aprotic organic solvent, such as n-methyl-2-pyrrolidone, carbonic acid Asia Propyl ester, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma-butyrolacton, 1,2- dimethoxy-ethane, Tetrahydroxy Frank (franc), 2- methyltetrahydrofuran, dimethyl sulfoxide, 1,3- dioxolanes, formamide, dimethylformamide, Dioxolanes, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphotriester, trimethoxy-methane, dioxolanes are derivative Object, sulfolane, methyl sulfolane, 1,3- dimethyl -2- imidazolidinone, polypropylene carbonate ester derivant, tetrahydrofuran derivatives, Ether, methyl propionate, ethyl propionate etc..

For example, organic solid electrolyte may include polythene derivative, polyethylene oxide derivant, polypropylene oxide derivative Object, poly-stabilized lysine, polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, contains ionic dissociation groups at phosphate ester polymer Polymer etc..

For example, inorganic solid electrolyte may include Li class nitride, halide or sulfate, such as Li₃N、LiI、 Li₅NI₂、Li₃N-LiI-LiOH、LiSiO₄、LiSiO₄-LiI-LiOH、Li₂SiS₃、Li₄SiO₄、Li₄SiO₄-LiI-LiOH、 Li₃PO₄-Li₂S-SiS₂Deng.

Lithium salts is readily soluble in non-aqueous electrolyte, it may include such as LiCl, LiBr, LiI, LiClO₄、LiBF₄、 LiB₁₀Cl₁₀、LiPF₆、LiCF₃SO₃、LiCF₃CO₂、LiAsF₆、LiSbF₆、LiAlCl₄、CH₃SO₃Li、(CF₃SO₂)₂NLi, chlorine boron Change lithium, lower alphatic carboxylic acid lithium, tetraphenylboronic acid lithium, acid imide etc..

In order to improve the charge/discharge characteristics and flame resistance in non-aqueous electrolyte containing lithium salt, for example, pyrrole can be used Pyridine, triethyl phosphite, triethanolamine, cyclic ethers, ethylenediamine, glycol dimethyl ether, hexaphosphoric acid triamide, nitrobenzene derivative, Imidazolidine, the ethylene glycol dioxane ether, ammonium salt, pyrroles, 2- methoxy of oxazolidone, the N that sulphur, quinoneimine dye, N- replace, N- substitution Base ethyl alcohol, alchlor etc..Optionally, the halogen-containing solvent such as carbon tetrachloride or trifluoro-ethylene can be added further to mention For flame resistance, or carbon dioxide can be added further to enhance high temperature retention performance, and can further add FEC (fluoro Ethylene carbonate), PRS (propene sultone) etc..

It in a specific embodiment, can will such as LiPF₆、LiClO₄、LiBF₄、LiN(SO₂CF₃)₂Equal lithium salts be added EC or PC cyclic carbonate (it is high dielectric solvent) and the mixing of DEC, DMC or EMC linear carbonates (it is low viscosity solvent) are molten Agent, to prepare non-aqueous electrolyte containing lithium salt.

The implementable battery module for comprising lithium secondary battery as element cell of the lithium secondary battery of one embodiment, Battery pack comprising the battery module, and the equipment comprising the battery pack as power supply.

In this regard, the specific example of the equipment includes electric car, mixed power electric car, plug-in hybrid Electric car, power storage system etc., but not limited to this.

Technical effect

The cathode mix of one embodiment includes the (Li containing lithium peroxide₂O₂) and platinum additive, positive electrode active materials And conductive material, wherein in the platinum and conductive material for amounting to 100 weight %, platinum content control is in 7 weight % up to 20 Weight % or less.Irreversible capacity between electrode is unbalance can effectively cancel out for this, and can dramatically increase the initial charge of anode The aspect of capacity has critical meaning.

Detailed description of the invention

Fig. 1 is to show initial charge/flash-over characteristic figure of the lithium secondary battery of embodiment 1 and comparative example 1；

Fig. 2 is to show initial charge/flash-over characteristic of the lithium secondary battery of Examples 1 and 2 and comparative example 1 and 2 Figure.

Specific embodiment

Hereinafter, by reference specific embodiment the effect and effect that the present invention will be described in more detail.However, these are implemented Example is for illustration purposes only, and the scope of the present invention is not restricted by the embodiments.