阅读说明：本技术 二次电池用正极和二次电池 (Anode of secondary cell and secondary cell ) 是由 大浦勇士 盐崎朝树 武泽秀治 中山贵仁 高桥崇宽 古泽大辅 于 2018-04-09 设计创作，主要内容包括：二次电池用正极具备正极集电体、正极复合材料层、和设置在正极集电体与正极复合材料层之间的中间层。中间层包含由导电材料构成的第1颗粒和由绝缘性无机材料构成且具有比第1颗粒的平均粒径大的平均粒径的第2颗粒。第1颗粒在中间层中所占的体积比率为25％以上且小于70％,第2颗粒在中间层中所占的体积比率为30％以上且小于75％,中间层的密度为大于1g/cm<Sup>3</Sup>且2.5g/cm<Sup>3</Sup>以下。(Anode of secondary cell has positive electrode collector, anode composite material layer and the middle layer being arranged between positive electrode collector and anode composite material layer.Middle layer includes the 1st particle being constructed from a material that be electrically conducting and the 2nd particle that the average grain diameter bigger than the average grain diameter of the 1st particle is made of and had insulating properties inorganic material.Shared volume ratio is 25% more than and less than 70% to 1st particle in the intermediate layer, and shared volume ratio is 30% more than and less than 75% to the 2nd particle in the intermediate layer, and the density of middle layer is greater than 1g/cm 3 And 2.5g/cm 3 Below.)

1. a kind of anode of secondary cell has positive electrode collector, anode composite material layer and is arranged in the positive pole current collections Middle layer between body and the anode composite material layer,

The middle layer includes: the 1st particle that is constructed from a material that be electrically conducting and being made of and has than described insulating properties inorganic material 2nd particle of the big average grain diameter of the average grain diameter of the 1st particle,

1st particle volume ratio shared in the middle layer is 25% more than and less than 70%, and the 2nd particle exists Shared volume ratio is 30% more than and less than 75% in the middle layer,

The density of the middle layer is greater than 1g/cm³And 2.5g/cm³Below.

2. anode of secondary cell according to claim 1, wherein the 1st particle is with the length-width ratio less than 10 Particle, the 2nd particle be the particle with 10 or more and 50 length-width ratios below,

The density of the middle layer is 1.4g/cm³Above and 2.5g/cm³Below.

3. anode of secondary cell according to claim 2, wherein the 1st particle is with the length-width ratio less than 10 Particle, the 2nd particle be the particle with 10 or more and 30 length-width ratios below.

4. a kind of secondary cell has anode, cathode and electrolyte,

The anode of secondary cell just extremely according to any one of claims 1 to 3.

Technical field

The present invention relates to the technologies of anode of secondary cell and secondary cell.

Background technique

In recent years, it as high output, the secondary cell of high-energy density, utilizes have anode, cathode and non-water power extensively It solves matter and moves lithium ion between a positive electrode and a negative electrode to carry out the non-aqueous electrolyte secondary battery of charge and discharge.

For example, patent document 1 discloses a kind of non-aqueous electrolyte secondary battery, have anode, cathode and non-aqueous solution electrolysis Matter, above-mentioned anode has positive electrode collector, the anode composite material layer that is formed on the collector and is formed in positive electrode collector With the middle layer between anode composite material layer, middle layer include be 100W/mK or more with thermal conductivity and resistivity is 10³ The particle that the material of Ω m or more is main component and Vickers hardness is 5GPa or more.

Summary of the invention

But inhibit battery when the foreign conducting matters such as nail, metal fragmentation are pierced into secondary cell etc. and generate internal short-circuit Calorific value is for being important project for improving the safety of battery.

Therefore, the purpose of the present disclosure is to provide the electricity being able to suppress when generating internal short-circuit due to foreign conducting matter The anode of secondary cell of pond calorific value and the secondary cell for having the anode.

The anode of secondary cell of one mode of the disclosure has positive electrode collector, anode composite material layer and setting and exists Middle layer between above-mentioned positive electrode collector and above-mentioned anode composite material layer.Above-mentioned middle layer includes to be constructed from a material that be electrically conducting It 1st particle and is made of insulating properties inorganic material and with the 2nd of the average grain diameter bigger than the average grain diameter of above-mentioned 1st particle Grain.Above-mentioned 1st particle volume ratio shared in above-mentioned middle layer is 25% more than and less than 70%, and above-mentioned 2nd particle exists Shared volume ratio is 30% more than and less than 75% in above-mentioned middle layer, and the density of above-mentioned middle layer is greater than 1g/cm³And 2.5g/cm³Below.

The secondary cell of one mode of the disclosure has an anode, cathode and electrolyte, and the two of above-mentioned just extremely above-mentioned record Primary cell anode.

According to a mode of the disclosure, it is able to suppress battery-heating when generating internal short-circuit due to foreign conducting matter Amount.

Detailed description of the invention

Fig. 1 is the cross-sectional view of the secondary cell of an example as embodiment.

Fig. 2 is the cross-sectional view of the anode of an example as embodiment.

Specific embodiment

The anode of secondary cell of one mode of the disclosure has positive electrode collector, anode composite material layer and setting and exists Middle layer between above-mentioned positive electrode collector and above-mentioned anode composite material layer, above-mentioned middle layer include to be constructed from a material that be electrically conducting It 1st particle and is made of insulating properties inorganic material and with the 2nd of the average grain diameter bigger than the average grain diameter of above-mentioned 1st particle Grain, above-mentioned 1st particle volume ratio shared in above-mentioned middle layer are 25% more than and less than 70%, and above-mentioned 2nd particle exists Shared volume ratio is 30% more than and less than 75% in above-mentioned middle layer, and the density of above-mentioned middle layer is greater than 1g/cm³And 2.5g/cm³Below.The internal voids of middle layer with such composition are small, have high heat capacity, therefore when in secondary cell When generating internal short-circuit, the heat of side of the positive electrode is absorbed by middle layer, is easy diffusion.In addition, due to will meet above-mentioned partial size ratio and 1st particle of volume ratio and the 2nd particle are set as conductive material and insulating properties inorganic material, thus due to foreign conducting matter and When internal short-circuit occurs, middle layer becomes big resistance components, therefore, it is considered that can inhibit the increase of the short circuit current of positive and negative interpolar. It is believed that being able to suppress battery-heating amount when generating internal short-circuit for these reasons.

An example of embodiment is described in detail below.The attached drawing of institute's reference is schematic in the explanation of embodiment It records, dimensional ratios of constituent element described in figure etc. are sometimes different from actual size.

Fig. 1 is the cross-sectional view of the secondary cell of an example as embodiment.Secondary cell 10 shown in FIG. 1 has: just Pole 11 and cathode 12 electrode body 14 winding-type made of the winding of separator 13；Electrolyte；It is arranged respectively at electrode body 14 Upper and lower insulation board 17,18；With the battery case for storing above-mentioned component.Battery case is by having the shell main body 15 of bottom cylindrical shape and envelope Mouth body 16 is constituted.It should be noted that the alternative as winding-type electrode body 14, also can be used anode and cathode every Separator it is alternately laminated made of laminated type other forms such as electrode body electrode body.In addition, as battery case, it can example Show: the made of metal shell such as cylinder-shaped, rectangular, coin-shaped, button-type；Resin shell (the laminated-type electricity that resin sheet is laminated and is formed Pond) etc..

Shell main body 15 is, for example, the metal container for having bottom cylindrical shape.It is provided between shell main body 15 and seal body 16 Gasket 27, to ensure the airtightness inside battery case.Shell main body 15 is preferably for example formed with pressurizeing from outside to side surface part , support seal body 16 protruding portion 21.Protruding portion 21 is formed as cyclic annular preferably along the circumferencial direction of shell main body 15, with thereon Surface support seal body 16.

Seal body 16 has the filter 22 for being formed with filter port portion 22a and configures the valve body on filter 22. The filter port portion 22a of valve body plug filter device 22, inner pressure of battery rises in the fever due to caused by internal short-circuit etc. In the case of be broken.In the present embodiment, as valve body, it is provided with lower valve body 23 and upper valve body 25, is additionally provided with configuration under Insulating component 24 between valve body 23 and upper valve body 25 and the lid 26 with cover gab portion 26a.Constitute each component of seal body 16 Such as with circular plate shape or ring-shaped, each component in addition to insulating component 24 is electrically connected to each other.Specifically, filter 22 It is interconnected with lower valve body 23 in respective peripheral part, upper valve body 25 and lid 26 are also interconnected in respective peripheral part.Lower valve Body 23 and upper valve body 25 are connected with each other in respective central portion, and insulating component 24 is between each peripheral part.It should be noted that If the fever due to caused by internal short-circuit etc. and internal pressure rise, such as lower valve body 23 is broken in thinner wall section, thus upper valve body 25 expand to 26 side of lid and are detached from from lower valve body 23, so that the electrical connection of the two is blocked.

In secondary cell 10 shown in Fig. 1, the positive wire 19 being mounted on anode 11 passes through the perforation of insulation board 17 Hole and extend to 16 side of seal body, the negative wire 20 being mounted on cathode 12 extends to shell master by the outside of insulation board 18 The bottom side of body 15.For example, positive wire 19 is connected under the filter 22 as the bottom plate of seal body 16 by welding etc. Surface, the top plate for the seal body 16 being electrically connected with filter 22 i.e. lid 26 become positive terminal.Negative wire 20 passes through welding etc. It is connected to the bottom interior surface of shell main body 15, shell main body 15 becomes negative terminal.

[anode]

Fig. 2 is the cross-sectional view of the anode of an example as embodiment.It is compound that anode 11 has positive electrode collector 30, anode Material layer 32 and the middle layer 31 being arranged between positive electrode collector 30 and anode composite material layer 32.

As positive electrode collector 30, can be used the metal stable in the potential range of anode such as aluminium, aluminium alloy foil, The film etc. of the metal is configured on surface layer.Positive electrode collector 30 has such as 10 μm~100 μm or so of thickness.

Anode composite material layer 32 includes positive active material.In addition, from positive active material can be bonded to one another with Ensure the mechanical strength of anode composite material layer 32 or improves the caking property of anode composite material layer 32 and middle layer 31 angularly It sets out, anode composite material layer 32 preferably comprises binding material.In addition, from the electric conductivity angularly that this layer can be improved, Anode composite material layer 32 preferably comprises conductive material.

As a positive electrode active material, the lithium transition-metal oxide containing transition metal elements such as Co, Mn, Ni can be illustrated. Lithium transition-metal oxide is such as Li_xCoO₂、Li_xNiO₂、Li_xMnO₂、Li_xCo_yNi_1-yO₂、Li_xCo_yM_1-yO_z、Li_xNi_{1- y}M_yO_z、Li_xMn₂O₄、Li_xMn_2-yM_yO₄、LiMPO₄、Li₂MPO₄F (M:Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, It is at least one kind of in Pb, Sb, B, 0 < x≤1.2,0 < y≤0.9,2.0≤z≤2.3).These can be used alone, can also To be used in mixed way a variety of.From the angle for the high capacity that secondary cell may be implemented, positive active material is preferably comprised Li_xNiO₂、Li_xCo_yNi_1-yO₂、Li_xNi_1-yM_yO_z(in M:Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb, B At least one kind of, 0 < x≤1.2,0 < y≤0.9,2.0≤z≤2.3) etc. lithium nickel composite oxides.

It can be mentioned, for example carbon system particles such as carbon black (CB), acetylene black (AB), Ketjen black, graphite etc. for conductive material.These can To be used alone, can also be used in combination of two or more.

It can be mentioned, for example the fluorine resins, polypropylene such as polytetrafluoroethylene (PTFE) (PTFE), Kynoar (PVdF) for binding material Nitrile (PAN), polyimides system resins, acrylic resin, polyolefin-based resins etc..Furthermore it is possible to by these resins and carboxylic first Base cellulose (CMC) or its salt (CMC-Na, CMC-K, CMC-NH₄Deng in addition can be the salt of part neutralization type), polycyclic oxygen second Alkane (PEO) etc. is applied in combination.These can be used alone, and can also be used in combination of two or more.

Middle layer 31 includes the 1st particle being constructed from a material that be electrically conducting and is made of and has than the 1st insulating properties inorganic material 2nd particle of the big average grain diameter of the average grain diameter of particle.As long as the 1st particle volume ratio shared in middle layer 31 is 25% is not particularly limited more than and less than 70%, and more preferably 33% or more and 70% hereinafter, further preferably 33% Above and 65% or less.As long as the 2nd particle volume ratio shared in middle layer 31 be 30% more than and less than 75% as long as do not have It is particularly limited to, more preferably 30% or more and 70% hereinafter, further preferably 35% or more and 65% or less.

By the way that above-mentioned partial size will be met as described above than being set as leading with the 1st particle of above-mentioned volume ratio and the 2nd particle Electric material and insulating properties inorganic material so that middle layer 31 becomes bigger resistance components in internal short-circuit, therefore can press down It makes the increase of the short circuit current of positive and negative interpolar, inhibit the calorific value of battery.It should be noted that passing through the conduction in middle layer 31 Material, is not generating internal short-circuit under normal conditions, ensures anode composite material layer by the conductive material in middle layer 31 32 conduct with positive electrode collector 30.

Conductive material can enumerate type identical with conductive material used in anode composite material layer 32, such as: charcoal The carbon system particle such as black (CB), acetylene black (AB), Ketjen black, graphite；The conductive metal oxides particle such as tin oxide of antimony dopant； The metallic particles such as aluminium, copper；It is coated with the inorganic filler etc. of metal.These can be used alone, can also be by two or more combinations It uses.From the electric conductivity of middle layer 31, manufacturing cost angularly, conductive material preferably comprises carbon system particle.

Insulating properties inorganic material is preferably for example with 10¹²The inorganic material of the resistivity of Ω cm or more, it can be mentioned, for example Metal oxide particle, metal nitride particles, metal fluoride particles, insulating properties magnetic substance particle etc..It is aoxidized as metal Composition granule, it can be mentioned, for example aluminum oxide, titanium oxide, Zirconium oxide, Si oxide, Mn oxide, magnesium oxide, nickel oxidations Object etc..As metal nitride particles, it can be mentioned, for example boron nitride, aluminium nitride, magnesium nitride, silicon nitrides etc..As metal pentafluoride Composition granule, it can be mentioned, for example aluminum fluoride, lithium fluoride, sodium fluoride, magnesium fluoride, calcirm-fluoride, barium fluoride, aluminium hydroxide, boehmites etc.. As insulating properties magnetic substance particle, it can be mentioned, for example Ni-Cu-Zn based ferrites etc..From insulating properties, high-melting-point, compare positive-active The viewpoints such as substance oxidizing force difference are set out, and insulating properties inorganic material preferably comprises aluminum oxide, titanium oxide, Si oxide, manganese oxygen At least any one in compound more preferably at least includes aluminum oxide.It should be noted that when generating internal short-circuit, sometimes Positive active material carries out redox reaction with positive electrode collector 30 (the especially positive electrode collector of aluminium, aluminium alloy) and sends out Heat, by using the insulating properties inorganic material lower than positive active material oxidizing force, can inhibit above-mentioned redox reaction, into The calorific value of one step inhibition battery.

The grain shape of 1st particle and the 2nd particle is not particularly limited, and it can be mentioned, for example rodlike etc..As rodlike, include Such as the shape of commonly referred to as plate, needle-shaped, flakey, sheet etc., specifically, to be 10 or more (long with length-width ratio Length/short axle length of axis) particle.

Length-width ratio is found out as follows: being seen using transmission electron microscope (TEM) observation or scanning electron microscope (SEM) The length of the long axis and short axle that measure at least 20 or more particles (the 1st particle, the 2nd particle) respectively is examined, finding out length-width ratio (will be small Value obtained by rounding up after several points), arithmetic average is carried out to these length-width ratios and is found out.It should be noted that particle (the 1 particle, the 2nd particle) long axis refer to: carrying out particle obtained from microscope (such as transmission electron microscope) observation Longest line segment in two dimensional image, in the line segment of particle.Short axle refers to: in orthogonal with long axis and line segment through particle Longest line segment.

As long as the density of middle layer 31 is greater than 1g/cm³It and is 2.5g/cm³It is not particularly limited below, more preferably greater than 1g/cm³It and is 2.0g/cm³Hereinafter, further preferably greater than 1.5g/cm³It and is 2.0g/cm³Below.1st particle is with small In the particle of 10 length-width ratio, the 2nd particle is with 10 or more and 50 or less, preferably 10 or more and 30 length-width ratios below When grain, the density of middle layer 31 is preferably 1.4g/cm³Above and 2.5g/cm³Hereinafter, more preferably 1.5g/cm³Above and 2.0g/cm³Hereinafter, being more preferably 1.5g/cm in turn³Above and 1.8g/cm³Below.1st particle is with the length and width less than 10 The particle of ratio, the 2nd particle are the particle with 10 or more and 50 or less, preferably 10 or more and 30 length-width ratios below, are had 1.4g/cm³The middle layer of above density with have be less than 1.4g/cm³The middle layer of density compare, show higher thermal capacitance Amount, can further suppress battery-heating amount when internal short-circuit.In addition, the 1st particle is with the length-width ratio less than 10 Grain, the 2nd particle are to have with the particle of the length-width ratio below of 10 or more and 50 length-width ratios below, preferably 10 or more and 30 2.5g/cm³The middle layer of density below with have more than 2.5g/cm³The middle layer of density compare, the flexibility of pole plate mentions Height is able to suppress pole plate rupture.

The density of middle layer 31 can pass through the 1st particle of control and the 2nd particle volume ratio shared in middle layer 31, grain The dispersion of particle contained in pressing force, middle layer slurry when diameter is than, length-width ratio, production anode when rolling middle layer 31 Property etc. adjusts.

The average grain diameter of 2nd particle is not particularly limited as long as the average grain diameter for being greater than the 1st particle.

The average grain diameter of 1st particle is preferably 0.01 μm or more and 2.0 μm hereinafter, the average grain diameter of the 2nd particle is preferably 0.01 μm or more and 7.0 μm hereinafter, the average grain diameter of the 1st particle is more preferably 0.03 μm or more and 0.05 μm hereinafter, the 2nd particle Average grain diameter be more preferably 0.4 μm or more and 2.0 μm or less.Average grain diameter by making the 1st particle and the 2nd particle meets State range, with outside the above range when compared with, the further densification of middle layer 31 can be made, inside can be further suppressed Battery-heating amount when short-circuit.

Average grain diameter refers to the volume average particle size measured using laser diffractometry, refers to the volume-cumulative in particle diameter distribution Value reaches 50% median particle diameter.Such as laser diffraction and scattering formula granularity can be used in the average grain diameter of 1st particle and the 2nd particle Distribution measurement device (Horiba Ltd's system) measures.

Middle layer 31 may include average grain diameter different from the 1st particle and the 3rd particle of the 2nd particle etc..For example, middle layer 31, which may include the 1st particle being constructed from a material that be electrically conducting, the 2nd particle being made of insulating properties inorganic material and average grain diameter, is greater than (or being less than) the 1st particle or the 3rd particle of the 2nd particle being constructed from a material that be electrically conducting etc..It should be noted that the 3rd particle is in Shared volume ratio is not particularly limited as long as within the scope of the effect without prejudice to the mode of implementation in interbed 31.

Angularly go out from the caking property for improving mechanical strength, raising and anode composite material layer 32 and positive electrode collector 30 Hair, middle layer 31 preferably comprise binding material.Binding material, which can be used, bonds material with used in anode composite material layer 32 Expect the fluorine resins such as identical material, such as polytetrafluoroethylene (PTFE) (PTFE), Kynoar (PVdF), polyacrylonitrile (PAN), gather Imide series resin, acrylic resin, polyolefin-based resins etc..These can be used alone, can also be by two or more groups It closes and uses.The content of binding material in middle layer 31 is preferably such as 0.1 mass % of mass %~5, more preferably 1 mass % ~3 mass %.

The thickness of middle layer 31 for example be preferably 0.5 μm or more and 10 μm of ranges below, more preferably 1.0 μm or more and 5.0 μm or less.When the thickness of middle layer 31 is less than 0.5 μm, compared with when meeting the above range, the thermal capacity of middle layer 31 sometimes Decline, the calorific value of the battery as caused by internal short-circuit become larger.When the thickness of middle layer 31 is more than 10 μm, and meet above-mentioned model It is compared when enclosing, does not generate the electricity between the anode composite material layer 32 and positive electrode collector 30 under normal conditions of internal short-circuit sometimes Resistance increases, the output characteristics of battery declines.

An example of the production method of anode 11 is illustrated.Firstly, coating is comprising being used as the 1st on positive electrode collector 30 The conductive material of particle, the middle layer slurry as the insulating properties inorganic material of the 2nd particle etc. and drying, to form centre Layer 31, rolls the middle layer 31.Then, positive composite wood of the coating comprising positive active material etc. in middle layer 31 Slurry material and drying roll the anode composite material layer 32 to form anode composite material layer 32.As described above Carry out then available positive 11.In addition, can applied when using insulating properties magnetic substance particle as insulating properties inorganic material Apply magnetic field after cloth middle layer slurry, makes the long axis of insulating properties magnetic substance particle along defined direction (such as positive pole current collections The face direction of body) orientation, then it is dried.

[cathode]

The anode material layer that cathode 12 has the negative electrode collector such as metal foil and is formed on negative electrode collector. As negative electrode collector, the foil of the metal stable in the potential range of cathode such as copper can be used, be configured with the gold on surface layer The film etc. of category.Anode material layer is including, for example, negative electrode active material, binding material, thickener etc..

Cathode 12 for example obtains as follows: will starch comprising the anode material of negative electrode active material, thickener, binding material Material is coated on negative electrode collector, dry, so that anode material layer is formed on negative electrode collector, by the cathode composite wood Bed of material calendering, to obtain.Anode material layer can be set on the two sides of negative electrode collector.

As long as the material that negative electrode active material can receive and discharge lithium ion is then not particularly limited, example can be enumerated Such as: lithium metal, lithium-aluminium alloy, lithium-metal, lithium-silicon alloy, lithium-tin alloy lithium alloy；Graphite, coke, organic matter are burnt The carbon materials such as adult；SnO₂、SnO、TiO₂Equal metal oxides etc..These can be independent one kind, can also be by two or more groups It closes and uses.

Be used in the same manner as binding material contained in anode material layer, when can be with anode fluorine resin, PAN, polyimides system resins, acrylic resin, polyolefin-based resins etc..Anode material is being prepared using water solvent When slurry, it is preferable to use butadiene-styrene rubber (SBR), CMC or its salt, polyacrylic acid (PAA) or its salt (PAA-Na, PAA-K etc., separately Be also possible to the salt of part neutralization type outside), polyvinyl alcohol (PVA) etc..

[separator]

As separator 13, the porosity piece etc. for example with ion permeability and insulating properties is used.As porosity piece Concrete example, micro- porous membrane, woven fabric, non-woven fabrics etc. can be enumerated.As the material of separator, preferably polyethylene, polypropylene etc. Olefin-based resin, cellulose etc..Separator 13 can be fine with the thermoplastic resins such as fibrous cellulosic layer and olefin-based resin Tie up the laminated body of layer.Alternatively, it is also possible to be the Multi-layer separated part comprising polyethylene layer and polypropylene layer, it can also use and separate The surface of part is coated with the separator of the materials such as aramid fiber system resin, ceramics.

[electrolyte]

Electrolyte includes the electrolytic salt of solvent and dissolution in a solvent.Electrolyte is not limited to liquid electrolyte (non-water power Solve liquid), it can be the solid electrolyte for using gelatinous polymer etc..As solvent, such as esters, ethers, acetonitrile can be used The nonaqueous solvents, water such as amides and the two or more mixed solvents in these such as equal nitriles, dimethylformamide.Nonaqueous solvents The halogen atoms such as useful fluorine, which can be contained, replaces halogen made of at least partly hydrogen in these solvents to replace body.

It as the example of above-mentioned esters, can enumerate: ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate etc. Cyclic carbonate；Dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), methyl propyl ester, carbonic acid The linear carbonates such as ethylpropyl, methyl isopropyl ester；The cyclic carboxylic esters such as gamma-butyrolacton, gamma-valerolactone；Methyl acetate, Chains carboxylates such as ethyl acetate, propyl acetate, methyl propionate (MP), ethyl propionate, gamma-butyrolacton etc..

As the example of above-mentioned ethers, can enumerate: 1,3-dioxolane, 4- methyl-1,3- dioxolanes, tetrahydrofuran, 2- methyltetrahydrofuran, propylene oxide, 1,2- epoxy butane, 1,3- dioxanes, 1,4- dioxanes, 1,3,5- trioxane, furans, The cyclic ethers such as 2- methylfuran, 1,8- cineole, crown ether；1,2- dimethoxy-ethane, diethyl ether, dipropyl ether, diisopropyl ether, two Butyl ether, two hexyl ethers, ethyl vinyl ether, butyl vinyl ether, methyl phenylate, ethyl phenylate, butyl phenylate, amyl phenylate, first Oxygroup toluene, benzyl ether, diphenyl ether, benzyl ether, o-dimethoxybenzene, 1,2- diethoxyethane, 1,2- dibutoxy second Alkane, diethylene glycol dimethyl ether, diethylene glycol ether, dibutyl ethylene glycol ether, 1,1- dimethoxymethane, 1,1- diethoxy second Chain ethers such as alkane, triethylene glycol dimethyl ether, tetraethyleneglycol dimethyl ether etc..

Replace body, it is preferable to use the fluoric cyclic carbonates such as fluoroethylene carbonate (FEC), fluoro chain as above-mentioned halogen Fluoro chain carboxylates such as shape carbonic ester, fluoropropionic acid methyl esters (FMP) etc..

Electrolytic salt is preferably lithium salts.As the example of lithium salts, LiBF can be enumerated₄、LiClO₄、LiPF₆、LiAsF₆、 LiSbF₆、LiAlCl₄、LiSCN、LiCF₃SO₃、LiCF₃CO₂、Li(P(C₂O₄)F₄)、LiPF_6-x(C_nF_2n+1)_x(1 < x < 6, n 1 Or 2), LiB₁₀Cl₁₀, LiCl, LiBr, LiI, chloroborane lithium, lower aliphatic lithium carboxylate, Li₂B₄O₇、Li(B(C₂O₄)F₂) etc. boron Barbiturates, LiN (SO₂CF₃)₂、LiN(C₁F_2l+1SO₂)(C_mF_2m+1SO₂) the acid imides salt such as { l, m are 1 or more integer } etc..Lithium Salt can be used alone one of these, can also be used in mixed way a variety of.It is steady from ionic conductivity, electrochemistry in these The viewpoints such as qualitative are set out, it is preferable to use LiPF₆.About the concentration of lithium salts, 0.8 is preferably set to relative to every 1 liter of solvent~ 1.8mol。