JPH09289038A - Polymer solid electrolyte and battery using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer solid electrolyte material with high ionic conductivity, high working capability, high softness, and high mechanical strength, and a battery using this material by forming the polymer solid electrolyte with a specific weight parts of a specific copolymer, an electrolyte, and a plasticizer. SOLUTION: A copolymer of (a) component of a polymer solid electrolyte contains at least one kind of a monomer unit comprising trifluorovinylether represented by formula (in the formula, X is a perfluoroalkyl group having 1-18 carbon atoms, the end of the carbon chain may be hydrogenated, and an ether group may be contained in the chain.), and a monomer unit comprising vinylidene fluoride. As an electrolyte of (b) component, inorganic acids, organic acids, and salts of them are listed. As the plasticizer of (c) component, ethylene carbonate or the like is listed. (a) and (c) components are 5-90 pts.wt., and (b) component is 1-90 pts.wt. based on 100 pts.wt. of the sum of (a), (b), and (c) components.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polymer material having excellent mechanical properties and ionic conductivity, and a battery using the polymer material as an ion transfer medium.

[0002]

2. Description of the Related Art A solid battery comprising a solid electrolyte as an ion transfer medium has less liquid leakage than a conventional battery using an electrolyte as an ion transfer medium, so that the reliability and safety of the battery are improved and a thin film is formed. It is expected that the structure, the formation of a laminate, the simplification of the package, and the weight reduction will be achieved. As this solid electrolyte material, an ion conductive ceramic material or a polymer material has been proposed, but the former ion conductive ceramic material has fragile properties and it is difficult to form a laminate with an electrode. On the other hand, since the ion conductive polymer material has processing flexibility, it forms a laminated structure with a battery as a solid electrolyte material,
It is preferable that the interface can be maintained following the volume change due to the occlusion and release of ions from the electrode.

As an attempt of this polymer solid electrolyte, W
The alkali metal salt complex of polyethylene oxide is converted to British Polymer Jou by right.
rnal, 7 p319 (1975), since then, solid electrolyte materials having polyacrylonitrile, polyphosphazene, polysiloxane, etc. as a skeleton have been actively studied centering on polyalkylene ether-based materials such as polyethylene glycol and polypropylene oxide. There is.

The ionic conductivity of a solid polymer electrolyte containing these polymers as a matrix and containing a metal salt as a solid solution is considerably smaller than the ionic conductivity of an electrolytic solution, and a battery constructed using this polymer has a charge / discharge current. There are problems such as limited density. Therefore, a solid polymer electrolyte material having high ionic conductivity is required. Gozd
Z et al. uses a copolymer of vinylidene fluoride and 8 to 25% by weight of hexafluoropropylene, and by adding an electrolyte and a large amount of a plasticizer to the polymer electrolyte material having relatively high ionic conductivity. Reported (US Pat. No. 5,296,318). However, in this case, the strength of the polyelectrolyte material is significantly reduced in the state where a large amount of the electrolyte and the plasticizer are added.
When laminated with the electrodes, problems such as crushing with a slight pressure and short-circuiting occurred, and it was difficult to say that the battery has sufficient mechanical characteristics in terms of battery manufacturing process and reliability.

[0005]

The present invention provides a polymer having high ionic conductivity even when impregnated with a large amount of an electrolyte and a plasticizer, and having excellent processability, flexibility and mechanical strength. The present invention provides a solid electrolyte and a solid battery using the same as an ion transfer medium.

[0006]

[Means for Solving the Problems] As a means for solving the above problems, the present inventors have newly investigated a polymer material, and have found a polymer solid electrolyte material having sufficient strength and high ionic conductivity. As a result of repeated studies to obtain the present invention, the present invention has been obtained. That is, the present invention is as follows. (1) (a) At least one of the monomer units composed of trifluorovinyl ether represented by the following general formula (1)
And a copolymer containing a monomer unit composed of vinylidene fluoride, CF ₂ ═CF—OX (1) (wherein, X is a perfluoroalkyl group having 1 to 18 carbon atoms, and these groups are carbon atoms). The chain end may be hydrogenated, and the carbon chain may contain an ether group.) (B) An electrolyte, and (c) a polymer solid electrolyte containing a plasticizer as a component. , And (a), (b),
The component (a) is 5 to 5 parts by weight based on the sum of the components (c).
90 parts by weight, component (b) is 1 to 90 parts by weight, and component (c) is 5 to 90 parts by weight, a solid polymer electrolyte. (2) A battery in which electrodes are joined via the solid polymer electrolyte of the above item 1.

The constituent elements of the polymer solid electrolyte and battery of the present invention will be described below. The copolymer used as the component (a) of the solid polymer electrolyte of the present invention is a polymer compound having a sufficiently fluorinated structure, and provides excellent properties in heat resistance and redox stability. is there. In the general formula (1), X is a perfluoroalkyl group having 1 to 18 carbon atoms, and in these groups, the end of the carbon chain may be hydrogenated, and the carbon chain contains an ether group. You may have.

Specific examples of X include those shown in the following chemical formula 1.

[0009]

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The copolymer which is the component (a) of the solid polymer electrolyte of the present invention comprises at least one monomer unit of trifluorovinyl ether represented by the general formula (1) and a monomer of vinylidene fluoride. Units, but usually 1 to 50% by weight, preferably 5 to 30% by weight of the monomer component represented by the general formula (1), and 50 to 99% by weight of vinylidene fluoride component, preferably Is 7
It contains 0 to 95% by weight. Further, monomer components other than these components may be contained in one or two or more kinds in a range of 49% by weight or less, preferably 20% by weight or less, and examples thereof include tetrafluoroethylene, trifluoroethylene and fluoroethylene. , Hexafluoropropylene, 3,3,3-trifluoropropylene, chlorotrifluoroethylene and other fluorine-containing monomers, ethylene, propylene, vinyl acetate, methyl vinyl ether,
Examples thereof include acrylonitrile, acrylamide, lithium acrylate, lithium methacrylate, methyl methacrylate, styrene and the like.

The copolymer can be synthesized by a general radical polymerization. The polymerization can be carried out by any method such as solution polymerization, suspension polymerization, emulsion polymerization and bulk polymerization. Examples of the polymerization initiator include diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-t-butyl peroxide, heptafluorobutyryl peroxide, 3,5,6-trichloroperfluorohexanoyl peroxide, Examples thereof include azobisisobutyronitrile, potassium persulfate, ammonium persulfate and the like.

The addition amount of the component (a) in the present invention is 5 to 90 parts by weight, preferably 10 to 60 parts by weight, based on 100 parts by weight of the sum of the above components (a), (b) and (c). .
If the amount of the added component (a) is less than 5 parts by weight, the solid polymer electrolyte becomes very brittle, and if it exceeds 90 parts by weight, the ionic conductivity is insufficient. As the electrolyte as the component (b) of the present invention, any of inorganic salts, organic salts, inorganic acids and organic acids can be used. Examples of this include inorganic acids such as tetrafluoroboric acid, perchloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, hydrochloric acid, trifluoromethanesulfonic acid, polyfluoropropylsulfonic acid, bis (trifluoromethanesulfonyl) imidic acid, Examples thereof include organic acids such as acetic acid, trifluoroacetic acid, and propionic acid, and salts of these organic acids and inorganic acids. In addition, an oligomer or polymer polyelectrolyte can also be used. Furthermore, mixtures of these organic acids, inorganic acids, and salts thereof can also be used as the electrolyte. Protons, alkali metals, alkaline earth metals, transition metals, rare earth metals and the like can be used alone or in a mixed state as cations of this salt type electrolyte, but alkali metals such as lithium and sodium are preferably used. The type of the electrolyte is not limited because the type of the cation varies depending on the use. For example, when the polymer solid electrolyte of the present invention is used as a lithium battery, it is preferable to use a lithium salt as the electrolyte to be added. In particular, when used as a lithium secondary battery, an electrochemically stable lithium salt is preferable because it uses a wide potential region. As an example, a fluorine salt such as CF ₃ SO ₃ Li or C ₄ F ₉ SO ₃ Li is used. Lithium sulfonate, (CF ₃ SO ₂ ) ₂ NL
i represented by sulfonylimide lithium salt, LiBF
₄ , LiPF ₆ , LiClO ₄ , LiAsF _{6 and the} like can be mentioned.

The addition amount of the component (b) in the present invention is 1 to 90 parts by weight, preferably 10 to 60 parts by weight, based on 100 parts by weight of the sum of the components (a), (b) and (c). .
If the amount of the added component (b) is less than 1 part by weight, the ionic conductivity will be insufficient, and if it exceeds 90 parts by weight, the solid polymer electrolyte will be very brittle. The plasticizer which is the component (c) of the present invention is used for accelerating ionic dissociation of the polymer solid electrolyte, adjusting strength such as processability and flexibility. As this plasticizer, ethylene carbonate, propylene carbonate, cyclic carbonate compounds such as butylene carbonate, dimethyl carbonate, diethyl carbonate, chain carbonate compounds such as methyl ethyl carbonate, tetrahydrofuran, ether compounds such as methyltetrahydrofuran, butyrolactone, propiolactone, Ester compounds such as methyl acetate, low molecular weight organic compounds such as nitrile compounds such as acetonitrile and propionitrile, oligoethylene oxides such as diglyme and tetraglyme, and derivatives thereof can be used. In addition, fluorine-based polymers such as aliphatic polyethers such as polyethylene oxide and polypropylene oxide, polyvinylidene fluoride, poly (vinylidene fluoride / hexafluoropropylene) copolymer, polyacrylonitrile, aliphatic polyester, aliphatic carbonate, etc. Mixtures of polymers with the above plasticizers can also be utilized as plasticizers.

When the polymer solid electrolyte of the present invention is used as an electrolyte for a lithium ion battery, compounds selected from cyclic carbonates, chain carbonates, ester compounds, and mixtures thereof are preferably used. In the present invention, by adding the component (c), the flexibility and ionic conductivity of the solid polymer electrolyte can be increased. The addition amount of the component (c) is the same as the above (a), (b),
5 to 90 parts by weight based on 100 parts by weight of the component (c),
Preferably it is 30 to 80 parts by weight. If the total amount of the component (c) added is less than 5 parts by weight, the ionic conductivity will not be sufficiently improved, and if it exceeds 90 parts by weight, the solid polymer electrolyte will be very brittle.

When the solid electrolyte is formed by using the components (a), (b) and (c) described above, a homogeneous mixture of the three may be used, or the polymer (a) may be porous by a treatment such as foaming. You may use it, having a quality structure, in which the components (b) and (c) are mixed non-uniformly. The solid electrolyte is constituted by selecting the constituent elements according to the use of the above-mentioned (a) copolymer, (b) electrolyte, and (c) plasticizer. If necessary, other polymers, ceramics and metals can be added for adjusting mechanical strength and heat resistance.

The method for producing a polymer solid electrolyte of the present invention is
For example, there may be mentioned a method in which the above-mentioned constituent elements of the polymer solid electrolyte are uniformly mixed and then molded into a predetermined shape. Specifically, a method of applying a solution of the constituents onto a substrate to form a sheet, a method of molding the constituents in a heating and melting state and then cooling, and a method of compressing and molding a powdery constituent into a predetermined shape. Any method can be used. Alternatively, a method of sequentially diffusing the electrolyte and the plasticizer into a polymer that has been molded into a predetermined shape can be used. Specifically, a method of dipping a polymer film obtained by casting or melting into an electrolyte and a plasticizer to impregnate it, and a method of immersing a film swollen with an organic solvent in the electrolyte and the plasticizer to replace the organic solvent are possible. Therefore, the electrolyte and the plasticizer may be impregnated with the electrode attached. In addition, after mixing the compound of the general formula (1) of the polymer solid electrolyte, the electrolyte, the plasticizer, the polymerizable monomer, and the initiator if necessary, the mixture is irradiated with radiant energy such as heat, electron beam, or radiation to form a mixture. It is also possible to form polymers. Further, for the purpose of adjusting the strength and solvent content of the molded solid polymer electrolyte, it is possible to irradiate it with radiant energy for modification.

The battery of the present invention is a polymer solid electrolyte as described above.
With a battery having a structure in which the positive electrode and the negative electrode are joined via
Yes, it can be used as a primary battery and a secondary battery. for example
For example, when the battery is a lithium battery, the solid polymer electrolyte of the present invention
It is preferable to use lithium salt as an electrolyte added to the electrolyte.
Good. At this time, lithium batteries are used as the positive and negative electrodes of the battery.
Use a substance that is capable of occluding and releasing the gas. This positive electrode material
Then, a material having a high potential with respect to the negative electrode is selected. With this example
And Li_1-xCoO_Two(0 <x <1), Li_1-xNi
O_Two, Li_1-xMn_TwoO_Four, Li_1-xMO_Two(M is C
o, a mixture of Ni, Mn, and Fe), Li_2-yMn_TwoO_Four
(0 <y <2), crystalline Li _1-xV_TwoO_Five, Amorpha
Lithium Li_2-yV_TwoO_Five, Li_{1.2-x '}Nb_TwoO_Five(0 <
x '<1.2) and other oxides, Li_1-xTiS_Two, Li
_1-xMoS_Two, Li_3-zNbSe_Three(0 <z <3) etc.
Metal chalcogenides, polypyrrole, polythiophene
, Polyaniline, polyacene derivative, polyacetylene
, Polythienylene vinylene, polyarylene vinylene,
Organic compounds such as dithiol derivatives and disulfide derivatives
Things can be mentioned.

As the negative electrode, a material having a lower potential than the positive electrode is used. Examples of this include lithium metal such as metallic lithium, aluminum-lithium alloys, magnesium-aluminum-lithium alloys, carbon-based materials such as graphite, coke, low-temperature calcined polymers, metal oxides such as titanium oxide and iron oxide, and lithium solid solution. Ceramics and the like. However, when lithium ions are reduced at the negative electrode and used as metallic lithium, the material is not limited to the above, as long as the material has conductivity.

The positive electrode and the negative electrode used in the battery of the present invention are formed by processing the above materials into a predetermined shape. Either a continuous body or a binder dispersion of powder material can be used as the form of the electrode. As the former continuous body forming method, electrolysis, vapor deposition, sputtering, CVD, melt processing, sintering,
Compression or the like is used. In the latter method, a powdery electrode material is mixed with a binder for molding. Polymers, polymer precursors, metals and the like are used as the binder material, and the polymer solid electrolyte of the present invention can be used as the binder. Further, in order to perform electron transfer of the positive electrode or the negative electrode material, a current collector can be provided on the electrode with a material having low electric resistance, and the current collector can be an electrode formed on the substrate by the above method. Also, positive electrode /
The plasticizer and the electrolyte, which are the constituent elements of the polymer solid electrolyte of the present invention, can be introduced into a battery having a polymer solid electrolyte / negative electrode structure by a method such as impregnation or diffusion.

In the case of a lithium battery, the form of the battery has a structure in which a positive electrode and a negative electrode are joined via a solid polymer electrolyte. For example, a positive electrode formed by sequentially stacking sheet-like components /
A sheet-like or roll-like structure can be formed with the polymer solid electrolyte / negative electrode as a unit. It is also possible to make an assembled battery in which the electrodes of the battery units are connected in parallel or in series. In particular, the solid electrolyte battery has a feature that the voltage can be increased depending on the number of serial connections. Also,
If necessary, it is possible to provide or package a battery electrode with a protective layer for connecting external terminals for current injection and injection, for preventing current absorption from the current / voltage control circuit element and battery unit / stack, and for structural protection. it can.

Since the polymer solid electrolyte of the present invention is excellent in flexibility, processability and mechanical strength, it is not limited to the above lithium batteries, but also alkaline batteries, lead batteries, nickel hydrogen batteries, fuel cells, photoelectrochemical cells, It is industrially useful because it can be applied to various electrochemical elements and devices such as electrochemical sensors.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described by way of examples to further clarify the present invention. The ionic conductivity of the polymer solid electrolyte of the present invention is determined by using an AC impedance method in which a polymer solid electrolyte is sandwiched between metal electrodes to form an electrochemical cell, an alternating current is applied between the electrodes and a resistance component is measured, and the Calculated from the real intercept of the plot.

[0023]

[Production Example 1] In a 300 ml pressure-resistant stainless steel container, 1.8 g of perfluoro (propyl vinyl ether) (X = CF ₂ CF ₂ CF ₃ in the general formula (1)),
25 ml of trichlorotrifluoroethane (hereinafter referred to as CFC113) and 1 ml of a 5% CFC113 solution of heptafluorobutyryl peroxide were charged, the inside of the reactor was replaced with nitrogen, and then the mixture was cooled to −78 ° C. and evacuated. Into this, 12.2 g of vinylidene fluoride was charged, and 2
Stirred for 0 hours. After the reaction, unreacted vinylidene fluoride was purged to take out a white powdery reaction product and dried to obtain 12.5 g of a white solid. The content of perfluoro (propyl vinyl ether) monomer unit in the copolymer was 14% in terms of weight ratio, which was determined from the NMR spectrum measured in heavy DMSO. Hereinafter, this reaction product is referred to as polymer A.

[0024]

EXAMPLE 1 Polymer A (1 g) synthesized in Production Example 1 was mixed with a solution of LiBF _{4 in} an ethylene carbonate (EC) / propylene carbonate (PC) mixed solvent (1: 1) (1 m).
ol / l) 4 g (EC: 1.956 g, PC: 1.76)
8, LiBF ₄ : 0.276 g) and 10 g of acetone were mixed, heated to 50 ° C. to obtain a uniform mixture, and cast to prepare a polymer electrolyte membrane. Impedance measurement by sandwiching the film with a stainless sheet as an electrode (Model 389 impedance meter manufactured by EG & G)
As a result, the room temperature ionic conductivity was 2.4 × 10 ⁻³ S
/ Cm.

[0025]

Example 2 Using the polymer A obtained in Production Example 1, a film (thickness 300 μm) produced by the same operation as in Example 1 was cut into a width of 10 mm, and RTM-50 manufactured by Orientec Co., Ltd.
When the chuck distance was set to 30 mm and the sample was pulled at a constant speed of 10 mm / min using a 0 tensile tester, the sample broke after stretching 135%, and the stress at break was 2.4.
It was kg / cm ² .

[0026]

Comparative Example 1 Instead of polymer A, vinylidene fluoride-
A film was prepared in the same manner as in Example 1 except that a hexafluoropropylene copolymer (hexafluoropropylene in the copolymer was 12% by weight, which will be hereinafter referred to as polymer B) was used to obtain an ionic conductivity. As a result of the measurement, the room temperature ionic conductivity was 2.3 × 10 ⁻³ S / cm.

[0027]

Comparative Example 2 A test piece was prepared using Polymer B (1 g) in the same manner as in Example 2 and subjected to a tensile tester. The sample was brittle and broke at the point of elongation of 22%, and the stress at rupture was 0.3 kg / cm ² . The stress-elongation curves of Comparative Example 2 and Example 2 are shown in FIG. In this composition, polymer B
Compared with the electrolyte material using the polymer A synthesized in Production Example 1, the ionic conductivity is the same, but the elongation and strength of the film are significantly inferior.

[0028]

Example 3 To examine the change in mechanical strength of an electrolyte material by adding an electrolyte and a plasticizer to a copolymer,
The properties of the polymer A obtained in Production Example 1 and the polymer B used in Comparative Example were compared. 1 g of each copolymer and 10 g of acetone, and the amount of LiB shown in Table 1
F ₄ ethylene carbonate (EC) / propylene carbonate (PC) mixed solvent (1: 1) solution (1 mol /
The film obtained by mixing and casting 1) was subjected to a tensile tester under the same conditions as in Example 2. The results of comparing the two are shown in Table 1, and it can be seen that the perfluoro (vinyl ether) of the present invention is superior in mechanical strength to the vinylidene fluoride-hexafluoropropylene copolymer. In particular, in a composition containing a large amount of electrolyte and a plasticizer, the electrolyte material comprising the copolymer of the present invention exhibits excellent mechanical properties.

[0029]

[Table 1]

[0030]

[Production Example 2] In the same manner as in Production Example 1, 11.2 g of perfluoro (propyl vinyl ether), 12.2 g of vinylidene fluoride and 1 ml of a 5% CFC113 solution of heptafluorobutyryl peroxide were reacted at room temperature for 20 hours. Drying gave 22.5 g of a white solid. Heavy DMS
The content of perfluoro (propyl vinyl ether) in the copolymer determined from the NMR spectrum measured in O was 48% in terms of weight ratio.

[0031]

Example 4 in the same manner as in Example 1, the copolymer obtained in Production Example 2 (1 g), LiBF ₄ ethylene carbonate (EC) / propylene carbonate (PC) mixed solvent (1: 1) solution ( 1 mol / l) 1 g (EC: 0.48
9 g, PC: 0.442 g, LiBF ₄ : 0.069
g), when a film was made from 10 g of acetone,
The room temperature ionic conductivity was 7.8 × 10 ⁻⁴ S / cm.

[0032]

MANUFACTURING EXAMPLE 3 By the same procedure as in Manufacturing Example 1, 1.8 g of perfluoro (methyl vinyl ether), 8.7 g of vinylidene fluoride and 5 parts of heptafluorobutyryl peroxide were used.
% Ml of CFC113 solution, reacted and dried to 9.5
g of a white solid were obtained. This reaction product is designated as Polymer C. The content of perfluoro (propyl vinyl ether) in the polymer determined from the NMR spectrum measured in deuterated DMSO was 13% in terms of weight ratio.

[0033]

Example 5 By the same operation as in Example 1, a solution of the polymer C (1 g) obtained in Production Example 3 and LiBF _{4 in} an ethylene carbonate (EC) / propylene carbonate (PC) mixed solvent (1: 1) solution (1 mol) was used. / L) 1 g (EC: 0.48
9 g, PC: 0.442 g, LiBF ₄ : 0.069
g), when a film was made from 10 g of acetone,
The room temperature ionic conductivity was 6.6 × 10 ⁻⁴ S / cm.

[0034]

Example 6 After mixing a predetermined amount of lithium hydroxide and cobalt oxide, the mixture was heated at 750 ° C. for 5 hours and the average particle size was 10 μm.
Of LiCoO ₂ powder was synthesized. A slurry was prepared by mixing and dispersing the powder, carbon black, and polyvinylidene fluoride (KF1100 manufactured by Kureha Chemical Industry Co., Ltd.) in N-methylpyrrolidone solution (5% by weight). The weight composition of solids in the slurry is LiCoO ₂ (8
5%), carbon black (8%), polymer (7%)
And This slurry was applied on an aluminum foil by a doctor blade method and dried to prepare a sheet having a film thickness of 110 μm. The LiCoO ₂ sheet was cut into 2 cm square, and the polymer solid electrolyte film (2.5 cm square) produced in Example 1 was placed on this surface. Further, a metal lithium foil (2 cm square) was laminated on the positive electrode (LiCoO ₂ )
The electrode laminate was composed of / polymer solid electrolyte / negative electrode (metal lithium). Then, stainless steel terminals were attached to the positive electrode and the negative electrode of the electrode laminate, which were respectively connected to the terminals of the glass cell and sealed in an argon atmosphere. The battery was charged and discharged with a current density of 0.
Charging / discharging was performed at a current density of 1 mA / cm ² . The inter-electrode potential after charging was 4.2 V (4.2 V constant potential charging after constant current), and charging was confirmed. The discharge was performed at a constant current of 2.7 V with a cutoff voltage of 2.7 V. As a result, it was found that the battery can be repeatedly charged and discharged and operates as a secondary battery.

[0035]

Example 7 N of polyvinylidene fluoride used in Example 6 was added to needle coke powder having an average particle size of 10 μm.
A 5% solution of methylpyrrolidone was mixed to form a slurry (dry weight mixing ratio: needle coke (92
%), Polymer (8%)). The slurry was applied to a metal copper sheet by a doctor blade method to form a film (electrode layer) with a dry film thickness of 120 μm. After the film was cut into 2 cm squares, the solid polymer electrolyte film prepared in Example 1 was cut into 2.5 cm and laminated on this surface, and then the LiCoO ₂ electrode prepared in Example 6 was laminated. A battery was formed by joining the positive electrode (LiCoO ₂ ) / solid polymer electrolyte / negative electrode (coke). Then, after enclosing the battery in a glass cell with an electrode, the battery was charged and discharged in the same manner as in Example 6 using a charger / discharger. As a result of constant current low potential (4.2V) charging and constant current discharging (2.7V cutoff) at a current density of 0.1 mA / cm ² , the battery voltage after charging was 4.2V.
It was possible to repeatedly charge and discharge.

[0036]

The solid polymer electrolyte material using the copolymer of the present invention has a high ionic conductivity and is excellent in processability, flexibility, mechanical strength and ionic transport number. By using it as a moving medium, it is possible to provide a solid-state battery having sufficient mechanical strength.

[Brief description of drawings]

FIG. 1 Perfluorovinyl ether used in the present invention
Vinylidene fluoride copolymer and commercial vinylidene fluoride
The graph which shows the comparison of the stress-strain curve of a hexafluoropropylene copolymer.

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[Procedure amendment]

[Submission date] May 14, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

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─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01M 8/02 G01N 27/58 A

Claims (2)

[Claims] 1. (a) A copolymer containing at least one monomer unit of trifluorovinyl ether represented by the following general formula (1) and a monomer unit of vinylidene fluoride, CF ₂ ═CF-OX. (1) (In the formula, X is a perfluoroalkyl group having 1 to 18 carbon atoms, and in these groups, the end of the carbon chain may be hydrogenated, and an ether group is contained in the carbon chain. (B) the electrolyte, and (c) a polymer solid electrolyte containing a plasticizer as a component, and (a), (b),
The component (a) is 5 to 5 parts by weight based on the sum of the components (c).
90 parts by weight, component (b) is 1 to 90 parts by weight, and component (c) is 5 to 90 parts by weight, a solid polymer electrolyte. 2. A battery characterized in that electrodes are joined via the polymer solid electrolyte according to claim 1.