RU2373592C1 - Polymer electrolyte, method of its production and electrochemical element - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, particularly to polymer electrolyte with high ionic conductivity that contains copolymer of ethylene unsaturated compound and carbon monoxide, to method of its production and electrochemical element made thereof. Proposed electrolyte comprises polymer material and electrolyte salt, or polymer material, solvent and electrolyte salt wherein copolymer made up of 50% to 90% molar of ethylene unsaturated compound and 1% to 50% molar of carbon monoxide makes from 66.7 to 100 % by weight of this polymer material. Method is described to produce such polymer electrolyte and electrochemical device made thereof.

EFFECT: high ionic conductivity and reliability of operation of electrochemical elements operated at over 100 V.

11 cl, 1 dwg, 11 tbl, 34 ex

Description

FIELD OF TECHNOLOGY

The present invention relates to a polymer polymer with high ionic conductivity containing a copolymer of ethylene unsaturated compounds and carbon monoxide, and a method for its preparation. The present invention further relates to an electrochemical device using this polymer electrolyte, which has excellent resistance to liquid leakage, heat resistance and safe operation.

The term "ethylene unsaturated compound and carbon monoxide copolymer" as used herein also includes examples of an alternating copolymer, and all are collectively referred to as an (alternating) copolymer depending on the context of the description.

BACKGROUND

Since portable information devices, such as a laptop computer and cell phone, have become popular, the need for electrochemical devices such as a primary current source battery, a rechargeable battery and a double electric layer capacitor used as power sources for these devices has been rapidly increased. These devices are especially required to be compact and lightweight like a thin film, and at the same time their reliability is also expected to improve. In recent years, in addition to power supplies for portable information devices, new applications have been developed, such as power supplies for hybrid electric vehicles and energy conservation, and thus reliability needs to be further improved.

Typically, in an electrochemical device, an electrolyte solution is used in which the electrolyte salt is dissolved in a solvent, and when the effluent and the electrolyte solution are non-aqueous electrolyte solutions, troubles such as ignition and fire are a major factor in reducing reliability. Accordingly, these problems can be solved using solid electrolyte instead of electrolyte solution. In particular, the polymer electrolyte easily forms a thin film and has excellent mechanical properties and flexibility, and therefore is a very promising material.

From these points of view, many studies have been carried out on polymer electrolyte in recent years, and there have been many proposals since it was first discovered that ionic conductivity was obtained by forming a composite of a certain type of alkali metal salt with a high molecular weight polyethylene oxide polymer (see non-patent document one).

Patent Document 1 proposes semi-solid gel polymer polymer electrolytes containing methyl polymethacrylate, electrolyte salts such as

LiClO ₄ or LiBF ₄ , and an organic solvent.

Patent Document 2 proposes an electrochemical generator using solid-phase polymer electrolytes in which the electrolyte salt is solubilized solid-soluble in a high molecular weight polymer containing heteroatoms such as oxygen or nitrogen, and polyethylene oxide and polyamide are shown as examples of the polymeric material in this document.

Patent Document 3 provides a gel polymer polymer electrolyte composition in which an electrolyte salt is dissolved in a mixture of a high molecular weight polymer having a dielectric constant of 4 or more and an organic solvent having a dielectric constant of 10 or more, and shows that examples of a polymer material satisfying such requirements include includes nitrocellulose, phenolic resin, polyvinylidene fluoride, polyacrylonitrile and chlorosulfonated polyethylene.

Patent Document 4 describes a lithium solid electrolyte cell using lithium as a negative electrode and metal chalcogenide as a positive electrode, and shows that examples of solid electrolyte include polymer electrolytes using a vinylidene fluoride copolymer, polyvinyl chloride, polyvinyl acetate, polyvinylpyrrolidone or the like.

Patent Document 5 provides an ion-conducting solid composition using a polymeric material and describes polysiloxane as an excellent polymeric material.

Patent Document 6 describes a hybrid ionic conductor using an oxyethylene (meth) acrylate polymer.

In addition, Patent Document 7 describes an aliphatic epoxy resin based ionic conductive resin composition, Patent Document 8 describes a polyphosphazene-based polymer electrolyte, Patent Document 9 describes an ionic polymer complex containing polyalkylene carbonate, metal salts and an organic solvent, Patent Document 10 describes a polymer solid. an electrolyte and a polymer solid electrolyte cell using polyurethane, and Patent Document 11 describes, for example, an ion conducting component itsiyu based on polyvinyl alcohol.

As for the polymer electrolyte, as described above, two types of polymer materials were proposed, namely, a solid-phase polymer electrolyte containing a polymer material and an electrolyte salt, and a gel-like polymer electrolyte mixed with a polymer material and an electrolyte salt, and additionally a solvent, but all the following significant problem still persists.

Namely, no material has been proposed that actually provides the necessary ionic conductivity for a solid-phase polymer electrolyte. In addition, it is necessary to mix a large amount of solvent to obtain the desired ionic conductivity in the case of a gel polymer electrolyte. Therefore, from the point of view of reliability, the reliability of each of these electrolytes is only one level better than the reliability of an electrochemical device using a conventional liquid electrolyte, and thus, the high reliability initially expected for a polymer electrolyte has not been achieved.

Subsequently, in connection with the commercial use of a lithium-ion battery, it was proposed to use a polymer electrolyte in a lithium-ion battery (see Patent Document 12). Thus, we actively studied polymer electrolyte, and a lithium-ion battery using a gel-like polymer electrolyte was put into serial production. However, as described above, this gel-like polymer electrolyte contained a large amount of solvent, and the high reliability initially expected for the polymer electrolyte was not obtained. As a result, in the lithium-ion battery market, most of the product is represented by liquid electrolyte batteries, and the market share of the lithium-ion battery using a gel polymer electrolyte is very small. To solve this problem, various polymeric materials were investigated, and Patent Document 13 proposes an ion-conducting polymer electrolyte containing polymer A having a carbonyl group (1 to 40% by weight), polymer B based on polyvinylidene fluoride (20 to 70% by weight) mass), a metal salt C (from 1 to 50% by mass) and an organic solvent D (from 20 to 85% by mass). Here, preferred examples of polymer A having a carbonyl group include polyesters, polycarbonates and polyester carbonates, and other examples thereof further include polyamides, polypeptides, polyurethanes and polyketones. However, this system also contains a large amount of organic solvent, and ionic conductivity is not always satisfactory.

As described above, although a lithium-ion rechargeable battery using a gel-like polymer electrolyte is only used in practice in cases of partial use of compact batteries for end users, the main problems in this situation are still the development of a polymer electrolyte.

Patent Document 1: JP-A-54-104541

Patent Document 2: JP-A-55-098480

Patent Document 3: JP-A-57-143356

Patent Document 4: JP-A-58-075779

Patent Document 5: JP-A-59-230058

Patent Document 6: JP-A-60-031555

Patent Document 7: JP-A-60-248724

Patent Document 8: JP-A-61-254626

Patent Document 9: JP-A-62-030147

Patent Document 10: JP-A-01-197974

Patent Document 11: JP-A-01-284508

Patent Document 12: JP-A-01-241767

Patent Document 13: JP-A-11-060870

Non-Patent Document 1: P.V. Wright, Polymer, 14, 589, (1973)

DESCRIPTION OF THE INVENTION

PROBLEMS SOLVED BY THIS INVENTION

As described above, it is difficult to achieve both ionic conductivity and reliability in a conventional polymer electrolyte. In particular, in recent years, a field of large-scale application has developed, such as hybrid electric vehicles, requiring higher reliability, and the demand for their inherent reliability, which a polymer electrolyte should naturally have, has increased more than ever. In addition, a polymer electrolyte is usually used at a high voltage of 100 V or more in a given large-scale field of application, and a polymer electrolyte having high ionic conductivity and high reliability was required to obtain a bipolar electrode, that is, the most rational electrode structure for use at such high voltages .

The present invention is implemented to solve these problems, and provides a solid-phase polymer electrolyte having high ionic conductivity by selecting a particular polymer material, namely a gel-like polymer electrolyte having high ionic conductivity, by adding a small amount of solvent to an extent that does not impair reliability, and a method for producing electrolyte data. In addition, the present invention also provides an electrochemical device having excellent output characteristics and high reliability through the use of these polymer electrolytes.

MEANS FOR SOLVING THESE PROBLEMS

The authors of the present invention conducted intensive research to solve the above problems. As a result, the authors found that the above problems can be solved by using the (alternating) copolymer of ethylene unsaturated compounds and carbon monoxide according to the present invention.

The polymer electrolyte of the present invention is a polymer electrolyte containing a polymer material and an electrolyte salt, or a polymer material, a solvent and an electrolyte salt, characterized in that from 66.7% by weight to 100% by weight of the polymer material is a copolymer from 50 to 99 mol.% ethylene unsaturated compounds and from 1 to 50 mol.% carbon monoxide.

In addition, the polymer electrolyte of the present invention is a polymer electrolyte containing a polymeric material and an electrolyte salt, or a polymeric material, a solvent and an electrolyte salt, characterized in that 100% by weight of the polymeric material is a copolymer of from 50 to 99 mol% of ethylene unsaturated compounds and from 1 to 50 mol.% carbon monoxide, and the mass ratio of solvent to the amount of solvent and polymer material is 0 or more, and less than 33.3%.

In addition, the polymer electrolyte of the present invention is characterized in that the copolymer comprises an alternating copolymer of ethylene unsaturated compound and carbon monoxide.

In addition, the method for producing a polymer electrolyte of the present invention is characterized in that it comprises the steps of: dissolving a polymer material containing from 66.7% by weight to 100% by weight of a copolymer from 50 to 99 mol% of an ethylenically unsaturated compound and from 1 to 50 mol .% carbon monoxide in solution, where from 30% by weight to 90% by weight of the electrolyte salt is dissolved in a solvent; molding the resulting mixture into arbitrary shape; and removing part or all of the solvent.

In addition, the method for producing the polymer electrolyte of the present invention is characterized in that it comprises the steps of: dissolving the copolymer from 50 to 99 mol% of an ethylenically unsaturated compound and from 1 to 50 mol% of carbon monoxide in a solution, where from 30% by weight to 90% by weight of the electrolyte salt dissolved in the solvent; molding the resulting mixture into arbitrary shape; and removing part or all of the solvent.

Furthermore, the method for producing the polymer electrolyte of the present invention is characterized in that it comprises the steps of: dissolving an alternating copolymer of ethylene unsaturated compound and carbon monoxide in a solution, where from 30% by weight to 90% by weight of the electrolyte salt is dissolved in a solvent; molding the resulting mixture into arbitrary shape; and removing part or all of the solvent.

In addition, the electrochemical device of the present invention is characterized in that it uses the above polymer electrolyte of the present invention.

RESULTS OF THIS INVENTION

The polymer electrolyte of the present invention achieves a result satisfying both high ionic conductivity and reliability. In addition, the electrochemical device of the present invention achieves a result consisting in high reliability and excellent output characteristics.

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the present invention will be described in detail.

One of the differences of the present invention is that a (alternating) copolymer of an ethylene unsaturated compound and carbon monoxide is used as a polymer electrolyte.

A copolymer of an ethylenically unsaturated compound such as ethylene and propylene and carbon monoxide has a photosensitivity based on carbonyl groups contained in the polymer backbone, and attention must be paid to this copolymer as a photosensitive polymer material and an easily photodegradable polymer material for a long time. As a manufacturing method, it is known that this copolymer is obtained by thermal polymerization or radical polymerization of an ethylenically unsaturated compound and carbon monoxide in the presence of an initiator such as peroxides, as described, for example, in JP-A-50-34087 and JP-A-53- 128690.

The present invention is based on the fact that a polymer electrolyte having high ionic conductivity can be obtained by using such a copolymer of an ethylenically unsaturated compound and carbon monoxide.

However, the copolymer obtained in the above radical polymerization was a random copolymer having a low carbon monoxide content.

Meanwhile, a copolymerization method has recently been discovered in which an ethylenically unsaturated compound and carbon monoxide are copolymerized by coordination polymerization using a transition metal compound such as palladium as a catalyst, as described, for example, in JP-A-01-092222. An alternating copolymer in which an ethylenically unsaturated compound and carbon monoxide are alternately copolymerized can be obtained by this coordination polymerization.

The present invention is also based on the discovered fact that a polymer electrolyte having high ionic conductivity can be obtained by using an alternating copolymer of ethylene unsaturated compound and carbon monoxide.

Examples of the ethylene unsaturated compound used in the present invention include α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene and 1-decene; alkenyl aromatic compounds such as styrene, α-methylstyrene and p-methylstyrene; cyclic olefins such as cyclopentene, norbornene and 5-methylnorbornene; vinyl halides such as vinyl chloride; and acrylic acid esters such as ethyl acrylate and methyl methacrylate.

Among them, the preferred ethylene unsaturated compound are α-olefins, and the more preferred ethylene unsaturated compound are α-olefins having from 2 to 4 carbon atoms.

These ethylenically unsaturated compounds may be used individually or as a mixture of a variety of such compounds. When many such compounds are used for an alternating copolymer, any of the ethylene unsaturated compounds can alternately copolymerize with carbon monoxide.

As a polymerization method for a copolymer that is not an alternating copolymer, polymerization is possible with a thermal polymerization initiator as described above, and examples of such an initiator include peroxides such as benzoyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, dicumyl peroxide and tert- butyl hydroperoxide; and azo compounds such as azobisisobutyronitrile and azobisvalerononitrile. As the form of polymerization, bulk polymerization, solution polymerization, suspension polymerization and the like can be selected.

As a coordination polymerization catalyst for producing an alternating copolymer, a combination of three components from a transition metal compound, in particular a palladium compound, a compound acting as a palladium ligand, and an anion is preferred. As the palladium compound, carboxylates, phosphates, carbamates, sulfonates, palladium halides or the like are used, and specific examples thereof include palladium acetate, palladium butyrate, palladium trifluoroacetate, palladium phosphate, palladium acetylacetonate, palladium trifluoromethanesulfonate, palladium chloride and ( N-diethyl carbamate) bis (diethylamine) palladium.

Examples of a compound acting as a palladium ligand include amine-based compounds and phosphine-based compounds. In addition, examples of the anion include an inorganic acid anion, such as sulfuric acid, nitric acid, perchloric acid or phosphoric acid; and an anion of an organic acid such as trifluoroacetate, methanesulfonic acid and trifluoromethanesulfonic acid.

Typically, an ethylenically unsaturated compound and carbon monoxide are copolymerized in the presence of a solvent in which said catalyst is dissolved or dispersed. Examples of the polymerization solvent include water, methanol, ethanol, propanol, acetone, methyl ethyl ketone, diethyl ether, tetrahydrofuran, ethyl acetate and acetonitrile.

The polymerization temperature usually lies in the range from 20 ° C to 200 ° C and preferably from 70 ° C to 150 ° C. The (alternating) copolymer of ethylene unsaturated compound and carbon monoxide used in the present invention can be obtained by polymerization under pressure from 1.013 × 10 ⁵ Pa to 2.026 × 10 ⁷ Pa (from 1 ATM to 200 ATM), if necessary.

Using ¹³ C-NMR spectral analysis method or the like, it is easy to verify whether the repeating units derived from the ethylene unsaturated compound and the repeating units derived from carbon monoxide are essentially alternating in this polymer.

The copolymerization ratio can be controlled, for example, using the starting ratio of ethylene unsaturated compound to carbon monoxide, and a copolymer in which the mole fraction of carbon monoxide is in the range of 1 to 50% can usually be obtained. To obtain higher ionic conductivity, the mole fraction of carbon monoxide is preferably from 5 to 50% and more preferably from 10 to 50%.

The weighted average molecular weight of the (alternating) copolymer of ethylene unsaturated compound and carbon monoxide is preferably from 5000 to 1,000,000, and more preferably from 10,000 to 1,000,000.

The (alternating) copolymer of the ethylene unsaturated compound and carbon monoxide of the present invention can be used alone, but the polymer electrolyte can be obtained by admixing other polymeric materials. When other polymeric materials are mixed in for use, it is preferable from 66.7 to 100% by weight of the (alternating) copolymer in the entire mass of polymeric materials, since the resulting polymer electrolyte has high ionic conductivity. By using an alternating copolymer mixed with other polymeric materials, functional effects, such as improved mechanical strength, flexibility, formability, and chemical resistance, without compromising ionic conductivity, can be obtained within the scope of the present invention.

Miscible polymeric materials can be appropriately selected according to this purpose from groups of polymeric materials such as materials obtained by vinyl polymerization, ring opening polymerization, polycondensation, polyaddition and polycondensation-polyaddition. Examples thereof include the following polymeric materials: polyolefin-based polymers and copolymers such as polyethylene, polypropylene and poly-4-methylpentene; polyalkadiene-based polymers and copolymers such as polybutadiene and polyisoprene; polyalkenyl-based polymers and copolymers such as poly-α-methylstyrene; vinyl ester-based polymers and copolymers such as polyvinyl acetate and polyvinyl butyrate; vinyl ether based polymers and copolymers such as polymethyl vinyl ether and polyethyl vinyl ether; (meth) acrylate-based polymers and copolymers such as polymethyl methacrylate and polybutyl acrylate; nitrile-based polymers and copolymers such as polyacrylonitrile and polymethacrylonitrile; nitrogen-containing polymers and copolymers based on vinyl compounds such as polyvinylpyridine, polyvinylimidazole, poly-N-methylvinylpyrrolidone and polyacrylamide; fluorine-containing polymers and copolymers based on vinyl and vinylidene, such as polyvinyl fluoride and polyvinylidene fluoride; polyesters and copolymers based on simple polyethers, such as polyethylene oxide and polypropylene oxide; polyimine-based polymers and copolymers such as polyethyleneimine and polypropyleneimine; polythioether-based polymers and copolymers such as polyethylene sulfide; polyamide-based polymers and copolymers such as nylon 6 and nylon 66; polymers and copolymers based on polyesters obtained by ring-opening polymerization and on the basis of other polyurethanes, such as polyethylene terephthalate and polylactic acid; polycarbonate-based polymers and copolymers.

Preferred examples of the electrolyte salt used as the polymer electrolyte of the present invention include inorganic salts such as LiClO ₄ , LiBF ₄ , LiPF ₆ , LiBr, LiI, LiSCN and LiAsF ₆ ; organic sulfonates such as CH ₃ SO ₃ Li and CF ₃ SO ₃ Li; and sulfonylimide salts such as (CF ₃ SO ₂ ) ₂ NLi, (CF ₃ CF ₂ SO ₂ ) ₂ NLi and (CF ₃ SO ₂ ) (CF ₃ CF ₂ SO ₂ ) NLi.

As for the cationic particles of the above electrolyte salt, alkali metal salts other than Li salts, for example, salts of alkali metals such as sodium and potassium, can also be used. In addition, cationic particles such as an aliphatic quaternary ammonium salt, an imidazolium salt, a pyrinidium salt and a piperidinium salt can also be used.

The amount of electrolyte salt is preferably in the range of 1 to 90% by weight, and more preferably 5 to 75% by weight, based on all of said polymeric material and said electrolyte salt.

A polymer electrolyte can be obtained by complexation of the above polymer material and an electrolyte salt, and there are conventional known, for example, the following complexation methods.

1. A method of producing a polymer electrolyte by dissolving the polymer material and the electrolyte salt in a solvent in which both of them can be dissolved, and then removing part or all of the solvent (method 1).

2. A method of producing a polymer electrolyte by first molding the polymer material into a form such as a film form, and then impregnating and swelling it with a solution in which the electrolyte salt is dissolved in a solvent and removing part or all of the solvent (method 2).

3. A method of producing a polymer electrolyte by melting and mixing a polymer material and an electrolyte salt (method 3).

4. A method of producing a polymer electrolyte by dissolving an electrolyte salt in a liquid monomer or polymer precursor and then polymerizing them (method 4).

As a method for complexing a polymer material and an electrolyte salt in the present invention, among the above methods, methods 1 to 3 are preferred. The complexation method will be described below.

The solvent used for the complexation according to method 1 is water and / or a non-aqueous solvent, and examples of non-aqueous solvents include cyclic carbonates such as propylene carbonate, ethylene carbonate and vinylene carbonate; linear carbonates such as diethyl carbonate, dimethyl carbonate and ethyl methyl carbonate; cyclic esters such as γ-butyrolactone; linear esters such as ethyl acetate and methyl acetate; ketones such as acetone and methyl ethyl ketone; alcohols such as methanol and ethanol; ethers such as tetrahydrofuran, 1,4-dioxane and 1,2-dimethoxyethane; nitriles such as acetonitrile and benzonitrile; amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; and sulfonates.

In addition, as a modified variant of method 1, a solution can be used in which the electrolyte salt is dissolved in water or an organic solvent at a high concentration, and this method is especially useful when the molar fraction of carbon monoxide in the polymer material used in the present invention is high. The concentration of electrolyte salt in this case is appropriately selected, but preferably the mass ratio of electrolyte salt to the total mass of electrolyte salt and solvent is from 30% by weight to 90% by weight, and more preferably from 50% by weight to 90% by weight, from the point view of good solubility.

The polymer electrolyte of the present invention can be obtained by molding a solution obtained by this method into an arbitrary shape, such as a sheet, by coating, casting, extruding or the like, and removing part or all of the solvent. In addition, an electrode for an electrochemical device using the polymer electrolyte of the present invention can be obtained by mixing the active material of the positive electrode or the active material of the negative electrode in this solution, molding the mixture into a sheet form or the like in the same manner as described above, and then removing part or all of the solvent.

The removal of part or all of the solvent can be controlled by using, for example, a hot plate, an oven and a temperature programmable cabinet in which a temperature program can be installed. Although the drying conditions vary depending on the type and amount of solvent to be removed, temperature drying conditions, for example from 50 to 250 ° C. for about 30 minutes to 10 hours, can preferably be applied. In addition, the solvent can be dried under reduced pressure using vacuum drying.

The polymer electrolyte of the present invention can be used in the form of a polymer electrolyte in the above dried state and can be used, if necessary, after the crosslinking reaction has been carried out. As the crosslinking method, conventional methods are used, such as electron beam crosslinking and chemical crosslinking with ammonia, diamine, a radical generator, and the like.

When the complexation is carried out according to method 2, the polymer electrolyte of the present invention can be obtained by impregnating and swelling a solution in which the electrolyte salts are dissolved in a solvent, the polymer material of the present invention, pre-molded into a shape such as a film, and removing part or all of the solvent. The same solvent as used in method 1 can also be used in method 2. In addition, an electrode for an electrochemical device using the polymer electrolyte of the present invention can be obtained by preliminary mixing and mixing the polymer material of the present invention with the active material of the positive electrode or the active negative electrode material, molding this mixture into a shape such as a sheet, then impregnating and swelling it with a solution in which the electrolyte salt is sol Rena in a solvent, and removing a part or all of the solvent.

When complexation is carried out according to method 3, a polymer electrolyte can be directly obtained by melting and mixing the polymer material and the electrolyte salt of the present invention and molding the mixture into a shape such as a film. In addition, an electrode for an electrochemical device using the polymer electrolyte of the present invention can be directly obtained by melting and mixing the active material of the positive electrode or the active material of the negative electrode with the polymer material and the electrolyte salt of the present invention, and forming the mixture into a shape such as a film .

When the copolymer of ethylene unsaturated compound and carbon monoxide used in the present invention is an alternating copolymer, this copolymer has high crystallinity and, thus, has a high melting point, and is also insoluble in most solvents. Therefore, the complexation of this copolymer with an electrolyte salt was not easy according to the above conventional methods.

The inventors of the present invention have invented a simple method for producing a polymer electrolyte based on the fact that a solution containing an electrolyte salt dissolved in water or an organic solvent at a high concentration unexpectedly dissolves an alternating copolymer of ethylene unsaturated compound and carbon monoxide.

As one of the methods for producing the polymer electrolyte of the present invention, called the modified method 1, a method using a concentrated solution of electrolyte salt will be described below.

The alternating copolymer of ethylene unsaturated compound and carbon monoxide is completely insoluble in water and ordinary non-aqueous solvents, but unexpectedly dissolved in a solution in which the electrolyte salt is dissolved in water, a non-aqueous solvent or a mixture thereof at a high concentration.

The solvent used here is water and / or a non-aqueous solvent, and preferred examples of the non-aqueous solvent include cyclic carbonates such as propylene carbonate, ethylene carbonate and vinylene carbonate; linear carbonates such as diethyl carbonate, dimethyl carbonate and ethyl methyl carbonate; cyclic esters such as γ-butyrolactone; linear esters such as ethyl acetate and methyl acetate; ketones such as acetone and methyl ethyl ketone; alcohols such as methanol and ethanol; ethers such as tetrahydrofuran, 1,4-dioxane and 1,2-dimethoxyethane; nitriles such as acetonitrile and benzonitrile; amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone; and sulfonates.

The concentration of electrolyte salt in this case is appropriately selected, but preferably the mass ratio of electrolyte salt to the total mass of electrolyte salt and solvent is from 30% by weight to 90% by weight, and more preferably from 50% by weight to 90% by weight, from the point view of good solubility.

An alternating copolymer of ethylene unsaturated compound and carbon monoxide can be dissolved in this concentrated solution by stirring and shaking. The dissolution temperature of the copolymer is appropriately selected, and the polymer can dissolve sufficiently even at room temperature, but the dissolution rate can be increased by heating. The heating temperature lies in the range from room temperature to 250 ° C, but without limitation only to those indicated, preferably in the range from 50 ° C to 200 ° C and more preferably from 80 ° C to 150 ° C.

Using this dissolving operation, a uniform, transparent solution can be obtained, and the polymer electrolyte of the present invention can be obtained by molding the solution into an arbitrary shape, such as a sheet, by a method of coating, casting, extruding or the like, and then removing part or all solvent. In addition, an electrode for an electrochemical device using the polymer electrolyte of the present invention can be obtained by mixing the active material of the positive electrode or the active material of the negative electrode in this solution, molding this mixture in a sheet form in the same manner as described above, and then removing part or all solvent.

The removal of part or all of the solvent can be controlled by using, for example, a hot plate, an oven and a temperature programmable cabinet in which a temperature program can be installed. Although the drying conditions vary depending on the type and amount of solvent to be removed, temperature drying conditions, for example from 50 to 250 ° C. for about 30 minutes to 10 hours, can preferably be applied. In addition, the solvent can be dried under reduced pressure using vacuum drying.

The polymer electrolyte of the present invention can be used in the form of a polymer electrolyte directly in the above dried state and can be used, if necessary, after the crosslinking reaction has been carried out. As the crosslinking method, conventional methods are used, such as electron beam crosslinking and chemical crosslinking with ammonia, diamine, a radical generator, and the like. The polymer electrolyte of the present invention also includes polymer electrolytes crosslinked using said crosslinking methods.

A first embodiment of a polymer electrolyte of the present invention includes, for example, a solid phase polymer electrolyte. That is, when all of the solvent is removed by method 1 (including a method using a concentrated electrolyte salt solution as a modified method) or 2, a solid-phase polymer electrolyte containing a polymer material containing (alternating) a copolymer of ethylene unsaturated compound and carbon monoxide can be obtained and electrolyte salt. In addition, a solid-phase polymer electrolyte can be directly obtained by method 3. The amount of solvent remaining after drying can be determined by NMR measurement and when this amount is 1000 ppm or less, the entire solvent is considered removed.

The solid state polymer electrolyte of the present invention is characterized in that it has a very high ionic conductivity, and an ionic conductivity equivalent to that of a liquid electrolyte has been detected. The reason why the solid-state polymer electrolyte of the present invention exhibits high ionic conductivity is not clear, but it is believed that the ketone carbonyl groups contained in the polymer interact strongly with ions.

As a solid-phase polymer electrolyte, for example, a polymer based on polyethylene oxide or its copolymer having ether bonds is known, but all of them have ionic conductivity substantially less than the conductivity of a liquid electrolyte and, therefore, do not reach a practical level.

As described above, the solid-phase polymer electrolyte of the present invention is absolutely free of liquid electrolyte, but has high ionic conductivity, and when it is used for non-aqueous electrochemical devices such as lithium primary battery, lithium secondary battery and non-aqueous double electric layer capacitor, the following effects occur .

1. This electrolyte exhibits high output characteristics equivalent to those of a liquid electrolyte.

2. This electrolyte is solid-phase and, therefore, does not leak liquid.

3. This electrolyte does not contain combustible material and, therefore, has no flammability.

4. This electrolyte has sufficient flexibility and workability, and is therefore excellent for random shape such as a thin film.

5. When this electrolyte is used as a bipolar electrode, in which the active material of the positive electrode and the active material of the negative electrode are located on the front surface and the back surface of the current collector, respectively, there is absolutely no concern about the connection of the positive electrode and the negative electrode formed on the front surface by ionic liquid and the back surface of the current collector, which can occur in the case of a liquid electrolyte, and can easily be obtained by ektrohimicheskoe device having a high electromotive force of a few tens of volts (V) or more.

As described above, a solid-state polymer electrolyte is used among the polymer electrolytes of the present invention, and thus the reliability, safety and characteristics of the resulting electrochemical device can be significantly improved.

A second aspect of the polymer electrolyte of the present invention includes, for example, a gel polymer electrolyte. That is, when a portion of the solvent is removed in method 1 (including a method using a concentrated solution of electrolytic salt as a modified method) or 2, a solid gel-like polymer electrolyte containing (alternating) copolymer of ethylene unsaturated compound and carbon monoxide, electrolyte, can certainly be obtained. salt and solvent. Although the compositional ratio of the solvent to the (alternating) copolymer of ethylene unsaturated compound and carbon monoxide is appropriately selected depending on the task, the mass ratio of the solvent to the total mass of solvent and the (alternating) copolymer is preferably less than 70% by mass, more preferably less than 50% by mass mass, and most preferably less than 33.3% by mass.

In addition, when 100% of the polymeric material is a copolymer of an ethylene unsaturated compound and carbon monoxide, the mass ratio of solvent to total solvent and copolymer is preferably less than 33.3% by weight, and more preferably less than 20% by weight. When this mass ratio is 33.3% by mass or more, reliability, such as resistance to liquid leakage, deteriorates, and the mechanical strength of the polymer electrolyte decreases.

Typically, in the case of a gelled polymer electrolyte, when the mass fraction of the added solvent is large, the resulting electrolyte is characterized by conflicting, interconnected parameters, when the ionic conductivity becomes high, but reliability, such as resistance to liquid leakage, deteriorates and the mechanical strength of the polymer electrolyte decreases.

However, as described above, a sufficiently high ionic conductivity can be obtained even when the polymer electrolyte of the present invention is a solid phase polymer electrolyte. Therefore, as the polymer electrolyte of the present invention, a gel-like polymer electrolyte is used that retains part of the solvent, and thus, this effect is achieved with a small amount of solvent compared to a conventional gel-like polymer electrolyte even in the case of an additional increase in ionic conductivity, in particular ionic conductivity at low temperatures , and therefore reliability, such as resistance to fluid leakage, is unlikely to decrease.

The gel polymer electrolyte of the present invention will be described later.

An aqueous gelled polymer electrolyte obtained when the solvent in the present invention is water, essentially retains its inherent high ionic conductivity of the aqueous electrolyte solution. Accordingly, when this electrolyte is used for aqueous electrochemical devices, such as a water ion battery and a water double electric layer capacitor, it does not cause a decrease in output characteristics, low temperature characteristics, and the like, and provides significantly improved reliability and, therefore, is applicable.

Further, the non-aqueous gel-like polymer electrolyte obtained when the solvent is a non-aqueous solvent substantially retains the ionic conductivity of the non-aqueous electrolyte solution and maintains high ionic conductivity, in particular in the low temperature region. Therefore, it is applicable to non-aqueous electrochemical devices such as a dye-sensitized solar cell and an electrochemical device in addition to a lithium primary battery, a lithium secondary battery and a non-aqueous double electric layer capacitor.

As described above, a polymer electrolyte having high ionic conductivity can be provided by using the (alternating) copolymer of the ethylene unsaturated compound and carbon monoxide of the present invention and can be used for various electrochemical devices in the form of a solid-phase polymer electrolyte or gel polymer electrolyte depending on the task. Here, the term "electrochemical device" means a device in which electrochemical phenomena involving ions are applied, and specific examples thereof include devices such as a storage device, an energy generation device, a display device, and a sensor device.

In the present invention, the polymer electrolyte can be a self-supporting film and not a self-supporting film, and can be used without any problems, even if there is a leak of liquid, but it is preferable if the electrolyte is a self-supporting film and there is no leak of liquid.

An example of an electrochemical device using the polymer electrolyte of the present invention will be described below.

The drawing shows a top view and a longitudinal sectional view showing an example of an electrochemical device of the present invention. In the drawing, reference numeral 1 denotes a positive electrode; 2 - indicates a negative electrode; 3 - indicates the terminal of the positive electrode; 4 - indicates the terminal of the negative electrode; 5 - indicates a polymer electrolyte; and 6 - indicates a battery case.

Specific examples of this electrochemical device include a lithium primary battery using lithium metal as a negative electrode and using manganese dioxide, carbon fluoride or the like as a positive electrode; a lithium ion secondary battery using a carbon material, metal oxide, lithium alloy or the like as a negative electrode and using lithium cobaltate, lithium nickelate, lithium manganate, lithium iron phosphate or the like as a positive electrode; and an electric double layer capacitor using activated carbon as a positive electrode and a negative electrode; and an aqueous ionic battery using a mixed lithium oxide and a transition metal containing vanadium, titanium, iron or the like as a negative electrode and using a mixed lithium oxide and a transition metal containing cobalt, manganese, iron or the like as a positive electrode.

EXAMPLES

Now the present invention will be specifically described using examples and comparative examples.

[Reference example 1 (obtaining polymer A)]

A 1 L SUS autoclave with a stirrer was charged with 800 ml of dimethyl carbonate as a polymerization solvent and 1.2 g of azobisisovalerononitrile as a polymerization initiator, and then mixed gas having an ethylene pressure ratio of carbon monoxide of 1 was charged so as to obtain a pressure of 4 5 MPa at room temperature. The temperature of the autoclave was raised to 60 ° C with stirring. The mixture was reacted for 6 hours with the addition of mixed gas so as to maintain a pressure at 5 MPa. After cooling, the reagents were removed and the solid content was washed to obtain a white powder.

From ¹³ C-NMR and infrared absorption spectra, it was confirmed that this polymer was a polymerization product of ethylene and carbon monoxide (hereinafter referred to as “polymer A”) and the mole fraction of carbon monoxide was 43.2%. In addition, this polymer A had a weight average molecular weight of 85,000.

[Reference example 2 (obtaining polymer B)]

The operation was carried out completely as in comparative example 1, except that the ratio of ethylene pressure to pressure of carbon monoxide was changed to 2 relative to reference example 1. After cooling, the reagents were removed and the solid content was washed to obtain a white powder.

From ¹³ C-NMR and infrared absorption spectra, it was confirmed that this polymer was a polymerization product of ethylene and carbon monoxide (hereinafter referred to as “polymer B") and the molar fraction of carbon monoxide was 21.3%. In addition, this polymer B had a weight average molecular weight of 56,000.

[Reference example 3 (obtaining polymer C)]

The operation was completely the same as in Reference Example 1, except that the ratio of ethylene pressure to carbon monoxide pressure was changed to 10 relative to Reference Example 1. After cooling, the reagents were removed and the solid content was washed to obtain a white powder.

From ¹³ C-NMR and infrared absorption spectra, it was confirmed that the polymer was a polymerization product of ethylene and carbon monoxide (hereinafter referred to as “polymer C”) and the mole fraction of carbon monoxide was 10.9%. In addition, this polymer C had a weight average molecular weight of 72,000.

[Example 1]

50 parts by weight of lithium bis (trifluoromethanesulfonyl) imide {(CF ₃ SO ₂ ) ₂ NLi} as an electrolyte salt was mixed and dissolved in 50 parts by weight of water to obtain a solution having a concentration of 50% by weight. 100 mass parts of this solution and 85 mass parts of polymer A were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then 0.1 mass parts of hexamethylenediamine as a crosslinking agent was added to 100 mass parts of this viscous solution, this mixture was cast to a thickness of 500 μm on a glass plate. Then the cast mixture was dried at atmospheric pressure at 80 ° C for 1 hour, obtaining a non-sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of polymer A and water, determined using ¹ H-NMR at this time, was 21.9% by weight. Here, NMR measurement was performed using a JNM-LA400 instrument manufactured by JEOL Ltd. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Example 2]

The same operation as in Example 1 was carried out, except that 85 parts by weight of polymer A in Example 1 was replaced with a mixture of 75 parts by weight of polymer A and 10 parts by weight of a polyester copolymer of ethylene oxide and 2- (2-methoxyethoxyethyl) glycidyl ether having the weighted average molecular weight of 14,000 (copolymerization ratio = 73:27, hereinafter referred to as "polymer D"). The result was a non-sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of polymer A, polymer D and water was 22.5% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Example 3]

The same operation was carried out as in Example 1, except that 85 parts by weight of polymer A in Example 1 was replaced with a mixture of 68 parts by weight of polymer A and 17 parts by weight of polymer D. As a result, a non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of polymer A, polymer D and water was 23.3% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Example 4]

The same operation was carried out as in Example 1, except that 85 parts by weight of polymer A in Example 1 was replaced with a mixture of 62 parts by weight of polymer A and 23 parts by weight of polymer D. As a result, a non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of polymer A, polymer D and water was 24.5% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Example 5]

The same operation was performed as in Example 1, except that 85 parts by weight of polymer A in Example 1 was replaced with a mixture of 58 parts by weight of polymer A and 27 parts by weight of polymer D. A non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of polymer A, polymer D and water was 21.9% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Comparative example 1]

The same operation was performed as in Example 1, except that 85 parts by weight of polymer A in Example 1 was replaced with a mixture of 55 parts by weight of polymer A and 30 parts by weight of polymer D. A slightly sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of polymer A, polymer D and water was 23.3% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Comparative example 2]

The same operation was carried out as in Example 1, except that 85 parts by weight of polymer A in Example 1 was replaced with a mixture of 35 parts by weight of polymer A and 50 parts by weight of polymer D. A very sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of polymer A, polymer D and water was 21.6% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

[Comparative example 3]

The same operation was carried out as in Example 1, except that 85 parts by weight of polymer A in Example 1 was replaced by 85 parts by weight of polymer D and no hexamethylenediamine was used. The result was a very sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of polymer D and water was 20.5% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 1.

Table 1 The content of the carbon monoxide copolymer in the polymer material
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 1 one hundred 9.5 Self-supporting liquid-free film 6.3 Example 2 88.2 9.0 Self-supporting liquid-free film 5.7 Example 3 80.0 7.9 Self-supporting liquid-free film 4.9 Example 4 72.9 7.2 Self-supporting liquid-free film 4,5 Example 5 68,2 6.1 Self-supporting liquid-free film 3.9 Comparative
example 1 64.7 1,1 Self-supporting film having a weak stickiness in which leakage of liquid was observed 0.9 Comparative
example 2 41.2 0.8 Non-self-sustaining, highly tacky film in which fluid leakage was observed 0.5 Comparative
example 3 0 0.2 Non-self-sustaining, highly tacky film in which fluid leakage was observed 0.1

[Example 6]

30 parts by mass of lithium tetrafluoroborate (LiBF ₄ ) as an electrolyte salt were mixed and dissolved in 70 parts by mass of γ-butyrolactone to obtain a solution having a concentration of 30% by weight. 100 mass parts of this solution and 120 mass parts of polymer B were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then this viscous solution was poured to a thickness of 500 μm on a glass plate, the spilled solution was dried at atmospheric pressure at 120 ° C for 1 hour. Then the glass plate was placed in a vacuum dryer set at 150 ° C, and further dried for 10 hours. As a result, a solid phase polymer film-shaped electrolyte was obtained having a γ-butyrolactone content of 1000 ppm or less, determined by ¹³ C-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C in an alternating current of 1 kHz. The result is shown in table 2.

[Example 7]

The same operation as in Example 6 was carried out, except that 120 parts by weight of polymer B in Example 6 was replaced with a mixture of 100 parts by weight of polymer B and 20 parts by weight of a vinylidene fluoride-hexafluoropropylene copolymer having a weight average molecular weight of 35,000 (copolymerization ratio = 88: 12, hereinafter referred to as "polymer E"). As a result, a solid phase polymer film-shaped electrolyte was obtained having a γ-butyrolactone content of 1000 ppm or less, determined by ¹³ C-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C in an alternating current of 1 kHz. The result is shown in table 2.

[Example 8]

The same operation as in Example 6 was carried out, except that 120 parts by weight of polymer B in Example 6 was replaced by a mixture of 85 parts by weight of polymer B and 35 parts by weight of polymer E. As a result, a solid-phase polymer film electrolyte having a γ content was obtained β-butyrolactone 1000 ppm or less, determined using ¹³ C-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C in an alternating current of 1 kHz. The result is shown in table 2.

[Comparative example 5]

The same operation as in Example 6 was carried out, except that 120 parts by weight of polymer B in Example 6 was replaced with a mixture of 45 parts by weight of polymer B and 75 parts by weight of polymer E. As a result, a solid-phase polymer film-shaped electrolyte having a γ content was obtained β-butyrolactone 1000 ppm or less, determined using ¹³ C-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C in an alternating current of 1 kHz. The result is shown in table 2.

[Comparative example 6]

The same operation was carried out as in Example 6, except that 120 parts by weight of polymer B in Example 6 was replaced by 120 parts by weight of polymer E. As a result, a film could not be obtained, but a white powder mixture was obtained.

The propylene carbonate content in this polymer E, determined by ¹³ C-NMR measurement, was 1000 ppm or less, but it was not possible to measure ionic conductivity.

table 2 The content of the carbon monoxide copolymer in the polymer material
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 6 one hundred 2.1 Self-supporting liquid-free film 1,6 Example 7 83.3 1.9 Self-supporting liquid-free film 1,2 Example 8 70.8 1,2 Self-supporting liquid-free film 0.9 Comparative
example 4 62.5 0.2 Fragile film 0.1 Comparative
example 5 37.5 0.09 Fragile film 0,03 Comparative
example 6 0 Immeasurably Powder form Immeasurably

[Example 9]

After 75 mass parts of polymer A and 25 mass parts of polymer E were melted and mixed, this mixture was formed into a film having a thickness of 150 μm. This film was irradiated with electron beams with a dose of 5.0 Mrad, obtaining a crosslinked film.

This film was immersed in a solution having a concentration of 20% by weight, in which 20 parts by weight of lithium tetrafluoroborate (LiBF ₄ ) were mixed and dissolved in 80 parts by weight of γ-butyrolactone, at 120 ° C. for 2 hours, and then the film was cooled to room temperature and the film surface was washed. The film was inflated, and the mass increased by 85% based on the initial mass.

The properties of the composition, ionic conductivity and polymer electrolyte of this film were as shown in table 3.

[Example 10]

The same operation was carried out as in example 9, except that the mixing ratio of the polymers in example 9 was replaced by the ratio of 68 parts by weight of polymer A and 32 parts by weight of polymer E. The result was a swollen film increased by weight by 215% based on the initial mass.

The properties of the composition, ionic conductivity and polymer electrolyte of this film were as shown in table 3.

Table 3 Solvent Weight /
(mass of solvent and high molecular weight polymer)
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 9 40.5 5.3 Self-supporting liquid-free film 3.2 Example 10 63,2 6.7 Self-supporting liquid-free film 4.1

[Example 11]

The present example shows an example of an electrochemical device of the present invention using the gel polymer electrolyte of the present invention, is a schematic sectional view of this electrochemical device.

<Preparation of polymer electrolyte solution (1)>

Lithium tetrafluoroborate (LiBF ₄ ), propylene carbonate and polymer A were charged at a mass ratio of 20: 70: 100, and this mixture was heated and stirred at 120 ° C. to obtain a viscous solution.

<Preparation of the positive electrode sheet>

LiCoO ₂ (average particle size: 5 μm) as the active material of the positive electrode, and graphite and acetylene black as conductive additives were mixed dry in a mass ratio of 100: 5: 2.5.

After 100 mass parts of a solution of (1) polymer electrolyte and 100 mass parts of a mixture of the active material of the positive electrode and the conductive additives were mixed in a paste form, this mixture was applied to one surface of the current collector of a positive electrode of aluminum foil having a thickness of 15 μm, with a thickness 200 microns. The current collector was dried at 150 ° C for 2 hours, obtaining a sheet of a positive electrode.

The content of propylene carbonate contained in this positive electrode sheet was 12.3% by weight based on the total weight of the positive electrode sheet except for the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

After 50 mass parts of graphite (average particle size: 10 μm) as a negative electrode active material were mixed with 100 mass parts of a polymer electrolyte solution (1) in a paste form, this mixture was applied to one surface of a negative foil collector made of copper foil, having a thickness of 18 microns, with a thickness of 150 microns. The current collector was dried at 150 ° C for 2 hours, obtaining a sheet of negative electrode.

The propylene carbonate content in this negative electrode sheet was 14.4% by weight based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode made of copper foil.

<Preparation of an electrochemical device>

Polymer C was formed by compression at 210 ° C. to obtain a film having a thickness of 18 μm. This film was immersed in a solution where the mass ratio of lithium tetrafluoroborate (LiBF ₄ ) to propylene carbonate was 40:60. The film was left at room temperature for 24 hours, and then received a swollen and increased by weight by 48.3% film of a polymer electrolyte based on the initial weight.

The sheet of the positive electrode and the sheet of the negative electrode were folded by placing this polymer electrolyte film between them, collecting the electrochemical device shown in the drawing.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging this electrochemical device was performed as follows. After charging in the charging mode, direct current / constant voltage with a maximum current of 50 mA and a maximum voltage of 4.2 V for 5 hours, the electrochemical device was discharged to 3.0 V at a constant current of 10 mA. The discharge value was 86.2 mA ∙ h. Then, the electrochemical device was recharged under the same conditions, the discharge value was estimated under constant current conditions, shown in table 4. The results are shown in table 4.

[Example 12]

<Preparation of polymer electrolyte solution (2)>

Lithium tetrafluoroborate (LiBF ₄ ), propylene carbonate, polymer A and polymer E were charged at a weight ratio of 20: 70: 75: 25, and this mixture was heated and stirred at 120 ° C. to obtain a viscous solution.

<Preparation of the positive electrode sheet>

A positive electrode sheet was obtained in the same manner as in Example 11, except that a polymer electrolyte solution (2) was used.

The propylene carbonate content in this positive electrode sheet was 11.9% by weight based on the total weight of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

A negative electrode sheet was obtained in the same manner as in Example 11, except that a polymer electrolyte solution (2) was used.

The propylene carbonate content in this negative electrode sheet was 14.9% by weight based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode made of copper foil.

<Preparation of an electrochemical device>

A polymer electrolyte film increased by 39.5% by weight based on the initial weight was obtained in the same manner as in Example 11, except that a mixture having a mass ratio of polymer C to polymer E 75 was used as the film material: 25.

The sheet of the positive electrode and the sheet of the negative electrode were folded by placing this polymer electrolyte film between them, collecting the electrochemical device shown in the drawing.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging of this electrochemical device was performed in the same manner as in example 11. The results are shown in table 4.

[Comparative example 7]

<Preparation of polymer electrolyte solution (3)>

Lithium tetrafluoroborate (LiBF ₄ ), propylene carbonate, polymer A and polymer E were charged at a mass ratio of 20: 70: 60: 40, and this mixture was heated and stirred at 120 ° C. to obtain a viscous solution.

<Preparation of the positive electrode sheet>

A positive electrode sheet was obtained in the same manner as in Example 11, except that a polymer electrolyte solution (3) was used.

The propylene carbonate content in this positive electrode sheet was 12.6% by weight based on the total weight of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

A negative electrode sheet was obtained in the same manner as in Example 11, except that a polymer electrolyte solution (3) was used.

The propylene carbonate content in this negative electrode sheet was 15.8% by weight based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode made of copper foil.

<Preparation of an electrochemical device>

A polymer electrolyte film increased by weight by 33.9% by weight based on the initial weight was obtained in the same manner as in Example 11, except that a mixture having a mass ratio of polymer C to polymer E was used as the film material 60:40.

The sheet of the positive electrode and the sheet of the negative electrode were folded by placing this polymer electrolyte film between them, collecting the electrochemical device shown in the drawing.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging of this electrochemical device was performed in the same manner as in example 11. The results are shown in table 4.

Table 4 The content of the carbon monoxide copolymer in the polymer material
(wt.%) Discharge conditions (mA) and discharge value (mA ∙ h) 10 mA 50 mA 100 mA Example 11 one hundred 86.2 mAh 80.6 mAh 76.7 mAh Example 12 75.0 80.1 mAh 75.3 mAh 69.6 mAh Reference Example 7 60.0 24.9 mAh 9.1 mAh not discharged

[Example 13]

50 parts by weight of lithium bis (trifluoromethanesulfonyl) imide {(CF ₃ SO ₂ ) ₂ NLi} as an electrolyte salt was mixed and dissolved in 50 parts by weight of water to obtain a solution having a concentration of 50% by weight. 100 mass parts of this solution and 75 mass parts of polymer A were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then 0.1 mass parts of hexamethylenediamine as a crosslinking agent was added to 100 mass parts of this viscous solution, this mixture was cast to a thickness of 500 μm on a glass plate. Then the cast mixture was dried at atmospheric pressure at 80 ° C for 1 hour, obtaining a slightly sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of polymer A and water, determined using ¹ H-NMR at this time, was 32.1% by weight. Here, NMR measurement was performed using a JNM-LA400 instrument manufactured by JEOL Ltd. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 5.

[Example 14]

The same operation as in Example 13 was carried out, except that hourly drying at 80 ° C. in Example 13 was replaced by 3 hours. As a result, a substantially non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of the polymer of ethylene and carbon monoxide and water was 19.3% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 5.

[Example 15]

The same operation as in Example 13 was carried out, except that hourly drying at 80 ° C. in Example 13 was replaced by 6 hours. The result was a completely non-sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of the polymer of ethylene and carbon monoxide and water was 9.2% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 5.

[Example 16]

After the viscous solution obtained in the same manner as in Example 13 was cast to a thickness of 500 μm on a glass plate, the cast solution was dried at atmospheric pressure at 120 ° C. for 3 hours. Then the glass plate was placed in a vacuum dryer set at 150 ° C, and further dried for 10 hours. As a result, a solid phase polymer electrolyte in the form of a film was obtained having a water content of 1000 ppm or less, determined by ¹ H-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 5.

[Example 17]

The same operation as in Example 13 was carried out, except that hourly drying at 80 ° C. in Example 13 was replaced with 0.5 hours. The result was a very sticky and non-self-sustaining gel-like polymer electrolyte.

The ratio of the mass of water to the total mass of the polymer of ethylene and carbon monoxide and water was 35.7% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 5.

Table 5 (Solvent weight) /
(mass of solvent and high molecular weight polymer)
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 13 32.1 10.3 Self-supporting film that has a weak stickiness but does not cause fluid to leak 7.1 Example 14 19.3 8.1 Self-supporting liquid-free film 5.2 Example 15 8.9 6.9 Self-supporting liquid-free film 3.9 Example 16 0 4.1 Self-supporting liquid-free film 1,2 Example 17 35.7 10.1 Non-self-sustaining, highly tacky film in which fluid leakage was observed 6.9

[Example 18]

30 parts by weight of lithium tetrafluoroborate (LiBF ₄ ) as an electrolyte salt were mixed and dissolved in 70 parts by weight of γ-butyrolactone to obtain a solution having a concentration of 30% by weight (hereinafter referred to as “solution A”). 100 mass parts of this solution and 95 mass parts of polymer B were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then this viscous solution was poured to a thickness of 500 μm on a glass plate, the spilled solution was dried at atmospheric pressure at 120 ° C for 2 hours. The result was a slightly sticky gel-like polymer electrolyte in the form of a film.

The mass ratio of γ-butyrolactone to the total weight of the polymer of ethylene and carbon monoxide and γ-butyrolactone, determined by ¹³ C-NMR measurement, was 31.9% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 6.

[Example 19]

The same operation was carried out as in Example 18, except that the drying conditions in Example 18 were replaced by drying at 120 ° C. for 3 hours. As a result, a substantially non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The mass ratio of γ-butyrolactone to the total weight of the polymer of ethylene and carbon monoxide and γ-butyrolactone was 18.3% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 6.

[Example 20]

The same operation as in Example 18 was carried out, except that the drying conditions in Example 18 were replaced by drying at 120 ° C. for 6 hours. The result was a completely non-sticky gel-like polymer electrolyte in the form of a film.

The mass ratio of γ-butyrolactone to the total weight of the polymer of ethylene and carbon monoxide and γ-butyrolactone was 7.2% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 6.

[Example 21]

100 parts by weight of this solution A, obtained in the same manner as in Example 18, and 95 parts by weight of polymer B were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then this viscous solution was poured to a thickness of 500 μm on a glass plate, the spilled solution was dried at atmospheric pressure at 120 ° C for 1 hour. After that, the glass plate was placed in a vacuum dryer set at 150 ° C, and further dried for 10 hours. As a result, a solid-state polymer film-shaped electrolyte was obtained having a γ-butyrolactone content of 1000 ppm or less, determined by ¹³ C-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C in an alternating current of 1 kHz. The results are shown in table 6.

[Example 22]

The same operation as in Example 18 was carried out, except that the drying conditions in Example 18 were replaced by drying at 120 ° C. for 1 hour. The result was a very sticky and not self-sustaining gel-like polymer electrolyte.

The mass ratio of γ-butyrolactone to the total weight of the polymer of ethylene and carbon monoxide and γ-butyrolactone was 41.3% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 6.

Table 6 (Solvent weight) /
(mass of solvent and high molecular weight polymer)
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 18 31.9 2.6 Self-supporting film that has a weak stickiness but does not cause fluid to leak 2.1 Example 19 18.3 2.1 Self-supporting liquid-free film 1.8 Example 20 7.2 1.9 Self-supporting liquid-free film 1,1 Example 21 0 1.3 Self-supporting liquid-free film 0.5 Example 22 41.3 2.7 Non-self-sustaining, highly tacky film in which fluid leakage was observed 2.2

[Comparative example 8]

100 parts by weight of polymer E, 25 parts by weight of lithium bis (trifluoromethanesulfonyl) imide {(CF ₃ SO ₂ ) ₂ NLi} as an electrolyte salt and 120 parts by weight of propylene carbonate were mixed and dissolved in 200 parts by weight of dimethylformamide at 60 ° C.

Then this solution was cast to a thickness of 500 μm on a glass plate; the cast solution was dried at atmospheric pressure at 120 ° C for 2 hours. The result was a slightly sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of propylene carbonate to the total weight of polymer E and propylene carbonate was 45.3% by mass at this point in time, and dimethylformamide was not left. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 7.

[Comparative example 9]

The same operation was carried out as in comparative example 8, except that the drying conditions in comparative example 8 were replaced by drying at 150 ° C. for 3 hours. As a result, a substantially non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the weight of propylene carbonate to the total weight of polymer E and propylene carbonate was 24.8% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 7.

[Comparative example 10]

The same operation was carried out as in comparative example 8, except that the drying conditions in comparative example 8 were replaced by drying at 150 ° C. for 6 hours. The result was a very fragile gel-shaped polymer electrolyte in the form of a film.

The ratio of the weight of propylene carbonate to the total weight of polymer E and propylene carbonate was 16.8% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 7.

[Comparative example 11]

After a solution containing polymer E and an electrolyte salt obtained in the same manner as in comparative example 8 was cast to a thickness of 500 μm on a glass plate, the cast solution was dried at atmospheric pressure at 120 ° C. for 2 hours. Then the glass plate was placed in a vacuum dryer set at 150 ° C, and further dried for 10 hours. As a result, the film could not be obtained, but a white powder mixture was obtained.

The propylene carbonate content in this mixture was 1000 ppm or less, but it was not possible to measure ionic conductivity.

[Comparative example 12]

100 parts by weight of polymer D and 25 parts by weight of lithium bis (trifluoromethanesulfonyl) imide {(CF ₃ SO ₂ ) ₂ NLi} as an electrolyte salt were mixed and dissolved in 250 parts by weight of acetonitrile.

Then this solution was cast to a thickness of 500 μm on a glass plate; the cast solution was dried at atmospheric pressure at 80 ° C for 2 hours. As a result, a solid-phase polymer electrolyte in the form of a film was obtained in which acetonitrile completely disappeared.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 7.

Table 7 (Solvent weight) /
(mass of solvent and high molecular weight polymer)
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Reference Example 8 45.3 0.93 Non-self-sustaining, highly tacky film in which fluid leakage was observed 0.29 Reference Example 9 24.8 0.39 A self-supporting film having a slight stickiness in which fluid leakage was observed 0.13 Reference Example 10 16.8 0.09 Fragile film 0.01 Reference Example 11 0 Immeasurably Powder form Immeasurably Reference Example 12 0 0.11 Self-supporting film 0,03

[Example 23]

The present example shows an example of an electrochemical device of the present invention using the gel polymer electrolyte of the present invention. The drawing is a schematic sectional view of this electrochemical device.

<Preparation of polymer electrolyte solution (4)>

Lithium tetrafluoroborate (LiBF ₄ ), propylene carbonate and polymer A were charged at a weight ratio of 20: 80: 100, and this mixture was heated and stirred at 120 ° C. to obtain a viscous solution.

<Preparation of the positive electrode sheet>

LiCoO ₂ (average particle size: 5 μm) as the active material of the positive electrode and graphite, and acetylene black as conductive additives were mixed dry in a mass ratio of 100: 5: 2.5.

After 100 mass parts of the polymer electrolyte solution (4) and 100 mass parts of the mixture of the active material of the positive electrode and conductive additives were mixed in a paste form, this mixture was applied to one surface of the current collector of the positive electrode of aluminum foil having a thickness of 15 μm, with a thickness of 200 microns. The current collector was dried at 150 ° C for 2 hours, obtaining a sheet of a positive electrode.

The propylene carbonate content in this positive electrode sheet was 11.8% by weight based on the total weight of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

After 50 mass parts of graphite (average particle size: 10 μm) as a negative electrode active material were mixed with 100 mass parts of a polymer electrolyte solution (4) in a paste form, this mixture was applied on one surface of a negative foil collector made of copper foil, having a thickness of 18 microns, with a thickness of 150 microns. The current collector was dried at 150 ° C for 2 hours, obtaining a sheet of negative electrode.

The propylene carbonate content in this negative electrode sheet was 15.4% by weight based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode made of copper foil.

<Preparation of an electrochemical device>

Polymer C was formed by compression at 210 ° C. to obtain a film having a thickness of 18 μm. This film was immersed in a solution where the mass ratio of lithium tetrafluoroborate (LiBF ₄ ) to propylene carbonate was 40:60. The film was left at room temperature for 24 hours, and then a polymer electrolyte film swollen and increased by 48.3% in weight based on the initial weight was obtained.

The sheet of the positive electrode and the sheet of the negative electrode were folded by placing this polymer electrolyte film between them, collecting the electrochemical device shown in the drawing.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging this electrochemical device was performed as follows. After charging in the charging mode, direct current / constant voltage with a maximum current of 50 mA and a maximum voltage of 4.2 V for 5 hours, the electrochemical device was discharged to 3.0 V at a direct current of 10 mA. The discharge value was 88.3 mAh. Then, the electrochemical device was recharged under the same conditions, the discharge value was estimated under constant current conditions, shown in table 8. The results are shown in table 8.

[Example 24]

The present example shows an example of an electrochemical device of the present invention using the solid state polymer electrolyte of the present invention. The drawing shows a schematic view in section of this electrochemical device.

<Preparation of the positive electrode sheet>

A mixture of a positive electrode active material and conductive additives obtained in the same manner as in Example 23, lithium bis (pentafluoroethanesulfonyl) imide {(CF ₃ СF ₂ SO ₂ ) ₂ NLi}, propylene carbonate and polymer A were charged at a mass ratio of 100: 20: 30:50, and this mixture was heated and kneaded at 150 ° C.

This kneaded product was extruded into a sheet form with a thickness of 200 μm onto a current collector of a positive electrode of aluminum foil having a thickness of 15 μm. Then the current collector was dried at 180 ° C for 2 hours, receiving a sheet of a positive electrode.

The propylene carbonate content in this positive electrode sheet was 1000 ppm or less, based on the total mass of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

Graphite (average particle size: 10 μm) as the active material of the negative electrode, lithium bis (pentafluoroethanesulfonyl) imide {(CF ₃ СF ₂ SO ₂ ) ₂ NLi}, propylene carbonate and polymer A were charged at a mass ratio of 50: 20: 30: 50 , and this mixture was heated and kneaded at 150 ° C.

This kneaded product was extruded into a sheet form with a thickness of 150 μm onto a current collector of a negative electrode of copper foil having a thickness of 18 μm. Then the current collector was dried at 180 ° C for 2 hours, receiving a sheet of negative electrode.

The propylene carbonate content in this negative electrode sheet was 1000 ppm or less, based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode of copper foil.

<Preparation of an electrochemical device>

Bis (pentafluoroethanesulfonyl) lithium imide {(CF ₃ CF ₂ SO ₂ ) ₂ NLi}, propylene carbonate and polymer A were charged at a mass ratio of 20:30:50, and this mixture was heated and kneaded at 150 ° C.

This kneaded product was extruded into a sheet form with a thickness of 20 μm on the surface of the above-prepared sheet of the positive electrode, and then the above-prepared sheet of the negative electrode was layered on it. Then this electrode group was dried at 180 ° C for 2 hours, the electrochemical device shown in the drawing was assembled.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging of this electrochemical device was performed in the same manner as in example 23. The results are shown in table 8.

[Comparative example 13]

This example shows a comparative example of an electrochemical device using a solid-state polyester polymer electrolyte. The drawing is a schematic sectional view of this electrochemical device.

<Preparation of polymer electrolyte solution (5)>

Bis (pentafluoroethanesulfonyl) lithium imide {(CF ₃ CF ₂ SO ₂ ) ₂ NLi} as an electrolyte, acetonitrile as a solvent and polymer D were charged at a mass ratio of 10: 100: 40, and then mixed and stirred to obtain a solution.

<Preparation of the positive electrode sheet>

A positive electrode sheet was obtained in the same manner as in Example 23, except that a polymer electrolyte solution (5) was used and the drying temperature was changed to 80 ° C.

The acetonitrile content in this positive electrode sheet was 1000 ppm or less, based on the total mass of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

A negative electrode sheet was obtained in the same manner as in Example 23, except that a polymer electrolyte solution (5) was used and the drying temperature was changed to 80 ° C.

The acetonitrile content in this negative electrode sheet was 1000 ppm or less, based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode made of copper foil.

<Preparation of an electrochemical device>

The polymer electrolyte solution (5) was applied to the surface of the above-prepared positive electrode sheet, and then dried to obtain a coating layer having a thickness of 20 μm.

A positive electrode sheet having a given coating layer and a negative electrode sheet prepared above were folded to assemble the electrochemical device shown in the drawing.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging of this electrochemical device was performed in the same manner as in example 23. The results are shown in table 8.

Table 8 Discharge conditions (mA) and discharge value (mA ∙ h) 10 mA 50 mA 100 mA Example 23 83.3 mAh 80.9 mAh 77.4 mAh Example 24 81.3 mAh 76.5 mAh 70.9 mAh Reference Example 13 11.4 mAh 5.3 mAh Immeasurably

[Reference example 4 (obtaining polymer F)]

1.0 μmol of palladium acetate, 1.2 μmol of 1,3-bis {di (2-methoxyphenyl) phosphino} propane and 50 μmol of sulfuric acid were dissolved in 100 ml of a mixed solvent of methanol and water containing 18% water, and this solution charged into a 200 ml stainless steel autoclave, purged with nitrogen. Then 1 mg of 1,4-benzoquinone was added, and the autoclave was hermetically sealed, then the contents were heated with stirring, and at the time when the internal temperature reached 90 ° C, ethylene was added until the pressure inside the reactor became 5.0 MPa. Then carbon monoxide was added until the pressure inside the reactor became 8.0 MPa. Stirring was continued for 4 hours, maintaining the internal temperature and internal pressure under these conditions. After cooling, the contents were recovered.

The reaction product was washed with methanol and then dried under reduced pressure to obtain 21.3 g of a polymer. ¹³ C-NMR and infrared absorption spectra confirmed that this polymer was essentially an alternating copolymer in which ethylene and carbon monoxide were alternately polymerized (hereinafter referred to as “polymer F”). This polymer F had a weight average molecular weight of 75,000.

[Reference example 5 (obtaining polymer G)]

The operation was performed in exactly the same manner as in Reference Example 4, except that propylene was used instead of ethylene in Reference Example 4.

The reaction product was washed with methanol and then dried under reduced pressure to obtain 18.7 g of a polymer. ¹³ C-NMR and infrared absorption spectra confirmed that this polymer was essentially an alternating copolymer in which propylene and carbon monoxide were alternately polymerized (hereinafter referred to as “polymer G”). This polymer G had a weight average molecular weight of 47,000.

[Example 25]

60 parts by weight of lithium bis (trifluoromethanesulfonyl) imide {(CF ₃ SO ₂ ) ₂ NLi} as an electrolyte salt were mixed and dissolved in 40 parts by weight of water to obtain a solution having a concentration of 60% by weight (hereinafter referred to as “solution B”). 100 parts by weight of this solution and 55 parts by weight of polymer F were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then 0.1 mass parts of hexamethylenediamine as a crosslinking agent was added to 100 mass parts of this viscous solution, this mixture was cast to a thickness of 500 μm on a glass plate. Then the cast mixture was dried at atmospheric pressure at 80 ° C for 1 hour, obtaining a slightly sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of polymer F and water, determined using ¹ H-NMR measurement at this time, was 25.3% by mass. Here, NMR measurement was performed using a JNM-LA400 instrument manufactured by JEOL Ltd. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 9.

[Example 26]

The same operation as in Example 25 was carried out, except that hourly drying at 80 ° C. in Example 25 was replaced by 3 hours. As a result, a substantially non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The ratio of the mass of water to the total mass of polymer F and water was 18.6% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 9.

[Example 27]

The same operation as in Example 25 was carried out, except that hourly drying at 80 ° C. in Example 25 was replaced with 6 hours. The result was a completely non-sticky gel-like polymer electrolyte in the form of a film.

The ratio of the mass of water to the total mass of polymer F and water was 9.2% by mass at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 9.

[Example 28]

After the viscous solution obtained in the same manner as in Example 25 was cast to a thickness of 500 μm on a glass plate, the cast solution was dried at atmospheric pressure at 120 ° C. for 3 hours. Then the glass plate was placed in a vacuum dryer set at 150 ° C, and further dried for 10 hours. As a result, a solid phase polymer electrolyte in the form of a film was obtained having a water content of 1000 ppm or less, determined by ¹ H-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 9.

[Comparative example 14]

The ionic conductivity of solution B used in Example 25 was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 9.

Table 9 (Solvent weight) /
(mass of solvent and high molecular weight polymer)
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 25 25.3 11,4 Self-supporting film that has a slight stickiness but does not cause fluid leakage 7.9 Example 26 18.6 9.5 Self-supporting liquid-free film 5.9 Example 27 9.2 7.8 Self-supporting liquid-free film 4.3 Example 28 0 5.5 Self-supporting liquid-free film 1,5 Reference Example 14 one hundred 52,4 Liquid 31.3

[Example 29]

40 parts by weight of lithium tetrafluoroborate (LiBF ₄ ) as an electrolyte salt was mixed and dissolved in 60 parts by weight of γ-butyrolactone to obtain a solution having a concentration of about 40% by weight (hereinafter referred to as “solution C”). 100 parts by weight of this solution and 60 parts by weight of polymer G were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then this viscous solution was poured to a thickness of 500 μm on a glass plate, the spilled solution was dried at atmospheric pressure at 120 ° C for 2 hours. The result was a gel-like polymer film-shaped electrolyte having a slight stickiness.

The mass ratio of γ-butyrolactone to the total mass of polymer G and γ-butyrolactone, determined using ¹³ C-NMR measurement, was 28.8% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 10.

[Example 30]

The same operation as in Example 29 was carried out, except that the drying conditions in Example 25 were replaced by drying at 120 ° C. for 3 hours. As a result, a substantially non-sticky gel-like polymer electrolyte in the form of a film was obtained.

The mass ratio of γ-butyrolactone to the total weight of polymer G and γ-butyrolactone was 18.5% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 10.

[Example 31]

The same operation as in Example 29 was carried out, except that the drying conditions in Example 29 were replaced by drying at 120 ° C. for 6 hours. The result was a completely non-sticky gel-like polymer electrolyte in the form of a film.

The mass ratio of γ-butyrolactone to the total weight of polymer G and γ-butyrolactone was 8.4% by weight at this point in time. The ionic conductivity of this gel-like polymer electrolyte was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 10.

[Example 32]

100 parts by weight of solution C obtained in the same manner as in Example 29, and 80 parts by weight of polymer G were charged into an autoclave, and this mixture was heated and stirred at 120 ° C. to obtain a clear, viscous solution.

Then this viscous solution was cast to a thickness of 500 μm on a glass plate, the cast solution was dried at atmospheric pressure at 120 ° C for 1 hour. After that, the glass plate was placed in a vacuum dryer set at 150 ° C, and further dried for 10 hours. As a result, a solid-state polymer film-shaped electrolyte was obtained having a γ-butyrolactone content of 1000 ppm or less, determined by ¹³ C-NMR measurement.

The ionic conductivity of this solid-phase polymer electrolyte was measured at 30 ° C in an alternating current of 1 kHz. The result is shown in table 10.

[Comparative example 15]

The ionic conductivity of solution C used in Example 29 was measured at 30 ° C and 0 ° C in an alternating current of 1 kHz. The results are shown in table 10.

Table 10 (Solvent weight) /
(mass of solvent and high molecular weight polymer)
(wt.%) Ionic conductivity
(mSm ∙ cm ^-1 )
Top row: 30 ° C
Bottom row: 0 ° C Polymer Electrolyte Properties Example 29 28.8 3,1 Self-supporting film that has a slight stickiness but does not cause fluid leakage 2,3 Example 30 18.5 2,8 Self-supporting liquid-free film 2.1 Example 31 8.4 2.1 Self-supporting liquid-free film 1.7 Example 32 0 1.9 Self-supporting liquid-free film 0.9 Reference Example 15 one hundred 3.4 Liquid 2.2

[Example 33]

The present example shows an example of an electrochemical device of the present invention using the gel polymer electrolyte of the present invention. The drawing is a schematic sectional view of this electrochemical device.

<Preparation of polymer electrolyte solution (6)>

Lithium tetrafluoroborate (LiBF ₄ ), propylene carbonate and polymer F were charged at a mass ratio of 40:60:60, and this mixture was heated and stirred at 120 ° C. to obtain a viscous solution.

<Preparation of the positive electrode sheet>

LiCoO ₂ (average particle size: 5 μm) as the active material of the positive electrode and graphite, and acetylene black as conductive additives were mixed dry in a mass ratio of 100: 5: 2.5.

After 100 mass parts of the polymer electrolyte solution (6) and 100 mass parts of the mixture of the active material of the positive electrode and the conductive additives were mixed in a paste form, this mixture was applied to one surface of the current collector of the positive electrode made of aluminum foil having a thickness of 15 μm, with a thickness 200 microns. The current collector was dried at 150 ° C for 2 hours, obtaining a sheet of a positive electrode.

The propylene carbonate content in this positive electrode sheet was 11.2% by weight based on the total weight of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

After 50 mass parts of graphite (average particle size: 10 μm) as a negative electrode active material were mixed with 100 mass parts of a polymer electrolyte solution (6) in a paste form, this mixture was applied to one surface of a negative foil collector made of copper foil, having a thickness of 18 microns, with a thickness of 150 microns. The current collector was dried at 150 ° C for 2 hours, obtaining a sheet of negative electrode.

The propylene carbonate content in this negative electrode sheet was 16.5% by weight based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode made of copper foil.

<Preparation of an electrochemical device>

The polymer electrolyte solution (6) was applied to the surface of the above-prepared positive electrode sheet and then dried at 100 ° C. for 1 hour to obtain a coating layer formed of a polymer electrolyte having a thickness of 20 μm.

The positive electrode sheet having this coating layer and the above prepared negative electrode sheet were folded, and then each of the terminals was mounted on the positive electrode and the negative electrode. The resulting laminate was placed in the battery case, collecting the electrochemical device shown in the drawing.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging this electrochemical device was performed as follows. After charging in the charging mode, direct current / constant voltage with a maximum current of 50 mA and a maximum voltage of 4.2 V for 5 hours, the electrochemical device was discharged to 3.0 V at a direct current of 10 mA. The discharge value was 95.3 mA ∙ h. Then, the electrochemical device was recharged under the same conditions, and the discharge value was evaluated under constant current conditions, shown in table 11. The results are shown in table 11.

[Example 34]

The present example shows an example of an electrochemical device of the present invention using the solid state polymer electrolyte of the present invention. The drawing is a schematic sectional view of this electrochemical device.

<Preparation of the positive electrode sheet>

A mixture of a positive electrode active material and conductive additives, obtained in the same manner as in Example 33, lithium bis (pentafluoroethanesulfonyl) imide {(CF ₃ СF ₂ SO ₂ ) ₂ NLi}, propylene carbonate and polymer F were charged at a mass ratio of 100: 20: 30:50, and this mixture was heated and kneaded at 150 ° C.

This kneaded product was extruded into a sheet form with a thickness of 200 μm onto a current collector of a positive electrode of aluminum foil having a thickness of 15 μm. Then the current collector was dried at 180 ° C for 2 hours, receiving a sheet of a positive electrode.

The propylene carbonate content in this positive electrode sheet was 1000 ppm or less, based on the total mass of the positive electrode sheet, with the exception of the current collector of the positive electrode made of aluminum foil.

<Preparation of the negative electrode sheet>

Graphite (average particle size: 10 μm) as the active material of the negative electrode, lithium bis (pentafluoroethanesulfonyl) imide {(CF ₃ СF ₂ SO ₂ ) ₂ NLi}, propylene carbonate and polymer F were charged at a mass ratio of 50: 20: 30: 50 , and this mixture was heated and kneaded at 150 ° C.

This kneaded product was extruded into a sheet form with a thickness of 150 μm onto a current collector of a negative electrode of copper foil having a thickness of 18 μm. Then the current collector was dried at 180 ° C for 2 hours, receiving a sheet of negative electrode.

The propylene carbonate content in this negative electrode sheet was 1000 ppm or less, based on the total weight of the negative electrode sheet, with the exception of the current collector of the negative electrode of copper foil.

<Preparation of an electrochemical device>

Bis (pentafluoroethanesulfonyl) lithium imide {(CF ₃ CF ₂ SO ₂ ) ₂ NLi}, propylene carbonate and polymer F were charged at a mass ratio of 20:30:50, and this mixture was heated and kneaded at 150 ° C.

This kneaded product was extruded into a sheet form with a thickness of 20 μm on the surface of the above-prepared sheet of the positive electrode, and then the above-prepared sheet of the negative electrode was layered on it. Then this electrode group was dried at 180 ° C for 2 hours, the electrochemical device shown in the drawing was assembled.

<Evaluation of the properties of the electrochemical device>

Evaluation of the properties of charging and discharging of this electrochemical device was performed in the same manner as in example 33. The results are shown in table 11.

Table 11 Discharge conditions (mA) and discharge value (mA ∙ h) 10 mA 50 mA 100 mA Example 33 95.3 mAh 92.7 mAh 88.3 mAh Example 34 89.3 mAh 86.1 mAh 83.2 mAh Reference Example 13 11.4 mAh 5.3 mAh Immeasurably

INDUSTRIAL APPLICABILITY

The polymer electrolyte of the present invention can be used for non-aqueous primary batteries such as a lithium metal battery, aqueous batteries such as a water ion battery, non-aqueous batteries such as a lithium ion battery, non-aqueous double electric layer capacitors, hybrid capacitors, and others electrochemical devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are a top view and a longitudinal sectional view showing an example of an electrochemical device of the present invention.

DESCRIPTION OF NUMERIC DESIGNATIONS

1. Positive electrode

2. Negative electrode

3. Positive electrode terminal

4. Negative electrode terminal

5. Polymer electrolyte

6. Battery case.

Claims (11)

1. A polymer electrolyte containing a polymeric material and an electrolyte salt, or a polymeric material, a solvent and an electrolyte salt, where from 66.7 to 100% by weight of the polymer material is a copolymer from 50 to 99 mol% of an ethylenically unsaturated compound and from 1 to 50 mol.% carbon monoxide. 2. The polymer electrolyte according to claim 1, where the ratio of the mass of the solvent to the total mass of the solvent and the polymer material is 0 or more and less than 33.3%. 3. The polymer electrolyte according to claim 2, where 100% by weight of the polymer material is this copolymer. 4. The polymer electrolyte according to claim 1, where the copolymer contains an alternating copolymer of ethylene-unsaturated compounds and carbon monoxide. 5. The polymer electrolyte according to claims 1, 3 or 4, where the electrolyte is a solid-phase polymer electrolyte containing this alternating copolymer and an electrolyte salt. 6. The polymer electrolyte according to any one of claims 1 to 4, where the electrolyte is a gel-like polymer electrolyte containing this alternating copolymer, an electrolyte salt and a solvent. 7. The polymer electrolyte according to any one of claims 1 to 4, where the polymer material is a crosslinked polymer material. 8. The method of producing a polymer electrolyte according to any one of claims 1 to 7, comprising the steps of: dissolving a polymer material containing from 66.7 to 100% by weight of a copolymer from 50 to 99 mol% of an ethylenically unsaturated compound and from 1 up to 50 mol.% carbon monoxide, in a solution in which from 30 to 90% by weight of the electrolyte salt is dissolved in a solvent; mold the resulting mixture into arbitrary shape; and partially or completely remove the solvent. 9. The method of claim 8, where 100% by weight of the polymer material is a copolymer. 10. The method of claim 8, where the copolymer contains an alternating copolymer of ethylene-unsaturated compounds and carbon monoxide. 11. Electrochemical device, characterized in that it uses a polymer electrolyte according to any one of claims 1 to 7.