JPH059253A - Solid polyelectrolyte - Google Patents

Abstract

PURPOSE:To prepare a solid polyelectrolyte which exhibits a high ionic conductivity and an excllent shape retention. CONSTITUTION:A solid polyelectrolyte (except one used for driving an electrolytic capacitor) is prepd. by curing a mixture which contains a cyclic compd. having an ester or carbonyldioxy group in the ring (e.g. gamma-butyrolactone or propylene carbonate), an org. polyisocyanate (e. g. TDI), and an electrolytic salt.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a solid polymer electrolyte.

[0002]

2. Description of the Related Art Conventionally, solid polymer electrolytes have been solidified using polyethylene glycol derivatives (Japanese Patent Laid-Open No. 61-260557 and US Pat. No. 4,654,279).
Etc.) are known. However, this product has an ionic conductivity of about 10 ⁻⁵ S / cm, which is about three orders of magnitude lower than that of the non-aqueous electrolyte. As a polymer having improved ionic conductivity, there has been proposed a polymer solid electrolyte in which an electrolytic solution is contained in a polymer matrix composed of the above polyethylene glycol derivative [JP-A-54-104541, US Pat.
P 4792504 etc.].

[0003]

However, even with this one,
There is still a problem that the ionic conductivity is low and the shape retention is insufficient.

[0004]

Means for Solving the Problems The present inventors have arrived at the present invention as a result of extensive studies to obtain a polymer solid electrolyte having high ionic conductivity and excellent shape retention. That is, the present invention relates to a compound (a) having a ring structure in the molecule and having an ester group or a carbonyldioxy group in the ring, an organic polyisocyanate (b), an electrolyte salt (c) and, if necessary, an acidic or alkaline catalyst. A polymer solid electrolyte-forming composition comprising the combination of (d); and a polymer solid electrolyte comprising a cured product of this polymer solid electrolyte-forming composition.

In the present invention, the compound (a) having a ring structure in the molecule and having an ester group or a carbonyldioxy group in the ring includes carbonates (propylene carbonate, ethylene carbonate, styrene carbonate, etc.), lactones. (Γ-butyrolactone, γ-valerolactone, δ-valerolactone, 3-methyl-1,3-
Oxazolidin-2-one, 3-ethyl-1, 3-oxazolidin-2-one, etc.) and mixtures thereof. The size of the ring is not particularly limited, but a 5-membered ring is preferable.

As the organic polyisocyanate (b),
What was conventionally used for manufacture of polyurethane can be used. Specifically, "Polyurethane Resin Handbook"
(Published by Nikkan Kogyo Shimbun Co., Ltd.), the compounds described on pages 90 to 98, and urethane prepolymers having terminal NCO groups (hereinafter abbreviated as prepolymers) obtained by reacting these with a polymer active hydrogen compound. However, these may be mixed and used. Of these, TDI, MD
I, HDI, IPDI and prepolymers thereof are preferred.

Examples of the polymer active hydrogen compounds include polyether polyols, polyester polyols, polysiloxane polyols, polybutadiene polyols and terminal amine compounds derived from them, which are described in the above-mentioned pages 99 to 119. Of these, preferred are polyether polyols, polyester polyols and terminal amine compounds derived therefrom.

The molecular weight of the high molecular weight active hydrogen compound is not particularly limited, but is preferably 100 to 10,000.
If it is less than 100, the ionic conductivity of the solid polymer electrolyte is low. If it exceeds 10,000, the shape retention property is deteriorated. If desired, the polymer active hydrogen compound may be contained in the polymer solid electrolyte forming composition of the present invention.

The NCO% by weight (hereinafter abbreviated as NCO%) of the organic polyisocyanate (b) is not particularly limited, but is usually 1 to 50%, preferably 1 to 45%. Outside this range, the shape-retaining property and the ionic conductivity decrease.

The compounding ratio (weight) of the compound (a) having a ring structure in the molecule and having an ester group or a carbonyldioxy group in the ring and the organic isocyanate (b) is (a).
(B) is usually 0.01 to 200 parts, preferably 0.01 to 100 parts per 100 parts. When (b) is less than 0.01, the curability is lowered, and when it exceeds 200 parts, the ionic conductivity of the solid polymer electrolyte is low. The addition amount (weight basis) of the electrolyte salt is not particularly limited, but it is 0.
1 part to 100 parts is preferable. Amount of catalyst added (weight basis)
Is not particularly limited, but is preferably 0.01 to 20 parts per 100 parts of (a). Outside this range, preferable curability cannot be obtained.

In the present invention, examples of the electrolyte salt (c) include metal salts and ammonium salts. Examples of the metal salt include salts of group I or group II metals, and among these, salts of Li, Na and K having a small cation radius are preferable. Examples of anions constituting these metal salts include halogen ions (F, Cl, Br, I, etc.), thiocyanate ion, perchlorate ion, trifluoromethanesulfonate ion and the like. Among the anions constituting the metal salt, preferred are thiocyanate ion, perchlorate ion, trifluoromethanesulfonate ion and fluoroborate ion. Examples of ammonium salts include carboxylic acids (adipic acid, phthalic acid, azelaic acid, etc.),
Examples thereof include ammonium salts of acids such as phosphoric acid, boric acid, sulfonic acid (aryl sulfonic acid etc.) and borofluoric acid. You may mix and use these. Among these ammonium salts, ammonium carboxylate, ammonium phosphate, and ammonium borate are preferable. A preferable one may be selected from the above metal salts and ammonium salts according to the use of the solid polymer electrolyte.

In the present invention, the acidic catalyst of the catalyst (d) is not particularly limited as long as it is an acidic compound, and examples thereof include organic acid compounds such as formic acid, oxalic acid and carboxylic acid, and inorganic acids such as hydrochloric acid and sulfuric acid. An acid compound is mentioned. Of these, formic acid, oxalic acid, hydrochloric acid and sulfuric acid are preferable.

In the present invention, as the alkaline catalyst of the catalyst (d), a compound showing alkalinity is used,
There is no particular limitation, and examples thereof include organic alkaline compounds such as primary to tertiary amine compounds and inorganic alkaline compounds such as sodium hydroxide and potassium hydroxide. Among these, tertiary amine compounds (triethylenediamine,
Tetramethylethylenediamine, tetraethylethylenediamine, N-ethylmorpholine and the like) are preferable.

The solid polymer electrolyte-forming composition of the present invention may contain a resin (e). For resin, "1088
9 chemical products ”(published by Kagaku Kogyo Nippo), pages 703-782.
Those described on the page can be used. Of these, thermosetting resins soluble in (a) or the following solvent (f), polyamide, polyvinyl chloride, polyvinyl acetate and the like are preferable.

The polymer solid electrolyte forming composition of the present invention may optionally contain a solvent (f) used in an electrochemical device. Examples thereof include water, an amide solvent (N-methylformamide, N, N-dimethylformamide, N
-Methylacetamide, N-methylpyrrolidinone, etc.),
Alcohol solvent (ethylene glycol, methyl cellosolve, propylene glycol, 1,4-butanediol,
Glycerin, polyoxyalkylene polyol, cyclohexanediol, etc.), ether solvent (methylal,
1,2-dimethoxyethane, 1-ethoxy-2-methoxyethane, 1,2-diethoxyethane, etc.), nitrile solvents (acetonitrile, 3-methoxypropionitrile, etc.), furan solvents (2,5-dimethoxytetrahydrofuran, etc.) ), 2-imidazolidinones (1,3-dimethyl-2-imidazolidinone, etc.) and pyrrolidones can be used alone or as a mixed solvent. Of these, water, alcohol solvents, ether solvents, nitrile solvents, and furan solvents are preferable.

The method for producing the polymer solid electrolyte-forming composition of the present invention will be exemplified. The compound (a) contains an organic polyisocyanate (b), an electrolyte salt (c), and optionally a catalyst (d) and a resin (e). Although the composition of the present invention in one liquid can be obtained by adding or (f), two liquids in which the organic polyisocyanate (b) and / or the catalyst (d) are separated from the constituents of the one liquid as required. It may be a 3-liquid composition of the present invention.

As an example of the method for producing the solid polymer electrolyte of the present invention, among the components constituting the composition of the present invention, (b) is added to a mixture of components other than (b) and mixed uniformly, By heating if necessary, the solid polymer electrolyte of the present invention can be obtained.

The solid polymer electrolyte of the present invention can be compounded by impregnating and hardening a secondary material with a solid polymer electrolyte-forming composition. Examples of auxiliary materials include films, papers, cloths, non-woven fabrics and the like.

[0019]

The present invention will be further described with reference to the following examples, but the present invention is not limited thereto. Hereinafter, parts are parts by weight.

Example 1 An electrolytic solution composition of the present invention comprising a combination of the following solutions A and B was obtained. Solution A: γ-butyrolactone 100 parts, adipic acid diammonium salt 10 parts, triethylenediamine 0.
A mixture of 1 part. Solution B: 20 parts of NCO% 5.2 prepolymer obtained by reacting polyoxypropylene glycol with a stoichiometric excess of TDI. Solution A and solution B were uniformly mixed and left at room temperature for 1 hour to prepare a polymer solid electrolyte of the present invention. This shows shape retention even at 100 ° C,
The ionic conductivity at 0 ° C. was 1 × 10 ⁻³ S / cm.

Example 2 An electrolytic solution composition of the present invention comprising a combination of the following solutions A and B was obtained. Liquid A: 100 parts of propylene carbonate, Li
A mixture of 10 parts of BF _{4 and} 0.1 part of triethylenediamine. Solution B: NCO% obtained by reacting polyoxypropylene glycol with a stoichiometric excess of TDI
10 parts of 5.2 prepolymer. Solution A and solution B were uniformly mixed and left at room temperature for 1 hour to prepare a polymer solid electrolyte of the present invention. This product exhibited shape retention even at 100 ° C., and had an ionic conductivity of 2.5 × 10 ⁻³ S / cm at 25 ° C. according to the AC impedance method.

Example 3 An electrolytic solution composition of the present invention comprising a combination of the following solutions A and B was obtained. Solution A: 3-methyl-1,3-oxazolidine-
A mixture of 100 parts of 2-one, 20 parts of NH ₄ BF ₄ , and 0.1 part of triethylenediamine. Solution B: 15 parts of a prepolymer having an NCO% of 10.3 obtained by allowing a stoichiometric excess of TDI with polyoxypropylene glycol. Solution A and solution B were uniformly mixed and left at room temperature for 1 hour to prepare a polymer solid electrolyte of the present invention. This is 10
The shape retention was exhibited even at 0 ° C., and the ionic conductivity at 25 ° C. by the AC impedance method was 1.8 × 10 ⁻³ S / cm.

[0023]

(1) The solid polymer electrolyte of the present invention can be easily obtained by simply casting the composition of the present invention into a predetermined shape. (2) The solid polymer electrolyte of the present invention is transparent, has no liquid leakage, has shape retention, and has high ionic conductivity, so that it can be used in batteries, electrocardiographic electrodes, electrochromic devices, conductive rollers, conductive mats, etc. It is particularly useful as the polymer solid electrolyte used.

Claims (2)

[Claims] 1. A compound (a) having a ring structure in the molecule and having an ester group or a carbonyldioxy group in the ring, an organic polyisocyanate (b), an electrolyte salt (c) and, if necessary, an acidic or alkaline compound. A polymer solid electrolyte-forming composition comprising a combination of a catalyst (d). 2. A polymer solid electrolyte comprising a cured product of the polymer solid electrolyte-forming composition according to claim 1, except for driving an electrolytic capacitor.