JPS60165058A - Solid electrolyte - Google Patents

Abstract

PURPOSE:To obtain a strong solid electrolyte with a homogeneous conductivity and good quality by homogeneously impregnating a fibrillar base material composed of a short-fibrous substance with an organic macromolecular substance and an electrolyte. CONSTITUTION:A base material 1 for holding an organic macromolecular compound 2 and an electrolyte 3, has a fibrillar structure composed of a vegetable, animal, mineral or synthetic-resin short-fibrous substance. For example, the base material 1 is prepared from filter paper, a nonwoven fabric or a polyacetylene film. After an organic macromolecular substance and an electrolyte are homogeneously dissolved in an organic solvent to prepare a solution, the fibrillar base material 1 is either immersed in or coated with the solution. After that, all or a part of the solvent is evaporated, thereby making a solid electrolyte.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel solid electrolyte, and more particularly, to a high-quality solid electrolyte having high strength and uniform conductive dust.

In recent years, there has been a trend towards smaller and thinner electronic devices, and as a result, there has been an increasing demand for thinner and lighter built-in batteries for wristwatches, calculators, and the like.

Conventional thin batteries include, for example, lithium-based batteries that use a liquid electrolyte made by dissolving lithium perchlorate, lithium fluoroborate, etc. in propylene carbonate, γ-butyrolactone, tetrahydrofuran, etc.; Manganese dioxide-zinc batteries using a liquid electrolyte containing ammonium chloride or the like are known.

However, since these batteries use a liquid electrolyte, they are not necessarily satisfactory in terms of leakage resistance and storage stability. Therefore, research on various solid electrolyte batteries has recently been actively conducted in order to completely improve the leakage resistance and storage stability.

As the solid electrolyte used in this battery, for example, one using lithium nitride or lithium iodide (Japanese Patent Application Laid-Open No. 56-5
No. 9474, No. 57-72268), lithium iodide with activated alumina and zeolite added (Japanese Unexamined Patent Publication No. 58-111201), polyacrylonitrile powder, stium perchlorate, and ethylene carbonate. However, these solid electrolytes have the disadvantage that it is difficult to obtain uniform quality because the conductive dust tends to vary due to poor contact between particles and variations in the distribution of each component.

1. A solid electrolyte has been proposed in which a polymer resin and an electrolyte are dissolved in an organic solvent such as ethylene carbonate or propylene carbonate, and then dried and solidified (Japanese Unexamined Patent Application Publication No. 1983-1982).
-75779). However, although this method produces uniform conductive dust, it is not necessarily satisfactory in terms of strength.

Furthermore, porous media such as filter paper, glass frit, porous ceramics, etc. impregnated with electrolyte have also been proposed (Patent Publication No. 136,469/1982). However, although this material has high strength, it is not fully satisfactory in terms of electrical conductivity.

The present inventors have conducted intensive research to overcome the drawbacks of the solid electrolytes that have been proposed in the past, and to provide a high-quality solid electrolyte that has high strength and uniform conductive dust. discovered that a base material with a fibrillar structure consisting of short fibers uniformly impregnated with an organic polymer substance and an electrolyte could be suitable for the purpose, and based on this knowledge, the present invention was completed. .

That is, the present invention provides a solid electrolyte made by uniformly impregnating an organic polymeric substance and an electrolyte into a base material having a fibrillar structure made of a short fibrous substance.

In the solid electrolyte of the present invention, the base material used to impregnate the organic polymer substance and the electrolyte may have a fibrillar structure made of a short fibrous material such as vegetable, animal, mineral, or synthetic resin. Preferred examples of such materials include filter paper, nonwoven fabric, and polyacetylene film.

The organic polymer used in the solid electrolyte of the present invention preferably has thermoplasticity and is soluble in an organic solvent, such as polyacrylonitrile, polymethacrylate, polyvinylidene fluoride, polystyrene, polyvinyl chloride, polyvinyl acetate, etc. can be mentioned.

Further, examples of the electrolyte used in the solid electrolyte of the present invention include lithium perchlorate, lithium borofluoride, lithium phosphorus fluoride, lithium iodide, lithium fluoride,
Preferred examples include lithium salts such as lithium chloride and lithium oxalide.

The solid electrolyte of the present invention can be manufactured, for example, as follows.

That is, the above organic polymer is added to an organic solvent such as esters such as ethyl acetate, ketones such as acetone and methyl ethyl ketone, amides such as N,N-dimethylformamide, and amines such as triethanolamine. The substance and the electrolyte are uniformly dissolved, and then the base material having the fibrillar structure is immersed in the resulting solution, or the solution is applied to the base material, and then all or most of the solvent is evaporated. obtained by

Alternatively, the organic polymer substance is dissolved in a solvent that is not related to the electrolyte solvent, such as methylene chloride or trichloroethylene, and this is mixed with a carbonate-based solvent such as ethylene carbonate or propylene carbonate, which has a higher boiling point than the solvent. It can be obtained by adding and mixing a solution of the electrolyte, and then treating the base material having a fibril structure in the same manner as described above.

At this time, the base material having a fibril structure is prepared in advance, for example, by
It is preferable to use the film after degassing it in a vacuum atmosphere of about It is necessary to prevent the reaction between the polyacetylene film and lithium perchlorate by applying a passivation treatment using a method or the like. Furthermore, the solvent may be evaporated by leaving it at room temperature, but in a non-oxidizing furnace at 70 to 80°C.
It is preferable to carry out heating to a temperature of .

The following table shows examples of useful organic solvents when polyacrylonitrile is used as the organic polymer material and lithium perchlorate is used as the electrolyte.

The structural model of the solid electrolyte of the present invention thus obtained is shown in the attached drawings. In the figure, 1 is a short fibrous substance, 2
is an organic polymer substance and 3 is an electrolyte.

In this solid electrolyte, its flexibility and thickness can be controlled by the shape of the base material having a fibrillar structure, and the amount of organic polymer material is kept as small as possible in order to increase the conductivity. In addition, it is preferable to prevent the organic solvent from completely evaporating.

The solid electrolyte of the present invention has uniform and high conductivity,
Furthermore, because it uses a base material with a fibrillar structure, it has high strength and flexibility.Furthermore, because it uses an organic polymer substance that is soluble in thermoplastic organic solvents, polyacetylene film and metal foil It has excellent features such as being able to be bonded by solvent or thermocompression to other electrodes.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing the structure of the solid electrolyte of the present invention,
In the figure, 1 is a short fibrous material, 2 is an organic polymer material, and 3 is a short fibrous material.
is an electrolyte. Patent applicant: Orient Watch Co., Ltd. Agent Akira Agata

Claims (1)

[Scope of Claims] 1. A solid electrolyte made by uniformly impregnating an organic polymer substance and an electrolyte into a base material having a fibrillar structure made of a short fibrous substance. 2. The solid electrolyte according to claim 1, wherein the organic polymer substance has thermoplasticity and is soluble in an organic solvent. 3. The solid electrolyte according to claim 1 or 2, wherein the electrolyte is a lithium salt.