JP3335664B2 - Solid electrolyte - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolyte having excellent ionic conductivity and suitable for forming a thin battery or the like.

[0002]

2. Description of the Related Art Heretofore, solid electrolytes in which an electrolyte is contained in polyethylene oxide or polysiloxane have been known. Also, a solid electrolyte in which an organic polymer such as polyacrylonitrile containing an electrolyte is held on a short fiber base material having a fibril structure has been known (JP-A-60-1650).
No. 58). However, there is a problem that the ionic conductivity is inferior due to the dispersion of carrier ions (electrolyte) and crystallization of a matrix polymer such as polyethylene oxide. Even in the latter case, the short fiber base material simply functions as a support, and ion conduction is caused by a matrix polymer such as polyacrylonitrile containing an electrolyte held by the short fiber base material, which has the same problem.

[0003]

An object of the present invention is to develop a solid electrolyte having excellent ionic conductivity.

[0004]

SUMMARY OF THE INVENTION The present invention provides a solid electrolyte obtained by impregnating an electrolyte into a nonwoven fabric of a fiber comprising an ether-based polymer having a polar group.

[0005]

The reason why the above configuration exhibits good ionic conduction characteristics is unknown, but the present inventors think as follows. That is, the electrolyte adhering to the surface of the fiber forming the nonwoven fabric, or the electrolyte penetrating into the fiber dissociates via the polar group in the ether-based polymer forming the fiber to cause pseudo-solvation, and carrier ions propagate through the fiber. It is believed that the gap formed between the fibers can be moved.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The solid electrolyte of the present invention is obtained by impregnating a non-woven fabric of a fiber comprising an ether polymer having a polar group with an electrolyte.

[0007] As ether-based polymer having a polar group, for example polyarylate, polysulfone, polyether imide, polyether sulfone, polyether ether ketone, etc. polyoxyethylene benzoyl emissions and the like. The nonwoven fabric may be formed as usual with fibers of such an ether-based polymer.

An appropriate electrolyte can be used as the electrolyte. Preferably, cations such as Li ion, Na ion and K ion, I ion, CF ₃ SO ₃ ion, B ion
F ₄ ion, ClO ₄ ion, AlCl ₄ ion, PF ₆
An alkali metal salt or the like formed in combination with an anion such as an ion or AsF ₆ ion is used.

The impregnation of the electrolyte into the nonwoven fabric can be performed by an appropriate method such as a method of immersing the nonwoven fabric in an electrolyte solution, particularly a solution using an organic solvent such as alcohol or acetonitrile. The concentration of the electrolyte may be appropriately determined, and the ionic conductivity can be controlled by the concentration. In preparing an electrolyte solution, it is preferable to dry the electrolyte sufficiently. It is also preferable to use a nonwoven fabric that has been sufficiently degassed in a vacuum atmosphere or the like.

The solid electrolyte of the present invention can be used for forming various products such as batteries. For practical use,
By controlling the gap between the fibers by compressing the nonwoven fabric or the like, a space corresponding to the ionic radius of the carrier ions can be formed. It can also control sites with a large number of carrier ions,
The ion conductivity can be improved.

Example 1 A non-woven fabric (1.29) made of polyetheretherketone fiber, which was sufficiently degassed in a 1/10 ³ vacuum atmosphere
6 g / cm ³ ) in a 0.5 wt%, 1.0 wt% or 3.0 wt% butanol solution of lithium perchlorate which has been thoroughly dried at 120 ° C. for 12 hours under a 1/10 ³ vacuum atmosphere. After immersion for 8 hours (50 ° C.), the solid was dried at 80 ° C. in a 1/10 ³ vacuum atmosphere to obtain a solid electrolyte.

Comparative Example 1 Example 1 except that a non-woven fabric made of polyimide fiber was used.
To obtain a solid electrolyte.

Comparative Example 2 A solid electrolyte was obtained in the same manner as in Example 1 except that a nonwoven fabric made of polyamideimide fiber was used.

Evaluation Test The solid electrolytes obtained in Examples and Comparative Examples were measured for ionic conductivity at room temperature using an AC impedance analyzer. The results are shown in the following table . Lithium perchlorate Ion conductivity concentration (% by weight) (S / cm) Example 1 0.5 7.2 / 10 ⁶ 1.0 8.5 / 10 ⁵ 3.0 1.4 / 10 ³ Comparative Example 1 0.5 1.5 / 10 ⁷ 1.0 3.4 / 10 ⁶ 3.0 5.3 / 10 ⁵ Comparative Example 2 0.5 9.2 / 10 ⁸ 1.0 2.7 / 10 ⁶ 3.0 3.8 / 10 ⁵

[0015]

The solid electrolyte of the present invention is excellent in ionic conductivity because it is impregnated with an electrolyte using a nonwoven fabric of a fiber made of an ether-based polymer having a polar group.

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01B 1/06 H01M 6/18 D04H 1/42

Claims (1)

(57) [Claims] 1. A solid electrolyte obtained by impregnating a nonwoven fabric of a fiber comprising an ether-based polymer having a polar group with an electrolyte.