JPH0815085B2 - Solid electrolyte ink - Google Patents

Description

The present invention relates to a solid electrolyte ink for a solid electrolyte battery whose constituent materials are all solid substances.

Conventional technology Solid electrolyte batteries, whose constituent materials are all solid substances,
Compared to batteries that use a liquid electrolyte that requires a certain size,
There is no worry of liquid leakage or gas generation. In addition, since a container of a certain size is not required, the shape can be selected arbitrarily, it is extremely easy to make it small and thin, and it can be stored in the same package as other electronic parts. Not have many advantages. However, this solid electrolyte battery
It has a problem that it is extremely weak against mechanical shock and is easily damaged.

In order to eliminate this problem, the present inventors have proposed a method of imparting flexibility to a solid electrolyte battery by mixing an organic binder having plasticity with an electrode or a solid electrolyte.

Problems to be Solved by the Invention Conventionally, since a solid electrolyte was decomposed by reacting with an organic substance such as alcohol, ketone or ester, a stable non-water-absorbing organic solvent such as toluene, xylene and cyclohexane was used. . However, in a solid electrolyte ink composed of a solid electrolyte powder, an organic binder and the above organic solvent, it is difficult to adjust the viscosity of the ink because the organic solvent is easily volatilized, and it is applied during the production of the solid electrolyte battery. Difficult to settle down the solid electrolyte powder quickly, and the organic binder is localized, resulting in a small output current. Large polarization causes the voltage to drop immediately after discharge and the discharge capacity does not occur, and individual battery characteristics may vary. There was a problem.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides an anhydrous or dehydration treatment for organic substances such as alcohols, ketones, or esters, so that the solid electrolyte does not react and decompose. It is a mixture of dehydrated alcohol, ketone, ester or high-boiling organic matter.

When the solid electrolyte ink according to the present invention is used, the organic binder having plasticity imparts flexibility to the solid electrolyte sheet of the solid electrolyte battery, which is a constituent element, and enables the production of a thin solid electrolyte sheet. It is a thing.

Examples Examples will be described below.

(Example 1) Copper ion-conductive solid electrolyte, for silver ion conductive solid electrolyte, a dry inert gas (N _2, Ar, the He) a copper ion conductive solid electrolyte in an air stream, each of the silver ion conductive solid electrolyte The powder was dispersed in various organic solvents and its stability was investigated.

The solid electrolyte is RbCu as a copper ion conductive solid electrolyte.
₄ I _1.5 Cl _3.5 and RbAg ₄ I ₅ as silver ion conductive solid electrolyte
Was used.

As the organic solvent and organic substance used, reagents manufactured by Kanto Chemical Co., Inc. were used.

For the dehydration treatment of the organic solvent and the organic substance, molecular sieve 0.3 nm (manufactured by Kanto Chemical Co., Inc.) dried under reduced pressure at about 300 ° C. was used. Further, a solution having a high viscosity was used by diluting with toluene to reduce the viscosity, dehydrating the solution, and removing toluene to some extent. The following table shows the results of examining the stability of copper ion conductive solid electrolytes dispersed in various organic solvents.

From the above results, the water-soluble organic solvent contains about 0.5% of water, whereas the water-insoluble organic solvent has a water content of 0.05% or less. It appears whether or not the solid electrolyte is decomposed. However, even with water-soluble organic solvents, molecular sieves 0.3 nm
The decomposition of the copper ion conductive solid electrolyte can be eliminated by performing a dehydration treatment using.

It was also found that when the organic binder powder was left to stand in a humid place, the organic binder contained water and decomposed the copper ion conductive solid electrolyte.

Further, a carboxylic acid that releases hydrogen ions, a solution containing oxygen or a solution containing peroxide that oxidizes monovalent copper ions in a copper ion conductive solid electrolyte, and a solution containing a halogen are copper ion conductive solids. R-
It was also found that CN, R-SH organic substance or amine type organic base substance also decomposes the copper ion conductive solid electrolyte.

Further, the same test as that for the copper ion conductive solid electrolyte was performed on the silver ion conductive solid electrolyte under a red lamp from which ultraviolet rays were removed. As a result, in the same manner as the copper ion conductive solid electrolyte even in the silver ion conductive solid electrolyte material, when using an organic solvent that is soluble in water that is not dehydrated or dehydrated, an organic substance, or an organic binder containing water, It was found that the silver ion conductive solid electrolyte decomposes, and that R-CN, R-SH organic substance or amine organic base substance also decomposes the silver ion conductive solid electrolyte.

However, in the case of a silver ion conductive solid electrolyte, it did not decompose even in a solution containing an oxidizing substance such as a halide or a peroxide.

(Example 2) Solid electrolyte as RbCu ₄ I _1.5 Cl _3.5 and the copper ion conductive solid electrolyte, the copper ion conductive solid electrolyte Cu ₂ Mo ₆ S _7.8 copper Chevrel as an electrode material was added 20 wt%, under reduced pressure , The case of using the one treated at 200 ° C for 17 hours is described.

First, 2.6% solid electrolyte powder was added in a dry active gas stream.
Wt% styrene-ethylene-butadiene-styrene copolymer (dried at 80 ° C under reduced pressure) Organic binder and toluene as an organic solvent are added and mixed by stirring to dissolve the organic binder, and then cyclohexanol is added and sonicated. After that, the viscosity was adjusted to be easy to apply to prepare a solid electrolyte ink.

At this time, the toluene and cyclohexanol used can be used as they are in the case of the new special grade reagent, but the reagent left in the air needs to be dehydrated by using molecular sieve 0.3 nm dried under reduced pressure at about 300 ° C.

Toluene and cyclohexanol do not react with the electrode active material and the solid electrolyte, and since they are completely removed during the preparation of the solid electrolyte sheet, the addition amounts of toluene and cyclohexanol do not affect the characteristics of the solid electrolyte sheet.

Next, a solid electrolyte battery was prepared as follows using the above solid electrolyte ink, the battery was charged at 0.6 V for 24 hours, and the discharge characteristics when left at 1 mA / cm ² are shown in FIG. .

The solid electrolyte battery is made by washing solid electrolyte ink, applying it to a dried polypropylene non-woven fabric, and drying it under reduced pressure at about 100 ° C to create a solid electrolyte sheet, and punching this solid electrolyte sheet into a disk shape with a diameter of 10 mm for 3 tons. / press molded in cm ^2, and the press-molded electrode molded electrode material powder (200 mg) in 3 t / cm ² created by pressing at 3 t / cm ² placed on both sides of the solid electrolyte sheet (about 70 mg) . A solid electrolyte battery prepared by press-molding electrode material powder (both positive and negative electrodes 200 mg) and solid electrolyte powder (500 mg) at 3 ton / cm ² was similarly charged and discharged, and its discharge characteristics are also shown in the first diagram. .

The solid electrolyte battery prepared using the above solid electrolyte ink also showed almost the same discharge characteristics as the solid electrolyte battery prepared using the electrode material powder and the solid electrolyte powder.

(Example 3) RbCu ₄ I _1.5 Cl _3.5 copper ion conductive solid electrolyte as a solid electrolyte and Cu ₂ Mo ₆ S _7.8 copper chevrel as an electrode material were added with 20% by weight of the above copper ion conductive solid electrolyte, and under reduced pressure,
Described below is the case where the product treated at 200 ° C. for 17 hours is used.

First, 2% by weight of polyvinyl butyral (80 ° C. vacuum dried) organic binder and diethylene glycol monobutyl ether acetate as an organic solvent were added to the electrode material powder in a dry inert gas stream, and the mixture was stirred and mixed to dissolve the organic binder. A solid electrolyte ink was prepared by adjusting the viscosity so that it could be easily applied.

When diethylene glycol monobutyl ether acetate is used as a solvent, diethylene glycol monobutyl ether acetate has a boiling point higher than that of toluene, xylene, etc. and does not evaporate immediately, so that the viscosity can be adjusted by the addition amount of diethylene glycol monobutyl ether acetate. Since polyvinyl butyral is difficult to dissolve in diethylene glycol monobutyl ether acetate, polyvinyl butyral is uniformly mixed with the electrode material powder using a solvent such as chloroform or toluene, or a solvent in which chloroform, toluene, etc. are mixed with diethylene glycol monobutyl ether acetate. It is possible to easily dissolve polyvinyl butyral in diethylene glycol monobutyl ether acetate. That.

Next, the above solid electrolyte ink was washed and applied to a dried detron nonwoven fabric, and then dried under reduced pressure at 130 ° C. to prepare a solid electrolyte sheet, and a solid electrolyte battery was prepared in the same manner as in Example 2 below. This battery was charged and discharged in the same manner as in Example 2, and its discharge characteristics are shown in FIG.

The solid electrolyte battery prepared by using the above solid electrolyte ink also showed almost the same discharge characteristics as the solid electrolyte battery prepared by using the electrode material powder and the solid electrolyte powder shown in FIG.

(Example 4) RbCu ₄ I _1.5 Cl _3.5 copper ion conductive solid electrolyte as a solid electrolyte and Cu ₂ Mo ₆ S _7.8 copper chebrel as an electrode material were added with 20% by weight of the above copper ion conductive solid electrolyte, and under reduced pressure,
Described below is the case where the product treated at 200 ° C. for 17 hours is used.

First, 2 wt% polystyrene (80 ° C vacuum drying) and cyclohexanone dehydrated using 300 nm vacuum drying molecular sieve 0.3 nm were added to the electrode material powder in a dry inert gas stream, and the mixture was stirred and mixed to form an organic binder. After the agent was dissolved, dehydrated ethylene glycol was added and ultrasonic treatment was performed to adjust the viscosity so that it could be easily applied to prepare a solid electrolyte ink.

Next, the solid electrolyte ink was washed and applied to a dried nylon mesh cloth, and then dried under reduced pressure at 130 ° C. to prepare a solid electrolyte sheet, and a solid electrolyte battery was prepared in the same manner as in Example 2 below. This battery was charged and discharged in the same manner as in Example 2, and its discharge characteristics are shown in FIG.

The solid electrolyte battery prepared by using the above solid electrolyte ink also showed almost the same discharge characteristics as the solid electrolyte battery prepared by using the electrode material powder and the solid electrolyte powder shown in FIG.

(Example 5) RbCu ₄ I _1.5 Cl _3.5 copper ion conductive solid electrolyte as a solid electrolyte and Cu ₂ Mo ₆ S _7.8 copper chebrel as an electrode material were added with 20% by weight of the above copper ion conductive solid electrolyte, and under reduced pressure,
Described below is the case where the product treated at 200 ° C. for 17 hours is used.

First, 2% by weight of dry styrene-butadiene copolymer and toluene were added to the electrode material powder in a dry inert gas stream.
Dehydrated methyl propyl ketone = 1: 1 was added and mixed by stirring to dissolve the organic binder, and then dehydrated diethyl phthalate was added and subjected to ultrasonic treatment, and the viscosity was adjusted to be easy to apply to prepare a solid electrolyte ink.

Next, the above solid electrolyte ink was washed and applied to a dried plain woven glass cloth, and then dried under reduced pressure at 130 ° C. to prepare a solid electrolyte sheet, and a solid electrolyte battery was prepared in the same manner as in Example 2 below. This battery was charged and discharged in the same manner as in Example 2, and the discharge characteristics are shown in FIG.

The solid electrolyte battery prepared by using the above solid electrolyte ink also showed almost the same discharge characteristics as the solid electrolyte battery prepared by using the electrode material powder and the solid electrolyte powder shown in FIG.

(Example 6) RbAg ₄ I ₅ silver ion conductive solid electrolyte as a solid electrolyte, Ag ₂ Mo ₆ S _7.8 silver electrode as an electrode material, 20% by weight of the above silver ion conductive solid electrolyte was added, and the pressure was reduced to 200
Described below is the case where the product treated at 17 ° C for 17 hours is used.

First, solid electrolyte powder in a dry inert gas stream 2.
6% by weight of styrene-ethylene-butadiene-styrene copolymer (drying at 80 ° C under reduced pressure) After adding an organic binder and toluene as an organic solvent with stirring to dissolve the organic binder,
Cyclohexanol was added and ultrasonic treatment was performed, and then the viscosity was adjusted to be easy to apply to prepare a solid electrolyte ink.

Next, a solid electrolyte battery was prepared as follows using the above solid electrolyte ink, and this battery was charged and discharged in the same manner as in Example 2, and the discharge characteristics are shown in FIG.

Next, the solid electrolyte ink was applied to a washed and dried polypropylene non-woven fabric and dried under reduced pressure at about 100 ° C. to prepare a solid electrolyte sheet, and a solid electrolyte battery was prepared in the same manner as in Example 2 below. Further, a solid electrolyte battery prepared by press molding the electrode material powder and the solid electrolyte powder at 3 ton / cm ² was similarly charged and discharged, and its discharge characteristics are also shown in FIG.

The solid electrolyte battery prepared using the above solid electrolyte ink also showed almost the same discharge characteristics as the solid electrolyte battery prepared using the electrode material powder and the solid electrolyte powder.

EFFECTS OF THE INVENTION As described above, by using the solid electrolyte ink of the present invention, it is possible to easily prepare a solid electrolyte battery and to reduce the thickness of the solid electrolyte, and it is possible to stabilize the characteristics of each solid electrolyte battery. It is possible.

[Brief description of drawings]

1 to 4 are discharge characteristic diagrams of a solid electrolyte battery using a copper ion conductive solid electrolyte ink and a solid electrolyte battery using a copper ion conductive solid electrolyte powder and an electrode material powder according to an embodiment of the present invention. FIG. 5 shows the discharge characteristics of a solid electrolyte battery using the silver ion conductive solid electrolyte ink of another embodiment of the present invention and a solid electrolyte battery prepared using the silver ion conductive solid electrolyte powder and the electrode material powder. It is a figure.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazunori Takada 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Shigeo Kondo, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A solid electrolyte comprising a copper ion solid electrolyte or a silver ion solid electrolyte, an anhydrous or dehydrated organic binder having plasticity, and an anhydrous or dehydrated organic solvent or a high boiling point organic substance. ink. 2. The organic binder, the organic solvent, and the high-boiling organic matter are
Ions or molecules of hydrogen, oxygen, halogen elements in a chemically active state, or hydrogen, carbon, nitrogen, oxygen,
The solid electrolyte ink according to claim 1, wherein the solid electrolyte ink is composed of an organic substance that does not dissociate or contain active ions, free radicals or molecules composed of at least two or more elements of sulfur and halogen elements. 3. An organic solvent, a high-boiling organic substance is alcohol,
The solid electrolyte ink according to claim 1 or 2, comprising a polar organic substance such as a ketone or an ester. 4. The copper ion solid electrolyte is RbCl, RbI, CuCl, C.
The solid electrolyte ink according to claim 1, 2, or 3, which is mainly composed of uI. 5. The solid electrolyte ink according to claim 1, 2, or 3, wherein the silver ion solid electrolyte is mainly composed of RbI and AgI.