JPH0433256A - Method for producing solid electrolyte composition - Google Patents

Abstract

PURPOSE:To increase mechanical strength by adding either a cationic surface active agent with the ethylene oxide chain or propylene oxide chain or a cationic surface active agent with the ethylene oxide chain and propylene oxide chain into slurry. CONSTITUTION:Thermoplastic resin is dissolved in a lipophillic solvent to obtain a solution, a cationic surface active agent is added, then solid electrolyte powder is added, and the mixture is crushed and mixed by a mixing crusher to obtain solid electrolyte slurry. This slurry is molded as it is, or it is extended or coated and molded on a supporter, and the solvent is dispersed to obtain a solid electrolyte composition material. The cationic surface active agent with the ethylene oxide chain or propylene oxide chain or both of them is used.

Description

[Detailed Description of the Invention] Industrial Application Field of the Invention Table 3 Solid Battery Capacity Relating to a method for manufacturing a solid electrolyte composition used in solid electrochemical elements such as sensors, display elements, recording elements, etc. Particularly solid electrolyte Conventional technology related to the manufacturing method of a solid electrolyte composition in which powder is uniformly dispersed without agglomeration device can be obtained.

However, because the device is made of a solid material that lacks elasticity, it is extremely brittle and easily damaged by mechanical shock.

A number to solve such problems: JP-A-63-24587
As stated in Publication No. 1, although it has been proposed that a thermoplastic resin such as synthetic rubber be mixed with a solid electrolyte or an electrode active material to impart flexibility and resist damage even against mechanical shock, an element that is less likely to be damaged by mechanical impact has been proposed. The solid electrolyte is mixed with an electrically insulating thermoplastic resin and used as a solid electrolyte composition.

Problems to be Solved by the Invention Such a solid electrolyte molded body made of a solid electrolyte powder and a thermoplastic resin can be obtained by dispersing the solid electrolyte powder in a thermoplastic resin. Generally, each powder is dispersed in a solution containing a thermoplastic resin to form a slurry, and after or during molding, the solvent is dissipated to obtain a solid electrolyte composition.In this case, the solid electrolyte powder is ionic. Therefore, if a hydrophilic or polar solvent such as acetone is used for dispersion, the solid electrolyte powder will dissolve slightly in the solvent and change its quality, so a lipophilic non-polar solvent such as toluene may be used. Hydrophilic solid electrolyte powder often forms secondary particles that are unevenly dispersed in the plastic resin, and in order to maintain sufficient ionic conductivity, it is necessary to reduce the amount of thermoplastic resin. Therefore, it is difficult to obtain a solid electrolyte molded body that is homogeneous and has sufficient mechanical strength.The present invention solves these problems by dispersing the solid electrolyte powder uniformly without agglomeration. The purpose of the present invention is to provide a method for producing a solid electrolyte composition that realizes a solid electrolyte element with excellent ionic conductivity, large area, and strong mechanical strength. In order to solve this problem, the present invention was developed as a result of repeated studies aimed at obtaining a solid electrolyte molded body with homogeneous properties in which solid electrolyte particles are uniformly dispersed, especially one with a large area. ) chains or cationic surfactants with ethylene oxide (EO) chains and propylene oxide (PO) chains.
By adding a cationic surfactant having a chain to a solvent in which solid electrolyte particles and plastic resin are dispersed or dissolved, it is possible to obtain a solid electrolyte composition in which solid electrolyte particles are uniformly dispersed without agglomeration. The effect of the solid electrolyte molded body obtained in this way is that the solid electrolyte particles can be uniformly dispersed even in a lipophilic solvent by the action of the thionic surfactant, and uniform ionic conductivity can be obtained. Example of an ion conductive composition with excellent flexibility and improved mechanical strength The present invention will be explained by examples below.The present invention is not limited to the following examples. N.

In addition, in the following Comparative Examples, % represents weight ratio unless otherwise specified.

As the solid electrolyte powder in the present invention (MCu4It
-xcls-x (x-0,25~1.0.M=R
b, K, NH4 or a mixture thereof), copper ion conductive solid electrolytes such as Cu1-Cu20-MoOs glass, RbAgaIs, Ag*Si, A
gI-AgeO-MoOa Gala 7, AgeI4W0
Silver ion conductive solid electrolytes such as 4, LiI, Lil
・H2C1, Li-β-AI201, LiI-Lia
Lithium ion conductive solid electrolyte such as S-B2Sa, PEO-LiCFs S02, Hs Mo+ e P0
4m・29H*Q, HsW+ePO4@・29H2
A proton-conducting solid electrolyte such as 0 can be used. Any particle having an average particle diameter ranging from ultrafine particles of 1 μm or less to particles of several tens of μm can be used. Even ultrafine solid electrolyte powders with an average particle size of 1 μm or less can be uniformly dispersed and used as thermoplastic resins (for example, 1,4-polybutadiene, natural rubber, polyisopress SBR, NBR, SB).
It is desirable to use polyethylene, polypropylene, polyethylene oxide, polystyrene, 1゜2-polybutadiene, polytetrafluoroethylene, etc.; As, n
-Hexane, n-hebutane, n-octane, cyclohexane, benzene, toluene, xylene, ethyl acetate, saturated hydrocarbons that do not react with lipophilic, non-water-absorbing solid electrolytes such as trichlene, dissolving aromatic hydrocarbons Meltdown
A halogenated hydrocarbon dissolving ester solvent is used.

Examples of the cationic surfactant having an EO chain or an EO chain, or the cationic surfactant having an EO chain and an EO chain include those represented by the following formula (1) or (2).

Adult X is nitrogen or phosphorus; Y is sulfur; A- is C1
-Br-, I-, F-, ClO4-, CH3COO-,
CFaSOs-, OH-.

CH35Ch-, AICIJ-, BF4-, PF6-
, NO2- or a combination thereof; R1, R2, R
3. At least one of R4 is a hydrocarbon group having 1 to 30 carbon atoms with or without a substituent having an EO chain, a PO chain, or a cationic surfactant having an EO chain and a PO chain, and the rest are substituted It is the same or different hydrocarbon group having 1 to 30 carbon atoms with or without a group. The number of moles of the EO chain and PO chain added is preferably 1 to 50. % The amount of the cationic surfactant added is preferably O, 5 to 20% based on the total amount of the solid electrolyte composition. Dissolve the cationic surfactant in a solvent to make a 1-20% solution and then add 0.0% of the cationic surfactant to the entire slurry. Next, add solid electrolyte powder to a ratio of 1 to 20%, and grind and mix with a mixing grinder such as Ballmino K Disperser until the solid content is 5 to 9.
Prepare a 5% solid electrolyte slurry by mixing and dispersing a slurry in which solid electrolyte powder is dispersed in a lipophilic solvent in which a cationic surfactant is dissolved, and a solution in which a plastic resin is dissolved in a lipophilic solvent. By doing this, you can obtain a solid electrolyte slurry.The slurry obtained in this way can be formed as it is, or it can be cast or coated onto a support such as a Teflon plate or a nylon mesh sheet to form a solvent-resistive material. Although a solid electrolyte composition can be obtained by dissipating the solid electrolyte composition, if the support is in the form of a mesh, it is possible to use the support as a solid electrolyte composition with the support integrated.These steps are performed at a relative humidity of 40%. It is also preferable to carry out in a dry atmosphere with a dew point of -20°C.
(Example 1) Low-density polyethylene (E-Selen VL-100, density = 0.9), which is a thermoplastic resin and acts as a binder (Sumitomo Chemical Co., Ltd.) Cationic surfactant (industrial product) was dissolved in toluene to prepare a 10% polyethylene solution, and a cationic surfactant represented by formula (3) was dissolved in toluene to prepare a 20% cationic surfactant solution (A). The solid content in the agent solution (A) is 5.
Copper ion conductive solid electrolyte powder (RbCu41+, 5C1s, g, density = 4.7) with an average particle size of 3 μm was dispersed so that the solid content was 0%.Polyethylene solution was added to form a solid electrolyte with a solid content of 50%. Obtain dispersion (B)
This copper ion conductive solid electrolyte has a predetermined amount of Rb.
9 obtained by heating a mixture consisting of C1, CuI, and CuC1 at 200°C for 17 hours in a closed glass container.
A predetermined amount of cationic surfactant solution (A), solid electrolyte dispersion (B), and toluene were mixed and ground in an alumina ball mill for 24 hours to obtain solid electrolyte slurries with different solid electrolyte contents. After applying the slurry on a smooth Teflon plate using a doctor blade, it was dried for 5 hours in dry nitrogen gas at 80°C until the size of the plate was 8.
A sheet-like solid electrolyte molded body (Bl to B3) with a thickness of 110±5 μm and a solid electrolyte content of 25.30.35% by volume was obtained (Comparative Example 1) instead of the solid electrolyte dispersion (B). Sheet-like solid electrolyte molded bodies (C1 to C3) with solid electrolyte contents of 25, 30, and 35% by volume were carried out in the same manner as in Example 1 except that a solid electrolyte dispersion (C) containing no cationic surfactant was used. (Example 2) Solid electrolyte powder with silver ion conductivity average particle size of 8μ
The solid electrolyte content <,
Ag5LaWO4i Ag2O, AgI, W
(Comparative Example 2) A solid electrolyte dispersion containing no cationic surfactant was used instead of the solid electrolyte dispersion (D). A sheet-like solid electrolyte molded body (El to E3) having a solid electrolyte content of 60.70.80% by volume was obtained in the same manner as in Example 2 except that liquid (E) was used (Example 3) Solid electrolyte As a powder, a solid electrolyte dispersion (F) containing lithium ion conductive Lil-H20 powder with an average particle size of 5 μm and a cationic surfactant represented by formula (5)
The same procedure was used as in Example 1 except that the solid electrolyte content was 40, 50, and 60% by volume and the thickness was 130±.
8 μm lithium ion conductive solid electrolyte molded body (F
1 to F3) was obtained.9 For LiI/H2O, a commercially available reagent was ground in ethyl ether using a ball mill (Comparative Example 3). A cationic surfactant was used instead of the solid electrolyte dispersion (F). A sheet-like solid electrolyte molded body (Gl-G3) having a solid electrolyte content of 40.50.60% by volume was obtained in the same manner as in Example 3 except that a solid electrolyte dispersion (G) containing no solid electrolyte was used. To evaluate the properties of the solid electrolyte molded bodies prepared as described above, the solid electrolyte molded bodies obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were punched out into 20 discs each with a diameter of 10 mm.
It was sandwiched between two platinum disks and pressurized from above and below at a pressure of 50 kg/cm'', heated at 130°C for 3 hours in a nitrogen gas atmosphere, and then heated at 100 mV amplitude and 10 K frequency.
The homogeneity of the solid electrolyte compact was evaluated by applying an AC signal of Hz between the platinum disks and measuring the AC resistance value of the solid electrolyte compact disk at 20°C. The standard deviation values are shown in Table 1.The bending strengths of the molded bodies of Examples are shown as relative bending strengths in Table 2, with the corresponding solid electrolyte molded bodies of Comparative Examples set as 100. A molded product with a width of 5 mm was repeatedly bent along a curved surface with a radius of 50 mm at a rate of 2 times per second. The evaluation was made based on the number of times it took to break. It can be seen that the surface relative bending strength values are smaller and more homogeneous than those of the comparative examples. Comparing the mechanical strength, the molded product of the present invention has greater strength than the conventional molded product. A solid electrolyte slurry that is stable for a long time can be obtained by the surfactant action of a cationic surfactant containing a chain or a PO chain, or a cationic surfactant having an EO chain and a PO chain, and the solvent is removed from this slurry to solidify it. By doing this, it is possible to obtain a solid electrolyte composition that is homogeneous and has excellent mechanical strength, and it is also possible to obtain a solid electrolyte composition that has a low electrical resistance value.
``4%=112≦2 tt-s-t 71 solid electrolyte molded body (standard deviation of electrical resistance value

Claims (1)

[Claims] A method for producing a solid electrolyte composition comprising the steps of dispersing solid electrolyte powder in a solution containing a thermoplastic resin to form a slurry, and removing a solvent from the slurry,
A solid electrolyte composition in which either a cationic surfactant having an ethylene oxide chain, a cationic surfactant having a propylene oxide chain, or a cationic surfactant having an ethylene oxide chain and a propylene oxide chain is added to the slurry. manufacturing method.