JPH0433255A - Manufacturing method of electrode composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a method for manufacturing an electrode composition used in solid electrochemical elements such as sensors, display elements, and recording elements. A cationic surfactant containing an oxide (EO) chain and/or a propylene oxide (PO) chain is added to a solvent containing an electrode active material powder, a solid electrolyte powder, and a thermoplastic resin.a Conventional technology: Using a solid electrolyte It is possible to obtain solid electrochemical devices such as small and thin batteries and electric double layer capacitors without leakage.

However, due to the fact that the device is made of a solid material that lacks elasticity, it is extremely brittle against mechanical shock.
It has the disadvantage of being easily damaged.

A method to solve such problems: Japanese Patent Application Laid-Open No. 63-2458
As stated in Publication No. 71, 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 give it flexibility and resist damage even under mechanical shock, this exception has been proposed. The electrode active material and the solid electrolyte are mixed with an electrically insulating thermoplastic resin and used as an electrode composition.

Problems to be Solved by the Invention Electrode active material powders such as these include electrode compositions consisting of solid electrolyte powders and thermoplastic resins (generally, each powder is dispersed in a solvent in which a thermoplastic resin is dissolved to form a slurry). It is also advantageous to dissipate the solvent after or during molding.In this case, since the solid electrolyte powder is ionic, dispersion using a hydrophilic or polar solvent such as acetone can cause the solid electrolyte powder to Even if lipophilic non-polar solvents such as toluene are used, the hydrophilic solid electrolyte powder forms secondary particles and is unevenly dispersed in the thermoplastic resin because it slightly dissolves in the solvent and changes its quality. In many cases, the solid electrolyte powder is not mixed uniformly with the electrode active material powder, and sufficient ionic conductivity cannot be maintained within the electrode composition, especially when the amount of solid electrolyte powder mixed is reduced in order to increase the capacitance of the electrode composition. In addition, it is difficult to obtain a homogeneous large-area electrode composition.The present invention solves these problems. An object of the present invention is to provide a method for producing an electrode composition that obtains an electrode composition with excellent flexibility and mechanical strength. A method for producing an electrode composition, which includes a step of dispersing an electrode active material powder and a solid electrolyte powder in a solvent in which a thermoplastic resin is dissolved to form a slurry, and a step of removing the solvent from the slurry, A cationic surfactant having an ethylene oxide chain and a propylene oxide chain, or a surfactant having either an ethylene oxide chain or a propylene oxide chain may be added to the slurry. Top: Because the electrode active material powder and solid electrolyte powder are uniformly mixed and dispersed by the action of the cationic surfactant having ethylene oxide (EO) chains and/or propylene oxide (PO) chains, the path for ion conduction is determined by the electrode composition. Example The following is a more detailed explanation of the method of manufacturing an electrode composition according to an example of the present invention (the present invention is not limited to the following example). Also, in the following Examples 1 and Comparative Examples, % represents a weight ratio unless otherwise specified.

The electrode active materials of this example include elemental gold such as metal lithium, KLi-AI, and LaN1r.

Alloys such as: Sulfide ore Sulfide ore Copper Chevrel compound track
Silver Chevrellization method Metal sulfides such as titanium sulfide, niobium sulfide, and molybdenum sulfide: Manganese dioxide, vanadium oxide Metal oxides such as cobalt oxide and chromium oxide: Melon chloride Iodide halides such as carbon fluoride; Activated carbon, black Materials that are solid at room temperature, such as carbon materials such as carbon black, can be used, and anything from ultrafine particles with an average particle size of 1 μm or less to particles of several tens of μm can be used, but the solid electrolyte powder is MCu4I2. -xc1s+x
(x=0.25-1.0. M-Rb, K, NHa
or a mixture thereof) or Cul-Cu20-M
Copper ion conductive solid electrolyte such as oOs glass, RbA
Silver ion conductive solid electrolytes such as g4I5, Ag5Si, Agl-Ag20-MoOs glass-containing AgalaWOa, LiI, LiI-HaQ, Li-β-A1203
, LiI-LiaS-B2Sa, PE0-L1CFsS
Lithium ion conductive solid electrolytes such as O3, HaM
o+ 2POa-・29H20゜Hs L t PO4
Although a proton-conducting solid electrolyte such as -.29HaO can be used, any particle having an average particle size from ultrafine particles of 1 μm or less to particles of several tens of μm can be used.

Even ultrafine solid electrolyte powder with an average particle size of 1 μm or less can be uniformly dispersed.
1,4-polybutadiene, natural rubber, polyisoprene, SBR, NBR.

SBS, SIS, 5EBS, to Petilgo
Contains phosphazengo polyethylene, polypropylene,
It is preferable to use polyethylene oxide, polystyrene, 1,2-polybutadiene, polytetrafluoroethylene, etc. In the production of the electrode composition, n-hexane, n-heptane, n-octane, cyclohexane, benzene, Toluene, xylene, ethyl acetate, +k
Saturated hydrocarbon solvents that do not react with lipophilic non-water-absorbing solid electrolytes such as trichlene, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, and ester solvents that have EO chains and/or PO chains. Examples of cationic surfactants include those represented by the following formula (1) or (2): x is nitrogen or phosphorus; Y is sulfur; A- is C1-
Brdo, F-, ClO4-, CHsCOO-, Cha
os-, OH-, CHsSOs-, AlCl4-, B
Fi-, PF*-, N0a- or a combination thereof; R
At least one of 1, R2, RsS R, is a hydrocarbon group having 1 to 30 carbon atoms with or without a substituent having an EO chain and/or a PO chain, and the rest have a substituent or is the same or different hydrocarbon group having 1 to 30 carbon atoms, and the number of moles of L EO chain and/or PO chain added is preferably 1 to 50.
The amount of the cationic surfactant added is preferably 0.5 to 20% based on the total amount of the solid electrolyte composition.

The electrode composition of this example was obtained as follows: A thermoplastic resin was dissolved in a lipophilic solvent to form a 1 to 20% solution. A cationic surfactant having an EO chain and/or a PO chain. 0 for the entire slurry. 1-20%
Electrode active material powder, solid electrolyte powder, and conductive agent powder if necessary, or a mixture of electrode active material powder, solid electrolyte powder, and conductive agent powder if necessary in a predetermined mixing ratio. An electrode slurry with a solids content of 5 to 95% is prepared by grinding and mixing using a mixing grinder such as a disperser. A mixture of electrode active material powder, solid electrolyte powder, and conductive agent powder if necessary, or a mixture of electrode active material powder, solid electrolyte powder, and conductive agent powder if necessary in a predetermined mixing ratio was dispersed in an oil-based solvent. Electrode slurry can also be obtained by mixing and dispersing the slurry and a solution of thermoplastic resin dissolved in a lipophilic solvent. Although the electrode composition can be obtained by dissipating the solvent when molded by casting or coating on a support such as a sheet, if the support is in the form of a mesh, it can be used as an electrode composition with the support integrated. Although it is possible, these steps should be carried out in a dry atmosphere with a relative humidity of 40% or less, but preferably with a dew point of -20°C.
(Example 1) Low-density polyethylene (Efselen VL-200, density = 0.9, density = 0.9, thermoplastic resin and binder) (manufactured by Kagaku Kogyo) in toluene to prepare a 10% polyethylene solution, and the cationic surfactant represented by formula (3) was dissolved in toluene to prepare a 20% cationic surfactant solution (A). Activator solution (A)
The average particle size is 1 μm so that the solid content is 50%.
Copper ion conductive solid electrolyte powder (RbCu4I+, 5
C1s, s.

copper Chebrel phase compound (Cu2MOeS) with an average particle size of 0.8 μm and density = 4.7), e, density = 5.8
) and then a polyethylene solution was added to obtain an electrode powder dispersion (B) with a solid content of 50%. A mixture consisting of CuI and CuC1 at 200
9 obtained by heating reaction in a closed glass container at ℃ for 17 hours Also, copper Chevrel phase compound f;L MO82,
A mixture of Cu and S was heated and reacted in vacuum at 1000°C for 48 hours to obtain a mixture of a predetermined amount of cationic surfactant solution (A), electrode powder dispersion (B), and toluene. Mix and grind in a ball mill for 24 hours to obtain an electrode powder slurry. Apply this slurry on a smooth Teflon plate using a doctor blade in dry nitrogen at 80°C.
After drying, the size is 80x80mm, thickness 154±5
A sheet-like electrode molded body (Bl) with a μm electrode powder content of 85% by volume was obtained, and an electrode molded body (D1) with a thickness of 125±10 μm was obtained.
By mixing gI and WOs in a predetermined ratio and heating and reacting at 400°C in the air for 6 hours, it can be obtained. Q Ags,
yVaOs was obtained by mixing Ag powder and V*Os at a predetermined ratio and heating the mixture in a sealed tube at 550°C for 6 hours (Comparative Example 1). A cationic surfactant was used instead of the solid electrolyte dispersion (B). A sheet-shaped electrode molded body (C1) having an electrode powder content of 85% by volume was obtained in the same manner as in Example 1 except that an electrode powder dispersion (C) containing no electrode powder was used (Example 2). A with a silver ion conductive average particle size of 8 μm as
ge I4 WO4 powder, silver vanadate powder (Ags, yVgOs) with an average particle size of 10 μm, and a mixture of Noko:2 were used (\ Electrode powder dispersion (D) containing a cationic surfactant represented by formula (4)) The electrode powder dispersion (E) containing no cationic surfactant was used instead of the electrode powder dispersion (D) in the same manner as in Example 1 except that the electrode powder content was 90% by volume (Comparative Example 2). Example 2 except that
A sheet-like electrode molded body (El) with an electrode powder content of 90% by volume was obtained in the same manner as in (Example 3).
A 1:1 mixture of 1 μm Lil-H20 powder and niobium sulfide powder (NbS*) with an average particle size of 6 μm was used (＼
Except for using the electrode powder dispersion (F) containing the cationic surfactant represented by formula (5)! In the same manner as in Example 1, an electrode molded body (Fl) with a thickness of 85 ± 5 μm and an electrode powder content of 90% by volume was obtained.
For bS2, a commercially available reagent was ground in ethyl ether using a ball mill, and for t (Comparative Example 3), instead of the electrode powder dispersion (F), an electrode powder dispersion (G) containing no cationic surfactant was used. Example 3 except that
In Examples 1 to 3 and Comparative Examples 1 to 3, a sheet-like electrode molded body (G1) having an electrode powder content of 90% by volume was obtained in the same manner as above.9 Characteristics of the electrode molded body were evaluated by the method described below. The obtained electrode molded bodies were punched into 20 discs each with a diameter of 10 mm and used as samples for characteristic testing.For the electrode discs of Example 1 and Comparative Example 1, RbCu4I+ and 6C were used as solid electrolytes.
1g of 1s, s powder was molded at a pressure of 200 kg/cm'', and one pellet with a diameter of 10 mm was placed on the top and bottom, and platinum disks were placed above and below the pellets, and the whole was molded with a pressure of 50 kg/cm'' With pressure applied from above and below,
Test battery B was heated at 130°C for 3 hours in a nitrogen gas atmosphere.
Assemble C2 (Example 1) and C2 (Comparative Example 1).
c' for the electrode discs of Example 2 and Comparative Example 2! ,
Similarly, test cells D2 (Example 2) and F2 (Comparative Example 2) were prepared using Age Ia 104 powder as the solid electrolyte.
) Assemble the electrode discs of Example 3 and Comparative Example 3 using LiI/HeO powder as the solid electrolyte, X, test battery F2 using a lithium disc with a thickness of 0.3 m and a diameter of 10 mm as the negative electrode. (Example 3) and G
2 (Comparative Example 3) was assembled (9) F2 and G2 were only pressurized without heating (9) Test batteries B2 and C2, each made up of 10 of the same batteries, were charged at a constant voltage of 0.6 V for 17 hours. almA
Discharge for 10 seconds at a constant current of ＼ Measure the difference in battery voltage (polarization) immediately before and after discharge, and calculate the average value and standard deviation value for 10 batteries.9 Also, at the same current value up to 0.3V Perform continuous discharge to find the discharge capacity. Find the utilization rate of the electrode active material relative to the theoretical capacity (100%). For test batteries D2 and B2, charge at a constant voltage of 0.50 V for 17 hours at a constant current value of 200 μA and charge ratio of 10 After discharging for seconds, the average value and standard deviation of polarization were determined.Also, continuous discharge was performed at the same current value to 0.3V, and the theoretical capacity (100
9) For test batteries F2 and G2 (1) at a constant current of 50 μA.
Discharge for 0 seconds and find the average value and standard deviation of polarization. 9. Also, at the same current value, 1. Continuously discharge up to Ov and find the utilization rate of the electrode active material with respect to the theoretical capacity (100%).
The results of polarization values are shown in Table 1, and the results of utilization rates are shown in Table 2.

In addition, the bending strength of the electrode molded body was determined by measuring 40 mm in length and 5 mm in width.
Table 3 shows the results of an evaluation based on the number of times a molded product of 50 mm was repeatedly bent at a rate of 2 times per second until breakage occurred along a curved surface with a radius of 50 mm. All of the above measured values are values at 20°C.

Example 1 Comparative example 1 Example 2 Comparative example 2 Example 3 Comparative example 3 Table 1 Polarization Table 2 Utilization rate * Example 1 Comparative example 1 Example 2 Comparative example 2 Example 3 Comparative example 3 The theoretical capacity is 1 Table 3 Mechanical strength Battery Mechanical strength.

B2 Example 1145 C2 Comparative Example 1100 B2 Example 2140 B2 Comparative Example 2100 F2 Example 3155 G2 Comparative Example 3100 It is clear from the results shown in Tables 1 to 3 that the bending strength of the corresponding comparative example is 100. The electrode composition according to this example has a higher electrode utilization rate than that of the comparative example, and the standard deviation of polarization is small, indicating that it is a homogeneous electrode composition in which the electrode active material and electrolyte are evenly mixed. Waka 4 Also, the average value of polarization is small (t) Furthermore, when comparing the mechanical strength, although the electrode composition of this example has greater strength than the conventional one, it is clear from the description of the example that the effect exceeds the effect of the invention. &mi CTCE○ chain and/or P○
Due to the surfactant action of the cationic surfactant containing chains, it is possible to obtain an electrode slurry that is stable for a long period of time, and by removing the solvent from this slurry and solidifying it, a homogeneous electrode composition can be obtained. This has the effect that a small electrode composition can be obtained.

Claims (1)

[Claims] In the method for producing an electrode composition, the method includes a step of dispersing an electrode active material powder and a solid electrolyte powder to form a slurry in a solvent in which a thermoplastic resin is dissolved, and a step of removing the solvent from the slurry, wherein the slurry contains: A method for producing an electrode composition, in which a cationic surfactant having an ethylene oxide chain and a propylene oxide chain, or a surfactant having either an ethylene oxide chain or a propylene oxide chain is added.