JPH0433263A - Manufacture of electrode composition material - Google Patents

Abstract

PURPOSE:To obtain a homogeneous electrode composition material with a high utilization factor by adding an amide compound which is a dehydration condensation reactant of polyalkylene imine and fatty acid into slurry. CONSTITUTION:Thermoplastic resin is dissolved in a lipophillic solvent to obtain a solution, an amide compound which is a dehydration condensation reactant of polyalkylene imine and fatty acid is added to the solution, electrode active material powder, solid electrolyte powder, conductive material powder as necessary, or a mixture mixed with electrode active material powder and solid electrolyte powder and conductive material powder as necessary at preset mixing ratios in advance are added, and it is crushed and mixed by a mixing crusher to obtain electrode slurry. This slurry is molded as it is, or it is extended or coated and molded on a supporter, then the solvent is dispersed to obtain an electrode composition material.

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. An amide compound, which is a dehydration condensation reaction product of an alkylene imine and a fatty acid, is added to a solvent containing an electrode active material, solid electrolyte powder, and thermoplastic resin.

BACKGROUND OF THE INVENTION By using a solid electrolyte, it is possible to obtain solid electrochemical devices such as small and thin batteries, electric double layer capacitors, etc. without liquid 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, but the only way to solve this problem is as described in Japanese Patent Application Laid-Open No. 63-245871.By mixing thermoplastic resin such as synthetic rubber with the solid electrolyte and electrode active material, it becomes flexible. Although an element has been proposed that imparts properties and is resistant to damage due to mechanical shock, the electrode active material and the solid electrolyte are mixed with an electrically insulating thermoplastic resin and used as an electrode composition. Such solid electrolyte powders Electrode compositions made of solid electrolyte powders and thermoplastic resins are generally made into a slurry by dispersing each powder in a solvent in which a thermoplastic resin is dissolved, and after molding or molding the slurry. However, the solid electrolyte powder is ionic, so if it is dispersed using a hydrophilic or polar solvent such as acetone, the solid electrolyte powder will dissolve slightly in the solvent. Moreover, lipophilic non-polar solvents such as toluene are used to avoid deterioration in quality. Therefore, hydrophilic solid electrolyte powders often form secondary particles and are unevenly dispersed in thermoplastic resins. In particular, if the amount of solid electrolyte powder mixed in order to increase the capacitance of the electrode composition is reduced, sufficient ionic conductivity may not be maintained within the electrode composition. The problem is that the electrode utilization rate is extremely low.
In addition, even though it is difficult to obtain a homogeneous electrode composition with a large area, the present invention solves such problems and provides a method for producing an electrode composition that yields a homogeneous electrode composition with a high electrode utilization rate. In order to solve the above-mentioned problems, the present invention aims to provide an electrode active material powder using an amide compound, which is a dehydration condensation reaction product of a polyalkylene imine and a fatty acid, and solid electrolyte particles. , and a thermoplastic resin.The action of the electrode composition obtained in this way (the action of the amide compound, which is a dehydration condensation reaction product of polyalkyleneimine and fatty acid) makes the electrode active material powder In order to uniformly mix and disperse the solid electrolyte powder, paths for ion conduction are uniformly constructed within the electrode composition. The present invention is not limited to the following Examples (-Also, in the following Examples and Comparative Examples, % represents a weight ratio unless otherwise specified.

As the electrode active materials of this example (Metallic grade: Metallic lithium, etc., elemental gold such as KLi-Al, LaNi5, etc. alloy; Sulfurization method: Copper Chevrehl compounding method; Silver Chevrehl compounding method; Titanium sulfide, Niobium sulfide, Molybdenum sulfide, etc.) Metal sulfides; Metal oxides such as manganese dioxide, vanadium oxide, cobalt oxide, chromium oxide;
Halogenated substances such as chloride melon, iodide, and carbon fluoride; Materials that are solid at room temperature, such as activated carbon and carbon materials such as blackboard carbon black; Ultrafine particles with an average particle size of 1 μm or less to particles of several tens of μm. ζ7 MCuaIa-xcli can be used as a solid electrolyte powder.
*x(x-0゜25-1.0. M= Rb, K,
NHJ or a mixture thereof) or CuI-Cus
List of copper ion conductive solid electrolytes such as p-Moss glass
bAgaIs, Ag5Si, Agl-Ag20-
List of silver ion conductive solid electrolytes such as MoOs Gala 7, Ag*InWO4 Lil, Lil-1hC1, Li
-β-AhOs, Lir-LiaS-BaS3, PE0
- Lithium ion conductive solid electrolyte such as LlCFsSOs, Hs Mo+ 2 PO4- 29hQ, Hs
A proton-conducting solid electrolyte such as W+ 2POs...29H20 can be used, or anything from ultrafine particles with an average particle size of 1 μm or less to particles of several 10 μm can be used. Even fine solid electrolyte powder can be uniformly dispersed. As thermoplastic resin it 1,4-polybutadiene, natural gobe polyisoprene, SBR, NBR, SBS, SIS,
SE B S, butylgo na phosphazengo na
It is preferable to use polyethylene, polypropylene, polyethylene oxide, polystyrene, 1,2-polybutadiene, polytetrafluoroethylene, etc. In producing the electrode composition, as a dispersion medium, n-hexane, n-hebutane, n-octane, Cyclohexane, benzene, toluene, xylene, ethyl acetate/l,
, Saturated hydrocarbon series that does not react with lipophilic non-water-absorbing solid electrolytes such as tricrene, Aromatic hydrocarbon series, Halogenated hydrocarbon series, Dehydration condensation reaction product of polyalkylene imine and fatty acid, even when an ester solvent is used. Examples of the polyalkylamine that provides the amide compound include polyethyleneimine, polypropyleneimine, polybutyleneimine, and the like.

It is obtained by polymerizing alkylene imines corresponding to these in an acidic catalyst, preferably polyethylene imine containing 8 to 160 nitrogen atoms in the molecule.
Stearin Ugly Oleic acid, linoleic acid, ricinoleic acid, etc. Can be obtained by condensing polyalkylene imine and fatty acid while stirring in a nitrogen stream and distilling off the reaction product water at 150 to 200 tons. The molar ratio of alkyleneimine to fatty acid (Table 1/2 to 1/80 is preferred) The electrode composition of this example is obtained as follows: The thermoplastic resin is dissolved in a lipophilic solvent to form a 1 to 20% solution.The amide compound is added at 0.1% to the entire slurry.
Electrode active material powder, solid electrolyte powder, and conductive agent powder if necessary, or electrode active material powder, solid electrolyte powder, and conductive agent powder if necessary in a predetermined mixing ratio. The mixed mixture is added to a lipophilic solvent in which a polyether compound is dissolved, and the electrode slurry is prepared by pulverizing and mixing using a mixing grinder such as a disperser. Active material powder and solid electrolyte powder A slurry in which a mixture of electrode active material powder, solid electrolyte powder, and conductive agent powder as necessary is dispersed, or a mixture of electrode active material powder, solid electrolyte powder, and conductive agent powder as necessary in a predetermined mixing ratio, and thermoplastic It is also possible to obtain an electrode slurry by mixing and dispersing a solution of the resin in a lipophilic solvent, but this is the next best option! The slurry obtained in this way can be used as is, or it can be supported with a Teflon plate or nylon mesh sheet. An electrode composition can be obtained by dissipating the solvent after casting or coating on a body and molding it.If the support is mesh-like, it is also possible to use the support as an electrode composition with the support integrated. These steps are carried out in a dry atmosphere with a relative humidity of 40% or less. Preferably, they are carried out in a dry inert gas atmosphere such as nitrogen or argon with a dew point of -20°C or less.

(Example 1) Low-density polyethylene (Efselen VL-200, density = 0.9, manufactured by Sumima Kagaku Kogyo), which is a thermoplastic resin and acts as a binder, was dissolved in toluene to prepare a 10% polyethylene solution. An amide compound obtained by condensing polyethyleneimine containing 120 nitrogen atoms and oleic acid at a molar ratio of 1/20 was dissolved in toluene to prepare a 20% amide compound solution (A). )
The average particle size is 1 μm so that the solid content is 50%.
Copper ion conductive solid electrolyte powder (RbCu411, s
C1$, '+ density = 4.7) and average particle size is 0.8μ
CuaMoaSv, s.

An electrode powder dispersion (B) with a solid content of 50% was obtained by adding a balanced polyethylene solution in which a 2:1 mixture of copper ion conductive solid electrolyte (density = 5.8) was dispersed. Obtained by heating a mixture consisting of quantitative amounts of RbC1, CuI, and CuC1 at 200°C for 17 hours in a closed glass container.
MoS2. A mixture of Cu, S and 1000
A plate containing a predetermined amount of polyether solution (A), electrode powder dispersion (B), and toluene mixed together by heating and reacting at ℃ for 48 hours. Mixed and pulverized for 24 hours in an alumina ball mill to obtain electrode powder. Obtaining slurry After applying the slurry using a doctor blade on a smooth Teflon plate, drying it in dry nitrogen at 80°C for 5 hours to obtain a size 8
A sheet-shaped electrode molded body (B1) with a size of 0x80 mm and a thickness of 154 ± 5 μm and an electrode powder content of 85% by volume was obtained t4 (Comparative Example 1) Electrode powder not containing polyether was used instead of the solid electrolyte dispersion (B). A sheet-like 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 the dispersion liquid (C) was used. (Example 2) Silver ion conductive material was used as the electrode powder. A with an average particle size of 8 μm
A 3=2 mixture of ga14WO4 powder and silver vanadate powder (Agv, Ve Os) with an average particle size of 10 μm was used (\ polyethyleneimine containing 56 nitrogen atoms and caprylic acid at a molar ratio of 1/8). Except for using an electrode powder dispersion (D) containing an amide compound obtained by condensation with (
KAgeI4WOd; L. An electrode composition (DI) having a thickness of 120±8 μm and having an electrode powder content of 90% by volume was obtained in the same manner as in Example 1.

Mix 10g of AgeO and AgI in a predetermined ratio and make 400
9 obtained by heating reaction in the atmosphere for 6 hours at t? Q
Ags, yV*os can be obtained by mixing Ag powder and V*Os at a predetermined ratio and heating and reacting in a sealed tube at 550°C for 6 hours (Comparative Example 2) Instead of electrode powder dispersion (D) A sheet-shaped electrode molded body (El) having an electrode powder content of 90% by volume was obtained in the same manner as in Example 2 except that an electrode powder dispersion (E) containing no amide compound was used (Example 3) Electrode As a powder, a 1=1 mixture of lithium ion conductive LiI-HaO powder with an average particle size of 5 μm and niobium sulfide powder (NbSp) with an average particle size of 6 μm was used.
Example 1 was carried out in the same manner as in Example 1 except that an electrode powder dispersion (F) containing an amide compound obtained by condensing polypropylene imine containing 40 nitrogen atoms and oleic acid at a molar ratio of 1/10 was used. An electrode molded body (F1) with a thickness of 85 ± 5 μm and an electrode powder content of 90% by volume was obtained.
iI・I20. Nb5a was obtained by pulverizing a commercially available test tube in ethyl ether using a ball mill (Comparative Example 3) Except for using an electrode powder dispersion (G) that does not contain an amide compound instead of the electrode powder dispersion (F). A sheet-like electrode molded body (G1) with an electrode powder content of 90% by volume was obtained in the same manner as in Example 3. Characteristics of the electrode molded body were evaluated by the method described below. Examples 1 to 3 and Comparative Example The electrode compositions obtained in 1 to 3 were punched out into 20 discs each with a diameter of 10 mm and used as samples for characteristic testing.9 For the electrode discs of Example 1 and Comparative Example 1, RbCu4I+ and 5C1 were used as solid electrolytes.
S, R, 1g of powder was molded at a pressure of 200 kg/cm2, and one pellet with a diameter of 10mm was placed on the top and bottom, and platinum disks were placed on top and bottom of the pellets. Test batteries B2 (Example 1) and C2 (Comparative Example 1) were assembled by heating at 130°C for 3 hours in a nitrogen gas atmosphere under pressure applied from above and below. Regarding the disk (top) Similarly test batteries D2 (Example 2) and F2 (Comparative Example 2) using Ags I4WO4 powder as solid electrolyte
Regarding the electrode disks of Example 3 and Comparative Example 3, which were assembled using Lil-I20 powder as the solid electrolyte,
,X.

Test batteries F2 (Example 3) and G2 were prepared using a lithium disk with a thickness of 0.3 mrrI and a diameter of 10 mm as the negative electrode.
(Comparative Example 3) was assembled, and for f, F2 and G2, only pressure was applied but no heating was performed.
Assemble 0 pieces at a time For test batteries B2 and C2, after charging at a constant voltage of 0.6V for 17 hours, 1m
Discharge was performed for 10 seconds at a constant current of A, uX, and the difference (polarization) between battery voltages immediately before and after discharge was measured, and the average value and standard deviation value were calculated for 10 batteries.Also, at the same current value, 0° Continuous discharge was performed up to 3 volts to determine the discharge capacity, and the utilization rate of the electrode active material with respect to the theoretical capacity (100%) was determined. Test batteries D2 and F2 were charged for 17 hours at a constant voltage of 0.50 V and a constant current value of 200 μA. So 10
Discharge for seconds and calculate the average value and standard deviation of polarization.
The theoretical capacity (1
For test batteries F2 and G2, the utilization rate of the electrode active material was determined for 0.00%) at a constant current of 50 μA.
After discharging for 0 seconds, the average value and standard deviation of polarization were calculated.
1 at the same current value. Continuously discharge to Ov and theoretical capacity (
100%) of the electrode active material.9 The results of the polarization value are shown in Table 1.The results of the usage rate are shown in Table 2. In addition, the bending strength of the electrode molded body was evaluated by the number of times it took to break when a composition with a length of 4.0 mm and a width of 5 mm was repeatedly bent at a rate of 2 times per second along a curved surface with a radius of 50 mm. The results are shown in Table 3. All of the above measured values are at 20°C.

Table 2 Utilization rate B2 Example 190 C2 Comparative example 182 B2 Example 279 B2 Comparative example 269 F2 Example 378 G2 Comparative example 358 *Theoretical capacity is 100% Table 3 Mechanical strength battery Mechanical strength B2 Example 1 125 C2 Comparative Example 1 100 D2 Example 2 130 E2 Comparative Example 2 100 F2 Example 3135 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 10. As shown, the electrode composition source according to this example has a higher electrode utilization rate than the comparative example, and the standard deviation of polarization is small, indicating that the electrode composition is a homogeneous electrode composition in which the electrode active material and electrolyte are evenly mixed. In addition, the average value of polarization is also small (1.%).Also, when comparing the mechanical strength, the electrode composition of this example has greater strength than the conventional one, but it is clear from the description of the example that the effect exceeds that of the invention. According to the method for producing an electrode composition of the present invention (L), it is possible to obtain an electrode slurry that is stable for a long period of time due to the surface active action of the amide compound, which is a dehydration condensation reaction product of polyalkylene imine and fatty acid.
By removing the solvent from this slurry and solidifying it, a homogeneous electrode composition can be obtained, and an electrode composition with low polarization can also be obtained.

E (゛mi E2\19 flea 2.ρ\ C5guJ,
'FF-God Se ゝ;111:2q〒 -'fX-rE-
・lzuhi.

Claims (1)

[Claims] The method for producing an electrode composition 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 method for producing an electrode composition by adding an amide compound which is a dehydration condensation reaction product of imine and fatty acid.