JPS63245871A - Solid electrochemical element and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a solid electrochemical element having flexibility sufficiently bearable to mechanical impact by using material consisting of solid electrolyte and electrode material enclosed by plastic resin as components. CONSTITUTION:Plastic resin 3 is dry- or wet-mixed with solid electrolyte grains 1 and electrode material grains 2 in a proper ratio respectively, and the surface of the grains 1, 2 is completely covered with the plastic resin 3. Then this mixture is pressure molded into a proper form by means of a press or the like while being heated if necessary. Molded bodies of electrode material A, C are pressure molded again with a thus molded solid electrolyte molded body B between them to be integrated with other components of an element such as current collecting bodies 4, etc., if necessary. By this, a solid electrochemical element having a mechanically strong flexibility which is less likely to be affected by oxygen, moisture, etc., can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to solid electrochemical devices such as solid electrolyte batteries and solid electric double layer capacitors whose constituent elements are all solid materials, and to the production thereof.

Conventional electrochemical devices in which all of the device components are solid materials have the advantage of not leaking and can be easily made smaller and thinner. When constructing such an element, an electrolyte in a solid state, that is, a solid electrolyte, is required to move ions within the element. Solid electrolytes are distinguished by moving ionic species, including Li + ion conductive solid electrolytes, Aq + ion conductive solid electrolytes, Cu + ion conductive solid electrolytes, and H
+Ionic conductive solid electrolytes, etc. A solid electrochemical device is constructed by combining these solid electrolytes with appropriate electrode materials.

Since these solid electrochemical devices are all composed of solid materials, powdered electrode materials are placed on both sides of the solid electrolyte and pressed under pressure to form three layers for the entire device to form a chip. It can be assembled into a pellet shape, or it can be assembled into a thin film shape on a substrate using physical vapor deposition or chemical vapor deposition.

In ordinary electrochemical devices that use liquid electrolytes, electrical and ionic bonding between the electrolyte and electrode materials is easy, whereas in devices that are made entirely of solid materials, the solid electrolytes are bonded to each other, the electrode materials are bonded to each other, and However, it is difficult to easily obtain electrical and ionic bonding between the solid electrolyte and the electrode material. For this reason, in devices using liquid electrolytes, impurities such as binders 5 and 7 are generally mixed into the electrodes or the electrolyte to prevent the electrolyte from penetrating too much into the electrodes and causing the electrodes to lose their shape. It becomes. However, in solid-state electrochemical devices, it is customary to avoid using contaminants as much as possible because they further deteriorate the bonding.

Problems to be Solved by the Invention As described above, since solid-state electrochemical devices do not use contaminants, when trying to construct a thin and large device, many of the constituent elements generally lack elasticity and mechanical The problem is that it is brittle against impact and easily breaks. In addition, solid electrolytes are generally conductive due to chemically active monovalent cations, and when exposed to acid accumulation and moisture in the atmosphere, they change in quality and oxidize into divalent cations or become oxides. There is a problem that the conductive function is lost due to the crystal becoming fixed within the crystal.

Means to Solve the Problem The present invention solves this problem by using a material in which a solid electrolyte and an electrode material are wrapped in a plastic resin as a component, thereby significantly impairing electrical and ionic contact between particles. Without,
The present invention provides a solid electrochemical device that has sufficient resistance to mechanical shock and has 6.\-2 vine removability, and a method for manufacturing the same. Furthermore, by using such a material, it is possible to provide a solid electrochemical element that is less susceptible to the effects of moisture and oxygen during or after manufacturing the element, and a method for manufacturing the same.

Function: In the present invention, contaminants which are normally avoided in solid-state electrochemical devices are mixed, that is, constituent elements wrapped in a plastic resin are used. As a result, when assembling an element or molding a solid electrolyte molded body or an electrode molded body, the plastic resin is pushed between the component particles, and the particles are in direct contact with each other to form an aggregate 1b that is entirely wrapped in the plastic resin. Ru. Therefore, the component particles maintain their shape as an aggregate and are electrically connected to each other.

Ensures ionic connection and also direct atmospheric oxygen.

It is not exposed to moisture and is less likely to deteriorate.

Example: In order to solve the above-mentioned problems, ordinary solid-state electricity 7 ・＼
-7 After repeated studies on the mixing of contaminants that had been avoided in Chemistry 1, it was discovered that the above-mentioned problems could be solved by using element components wrapped in plastic resin.

Solid electrolyte powder containing plastic resin in an appropriate proportion.

When the electrode material particles are dry-mixed or wet-mixed, the surface of the solid electrolyte powder 1 or the electrode material powder 2 is completely covered with plastic resin, as shown in 18 in FIG. 1 or 2a in FIG. It can be completely covered. Then, the mixture thus prepared is pressure-molded into an appropriate shape using a press or the like, heating as necessary.
At this time, the plastic resin, which is more susceptible to mechanical deformation than the powder, becomes fluid, and as shown in 1b in Figure 1 or 2b in Figure 2, part of the resin that covered the surface of the powder before molding becomes fluid. is pushed into the gap created between the powder and granules, and the particles become electrically and ionically connected. At the same time, the resin forced into the gap acts to effectively bind the powder particles together. The electrode material molded body is then pressure-molded again through the solid electrolyte molded body formed in this manner, and other element components such as a current collector are integrally formed as required, thereby forming a solid electrochemical device. is obtained. A part of the cross section of the solid electrolyte element is shown in FIG.

A and C are electrode material molded bodies, B is solid electrolyte molded body,
4 is a current collector. At this time as well, the plastic resin flows in the same way as described above, and the resin is also pushed out between the powder particles that were not filled with plastic resin enough when pressure-molded with the molded body, and The electrical and ionic connections between the powder and granules become even stronger when the powder and granules are wrapped in resin, resulting in a flexible solid electrochemical element.

As mentioned above, pre-form solid electrolyte.

An electrode molded body may be molded and these may be integrally molded to form an element, or a mixture with a resin may be directly molded into an element without going through these molded bodies.

In the present invention, a solid electrolyte molded body in which solid electrolyte particles are covered with a plastic resin is used, but when this solid electrolyte molded body is in an electrochemical element in which it is used,
It is used with electrodes arranged on its upper and lower surfaces. Therefore, in order to obtain a good ionic connection with the electrodes, the upper and lower parts of the solid electrolyte molded body that come into contact with these electrodes are coated with a very thin plastic resin or are not substantially covered with the plastic resin. A solid electrolyte molded body previously molded in a state may be used.

Still especially chemically active Li+, Ag+, Cu
”.

By covering the surface of solid electrolyte particles, in which monovalent cations such as H+ are conductive ions, with plastic resin during raw material preparation, it is possible to reduce the influence of oxygen and moisture in the subsequent device manufacturing process. . However, when the powder and granules obtained in this way are used as devices, they are covered with plastic resin except for the parts that provide electrical and ionic connections between the powder and granules, so they cannot be placed directly in the atmosphere. Substantially, each powder does not come into direct contact with acid or moisture, resulting in a solid electrochemical element with extremely high environmental resistance.

Next, examples will be described in more detail.

The plastic resin according to the present invention has a commercially available plasticity of 1o.\
-2 Any resin may be used, but among these plastic resins, polyethylene and polypropylene are particularly preferred.

Synthetic rubbers such as styrene-butadiene rubber or neoprene rubber, silicone resins, and acrylic resins are preferably used.

When polyethylene, polypropylene, or acrylic resin is used, fine powders of these resins are used and dry mixed with element constituent material powders such as solid electrolyte powders and electrode material powders. The particle size of the resin is preferably 1/10 to 1/10000 of the particle size of each of these powders. During mixing, static electricity generated between particles produces a mixture in which polyethylene, polypropylene, or acrylic resin particles coat the element constituent material powder.

When using synthetic rubber such as styrene/butadiene or neoprene, silicone resin, or acrylic resin, wet mixing is performed using an organic solvent such as toluene or xylene. Synthetic rubber, acrylic resin or silicone resin at 5~2o
Weight percent dissolution 11...-/ Into the solvent, powder and granules of the component material were added and mixed to form a slurry, which was applied onto a plate of plastic resin, etc., and then the solvent was removed under reduced pressure. If necessary, the solvent can be dissipated under heating to form a film, or the slurry may be placed under reduced pressure to dissipate the solvent, and the resulting mixture may be pressure-molded.

The solid electrolyte used in the present invention is LiI.

Lil-H2O, L 1 s N, L x 4S
104-L 13P Li+ ion conductive solid electrolyte such as O4, RbAg4I5゜A g 3S I, A
g I A g 20- M o O3 Galanu et al.
q+ ion conductive solid electrolyte, RbCu4 engineering 1.75
"3.25Rbcu4 Ll, 6"3.5, RbC
u4 engineering 1.25 C13, 75゜Ko, 2Rb0.8C
u411.5Ce3.5. Cu knee Cu20- Mo
Cu+ ion conductive solid electrolyte such as O3 glass, H
3M012PO4o・29H20,H3W12Po4o
・There are H+ ion conductive solid electrolytes such as 29HO.

The electrode material used in the present invention is graphite.

Carbon materials such as acetylene plastic, Tsuku, activated carbon, titanium sulfide, niobium sulfide, copper sulfide, silver sulfide, lead sulfide.

Sulfides such as silver chevrell (silver molybdenum sulfide), copper chevrell (copper molybdenum sulfide), iron sulfide, tungsten oxide, vanadium oxide, chromium oxide.

Molybdenum oxide, titanium oxide, iron oxide, silver oxide.

Oxides such as copper oxide, halides such as silver chloride and lead iodide,
Metal materials such as copper, silver, lithium, gold, platinum, titanium, or alloys thereof can be used. A solid electrolyte battery can be constructed by using an electrode material that exchanges ions with a solid electrolyte, such as titanium disulfide, and an electrode material that exchanges ions with a solid electrolyte and optically changes accordingly, such as titanium disulfide. When tungsten oxide is used, a solid electrochemical display element (electrochromic element) can be constructed. Although ions are not exchanged with the solid electrolyte yet, a solid electric double layer capacitor can be constructed by using an electrode material that forms an electric double layer at the interface with the solid electrolyte, such as activated carbon. According to the present invention, any solid electrochemical bond will be highly flexible, extremely strong against mechanical shock, and excellent in environmental resistance.

[Example 1] 100 parts by weight of Cu"4-on conductive solid electrolyte powder represented by RbCu411.5C13,5 with an average particle size of 1 μm and an average particle size of 0.1 μm as a solid electrolyte.
A mixture obtained by mixing 20 parts by weight of polyethylene powder of
Formed into a size of 5 my x 20 mm with a thickness of 10 mm using a pressure of cA.
A solid electrolyte molded body of 0μ was obtained. Next, a mixture of 50 parts by weight of a positive electrode active material powder represented by CuO, 1NbS2 having an average particle size of 15 μm, 50 parts by weight of the above solid electrolyte powder, and 15 parts by weight of the above polyethylene powder was prepared in the same manner. A positive electrode molded body having a size of 5×20 and a thickness of 200 μm was obtained. Further, from a mixture consisting of 50 parts by weight of a negative electrode active material powder made of metallic copper having an average particle size of 8 μ, 50 parts by weight of the solid electrolyte powder, and 25 parts by weight of the polyethylene powder, the size of the powder was 5πm x 20 mm, and the thickness was 50 mm. A 120 μm negative electrode molded body was obtained. Each molded body obtained in this way was
50K! Pressurize the three layers together with a pressure of 7/d 14・＼
-7 A Cu-based solid state battery A was obtained by molding.

[Example 2] A Cu-based solid state battery B was obtained in the same manner as in Example 1, except that polypropylene powder with an average particle size of 0.1 μm was used instead of polyethylene powder.

[Comparative Example 1] A Cu-based solid state battery C was obtained in the same manner as in Example 1 except that polyethylene powder was not mixed.

[Example 3] Aq+ ion conductive solid electrolyte powder represented by RbAg4I6 with an average particle size of 8μ as a solid electrolyte, Aqo, 1
Example 1 except that a positive electrode active material powder represented by NbS2 with an average particle size of 15μ and a metal silver powder with an average particle size of 8μ were used.
An Ag-based solid battery was obtained in the same manner as above.

[Comparative Example 2] Aq-based solid battery E was obtained in the same manner as in Example 3 except that polyethylene powder was not mixed.

[Example 4] As a solid electrolyte, LiI with an average particle size of 15 μm was used as a solid electrolyte.
・Using Li + ion conductive solid electrolyte powder represented by ＼-, positive electrode active material powder represented by WO3 with an average particle size of 12μ, and negative electrode active material powder represented by Li1.5WO3 with an average particle size of 10μ. A Li-based solid state battery F was obtained in the same manner as in Example 1 except that

[Ratio 11o Example 3] A LL solid state battery G was obtained in the same manner as in Example 4 except that polyethylene powder was not mixed.

[Example 5] H3M012P0 with an average particle size of 20μ as a solid electrolyte
・H+ ion conductive solid 4° blackout solute powder represented by 29H2o, positive electrode active material powder with an average particle size of 8μ represented by WO3, and negative electrode powder represented by H'wo3 with an average particle size of 8μ. An H photosolid battery H was obtained in the same manner as in Example 1, except that acrylic resin powder with an average particle size of 0.2 μm was used as the resin powder instead of polyethylene powder.

[Comparative Example 4] H photosolid battery I was obtained in the same manner as in Example 5 except that acrylic resin powder was not mixed.

[Example 6] Cu+ represented by RbCu411.75 C13,26 with an average particle size of 2μ as a solid electrolyte
100 parts by weight of ion conductive solid electrolyte powder was mixed with 30 parts by weight of a toluene solution in which 10% by weight of styrene-butadiene rubber was dissolved to obtain a solid electrolyte slurry. The slurry was dried on a fluororesin flat plate with a bar coater to a thickness of 2.
Develop it so that it becomes 0 μ, and then reduce the thickness by 1 TorrO.
By vacuum heating drying at 0℃ for 3 hours, the thickness is 20μ and the width is 6.
A solid electrolyte thin film with a thickness of 0 mm and a length of 800 tntn was obtained. Next, 50 parts by weight of graphite powder with an average particle size of 0.5 μm and 50 parts by weight of the above solid electrolyte powder were mixed with 35 parts by weight of the above toluene solution to obtain a positive electrode slurry, and in the same manner, a positive electrode slurry was obtained with a thickness of 30 μm.
A positive electrode thin film with a width of 60 mm and a height of 800 mm was obtained. Further, 50 parts by weight of metallic copper powder having an average particle size of 2 μm.

A negative electrode slurry was obtained from 5 o parts by weight of solid electrolyte powder and 18 parts by weight of toluene solution, and this was used to form a negative electrode slurry with a thickness of 2 oμ and a width of eo.
A negative electrode thin film with a length of 800 mm and a length of 800 mm was obtained. A positive electrode thin film was placed on one side of the solid electrolyte thin film obtained in this manner, and a negative electrode thin film was placed on the other side.
Pressure-molded into three layers with a pressure of Kg/cm, width 65, length 1000 tnm, thickness 55-60
5 my x 20 rxyn
A solid battery ■ was obtained by cutting into pieces.

[Example 7] A solid battery K was obtained in the same manner as in Example 6 except that silicone resin was used instead of styrene-butadiene rubber.

[Example 8] A solid battery resin was obtained in the same manner as in Example 6 except that acrylic resin was used instead of styrene-butadiene rubber.

[Example 9] Thickness 3 consisting of graphite powder, solid electrolyte powder, and styrene-butadiene rubber obtained in the same manner as in Example 6 was passed through a solid electrolyte thin film with a thickness of 20 μm obtained in the same manner as in Example 6.
Oμ electrode thin films are placed on top and bottom, and 2
18 A at a pressure of 0 Ky/cm.

The three layers were pressure-molded at 130 to 150" C to form a thin film with a width of 65 mm, a length of 100 mm, and a thickness of 60 to 65 μm. This was cut into 5 nm x 20 mm to form a solid electrical double layer capacitor. I got K.

[Example 1o] H3M012 with an average particle size of 20/Im as a solid electrolyte
In Example 1, 50 parts by weight of H + ion conductive solid electrolyte powder represented by Po4°・29H20, 20 parts by weight of acrylic resin powder with an average particle size of 0.2 μm, and graphite powder with an average particle size of 0.5 μm. Mix and mold in the same way to size 6mm x
A graphite electrode with a thickness of 20 tnm and a thickness of 3Q11 m was made. This electrode, a display electrode with a thickness of 1 μm and a size of 5 my x 20 mm containing WO3 made in the same manner as in Example 5, and a display electrode with a thickness of 5° made of an H + ion conductive solid electrolyte and an acrylic resin. μm, size 5 mm x 20 v
tm solid electrolyte thin film and pressurized three layers together with the solid electrolyte thin film as an intermediate layer to a thickness of about 85 μm and a size of 6 f.
A solid electrochromic device between 1×20 was obtained.

Solid state batteries A to 11 obtained in this way solid state 19 ・
Solid electrochromic 1 in electric double layer capacitor
A repeated bending test at an angle of 3o0 in the longitudinal direction was conducted with the child in the bare state. The number of bends before breakage occurs is shown in the table below. The table below also shows the ratio of internal resistance R1 to initial internal resistance R0, R1/Ro, when each battery, capacitor, and electrochromic device were left in the atmosphere at 45° C. and 60% humidity for 48 hours.

In addition, in the examples, as the electrolyte material, Li
",Ag",Cu+,H", LiI, RbAq4I6゜R as representative ion conductive solid electrolyte materials.
bCu411.5C43,5,H3M○12PO4゜・
Although 29H20 was used, it goes without saying that similar effects can be obtained by using other electrolyte materials. In addition to the typical solid electrolyte materials mentioned above, examples of the solid electrolyte materials used in the present invention include materials in which sulfuric acid is retained in silica gel, etc., in which a liquid substance is retained in a solid material to the extent that the physical shape of the solid does not change. Also includes materials that have been used.

The same applies to the positive electrode active material and the negative electrode active material.

21,,-7 As described above, according to the present invention, a solid electrochemical monomer can be obtained which has excellent mechanical strength, is flexible, and is not easily affected by oxygen, moisture, etc.

[Brief explanation of drawings]

Figure 1 shows a solid electrolyte powder whose surface is covered with plastic resin and an aggregate of solid electrolyte powder obtained by pressure molding these powders, and Figure 2 shows the plastic resin. A diagram showing a solid electrolyte powder and an electrode material powder whose surfaces are covered with , and an aggregate of the electrode material powder and solid electrolyte powder obtained by pressure-molding these powders. , FIG. 3 is a diagram showing a part of a cross section of a solid electrolyte element composed of a solid electrolyte molded body B and electrode material molded bodies A and C. 1... Solid electrolyte powder, 2... Electrode material powder, 3... Plastic resin.

Claims (9)

[Claims] (1) A molded body of solid electrolyte particles coated with a plastic resin and an electrode material molded body are disposed on each of a pair of opposing surfaces of the solid electrolyte particle molded body, and the opposed surface of the solid electrolyte particle molded body is disposed. Solid electrochemistry, characterized in that an ionic conductive path is formed by substantial contact between the solid electrolyte particles, and the other surface of the solid electrolyte particle molded body is coated with the plastic resin. element. (2) The solid electrochemical device according to claim 1, wherein the electrode material molded body is a mixture of electrode material particles and solid electrolyte particles. (3) The solid electrochemistry according to claim 1 or 2, wherein at least one of the electrode material particles and the solid electrolyte particles of the electrode material molded body is coated with a plastic resin. element. (4) The solid electrochemical device according to claim 1, wherein the solid electrolyte particles are monovalent cation conductive solid electrolyte particles. (5) The plastic resin is a thermoplastic resin selected from polyethylene, polypropylene, styrene-butadiene rubber, synthetic rubber such as neoprene rubber, silicone resin, acrylic resin, or a mixture thereof. The solid electrochemical device according to item 1. (6) Electrode material particles and solid electrolyte particles are dispersed together or separately in a solvent containing a plastic resin, a plastic resin layer is formed on the particle surface, and a solid electrolyte molded body is obtained.
A method for manufacturing a solid electrochemical device, characterized by making electrode material molded bodies and integrally molding these molded bodies. (7) The plastic resin is a thermoplastic resin selected from synthetic rubbers such as styrene-butadiene rubber and neoprene rubber, silicone resins, acrylic resins, or mixtures thereof. A method for manufacturing solid-state electrochemical devices. (8) Solid electrolyte particles and electrode material particles can be molded together on three pages or separately, and a solid electrolyte molded body and an electrode material molded body made from a mixture of plastic resin powder and granules are molded together. Characteristic manufacturing method for solid-state electrochemical devices. (9) The method for producing a solid electrochemical device according to claim 8, wherein the plastic resin powder is selected from polyethylene and polypropylene acrylic resin powder.