JPH01187772A - Electrode material for battery - 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 Application Field) The invention relates to an electrode material for batteries, and in particular to a material made of carbon cloth, which can be suitably used in large capacity batteries such as Redox F17-type batteries. The present invention relates to an electrode material.

(Previous technology) Zn C12 batteries used for power storage, etc.
Large-capacity batteries such as Br2 batteries and redox flow batteries usually have single cells (as shown in the cross-sectional schematic diagram in Figure 2).
It is constructed using a large number of cells. In the cell, an electrode material 2.2 made of carbon cloth was arranged through a recess 3 for separating the anode and cathode, and conductive carbon such as conductive carbon black was contained on the outside of the picture electrode. It is constructed by combining conductive carbon plates 1.1.

(Problems to be Solved by the Invention) The electrode material 2 made of carbon cloth in the above-mentioned unit cell is usually made by weaving carbon fiber into a net or cloth shape, and it easily comes apart during assembly, as shown in FIG. As a result, the fibers become frayed from the peripheral edge, and the frayed fibers diffuse into the electrolyte and accumulate in the electrolyte flow path, blocking the flow path and potentially impairing the battery's function.

An object of the present invention is to prevent fibers from fraying at the peripheral edges of an electrode material made of carbon cloth without impairing the conductivity of the electrode material.

(Means for Solving the Problems) In order to achieve the above object, the present invention impregnates and solidifies the peripheral edge of a carbon cloth with a thermoplastic resin having a specific content. , a battery electrode material characterized in that a peripheral end of an electrode material 2 made of carbon cloth is impregnated with a chlorine-based thermoplastic resin 21 containing conductive carbon and solidified.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a cell using the electrode material of the present invention. The structure of the unit cell is the same as the conventional one shown in FIG.
is arranged, and a conductive carbon plate 1.1 is combined on the outside of the picture electrode.

As the carbon cloth used for the electrode material 2, a woven cloth of about 0.5 to 3 mm in thickness and a volume resistivity of about 10 to 10<-1>Ω, which is made by knitting ordinary charcoal and fibers, can be suitably used. In the battery electrode material of the present invention, it is necessary to impregnate and solidify the chlorine-based thermoplastic resin 21 containing conductive carbon (hereinafter referred to as "r-carbon-containing resin") in the peripheral end portion of the electrode material 2. The carbon-containing resin is solidified either locally at the peripheral end of the electrode material 2 or around the entire circumference, taking into account the ease with which the fibers fray.

The above-mentioned carbon-containing resin has a solid content of a chlorinated thermoplastic resin and conductive carbon, and a solution-type resin using a solvent is advantageous from the viewpoint of workability.

The solution type will be explained below. The above-mentioned chlorinated thermoplastic resin is used because it has excellent sweat resistance against electrolyte, and long resins include polyvinyl chloride resin, chlorinated polyethylene resin, or mixtures thereof. Examples include copolymers mainly composed of these. Further, as the conductive carbon to be used, for example, graphite, carbon black, carbon fiber, etc. are conveniently used.

Furthermore, if necessary, stabilizers and dispersants may be used as long as they do not adversely affect solvent resistance or conductivity.

The solvent used may be any solvent that dissolves the above-mentioned chlorinated thermoplastic resin.
'HF), methyl ethyl ketone (MEK), cyclohexanone, etc. can be used, and a poor solvent such as toluene, xylene, etc. may be added to adjust the drying rate of the solvent.

The concentration of solid content consisting of the above composition is 3 to 3 from the viewpoint of workability etc.
It is preferably about 20% by weight, and the amount of conductive carbon used is 15 to 50% by weight based on the solid content. ! The amount of c is good, and the volume resistivity after drying is 10-3 to 10'Ω.
It should be about rn.

Note that there are various methods for impregnating the peripheral edges of the electrode material 2 with the carbon-containing resin, such as immersing only the edges that require assimilation into a solution containing the carbon-containing resin. It can be provided by brush painting or by dropping the above solution.

The impregnated carbon-containing resin can then be solidified by volatilizing the solvent.

By using the above-mentioned carbon-containing resin, the fibers will not fray after assimilation, and since it uses a chlorine-based thermoplastic resin, it has excellent solvent resistance. Furthermore, it has excellent conductivity, so it can be used as a conductive carbon. The electrical conductivity to the plate 1 is not impaired at all.

The present invention will be explained below with reference to Examples.

(Example) Using an electrode material made of carbon cloth with a thickness of 3 mm, the following carbon-containing resin was applied to the peripheral edge.

(1) Carbon-containing resin Polyvinyl chloride resin 77
Nolcyclohexanone 400++ (2) After coating, the solvent was evaporated and the area was solidified. As a result, there was no fraying of the fibers at the ends, and when used in a single cell, there was almost no decrease in power.

(Effects of the Invention) As explained above, the electrode material of the present invention has the advantage that the fibers do not fray at the ends and does not reduce conductivity, so it can be suitably used in various large-capacity batteries. It is something.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a cell using the electrode material of the present invention;
FIG. 2 is a schematic cross-sectional view of a conventional unit cell. 2... Electrode material 21... Chlorinated thermoplastic resin containing conductive carbon Official license applicant Mitsubishi Plastics Co., Ltd. Agent Patent attorney Hisami Kondo

Claims (1)

[Claims] An electrode material for a battery, characterized in that a peripheral end portion of an electrode material (2) made of carbon cloth is impregnated with a chlorine-based thermoplastic resin (21) containing conductive carbon and solidified.