JPS60127664A - Plastic electrode - Google Patents

Abstract

PURPOSE:To provide a plastic electrode with a barrier function by orientating the directions of graphite layers in parallel to the sheet face by means of extrusion-forming a mixed compound of plastic material, carbon black, and graphite. CONSTITUTION:Carbon black and graphite are mixed with the prescribed plastic material. For graphite, the one whose grain diameter is approximately 100- 20mum is used. This mixed compound is extrusion-molded to form a sheet-like plastic electrode. Through this extrusion-molding, the directions of graphite layers are orderly orientated in parallel to the sheet face. This plastic electrode has a function as a barrier against the permeability of an active material without causing any degradation of the conductive characteristics. Therefore, when it is used for a bromine-zinc battery, it can maintain a stable performance for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a plastic electrode that is imparted with electrical conductivity without containing metal in its components.

[Prior art]

In recent years, the field of use of plastic materials in home appliances, computers, and other parts has been rapidly expanding.

General plastic electrocardiographic materials include those used as so-called plastic moldings, as well as synthetic resin paints, and are made by dispersing very fine metal powders (usually silver, copper, or aluminum) into plastic. It is known that carbon fibers are made by dispersing fine powder such as carbon. However, since these materials simply disperse the conductive material as described above, if the uniformity of the dispersion cannot be maintained, the conductivity 1. Not only does the rate vary, but there are limits to the conductivity itself. For example, dispersing metal powder ^
1 combined ψ heavy paint 104~i Q5Ω1・crn-
Some materials exhibiting a conductivity rate of 1 are known, but they are naturally limited in the area around which they can be used as conductive materials.

Recently, a number of attempts have been reported to obtain conductive and sexual materials by reacting various dopants with polyacetylene, polypyrrole, or polybaraphenylene sulfide, but the devices are complicated and Many problems remain, such as poor performance and unstable characteristics.

Considering the busy use of glass conductive materials, especially as N electrodes, batteries using metal-halogen as active materials have been attracting attention in recent years, which have been extensively developed from the viewpoint of effective energy utilization.

For example, as an example of a battery using a metal-halogen as an active material, FIG. 1 is an exploded perspective view showing the stacked structure of a metal-halogen electrolyte circulating type stacked secondary battery. In Figure 1, each electrode 1
As shown in the figure, the separators 2 are stacked and sandwiched from both sides by aluminum fastening end plates 11, and the whole is integrally constructed with a fastening bolt 12 and a fastening nut 16. Electrolyte flows from manifold 14 to channel 15 and microchannel 19
It is supplied to the surface of the electrode part through the trap, and is circulated by a circulation device (not shown). 16 is a resin fastening end plate, 17 is an electrode end plate, and 18 is a terminal composed of a metal net.

A monovalent alkali metal such as Lb Na is used as the metal in a battery using the above-mentioned metal-halogen as an active material.

K or divalent metal Zn* Cdt NL Cot Fe
etc. is also CJ as a halogen! , Brt I, etc., and both non-aqueous solutions and aqueous solutions are used as electrolytes. In addition, carbon plastic electrodes have excellent moldability and can be easily made into various shapes as electrodes for batteries that use the metal-halogen as the active material, and have the following advantages: 1. Good halogen resistance and can be manufactured at low cost. It has been used because it is preferable to have it. However, conventional carbon plastic batteries have the disadvantage that when used for a long period of time, rogens diffuse from one side of the electrode through the electrode plate and self-discharge, causing the cell to lose its function as a battery.

That is, when halogen passes through the electrode, b) The outer battery case that makes up the battery corrodes.

(1) The energy efficiency of the battery decreases in proportion to the amount of halogen used; (3) Bipolar batteries in particular self-discharge due to the penetration of halogen; (4) Diffusion of halogen into the electrodes causes the electrodes to deteriorate; The current situation is that there are many problems that need to be resolved.

[Purpose of the invention]

The present invention provides a plastic material containing a material that acts as a barrier to the permeability of an active material without causing a decrease in conductive properties in the plastic electrode.
The purpose is to provide a pole.

[Summary of the invention]

In the present invention, when forming an electrode from a mixture containing a plastic material, carbon black, and graphite, the layer direction of the graphite is aligned parallel to the surface of the plastic sheet by extrusion molding a mixture of the above-mentioned components. The present invention relates to a plastic double weld characterized in that it is oriented toward the surface of the plastic.

Plastic materials targeted by the present invention can be substituted with phenol, urea, melamine, epoxy, alkyd, etc.
thermoplastic resins from the group such as ff4i thermoplastic resins, polyolefins, polyethylene, PMMA, polyvinyl acetate, PVA, polyvinyldene chloride, nylon, synthetic resin paints containing these synthetic resins, SBR, butadiene rubber, isoprene Rubber, EP rubber, NBR,
Contains synthetic rubber such as urethane rubber, silicone rubber, and various synthetic fibers.

Carbon black may be any commercially available carbon black, but it is preferable to use a conductive or super-tetraconductive type carbon black.

The grain size (long length in the layer direction) of graphite is ','
A material with a thickness of 100 to 20 μm is used. If it is longer than this, problems tend to occur in terms of processability (flow characteristics of the molding material), uniform dispersibility, etc. during extrusion molding, and if it is too small, it becomes difficult to exhibit a sufficient barrier effect.

The amount of graphite used is 10% compared to the plastic material when combined with the carbon blank.
It is preferable that the ratio be 0:150 to 100:10 (military/ratio), and for graphite alone, it is preferable that the number of layers is at least 15 on the plastic base side.

A mixed compound that satisfies the above conditions is molded into a plastic electrode by extrusion molding.

Press molding or calender molding are common methods for molding, but these methods do not require the use of a plastic electrode (h electrode) intended for the present invention, that is, a plastic material with a barrier function against penetration of the active material. You can't get a box bar.

By using extrusion as a molding method, and by meeting specific conditions in the blended mixture and using hard graphite, the layer direction of the graphite is oriented parallel to the sheet surface with good regularity. This makes it possible to form a glass that prevents the diffusion of host substances.

[Embodiments of the invention]

Implementation fj01-6 Comparative example (11-(3) Density 0.96
6'/cms r MF'Rb, 6/ml. The indicated amount of each compound was added to 100 parts by weight of density polyethylene (II (DPE)), kneaded, and formed into a sheet according to each indicated forming method. Using a bromine diffusion measuring device, bromine expansion H'1M was added for n.

The carbon blacks (CB (!: abbreviation) used were 1 (GP-44 (manufactured by Jusumi Aluminum) and G-200 Under (manufactured by Tokai Carbon)).

Further, as a comparative example, the results of measuring the amount of bromine diffusion, which is an active material, obtained by calender molding and press molding under the same conditions are shown in Section 4-1 together with the results of Examples.

*For the degree of orientation of 1, 2 and 6, refer to the electronic tax collection photo shown as a reference photo. Mix cylinder temperature 200℃, 150℃
rpm extruder (Ikegai Iron Works, P CM 6 b
+ 3.5 W mψ (1 nozzle die) 20
Obtain a beret with a capacity of kg/h.

Sheet forming conditions: 2) The pellet obtained by the above method was placed in a cylinder at a temperature of 200°C and a screw rotation of 150r pl'1.
A sheet with a width of 300 mm and a thickness of 1 type was prepared using a No. 1 extruder (PCM-65) at an extrusion rate of 20 kg/h at a linear velocity of 50/feed.

In addition, Example 2. The one used in step 5 is extrusion x6o"yh among the pellet creation conditions, and sheet extrusion condition is 20
kg/h.

Comparative Example 1: 6 (J
Two rolls (16" wide x 48" long) at 150°C after 6 minutes at rprn and 12 minutes at 90 rpm.
Knead further with a calendar molding machine (made by Nippon Roll, reverse L).
width 3 under molding conditions of 150℃ and 6 seams using
A sheet with a thickness of 0.00 mm and a thickness of 1 shrinkage is prepared.

Comparative Examples 2 and 6: The crosstalk conditions using the pressure kneader were the same as in Comparative Example 1. Put the kneaded mixture into the heating press 1
After preheating at 50 to 170℃ for 5 minutes,
l Apply pressure to the bow and press for 5 minutes to form a sheet with a thickness of 1 cavity.

11 Fixed pupil for bromine diffusion: The basic configuration is roughly U-shaped as shown in Fig. 2, and in the middle part, sheet 1 of the sample shown in the enlarged view in No. 6 1 is placed. The sides of the pot are covered with glass that has an opening in the medium heat part, but the opening is exposed with a U-shaped tube connection, and one tube has a 3""J
'ZnBrz + 6mob, Bri's mixed solution 25 Biao, 9oVs on 5 sides of Xian is 3 4 ZnBr
It accommodates z 2'5-.

[Effect of invention]

It has been found that the plastic electrode obtained according to the present invention has extremely good barrier properties against bromine diffusion, as seen in the bromine diffusion behavior in Figure 4, and when used in a bromine-zinc battery, it has a long lifespan. It is possible to maintain stable performance over a period of time.

[Brief explanation of drawings]

Figure 1 is an exploded perspective view showing the stacked structure of a metal-halogen electrolyte circulation type stacked secondary battery, Figure 2 is a cross-sectional view of the bromine diffusion measuring device, and Figure 6 is an enlarged view of the sample holding part of the bromine diffusion device. The cross-sectional view and FIG. 4 are graphs. 1... Electrode, 2... Separator, 17: Electrode end plate,
21...Measurement sample. Agent Patent Attorney Sanro Kimura 2nd rI! J Figure 3 Figure 4

Claims (6)

[Claims] (1) When forming an electrode from a mixture containing a plastic material, carbon black, and graphite, the layer direction of the graphite is oriented parallel to the surface of the plastic sheet by extrusion molding a mixture of the above-mentioned components. A plastic electrode featuring: (2) The plastic electrode according to claim 1, in which a polyolefin resin, a fluorine resin, or both are used as the plastic material. (3) The weight ratio of carbon blank and graphite to the glass material is 100:15.
The plastic electrode according to claim 1, wherein the ratio is 0 to 100:10. (4) The plastic electrode according to claim 1, wherein the amount of graphite blended in the glass material is at least 15% by weight. (5) The glass electrode according to claim 1, which uses graphite having an average maximum length in the layer direction of 100 to 100 μm and an aspect ratio of approximately 10 to 6 U. (6) The plastic electrode according to claim 1, which is used in a stone loading device that performs an air chemical reaction. (Plastic electrode according to claim 1 for use in a metal-halogen battery.