Electrochemical element electrode and battery using such electrode

Abstract

An electrode according to the present invention employs the metal plate having the specified structure as the electrode substrate. The metal plate has a plurality of protuberances that are alternately protruded on both front and back sides thereof. Each of the protuberances is formed in a pyramid shape in which an area of upper bottom (a protruded part) thereof is smaller than that of a lower bottom. The upper bottom in each of the protuberances is formed with an aperture having blanking burr blinked in a substantially pyramid shape along a direction from the upper bottom to the lower bottom so that an opening of the upper bottom part is formed in a polygon shape. Further, the size of each portions is set in accordance with c>s>=0.1 mm<2 >and 0.2<=h / d<=0.95 where c is the area of the upper bottom of each of the protuberances, s is the area of the opening of the upper bottom parts, h is the height of the blanking burrs is h, and d is the total thickness of the electrode substrate before compressing.

Description

technical field [0001] The present invention relates to an electrode that can be used for electrochemical elements such as batteries and capacitors, and a battery using the electrode. technical background [0002] In electrochemical devices such as batteries and capacitors, various researches are continuing to achieve cost reduction. For example, in alkaline storage batteries that use nickel hydroxide, one of the nickel oxides, as the positive electrode, it is widely used to disperse nickel hydroxide together with binders and tackifiers in water or solvents to form a paste. , and then coated and filled with non-sintered nickel electrodes on conductive porous substrates such as foamed nickel. In addition, polytetrafluoroethylene (PTFE) is usually used as a binder in a non-sintered nickel electrode using the above-mentioned porous substrate. In the battery, since the nickel electrode is overcharged in the alkaline solution and is in an oxygen atmosphere, the binder must be a...

AI Technical Summary

Problems solved by technology

Therefore, during the process of pressing, cutting, etc., the phenomenon of slipping from the base material of the positive electrode mixture will occur, which will easily cause peeling and falling off.

In addition, when charging and discharging the battery, due to the repeated expansion and contraction of the active material, the positive electrode mixture is also easily peeled off from the substrate, which not only increases the contact resistance with the substrate and makes charging difficult, but also increases the generation of oxygen during charging.

As a result, sufficient discharge capacity cannot be obtained, and cycle degradation is caused prematurely

In order to solve such problems, various researches have been carried out on other adhesives, but the good properties obtained have not been put into practical use so far.

[0006] In addition, compared with existing porous substrates, when using the above-mentioned substrates, there is also the problem that its current collection performance is poor, and the utilization rate of the positive electrode cannot be improved.

[0007] In addition, since the surface of the substrate needs to be processed, there will be a problem that the scraper is caught during continuous coating, causing the substrate to break, or the problem that it cannot be coated uniformly, and a part of the substrate is exposed on the surface of the formed electrode. causing short circuit problems

In addition, in order to avoid such a problem, when the gap distance of the squeegee is increased, the problem that the center of the substrate is not easily exposed will cause the problem that both sides cannot be uniformly coated, and the amount of active material detached from the substrate will increase, causing the accumulation The problem of reduced utilization due to power difficulties

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