Battery electrode substrate, and electrode employing the same

Abstract

An electrode substrate for a battery has nickel applied as a coat on the surface of a base constituted of crossing of a plurality of fibers including a core formed of synthetic resin and a coating of synthetic resin having a softening temperature lower than the softening temperature of the synthetic resin forming the core. The electrode substrate has the fibers of the base fusion-bonded at a cross point by heat treatment. The ratio of the coating occupying a II-II cross section of the fiber cross point is larger than the ratio of the coating occupying a fiber cross section (III-III cross section) at a site other than at the cross point.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an electrode substrate for a battery, and an electrode for a battery. Particularly, the present invention relates to an electrode substrate and an electrode for a battery, having high capacity maintaining rate and superior in high rate discharge property. [0003] 2. Description of Related Art [0004] Conventionally, alkaline secondary batteries as well as lead storage batteries and lithium ion batteries achieve widespread use as secondary batteries for portable applications, mobile usage, industrial usage, and the like. [0005] The alkaline secondary battery is used in various fields by virtue of its high reliability, long lifetime, and its advantage over the lithium ion battery in terms of reducing the cost, size, and weight. Particularly, from the standpoint of saving energy and promoting environmental conservation, automobile manufacturers are now adapting alkaline secondary batterie...

AI Technical Summary

Benefits of technology

[0017] In view of the foregoing, an object of the present invention is to provide an electrode substrate and an electrode for a battery, having a capacity less likely to be reduced even by repetitive charging and discharging.

Problems solved by technology

However, such a nickel electrode has not yet arrived at the stage of practical use due to various problems thereof.

At the initial stage of development, nickel foam had the problem that it was readily damaged.

For example, when a nickel electrode in sheet form was rolled up and stored in a cylindrical battery container, cracks appeared in the nickel foam.

The remaining issue is to render the nickel electrode inexpensive by reducing the amount of nickel that corresponds to most of the cost of the nickel electrode.

However, the strength of the nickel electrode will be degraded if the amount of nickel is further reduced.

Even if nickel foam can be produced, the possibility of fracture during the fabrication step of the nickel electrode or during production of the battery is extremely high.

However, the battery such as of the type disclosed in the aforementioned Japanese Patent Laying-Open No. 2005-347177 is disadvantageous in that the battery performance is readily degraded in accordance with the repetitive charging and discharging.

If the fiber cross point is modified between the state prior to compression and after compression as in this case, the three dimensional mesh structure of the electrode substrate will fracture to cause a crack in the nickel coated on the surface of the fiber and / or constriction of the pore in the electrode substrate, leading to degradation of the battery performance.

There is a possibility of the bonding of the fibers being broken in the compression stage of the electrode substrate to result in damage of the three dimensional mesh structure of the electrode substrate.

There is a possibility of the three dimensional mesh structure of the electrode substrate being damaged by this bulging of the electrode.

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