Nickel-hydrogen battery

Abstract

A nickel metal hydride storage battery which includes a positive electrode containing nickel hydroxide as a active material, a negative electrode containing a hydrogen absorbing alloy which contains aluminum, a separator and an alkaline electrolyte, wherein a complex-forming agent which forms a complex with aluminum is included in the negative electrode.

Description

technical field [0001] The invention relates to a nickel-hydrogen accumulator which has a positive electrode with nickel hydroxide as an active material, a negative electrode with a hydrogen storage alloy as an active material, a separator and an alkaline electrolyte in a battery container, and specifically relates to hydrogen storage on the negative electrode When the alloy contains aluminum, it is possible to suppress the nickel-hydrogen storage battery in which aluminum is eluted from the hydrogen storage alloy and deposited on the positive electrode due to charging and discharging. Background technique [0002] In recent years, portable devices and electric vehicles use alkaline storage batteries. Compared with nickel-cadmium storage batteries, alkaline storage batteries have higher capacity and better environmental safety, so nickel-hydrogen storage batteries using hydrogen storage alloys as negative electrodes are widely used. [0003] Here, for such a nickel-hydrogen ...

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Problems solved by technology

[0005] However, even when a complexing agent or the like that forms a complex with the metal ion eluted from the hydrogen storage alloy into the alkaline electrolyte is added to the alkaline electrolyte, it is difficult to capture the above-mentioned metal ion and form a complex, and the metal is still present. Ions are precipitated on the separator, reducing the insulation performance of the separator, and precipitated on the positive electrode, resulting in self-discharge, reducing the discharge capacity and high-efficiency discharge characteristics.

Especially when aluminum-containing hydrogen storage alloys are used, if the leached aluminum ions are precipitated on the positive electrode, there will be problems of self-discharge, reduced discharge capacity, or reduced high-efficiency discharge characteristics.

[0006] In addition, if the above-mentioned complexing agent is added to the alkaline electrolyte, the complexing agent becomes an impurity ion, and the impurity ion moves between the positive electrode and the negative electrode, etc., causing the problem of self-discharge.

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