PURPOSE: To enhance battery capacity by locating the end portions of a hydrogen absorbing alloy electrode at the innermost peripheral end and the outermost peripheral end of a group of electrodes which are spirally wound up.
CONSTITUTION: The end portions of a hydrogen absorbing alloy electrode 1 are located at the innermost peripheral end and the outermost peripheral end of a group 14 of electrodes which are spirally wound up. The hydrogen absorbing alloy electrode is thus opposite to the whole surface of a nickel oxide electrode and oxygen gas generated from the nickel oxide electrode during overcharge is promptly reduced to water by the hydrogen absorbing alloy electrode opposite to the nickel oxide electrode so that rise of pressure within the battery is restrained, and also that the nickel oxide electrode is effectively utilized. The current density of the battery is thus reduced and voltage drop caused by polarization at the discharge of large current is reduced so that the battery capacity can be enhanced.
TAKENO KAZUHIRO
HAYASHIDA HIROTAKA
TAKAHASHI HIROYUKI
SARUWATARI ICHIRO
HASEBE HIROYUKI
TOSHIBA CORP