Hiromu Matsuda

Rectangular sealed alkaline storage battery and module battery thereof

A relatively large rectangular sealed alkaline storage battery used for electric cars, etc. is disclosed. The battery has such an inner construction as to inhibit deformation of the electrode group caused by charging and discharging so as to improve the life characteristics. The electrode group comprises positive electrode plates alternating with negative electrode plates in a planar direction and separators between the adjacent electrode plates. The electrode group and an alkali electrolyte are inserted in a container, which is sealed by a cover provided with a safety vent and the position of the electrode group in the container is controlled by fixing poles to the cover. The amount of the alkali electrolyte is 1.5-2.5 cm3/ battery capacity 1 Ah. Especially, for a module battery, a given distance is provided between the shorter side face of the electrode group and the inner wall of the container, and the outer longer side faces of the container are constrained by a metallic plate.

Surface Structure and Electrochemical Characteristics of Ti-V-Cr BCC-Type Solid Solution Alloys Sintered with NI

Ti-V-Cr bcc-type solid solution alloys can absorb a large amount of hydrogen and be applied to active materials of the negative electrode in Ni-MH batteries. However, because of the insolubility of Ni into these alloys, the electrochemical characteristics like discharge capacity and cycle life were poor. In order to increase the discharge capacity of hydrogen absorbing alloy electrodes, Ti-V-Cr bcc-type alloy powders were sintered with Ni in order to form Ni contained surface layer on the alloy surface. As sintering temperature rose up, the surface composition changed from TiNi to Ti{sub 2}Ni. TiNi surface layer showed better electrochemical characteristics. For the Ni adding method, Ni electroless plating was preferred because of good adhesion. As a result of optimized conditions, a discharge capacity of 570 mAh/g and an improvement of cycle life were achieved.