This paper reports the study results on R and D of nickel-hydride storage battery for photovoltaic generation systems in fiscal 1994. (1) On the study on low-cost electrode materials, the physical properties and electrode characteristics were studied of the prototype hydrogen absorbing alloys prepared by substituting Cu or Ni for Co in Mm(Ni-Co-Mn-Al)5 (Mm: mixture of rare earth elements). The result clarified that it is difficult to reduce Co content in the alloy to 0.4 atom or less. Simple heat treatment and milling processes in production of hydrogen absorbing alloy electrodes were achieved by adopting an improved metal mold and gas atomization method. Characteristics and cycle life of the Ni positive electrode prepared by applying active paste material of Ni(OH)2 were studied, however, the result showed only lives of nearly 300 cycles. (2) On the study on electrode structure for high-performance (long-life) battery, the 3-D porous metal electrode support was evaluated, and various battery configurations were studied. 11 figs., 1 tab.
Tatsuta, M 
- New Energy and Industrial Technology Development Organization, Tokyo (Japan)