| 摘要 |
PURPOSE:To prevent pressure from being increased by oxygen in a battery at the end of charging and the time of overcharging, by forming the first layer whose active material is a cadmium in the center of a negative electrode and the second layer comprising a hydrogen storage alloy on its surface. CONSTITUTION:The first layer 4 whose active material is Cd in a negative electrode 1 is coated with the second layer 5 made of a hydrogen storage alloy. The inner first layer may be of the same structure as that a sintered-Cd elec trode or that of a Cd electrode called as a paste type or a binder type. As for a hydrogen storage alloy used for the second layer on the surface, LaNi5 MmNi5(Mm is a misch metal) or Ni in these alloys displaced with other elements, for example one or two or more than two elements out of, for sample, Co, Al, Mn, Mg, etc., or at least one part of La, Mm out of these alloys dis placed with Ca or Mg2Ni system, TiNi system, TiMn system may be used. Therefore, an internal pressure of a battery can be extremely low even if high- rate charging is carried out. |
