| 摘要 |
PURPOSE:To provide a battery of large capacity by specifying concentration of an alloy component element to suppress a cycle characteristic from deteriorating as a hydrogen storage alloy of rare earth-nickel. CONSTITUTION:A hydrogen storage alloy, in which dispersion of element concentration is within 200mum separating distance of the largest alloy component element and a difference between element concentrations per 2mum<3>, of two points where the element concentration adjacent to each other is maximum, in the point where the element concentration is higher, and in the point where the element concentration on a line of connecting these two points is minimum, is 3.0wt.% or less, is used. Thus by lessening segregation with a crystal grain boundary in a fine uniform composition, internal stress, generated according to expansion/contraction at the time of emitting hydrogen storage, is relaxed to prevent easy pulverization. Accordingly, when used, reaction with an electrolyte and oxygen is suppressed to prevent the alloy from being easily oxidized. |
