| 摘要 |
PURPOSE:To provide an electrode excellent in high-rate discharge characteristic at a charge/discharge cycle initial stage in particular and moreover providing stable voltage at the time of discharge, by composing the electrode of hydrogen storage alloy of nonstoichiometric composition, to which annealing treatment is applied, and a conductive core body. CONSTITUTION:In the structure of an hydrogen storage alloy of nonstoichiometric composition, to which annealing treatment is not applied. A rich phases or B rich phases are scattered in a relatively wide range. On the other hand, the applying of annealing treatment causes the local concentration of the A or B rich phases to produce cracks. Applying of charge/discharge to this alloy causes the expansion and contraction of the alloy due to the storage release of hydrogen to produce cracks due to stress along each phase. This surface is in contact with an electrolyte to conspicuously increase an electrode reaction speed. It is preferable to set annealing treatment temperature at 700-1150 deg.C because a voltage effect following the increase of discharge current of an electrode, can be restrained. |
