| 摘要 |
PROBLEM TO BE SOLVED: To suppress an increase in internal pressure at the time of over-charge without damaging paste-coatability or strength and therefore improve a charge/ discharge cycle life, by providing a paste-type negative electrode including a conductive carbon material and a porous carbon material, each having a specific value of specific surface area. SOLUTION: A negative electrode is manufactured by coating a conductive substrate with a paste made by kneading a conductive material, a hydrogen storage alloy powder, etc., a binder, and pure water together, and then drying and roll-molding it. A conductive carbon material included in the conductive material has a specific surface area of 1000 m2/g or more, and suppresses a fall in the reactivity of the hydrogen storage alloy and a fall in the binding action of the binder. The porous carbon material together included therein has a specific surface area of 2000 to 3400 m2/g, and effectively absorbs hydrogen gas generated in a container at the time of charging without lowering the binding action of the binder. It is suitable to adapt the conductive carbon material to be 0.1 to 2.0 pts.wt., the porous carbon material to be 0.3 to 3.0 pts.wt. and the total of the two to be 0.4 to 4.0 pts.wt., per 100 pts.wt. of the hydrogen storage alloy. |
