| 摘要 |
PURPOSE:To make it resistible to over charge as well as to make improvements in cycle life by using manganese dioxide for a positive electrode and a lithium occlusion alloy for a negative electrode respectively, and specifying a filling quantity of lithium and a quantity of the manganese dioxide. CONSTITUTION:In a charging state, a filling quantity of lithium in a lithium occlusion alloy of a negative electrode 6 is set to be less than 20% of weight of manganese dioxide for a positive electrode 4, and a lithium quantity is set to more than 1wt.% to the lithium occlusion alloy. With this constitution, when the manganese dioxide is discharged, battery voltage is zeroed by a potential rise in the negative electrode before it goes down to 1V to pure lithium. Consequently, even if over charge takes place, electric potential of the manganese dioxide will not come to less than 1V to the pure lithium, and such a fear that an electrolyte is decomposed and the manganese dioxide is broken is not brought to nothing. Accordingly, it is resistible to the over charge and, what is more cycle life is thus improved. |
