| 摘要 |
PURPOSE:To provide an excellent discharging characteristic, by using a positive electrode active material made from water-washed or neutralized electrolytic manganese dioxide mixed and treated with water solution of manganic salt or the like. CONSTITUTION:Electrolytic manganese dioxide washed in water or neutralized with an alkaline water solution of sodium or ammonia is mixed and treated with a solution of manganic salt in water or a mixture of manganese hydroxide and water, and thus the positive electrode active material is provided. As the manganic salt, chloride, nitrate, or sulfate, for example, is usable. As the result, protons, sodium ions, or ammonium ions on the surface of the manganese dioxide are replaced with bivalent manganese ions, whereby the intersection of the two straight lines represented the relationship between the potential on the manganese dioxide and the PH value is shifted toward the acidic side and therefore the potential variation per PH is kept low in a wider range of PH values. Thus, the excellent discharging characteristic can be provided, that is, the voltage drop of the cell during its discharging is suppressed and, in particular, the increase in the impedance in and after the middle period of the discharging is made practically negligible. |
