| 摘要 |
PROBLEM TO BE SOLVED: To improve the charge and discharge cycle characteristic in the temperature condition, which exceeds room temperature, by specifying percentage content of alkali metal carbonate in the positive electrode mix. SOLUTION: Content of alkali metal carbonate in the positive electrode mix is set at 0.5-20wt.% with dry weight conversion. As an alkali metal carbonate, lithium carbonate and sodium carbonate can be used. Carbonate salt is used as one of positive electrode component because this carbonate salt selectively reacts with a trace quantity of acidic impurities, which exists in the non- aqueous electrolyte, and the material, which is generated in the electrolyte at the time of charge and discharge, so as to restrict the deterioration of the positive electrode active material due to the reaction of the positive electrode active material with the impurities. As a positive electrode active material of the positive electrode mix, manganese oxide or manganese compound oxide is used, and practically, manganese dioxide and a material having the spinel type crystal structure is used. |
