| 摘要 |
PURPOSE:To obtain a lithium manganese dioxide dry cells with high power generating efficiency by using as the positive electrode active material, a highly qualified, chemically synthesized, and manganese dioxide treated material including rho-MnO2 obtained by a specific manufacturing method. CONSTITUTION:A dry cell is assembled by using only a highly qualified, chemically synthesized, and dehydrated material as the positive electrode active material. The manganese dioxide used is manufactured by the following method. A manganese dioxide of 88% or more in MnO2 content obtained by oxidizing MnCO3 is added with a necessary quantity of manganese carbonate or manganese sulfate. The resulted product is further added with a necessary quantity of chlorate and sulfuric acid to cause reaction by keeping the sulfuric acid concentration to 1 normal or more at 50 deg.C or less to synthesize manganese dioxide containing rho-MnO2 in 15-20% of the whole MnO2. The resulted manganese dioxide is heat-dehydrated in the atmosphere of oxygen or air at 360-400 deg.C. Such active material can be easily and inexpensively manufactured and yet can increase the discharge efficiency of the dry cell. |
