PREPARATION OF ELECTROLYTIC MANGANESE-DIOXIDE AT LOW-TEMPERATURE AND ITS DISCHARGE CHARACTERISTICS AS A CATHODE MATERIAL OF LITHIUM PRIMARY-CELL

Electrolytic manganese dioxides (EMDs) formed by electrolyzing 1mol.dm (-3) MnSO4+0.5mol.dm(-3) H2SO4 solution at lower temperature(90,80,75 and 70 degrees C) than 95 degrees C for commercial electrolysis and a current density of 1.0A.dm(-2) were heated at 400 degrees C for 4h in air to be used as a cathode active material of lithium primary cell. T he discharge characteristics at 30 degrees C were almost same with eac h other, but those at -20 degrees C scattered significantly in such ma nner that the active materials made of the EMDs formed at 70 and 75 de grees C provided higher discharge voltage and larger discharge capacit y than those made of the EMDs at 80 and 90 degrees C. The discharge pe rformances were discussed on the characteristics of the EMDs and heate d EMDs determined by thermal analysis, porosimetry, and potentiometric titration.