| 摘要 |
PURPOSE:To obtain the positive electrode active material of a high energy density by using lithium cobalite having the composition, in which free cobalt oxide is restricted a specified value or less. CONSTITUTION:Mixture of lithium carbonate and cobalt oxide is burned at 600-1000 deg.C by controlling the oxygen density in the burning atmosphere at 5 capacity 8 or more and setting the temperature rising speed in the condition at 500 deg.C or more of heating temperature at 5 deg.C/min. LiCoO2 having the composition, in which free Co3O4 is restricted at 0.5% by weight or less, is thereby obtained. This LiCoO2 is used for the positive electrode active material, and in a secondary battery formed of a positive electrode 3, a negative electrode 2 made of metal lithium, a separator 1 and the electrolyte 7, discharging capacity and the capacity preservation factor are improved. |
