PROCESS FOR PRODUCING POSITIVE-ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY CELL

摘要

A process for producing a lithium/cobalt composite oxide for positive electrodes for lithium secondary cells from cobalt hydroxide and lithium carbonate, which are inexpensive. The lithium/cobalt composite oxide produced is excellent in volume density, safety, durability in charge/discharge cycling, density after pressing, and productivity. A mixture obtained by mixing a cobalt hydroxide powder with a lithium carbonate powder in such a proportion so as to result in a lithium/cobalt atomic ratio of from 0.98 to 1.01 is burned at 250 to 700°C in an oxygenic atmosphere. The product of burning is further burned at 850 to 1,050°C in an oxygenic atmosphere, or is heated at a rate of 4 °C/min or less with respect to heating from 250 to 600°C and then burned at 850 to 1,050°C in an oxygenic atmosphere.