LITHIUM-CONTAINING COMPOUND OXIDE FOR LITHIUM ION SECONDARY BATTERY AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To restrict the decrease of electric capacity and improve cycle property by coprecipitating at least two types of hydroxide containing cobalt with nickel hydroxide in a reaction tank and additionally coprecipitating other hydroxide than cobalt therewith. SOLUTION: A reaction tank is used to supply nickel-cobalt-M salt water solution with the controlled concentration of salt, complexing agent to form complex salt with the water solution and alkali metal hydroxide in succession. Nickel-cobalt-M complex salt is produced and then decomposed with alkali metal hydroxide to precipitate nickel-cobalt-M hydroxide. The production and decomposition of the complex salt circulated in the tank are repeated to overflow and pick up the nickel-cobalt-M hydroxide. At this time, the concentration of salt in the reaction tank is kept at 50-200mS/cm, pH is at 11.0-13.0±0.05 and a temperature is at 20-80±0.5 deg.C. In this way, initial capacity is increased and the decrease of electric capacity with the repetition of charge and discharge is restricted.