METHOD FOR PRODUCING LITHIUM-CONTAINING COMPLEX OXIDE FOR POSITIVE ELECTRODE OF LITHIUM SECONDARY BATTERY

摘要

It is aimed to provide a positive electrode active material for lithium secondary batteries which has high volumetric capacity, high safety, excellent uniform coating properties while being excellent in charge/discharge cycle durability and low-temperature characteristics even at high charging voltages. Specifically disclosed is a method for producing a lithium-containing complex oxide represented by the general formula: LipNxMyOzFa (wherein N represents at least one element selected from the group consisting of Co, Mn and Ni; M represents at least one element selected from the group consisting of transition metal elements other than the element N, Sn, Zn, Al and alkaline earth metal elements; and 0.9 <= p <= 1.1, 0.97 <= x < 1.00, 0 < y <= 0.03, 1.9 <= z <= 2.1, x + y = 1, 0 <= a <= 0.02). In this method, there are used an element M source, a carboxylic acid having at least a carboxylic acid group in a molecule wherein the number of the carboxylic acid groups or the total number of the carboxylic acid groups and the hydroxyl groups is not less than 2, an element N source powder having an average particle size (D50) of 2-20 mum, a lithium source powder, and if necessary a fluorine source. An aqueous solution of the element M salt of carboxylic acid is produced from at least the element M source and the carboxylic acid, and the element N source powder is impregnated with the aqueous solution of the element M salt. The thus-prepared dry mixed powder is fired in an oxygen-containing atmosphere at 700-1050˚C.