POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, METHOD FOR PRODUCING SAME, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

Provided are: a positive electrode active material for nonaqueous electrolyte secondary batteries, which has a good balance between thermal stability and charge/discharge capacity at high levels, while having excellent cycle characteristics; a simple and safe production method for this positive electrode active material for nonaqueous electrolyte secondary batteries; and a nonaqueous electrolyte secondary battery which uses this positive electrode active material. A method for producing a positive electrode active material for nonaqueous electrolyte secondary batteries, which is characterized by comprising: a crystallization step for obtaining a nickel-containing hydroxide represented by general formula Ni1-a'-b'Coa'Mb'(OH)2 by adding, for crystallization, an aqueous alkaline solution to a mixed aqueous solution containing at least nickel and cobalt; a mixing step for obtaining a lithium mixture by mixing the thus-obtained nickel-containing hydroxide with a lithium compound and a niobium compound; and a firing step for obtaining a lithium-transition metal composite oxide by firing the lithium mixture in an oxidizing atmosphere at 700-840°C.