Patent ID: 6344294
Filing Date: 2002-02-05
Classification: C01G,C01P,H01M,Y02E

Abstract:
A process for producing a positive electrode active material for a nonaqueous secondary battery comprising the steps of:(a) dissolving compounds capable of providing lithium ions, nickel ions and optionally ions of at least one element selected from the group consisting of transition metals, 3B-group elements, 4B-group elements and 5B-group elements in a buffer solution containing at least lithium ions, thereby to prepare a starting aqueous solution; (b) adding oxalic acid to the starting aqueous solution to form a precipitate of oxalates of said ions and separating the precipitate; (c) calcining the resulting precipitate to produce LiNi1âˆ’xMxO2, wherein 0&lE;X<0.5 and M is at least one element selected from the group consisting of the transition metals, 3B-group elements, 4B-group elements and 5B-group elements; and (d) re-using a residual liquid after the precipitate is separated for preparing the starting aqueous solution.