Lithium-containing composite oxide and its production process

Claim 1

A process for producing a lithium-containing composite oxide represented by the formula Li p N x M y O z F a , where N is at least one element selected from the group consisting of Co, Mn and Ni, M is at least one element selected from the group consisting of Al, alkaline earth metal elements and transition metal elements other than Co, Mn and Ni, 0.9≦p≦1.2, 0.95≦x<2.00, 0<y≦0.05, 1.9≦z≦4.2 and 0≦a≦0.05, the process comprising a step 1 of mixing a lithium source, an N element source, an M element source containing at least Al, and if necessary, a fluorine source, and firing the mixture in an oxygen-containing atmosphere at from 700 to 1,100° C. to obtain a fired powder; and a step 2 of mixing the fired powder obtained in step 1, an M element salt aqueous solution containing at least Zr and/or Ti, and if necessary, a fluorine source, and firing the mixture in an oxygen-containing atmosphere at from 300 to 1,100° C. to produce the lithium-containing composite oxide, wherein the amount of Zr and/or Ti contained in the lithium-containing composite oxide powder obtained in step 2 is from 0.1 to 30 weight % based on the M elements.