PRECURSOR, METHOD FOR MANUFACTURING PRECURSOR, POSITIVE ELECTRODE MATERIAL, METHOD FOR MANUFACTURING POSITIVE ELECTRODE MATERIAL, AND LITHIUM-ION SECONDARY CELL

Provided are a precursor of a positive electrode material with which it is possible to obtain a lithium-ion secondary cell having an excellent discharge capacity and cycle characteristics, and a method for manufacturing the precursor. The precursor is a precursor of a positive electrode material used for a lithium-ion secondary cell, wherein the precursor is at least one substance selected from the group consisting of nickel-manganese composite hydroxides and nickel-manganese composite oxides, the precursor contains nickel and manganese, the ratio of the nickel content relative to the nickel content and the manganese content is 0.45-0.60 inclusive in molar ratio, and the average valence of manganese is below 4.0. 本发明提供可以得到放电容量和循环特性优良的锂离子二次电池的正极材料的前体及其制造方法。所述前体是锂离子二次电池中使用的正极材料的前体，其中，所述前体为选自由镍锰复合氢氧化物和镍锰复合氧化物组成的组中的至少一种，含有镍和锰，镍含量相对于镍含量与锰含量的合计的比以摩尔比计为0.45以上且0.60以下，锰的平均价数小于4.0。