PRECURSOR, PROCESS FOR PRODUCTION OF PRECURSOR, PROCESS FOR PRODUCTION OF ACTIVE MATERIAL, AND LITHIUM ION SECONDARY BATTERY

摘要

Provided is a precursor of an active material that has a high capacity and can exhibit excellent charge-discharge cycle durability at a high voltage. The active material produced by burning the precursor in the atmosphere has a layered structure and is represented by compositional formula (1). The temperature at which the precursor is burned in the atmosphere and is converted into a compound having a layered structure is 450°C or lower. Alternatively, the endothermic peak temperature of the precursor in the differential thermal analysis of the precursor in the atmosphere is 550°C or lower when the temperature of the precursor is raised from 300°C to 800°C. LiyNiaCobMncMdOxFz (1) [In formula (1), the element M represents at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V; 1.9 = (a+b+c+d+y) = 2.1; 1.0 = y = 1.3; 0 < a = 0.3; 0 = b = 0.25; 0.3 = c = 0.7; 0 = d = 0.1; 1.9 = (x+z) = 2.0; and 0 = z = 0.15.]