POSITIVE ELECTRODE ACTIVE MATERIAL AND NONAQUEOUS ELECTROLYTE SECONDARY CELL

A positive active material including a compound expressed by a general formula LiMM'M"O(here, M designates at least one kind of element selected from Co, Ni and Mn, M' designates at least one kind of element selected from Al, Cr, V, Fe, Cu, Zn, Sn, Ti, Mg, Sr, B, Ga, In, Si and Ge, and M" designates at least one kind of element selected from Mg, Ca, B and Ga. Further, x is designated by an expression of 0.9 ≤ x < 1, y is indicated by an expression of 0.001≤ y ≤ 0.5, z is indicated by an expression of 0 ≤ z ≤ 0.5, and m is indicated by an expression of 0.5 ≤ m) and lithium manganese oxide expressed by a general formula LiMnMaO(here, the value of s is expressed by 0.9 ≤ s, the value oft is located within a range expressed by 0.01 ≤ t ≤ 0.5, and Ma indicates one or a plurality of elements between Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge) are included, so that both a large capacity and the suppression of the rise of temperature of a battery upon overcharging operation are achieved.