| abstract |
Lithium nickel suitable for a positive electrode active material for a lithium ion secondary battery having low reactivity with an electrolyte, low internal electrical resistance when used as a battery, and high resistance to molding pressure A composite oxide is provided. A composition is represented by the following general formula, Li x Ni 1-pqr Co p Al q A r O 2-y ( here, x in the formula, p, q, r, the range of values of y, 0.8 ≦ x ≦ 1.3, 0 <p ≦ 0.2, 0 <q ≦ 0.1, 0 ≦ r ≦ 0.1, −0.3 <y <0.1, A consists of Ti, V, In, Cr, Fe, Sn, Cu, Zn, Mn, Mg, Ga, Ni, Co, Zr, Bi, Ge, Nb, Ta, Be, Ca, Sr, Ba, Sc. And at least one element selected from the group) and primary particles having a single crystal and an average particle diameter of 2 to 8 μm. [Selection figure] None |