Active material for battery, nonaqueous electrolyte battery, battery pack, and method for manufacturing active material for battery

A method for manufacturing an active material for battery, comprising:

• pulverizing and mixing a raw material compound containing at least one element M1 selected from the group consisting of Ti, Zr, Si, and Sn, and a raw material compound containing at least one element M2 selected from the group consisting of Nb, V, Ta, Bi, and Mo to obtain a mixture;
• sintering the mixture at 1100 to 1500° C.;
• and
• annealing the sintered product at a temperature lower than 1000° C. to obtain an active material for battery comprising a monoclinic complex oxide which is expressed by the general formula LixM1M22O(7±δ) (wherein M1 and M2 are as defined above, 0≦x≦5, and 0≦δ≦0.3), and has symmetry belonging to the space group C2/m (International tables Vol. A No. 12), one element of the M2 or M1 being maldistributed in the occupied 2a and 4i sites in a crystal of the monoclinic complex oxide.