POSITIVE ACTIVE MATERIAL, POSITIVE ELECTRODE, NONAQUEOUS ELECTROLYTE ENERGY STORAGE DEVICE, METHOD OF PRODUCING POSITIVE ACTIVE MATERIAL, AND METHOD OF PRODUCING NONAQUEOUS ELECTROLYTE ENERGY STORAGE DEVICE

One aspect of the present invention is a positive active material containing an oxide containing lithium and a transition metal element M, in which the transition metal element M is cobalt, iron, copper, manganese, nickel, chromium, or a combination thereof, and in an X-ray diffraction pattern of the oxide, a ratio (Ia/Ib) of peak intensity Ia appearing in a range where 2θ is 20 to 25° and peak intensity Ib appearing in a range where 2θ is 30 to 35° is 0.2 or more and 0.8 or less.