Active materials for positive electrodes of rechargeable batteries and the methods of fabrication for the active materials as well as positive electrodes thereof are provided, where the active material comprises of a mixture of two components, A and B. A are compounds of lithium nickel cobalt metal oxide while B are oxides of lithium cobalt. In a preferred embodiment, a formula for the compounds of lithium nickel metal oxide, A, is LiaNi1-b-cCobMcO2 where 0.97≦a≦1.05, 0.01≦b≦0.30, 0≦c≦0.10, and M is one or more of the following: manganese, aluminum, titanium, chromium, magnesium, calcium, vanadium, iron, and zirconium. The weight ratio of A:B is between 20:80 and 80:20.