Abstract: The secondary nickel-metal hydride (Ni/MH) batteries were developed and their performance was investigated, of which the active material of positive electrodes were made from commercial Ni(OH)2 spherical powder doped with NiOOH that was proportionately synthesized via oxidation. Constant current charge/discharge and AC internal impedance were tested to characterize the electrochemical performance of AA-type cylindrical alkaline Ni/MH batteries with rated capacity 1.5 Ah. The experimental results showed that the Ni/MH batteries developed exhibit better performances in activation efficiency and cycle life than the conventional ones because of their higher reaction activity and lower electrochemical impedance to NiOOH. It was proved that when the content of the dopant NiOOH was 1%-3% in the active material for nickel positive electrode, the electrochemical performance of the batteries can further be improved. Otherwise, overdoping of NiOOH will decrease the discharge capacity of the batteries.