The positively active matter Ni(OH)2.05 for Ni-based rechargeable alkaline batteries was prepared through a simple route of chemical oxidation, and its electrochemical performance was investigated. Results illuminate that the simulant Ni/MH battery with the above treated sample as positively active matter shows considerable electrochemical performance with a discharge capacity of 281 mAh•g－1 under 0.2 C and a capacity maintenance of 98% after 270 cycles under 1 C. Cyclic voltammograms indicate a faster diffusion rate as well as a better electrochemical reversibility for the modified electrode than that of the aboriginal one. Besides, a lower charge-transfer resistance for the modified electrode was detected by impedance spectrum. The charge/discharge tests under different cut voltage indicate that the modified electrode shows an unconspicuous second discharge plateau compared with the untreated one, which results in a comparable capacity between the modified electrode at the first discharge plateau and the primary electrode at a deeper cut voltage.

Key words: Ni(OH)2.05, second discharge plateau, Ni/MH battery, electrochemical performance