Electrochemical Performance of Multiphase Ni(OH)_2 Added with NiOOH

Micron-size multiphase nickel hydroxides with nanosheets structure were synthesized by coordination homogeneous precipitation method.Chemically oxidized NiOOH nanoparticles were added subsequently in order to improve their electrochemical performance.The samples were characterized by XRD and SEM.The results show that the NiOOH particles with flake-like morphology are dispersed randomly on the surface of the multiphase Ni(OH)2.The simulated Ni/MH battery with the multiphase Ni(OH)2 as positive active material has the discharge capacity of 306 mAh/g at 0.2C charge/discharge rate.The existence of chemically oxidized NiOOH in the nickel electrode exert great effect on the improvement of electrochemical performance.The discharge capacity of the sample added with 7 wt% NiOOH reaches 326 mAh/g at 0.2C and 311mAh/g at 2C.