Multiphase nano-Ni(OH)2 doped with Y or La was prepared by supersonic co-precipitation method.The crystal morphology,structure and particle size were characterized by transmission electron microscopy (TEM),X-ray diffraction (XRD) and particle size distribution (PSD).The electrochemical performance of samples was investigated by electrochemical workstation and battery tested system.The results indicated that micro-morphology and grain size were changed with the changing of supersonic power,pH values and doping elements.The morphology of Y doped sample was from the flake-like to the needle-like with the increase of supersonic power; Particles were from quasispherical particles into needle-like with the increase of pH values; As the supersonic power increased,the proportion of α-Ni(OH)2 increased initially and then decreased.pH value was very important to the formation of crystalline phase.Lower pH value was beneficial to the formation of α-Ni(OH)2.However,the pH values had a slight effect on the reaction reversibility.Complex electrodes were prepared by mixing 8 wt.％ nickel hydroxides with commercial micro-size spherical nickel.The discharge capacity of electrodes increased initially and then decreased with the increase of supersonic power.When the supersonic power was 60 W and the pH value was 9,the sample had the largest discharge capacity (358 mAh/g) at 0.5 C rate,which was 122.7 and 76 mAh/g higher than the spherical nickel electrode and La doped sample electrode,respectively.