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-ra...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 quasi-spherical 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 dis-charge 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.展开更多
基金Project supported by the National Natural Science Foundation of China (10774030)College Students' Experimental Innovation Projects of Guangdong (1184510153)+1 种基金the Science and Technology Program of Guangzhou City of China (2008J1-C161)the Major Projects on Education and Teaching of Guangdong University of Technology (2010Z015)
文摘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 quasi-spherical 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 dis-charge 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.
