Electrochemical Performance of Ni(OH)2 Positive Materials

Five kinds of Ni(OH)2 positive materials with different chemical compositions were prepared by a chemical coprecipitation method. The compounds with Co, Zn, Ca, Mg, Cu or Mn elements were mixed with nickel sulfate and reacted with each other at a special temperature and pH value under stirring. The XRD analysis indicates that the microstructure of as-prepared materials is β-Ni(OH)2. SEM images show the particles are spherical with a little rough surface. The electrochemical results indicate that the Ni(OH)2 B has the best performances at different rates and temperatures. The discharge capacities for Ni(OH)2 B sample can achieve more than 285 mAh·g−1 at 1 C/3 C rate both at 25 and 65 °C. The experiment shows that the Ni(OH)2 positive materials with perfect properties can be synthesized by coprecipitating other elements, which is helpful for the improvement of Ni-MH batteries.