Y(OH)3-coated Ni(OH)2 tube as the positive-electrode materials of alkaline rechargeable batteries

Y(OH)3-coated Ni(OH)2 tubes with mesoscale dimensions were synthesized by a two-step chemical precipitation method under ambient conditions. The products were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) equipped with energy dispersive spectroscopy (EDS). The instrumental analyses showed that the size of the tubes was of mesoscale dimension and the proportion of the tube morphology was about 95%. The as-prepared Y(OH)3-coated Ni(OH)2 tubes were further used as the active material of alkaline rechargeable batteries. The electrochemical studies revealed that the composite tubes exhibited superior electrode performance such as high discharge capacity, good redox reversibility and excellent charge–discharge properties at high-temperature and high-discharge rate. The reason for the working mechanism is also discussed, showing that the tube hollow structure plays important roles in optimizing the performance of the Y(OH)3-coated Ni(OH)2 tube electrodes.