Aligned nickel-cobalt oxide nanosheet arrays for lithium ion battery applications

Aligned nickel-cobalt nanosheet arrays are deposited on nickel foam substrates by means of chemical bath deposition technique. The nanosheet arrays are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrochemical performances as anode materials of lithium ion batteries are investigated by galvanostatic charge-discharge cycle and cyclic voltammetry (CV) tests. The results show that the nickel-cobalt oxide film prepared from the solution in which Ni/Co = 3/1 has the best performance. Its initial charge capacity at 0.1 A g−1 is 798 mAh g−1. When cycled at higher current densities of 0.5 and 1.0 A g−1, the initial charge capacities are 570 and 500 mAh g−1, and 84% and 86% can be retained after 50 cycles, respectively. It is believed that the interconnected nanosheet-array structure and the nickel-cobalt binary composition play important roles in their electrochemical performances.