Effect of interlayer anions on the electrochemical performance of Al-substituted α-type nickel hydroxide electrodes

Al-substituted α  -type nickel hydroxides with different interlayer anions (NO3− or SO42−) have been synthesized by chemical coprecipitation method. The microstructure and morphology of the prepared samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscope (SEM). The effect of interlayer anions on the electrochemical performance of the prepared nickel hydroxides were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge tests. The results demonstrated that the Al-substituted α  -type nickel hydroxide with interlayer NO3− has better electrochemical performance, such as better reaction reversibility, higher proton diffuse coefficient, lower electrochemical impedance, higher specific capacity, and better cyclic stability, than that of the Al-substituted α  -type nickel hydroxide with interlayer SO42−.