Synthesis and electrochemical performance of α-nickel hydroxide codoped with Al3+ and Ca2+

Abstract

α-Nickel hydroxide codoped with Al3+ and Ca2+ was prepared by chemical coprecipitation method. The phase structure and surface morphology of the prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrochemical performances of the prepared samples were analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge tests. XRD and SEM tests reveal that the Al3+/Ca2+ codoped α-nickel hydroxide has a relatively good crystallization and a very coarse surface. Electrochemical tests show that the Al3+/Ca2+ codoped α-nickel hydroxide has higher proton diffusion coefficient, lower electrochemical reaction resistance, and higher discharge capacity (395.3 mAh g−1 at 0.2 C) than the Al3+ singly doped α-nickel hydroxide, which indicates its potential application as an electrode material for secondary alkaline batteries.