The electrochemical behavior of Ni–MH battery, Ni(OH)2 electrode and metal hydride electrode

In the past years, the nickel–metal hydride rechargeable battery is already been widely used in many application fields, and is now replacing the nickel–cadmium battery. Electrochemical impedance spectroscopy technique is extensively used to reveal the electrode process kinetics, for example, Pb–H2SO4 battery, Ni–Cd battery. There are few reports on the EIS of Ni–MH battery. In this paper, an extensive study is focused on the electrochemical impedance spectroscopy of metal hydride electrode, β–Ni(OH)2 electrode and Ni–MH battery with different states of charge.