Effect of Ni-Co-P Coating on Kinetic Properties in Hydride Electrode for Mm(NiCoAlMn)_5 Hydrogen Storage Alloy

The effect of electroless plated Ni Co P alloy coating on the kinetic properties of Mm(NiCoAlMn) 5 rare earths based hydride electrode was investigated by electrochemical techniques. The results indicate that the kinetic properties of MH electrode, including exchange current density i 0, limiting current density i L, and diffusion coefficient of hydrogen in α phase D α(H) are improved markedly. These improvements of kinetic properties lead to the increase of anodic peak current and peak integration area of MH electrode modified by Ni Co P alloy in CV curve as well as the decrease of overpotential of anodic and cathodic polarization.