Physicochemical Properties and Electrochemical Performance of Al-substituted α-Ni(OH)[sub 2] with Additives for Ni-Metal Hydride Batteries

Al-substituted coprecipitated with the additives and was prepared by a complexation-coprecipitation method. The physical properties of Al-substituted samples containing different amounts of or were examined by X-ray diffraction, AES and ICP. The effects of and on the electrochemical performance of Al-substituted such as charge-discharge and diffusion coefficient of the proton measured by current pulse relaxation and cycle life were investigated. The results show that the addition of increases the crystal cell parameters and the charge and discharge potentials and decreases the electrochemical polarization. A higher charge efficiency and cycle life are obtained by the addition of The addition of both and improves and the stability in alkaline solution at high temperature. The and of electrode reach their maximum and minimum values at about 50% depth of discharge (DOD) and 75% DOD, respectively. © 2003 The Electrochemical Society. All rights reserved.