Effect of additives in the stabilization of the α phase of Ni(OH)2 electrodes

The present work deals with the voltammetric and electrogravimetric behavior of Ni(OH)(2) electrodes in alkaline solutions and the effect of some additives, such as Co2+, Cd2+, and Zn2+, in the active material. The electrochemical behavior of the alpha or beta phases with the incorporation of the additives is analyzed by use of the electrochemical quartz crystal microbalance. Only Zn2+ as additive leads to the complete stabilization of the a phase avoiding, since the first cycle, the insertion of alkaline cations from the electrolyte. In all other alpha phases, the electroneutralization of charge is achieved by a small but representative participation of cations. In the case of beta electrodes, protons are the responsible for charge compensation, the cations movement being negligible. (C) 2001 The Electrochemical Society.