EFFECT OF SUBSTITUTED ZINC ON THE ELECTROCHEMICAL BEHAVIOUR OF NICKEL HYDROXIDE

摘要

Nickel hydroxide is widely used as positive electrode material in Ni//Cd,Ni//MH and Ni//H_2 batteries.The electrochemical cycling is commonly performed between the beta(II)-Ni(OH)_2 and beta(III)-NiOOH phases,the structure of which consists of packed NiO_2 brucite type slabs,between which protons can be reversibly intercalated and deintercalated.Long term overcharge or floating leads to the formation of the gamma oxyhydroxide,with an expanded inters lab apace,by intercalation of water molecules and K~+ ions.The repeated shift cycle after cycle,from the unhydrated pluses to the hydrated ones (and vice versa),entails mechanical strains and irreversible damages to the electrode.