Zinc deposition during charging nickel/zinc batteries

A method of solving the classical problem of short cycle life with nickel/zinc secondary batteries is suggested by studying the effects of the negative electrode substrate on Zn deposition. The use of different coatings on the substrate, (the so-called current-collector) is studied by testing several working electrodes (Zn, Cd and Pb) in a zinc oxide saturated potassium hydroxide electrolyte. Cyclic voltammograms show that the nucleation potential of the Zn deposition on a Pb substrate is lower than that on Zn or Cd. Cathodic polarization curves at various temperatures are also obtained and reveal that slower electrode kinetics and more Cd or Pb coating can retard shape change and dendritic growth by leading to slow electrode kinetics and uniform current distribution. These coatings are applied to a Cu mesh and the effects of coating materials on the current-collector on Zn deposition in Ni/Zn secondary batteries are also studied. Application of Pb as a coating metal on the current-collector of negative electrode retards shape change and the dendritic Zn growth and, hence, increases cycle life.