Zinc-substituted alpha-nickel hydroxide as an electrode material for alkaline secondary cells

Double hydroxides of the formula, Ni1-xZn2x (OH)(2) (CO3)(x). nH(2)O (x = 0 .1 to 0.25) having the same structure as that of alpha-nickel hydroxide hav e been synthesized by partial substitution of zinc for nickel. The hydroxid e having the composition x = 0.25 exhibits prolonged stability in 6 M KOH. Pasted electrodes comprising this material are rechargeable with a stabiliz ed reversible discharge capacity of 410 +/- 15 mAh g(-1) of nickel even und er suboptimal conditions of electrode fabrication. This compares favorably with the capacity values achieved for beta-nickel hydroxide (221 mAh g(-1)' , This work; 297 mAh g(-1), Delahaye-Vidal and Figlarz;(1) 456 mAh g(-1), t heoretical). (C) 1999 The Electrochemical Society. S0013-4651(98)01-071-4. All rights reserved.