Inclusion of Co metal as an additive during the preparation of pasted electrodes enhances the reversible discharge capacity of beta-nickel hydroxide from 220 mAh g(-1) of Ni to 400 mAh g(-1) (theoretical, 456 mAh g(-1) Ni). In contrast, the performance of beta(bc) (bc badly crystalline) and alpha-nickel hydroxide is relatively unaffected by addition of Co. In electrodes comprising the crystalline-layered double hydroxide of Ni with Al, Co addition not only results in enhancement of the capacity from 375 to 585 mAh g(-1) but also increases capacity retention.