A novel electro-active material was synthesized by precipitation under high levels of supersaturation. The compound was pure beta-Co(OH)(2) with hexagonal crystal structure by XRD analysis, and it was flake-shaped, 50-200 nm in particle size and similar to 20 nm in thickness by FE-SEM observation. The quasireversible electrochemical reaction between beta-Co(OH)(2) and Co upon charging/discharging produced a maximum discharge capacity of 462 mAh g(-1), and furthermore the discharge capacity retained 97.6% of the initial capacity at the 100th cycle. These findings highlight the potential for beta-Co(OH)(2) compound in applications to negative electrode materials of alkaline rechargeable batteries. (C) 2010 Elsevier B.V. All rights reserved.