Electrochemical properties of Co(OH)₂ powders as an anode in an alkaline battery

摘要

The structure and electrochemical properties of β-Co(OH)₂ powders, synthesized by a chemical precipitation method, were investigated. The results of X-ray diffraction show that a reversible reaction between β-Co(OH)₂ and hcp Co occurs. The cycling induces a capacity loss of β-Co(OH)₂ electrode, which is probably attributed to the dissolution of β-Co(OH)₂ and the subsequent formation of α-Co(OH)₂ and CoOOH. The results of electrochemical impedance spectra indicate that the electrochemical discharge process of the as-prepared Co(OH)₂ powders consists of three steps, namely the charge-transfer reactions of Co/CoH _x and Co/Co(OH)₂, and the hydrogen diffusion within Co, depending on the depth of discharge.