Calcium Zincate Synthesized by Ballmilling as a Negative Material for Secondary Alkaline Batteries

Calcium zincate has been successfully synthesized by a high-energy ballmilled method. The crystal structure, chemical composition, surface morphology, granularity distribution, and electrochemical performance have been investigated to compare with that prepared by a conventional chemical precipitation method. X-ray powder diffraction results revealed that the calcium zincate prepared by the two methods had a well-defined monoclinic structure using a Rietveld refinement method. Scanning electron microscope images and granularity analysis indicated that the ballmilled material was a finer powder with a higher specific surface area. The thermogravimetric and differential thermal analysis showed that there was a slight difference in the crystalline water content in the chemical composition of the powders prepared by the two methods. The galvanostatic charge and discharge results showed that the ballmilled powder had a promising cyclic behavior due to the better electrochemical stability as revealed from the cyclic voltammetry. It is suggested that the ballmilled calcium zincate is more suitable for applications in secondary alkaline batteries. © 2004 The Electrochemical Society. All rights reserved.