Synthesis and characterization of nano-sized calcium zincate powder and its application to Ni-Zn batteries

Nano-sized calcium zincate powders used as active materials for a secondary Zn electrode were prepared by a chemical co-precipitation method. The properties were studied by thermal gravimetric analysis (TGA), micro-Raman spectroscopy and nitrogen adsorption-desorption experiments. The secondary Zn electrodes using chemical co-precipitation calcium zincate powders (CP-ZnCa) and ball-milled calcium zincate powders (BM-ZnCa), were examined and compared. The electrochemical performance of the secondary Zn electrodes was systematically investigated by cyclic voltammetry and galvanostatic charge/discharge measurements. It was demonstrated that the electrochemical properties of the secondary Zn-pasted electrode using CP-ZnCa powders were greatly improved, as compared with conventional secondary ZnO electrodes. The results indicated that secondary Ni-Zn batteries using CP-ZnCa powders exhibited a better charge/discharge property and a longer life-cycle performance, compared with those based on ball-milled ZnO + Ca(OH)(2) (BM-ZnCa) powders.