Synthesis of Calcium Zincate Powders by a Chemical Co-Precipitation Method and Their Electrochemical Performances

摘要

Calcium zincate powders used as active materials for a secondary Zn electrode were prepared by a chemical precipitation (CP) method. The characteristic properties of calcium zincate powders were examined by thermal gravimetric analysis (TGA), X-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET) measurement, Transmission electron microscope (TEM) and micro-Raman spectroscopy. For comparison, the secondary Zn electrodes using CP-calcium zincate powders, so-called the CP-ZnCa, were obtained and examined. The electrochemical performances of the secondary Zn electrodes were investigated by galvanostatic charge/discharge measurements. As a result, the best performance of the CP-ZnCa powders were synthesized at pH 12 with a mole ratio of Zn:Ca=2.5:1. The experimental results indicated that the secondary Zn electrode based on the CP-ZnCa powders exhibited better charge/discharge reversibility and longer cycle-life performance.