表面包覆CaSn(OH)_6的锌酸钙的制备及其性质

Preparation and characteristics of calcium zincate coated by calcium stannate

采用化学沉积法在四边形锌酸钙表面包覆一层金属锡化合物。利用X射线衍射、扫描电子显微镜、电化学阻抗谱、Tafel曲线以及充放电循环(用做锌镍电池的负极材料)等方法,对包覆前后的锌酸钙样品进行表征。结果表明:包覆物化学组成为CaSn(OH)6,该包覆物在锌酸钙的表面分布均匀,沉积较为致密;包覆后的锌酸钙材料具有更好的耐腐蚀性能,且其电化学循环性能良好,经过135次循环后,电池放电容量仍保持设计容量的65.5%。

Tin compound was coated on the surface of the calcium zincate by chemical deposition. The properties of the samples were characterized by XRD, SEM, EIS, Tafel plot, and charge-discharge test as the cathode materials for Ni/Zn battery. The results show that the chemical composition of coating material, CaSh（OH）6. CaSn（OH）6 can be tightly coated and distributed uniformly on the surface of calcium zincate. The CaSn（OH）6-coated calcium zincate has a better alkali-tolerant performance than pure calcium zincate. The CaSn（OH）6-coated sample shows a much better capacity retention, and it can be retained about 65.5% after 135 charge-discharge cycles.