超级电容器水合氧化锡电极材料的水解沉淀法制备

Hydrolysis precipitation synthesis of SnO2.xH2O as electrode materials for supercapacitors

摘要:

采用化学沉淀法在低温下制备SnO2?xH2O电极材料，经过不同温度的焙烧，将得到的不同样品的SnO2?xH2O电极材料经X粉末衍射（XRD），透射电子显微镜（TEM），测试表明SnO2?xH2O电极材料为金红石结构和粉末形貌，热失重测试分析(TGA)表明随着SnO2?xH2O电极材料焙烧的温度的升高，焙烧后含水量降低。在0.5M H2SO4溶液中和电位范围0-0.9V（vs Hg/HgCl）内，通过循环伏安法，循环寿命和恒流充放电的电化学测试表明在200℃温度下焙烧的SnO2?xH2O电极材料在5 mV s-1扫描速率下的比电容在36.1 F g-1，经过2000次循环后对比首次循比容量减少了的2%，这些结果表明用化学沉淀法制备的SnO2?xH2O应用在超级电容器中是性能比较好的电极材料。

Abstract:

Electrode materials of SnO2.xH2O are synthesized at low temperature by hydrolysis precipitation process. After calcination at various temperatures, the as-prepared powders are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA). XRD patterns confirm the structure of SnO2.xH2O powders to be tetragonal. TEM images reveal the morphology of the as-prepared SnO2?xH2O powders, and TGA shows the water content in SnO2.xH2O, which decreases as the calcination temperature increases. Electrochemical tests, such as cyclic voltammetry (CV), cycling and chronopotentiometry test are also performed to study the supercapacitor behavior of the calcined SnO2?xH2O powders. Cyclic voltammetric results indicate that SnO2?xH2O powders calcined at 200℃ has a maximum specific capacitance of 36.1 F g-1 at the scan rate of 5 mV s-1 in 0.5 M H2SO4 aqueous electrolyte. Cycling test on the same sample also shows excellent long-term cyclic stability, which has lost less than 2 % of the total specific capacitance after 2000 cycles. These results indicate that SnO2.xH2O powders prepared from hydrolysis precipitation process are excellent candidates as electrode materials towards the applications of supercapacitor.