水解沉淀法制备超级电容器SnO_2·XH_2O电极材料（英文）

Hydrolysis Precipitation Synthesis of SnO_2·XH_2O as Electrode Materials for Supercapacitors

采用水解沉淀法制备SnO_2·XH_2O电极材料。经过不同温度的焙烧,将得到的SnO_2·XH_2O电极材料用X射线粉末衍射(XRD),透射电子显微镜(TEM)和热失重测试(TGA)进行分析。XRD测试表明,SnO_2·XH_2O电极材料为金红石结构。TEM证实了SnO _2·XH_2O的形貌。TGA表明,随着焙烧温度的升高,SnO _2·XH_2O含水量降低。通过循环伏安法,恒流充放电和循环寿命研究了Sn _2·XH_2O的电化学行为。CV测试表明,在200℃下焙烧的SnO _2·XH_2O电极材料在5 mV/s,0.5 mol/L H_2SO4中的比电容为36.1 F/g。经过_2000次循环后,比电容与首次循环的比电容相比减少了2%。这些结果表明用化学沉淀法制备的Sn O_2·XH_2O是超级电容器良好的候选材料。

Electrode materials of SnO2·XH2O were synthesized by hydrolysis precipitation process. After calcination at various temperatures, the materials were characterized by X-ray diffraction（XRD）, transmission electron microscopy（TEM） and thermogravimetric analysis（TGA）. XRD patterns confirm that the structure of SnO2·XH2O is tetragonal（rutile）. TEM images reveal the morphology of the SnO2·XH2O. TGA shows the water content in SnO2·XH2O decreases as the calcination temperature increases. Electrochemical tests, such as cyclic voltammetry（CV）, chronopotentiometry and cycling were also performed to study the supercapacitor behavior of SnO2·XH2O. CV results indicate that SnO2·XH2O calcined at 200 °C has a specific capacitance of 36.1 F/g at the scan rate of 5 mV /s in 0.5 mol/L H2SO4 electrolyte. Cycling test of 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 the prepared SnO2·XH2O materials are excellent candidates as electrode materials for supercapacitors.