Effect of synthetic methods on electrochemical performances of VOPO4·2H2O supercapacitor
Effect of synthetic methods on electrochemical performances of VOPO4·2H2O supercapacitor
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DOI：
10.1007/s11581-014-1317-7
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发表时间：
2014
期刊：
影响因子：
2.8
通讯作者：
Zhenyu Luo;E. Liu;Tiantian Hu;Zengpeng Li;Tiantian Liu
中科院分区：
文献类型：
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作者：
Zhenyu Luo;E. Liu;Tiantian Hu;Zengpeng Li;Tiantian Liu
本文对VOPO4·2H2O作为超级电容器电极材料进行了研究。对回流法制备的VOPO4·2H2O和水热法制备的VOPO4·2H2O进行了详细的分析，包括粉末X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)和扫描电子显微镜(SEM)。通过循环伏安(CV)、恒流充放电(GCD)和交流阻抗谱(EIS)对其电化学性能进行了研究。同时，我们提出了VOPO4·2H2O电极表面可能的电荷储存机理。回流法制备的VOPO4·2H2O材料的比容量性能优于水热法合成的材料，在2 mV/S下比容量达到202F/g，电流密度从0.2~2.0A/g时，VOPO4·2H2O的总比容量保持在67.4A/g，远高于水热合成的42.5%。回流合成的VOPO4·2H2O超级电容器在290W/kg时的能量密度为18.7Wh/kg，在1,421W/kg时的能量密度为6.2Wh/kg，远高于水热合成的VOPO4·2H2O超级电容器。我们的工作证实了VOPO4·2H2O是一种潜在的超级电容器电极材料。
In this paper, we studied the VOPO4·2H2O as an electrode material for supercapacitors. A systematic comparison of VOPO4·2H2O prepared by reflux and hydrothermal methods was carried out through detailed analyses that included power X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Their electrochemical performances were also investigated by using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Meanwhile, we proposed a possible charge storage mechanism on the VOPO4·2H2O electrode surface. The material synthesized by reflux method had better performance in the capacitance than that by hydrothermal method, and its specific capacitance was up to 202 F/g at 2 mV/s. A total of 67.4 % of capacitance was maintained for the VOPO4·2H2O synthesized by reflux method when current density changed from 0.2 to 2 A/g, much higher than those obtained from the hydrothermal-synthesized VOPO4·2H2O supercapacitor of 42.5 %. The energy density of VOPO4·2H2O supercapacitor synthesized by reflux method was 18.7 Wh/kg at 290 W/kg and maintained 6.2 Wh/kg at 1,421 W/kg, much higher than the hydrothermal-synthesized VOPO4·2H2O supercapacitor. Our work confirms that VOPO4·2H2O is a potential electrode material for supercapacitors.