Chemistry and Life Science School, Changchun University of Technology , 2055 Yanan Street, Changchun, People's Republic of China.
ACS Appl Mater Interfaces. 2013 Nov 13;5(21):11462-70. doi: 10.1021/am403739g. Epub 2013 Oct 31.
Vanadium pentoxide (V2O5) has attracted much attention for energy storage application because of its high Faradaic activity and stable crystal structure, which make it a promising electrode material for supercapacitors. However, the low electronic conductivity and small lithium-ion diffusion coefficient of V2O5 limit its practical applications. To overcome these limitations, a facile and efficient method is here demonstrated for the fabrication of V2O5/reduced graphene oxide (rGO) nanocomposites as electrode materials for supercapacitors. With this method, the reduction of graphene oxide can be achieved in a cost-effective and environmentally friendly solvent, without the addition of any other toxic reducing agent. Importantly, this solvent can control the formation of the uniform rodlike V2O5 nanocrystals on the surface of rGO. Compared to pure V2O5 microspheres, the V2O5/rGO nanocomposites exhibited a higher specific capacitance of 537 F g(-1) at a current density of 1 A g(-1) in neutral aqueous electrolytes, a higher energy density of 74.58 Wh kg(-1) at a power density of 500 W kg(-1), and better stability even after 1000 charge/discharge cycles. Their excellent performances can be attributed to the synergistic effect of rGO and rodlike V2O5 nanocrystals. Such impressive results may promote new opportunities for these electrode materials in high-energy-density storage systems.
五氧化二钒（V2O5）因其高法拉第活性和稳定的晶体结构而在储能应用中引起了广泛关注，这使其成为超级电容器的一种有前途的电极材料。然而，V2O5 的低电子电导率和较小的锂离子扩散系数限制了其实际应用。为了克服这些限制，本文展示了一种简便有效的方法，用于制备 V2O5/还原氧化石墨烯（rGO）纳米复合材料作为超级电容器的电极材料。该方法可以在具有成本效益和环保的溶剂中实现氧化石墨烯的还原，而无需添加任何其他有毒还原剂。重要的是，这种溶剂可以控制均匀的棒状 V2O5 纳米晶在 rGO 表面的形成。与纯 V2O5 微球相比，V2O5/rGO 纳米复合材料在中性水电解质中以 1 A g-1 的电流密度表现出更高的比电容（537 F g-1），在 500 W kg-1 的功率密度下具有更高的能量密度（74.58 Wh kg-1），即使经过 1000 次充放电循环也具有更好的稳定性。它们优异的性能可归因于 rGO 和棒状 V2O5 纳米晶的协同效应。这些令人印象深刻的结果可能为这些电极材料在高能密度储能系统中带来新的机遇。
