碳纳米管/五氧化二钒空心球的制备及其电化学性能研究

采用溶剂热法制备了碳纳米管穿插的分级结构五氧化二钒空心球（VOC_x）. 使用XRD、SEM、循环伏安曲线和充放电曲线研究了不同碳纳米管量对产物结构、形貌和电化学性能的影响. 结果表明，碳纳米管的加入明显改善了VOC的倍率特性. 碳纳米管含量为7.1%时，0.5 A·g^-1电流密度下，其比电容达到346 F·g^-1，8 A·g^-1电流密度时，其电容保持率可达75%. 与活性炭组装成混合电容器，在功率密度为700 W·kg^-1时，能量密度达12.6 Wh·kg^-1.

Synthesis and Electrochemical Properties of CNTs/V2O5 Hollow Microspheres

The carbon nanotubes/vanadium oxides (CNTs/V₂O₅) hollow microspheres (VOC) were prepared via solvothermal process. The effects of the ratio for CNTs to V₂O₅ on the morphologies, structures and electrochemical performances were systemically investigated. The results indicate that CNTs dramatically enhanced the rate performances of VOC composite electrodes. When the ratio of CNTs is 7.1%, the VOC composite electrode exhibited the best electrochemical performance, which delivered a specific capacitance of 346 F·g^-1 at 0.5 A·g^-1 and maintained 75% at 8 A·g^-1 in 5 mol L^-1 LiNO₃. A hybrid capacitor was assembly using commercial activated carbon as the negative electrode and VOC as the positive electrode. The hybrid capacitor exhibited an energy density of 12.6 Wh·kg^-1 and power density of 700 W·kg^-1.