Synthesis and characterization of carbon supported V2O5 nanotubes and their electrochemical properties

Vanadium pentoxide (V₂O₅), as one of the most important electrode materials for lithium ions batteries, attracts tremendous attention. Here, carbon supported V₂O₅ hollow nanotubes are synthesized using carbon fibers as templates through solvothermal reaction with subsequent annealing treatment. Morphological features of the samples are investigated by field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) patterns confirm the formation of phase-pure structure. Elemental mapping and XPS studies are used to confirm the existence of carbon and V⁴⁺ in nanotubes. Electrochemical Li insertion behavior of nanotubes are explored as cathode in half cell configuration (vs. Li) using cyclic voltammetry, galvanostatic charge-discharge studies and rate tests. The V₂O₅ hollow nanotubes display a good cycling performance with a specific capacity of 237 mA h g⁻¹ after 50 cycles at 100 mA g⁻¹ in the voltage range of 2.0-4.0 V. Moreover, the nanotubes cathode delivers specific capacities of 165.8, 140.3 and 109.6 mA h g⁻¹ at 1000, 2000 and 5000 mA g⁻¹, respectively, indicating a desirable rate capability. The good electrochemical performance of carbon supported V₂O₅ hollow nanotubes can be attributed to the unique hollow nanotubes and the existence of carbon and V⁴⁺.