Controllable Preparation of V₂O₅ Hollow Microspheres as Cathode Materials for Lithium-Ion Batteries

摘要

Hollow-structured vanadium oxides with tunable interiors have attracted significant attention in energy storage and conversion systems. In this work, we report the continuous structural engineering of VO2 solid microspheres utilizing a second solvothermal solution under the driving force of an Ostwald- ripening mechanism. The VO2 microspheres with diversified interior structures, such as yolk-shelled, double-shelled and complete hollow microspheres, were obtained by simply controlling the solvothermal duration in the new solvothermal solution. The obtained VO2 microspheres were converted into V2O5 microspheres with good structural preservation after calcination. As a cathode material for lithium batteries, the V2O5 hollow microspheres exhibited high capability and good ?1 cycling stability. A high specific discharge capacity of 129.4 mA h g was obtained for the V2O5 hollow microsphere electrode, which retained 114.5 mA h g?1 after 200 cycles. The superior electrochemical properties were attributed to the promising features of the hollow microspheres.