Vanadium-Substituted Formation of Anatase (V, Ti)O-2: Enhanced Electrochemical Performance for Lithium Ion Batteries

TiO2 has been used as a commercial anode material in lithium ion batteries (LIBs) owing to security and outstanding cycle stability. However, the lower specific capacity has limited its application. In this work, nanocrystalline anatase (V-0.47, Ti-0.53)O-2 is prepared via a hydrothermal process. When evaluated as an anode material for LIBs, nanocrystalline (V, Ti)O-2 exhibits enhanced specific capacity, high rate performance, and excellent cyclic stability. The specific capacity of the (V, Ti)O-2 anode reaches 370 mAh g(-1) in the first cycle, about 2.2 times the theoretical capacity of anatase TiO2, and it retains a value of 320 mAh g(-1) after 500 cycles at a current density of 168 mA g(-1). At a current density of 1680 mA g(-1) (10 C), a specific capacity of as high as 137 mAh g(-1) is achieved after 1000 cycles. The high capacity is ascribed to the incorporated vanadium element, which undergoes the redox reactions of V4+ -> V3+ -> V2+ during the lithium storage process according to the ex-situ XPS results. The increased conductivity and surface pseudocapacitive contribution of the (V, Ti)O-2 anode as evidenced by the EIS and rate-changing CV investigation account for the improved rate performance with respect to TiO2. This work demonstrates that (V, Ti)O-2 nanoparticles are a promising candidate for LIB anode materials.