Boosting High-Rate Lithium Storage of V₂O₅ Nanowires by Self-Assembly on N-Doped Graphene Nanosheets

V₂O₅ is a promising cathode material for lithium-ion batteries owing to its extremely high theoretical capacity (440 mA h g⁻¹ when storing 3 Li⁺ ions and 294 mA h g⁻¹ when storing 2 Li⁺). However, drawbacks such as a strong inclination to aggregate and the low conductivity inherent to nanostructured V₂O₅ drastically deteriorate its cycle and rate performances. Hence, hybridizing it with a conductive matrix (e.g. graphene) for improved electrochemical performance is an interesting concept. It is well established that heteroatom functionalization (e.g. N doping) can tailor the chemical properties of graphene by influencing the neighboring carbon atoms to enhance conductivity and electrochemical activity. Herein, a high-rate cathode material is fabricated by self-assembly of V₂O₅ nanowires on N-doped graphene nanosheets, followed by heat treatment to optimize the electrochemical performance. The synergistic effects of the resulting V₂O₅/N-doped graphene nanohybrids are demonstrated by their excellent rate capability: they deliver very high capacities of 273, 242, 206, 181, and 161 mA h g⁻¹ at current densities of 100, 200, 500, 1000, and 2000 mA g⁻¹.