V<sub>2</sub>O<sub>5</sub> Nanowire Composite Paper as a High-Performance Lithium-Ion Battery Cathode

Ultralong, as long as ∼1 mm, orthorhombic vanadium pentoxide (V<sub>2</sub>O<sub>5</sub>) nanowires were synthesized using a hydrothermal method. Free-standing and binder-free composite paper was prepared on a large scale by a two-step reduction method using free-standing V<sub>2</sub>O<sub>5</sub> nanowires as the skeleton and reduced graphene oxide (rGO) nanosheets as the additive. Such a free-standing V<sub>2</sub>O<sub>5</sub>/rGO composite paper as a cathode for lithium ion batteries possesses both structural integrity and extraordinary electrochemical performance. The reversible specific areal capacity of the V<sub>2</sub>O<sub>5</sub>/rGO composite paper electrode is 885 μAh/cm<sup>2</sup> at 0.09 mA/cm<sup>2</sup>, much higher than that of the pure V<sub>2</sub>O<sub>5</sub> nanowire paper electrode (570 μAh/cm<sup>2</sup>). It also shows excellent cycling performance at high rates with 30.9% loss of its initial capacities after 1000 cycles at a current rate of 0.9 mA/cm<sup>2</sup>. The excellent performance was attributed to the improved electronic conductivity and Li<sup>+</sup> ion transport from the rGO addition.