Controlling the morphology, size and phase of Nb2O5 crystals for high electrochemical performance

The morphology, size and phase of the material play a crucial role in its electrochemical performance. Herein, the nano-sized niobium pentoxide (Nb2O5) with different morphologies and phase structures are synthesized through a very simple thermal treatment method, including the pseudohexagonal Nb2O5 nanosheets and pseudohexagonal Nb2O5 nanoparticles, orthorhombic Nb2O5 nanoparticles. The synthesized pseudohexagonal Nb2O5 nanosheets and orthorhombic Nb2O5 nanoparticles exhibit better cycling and rate performance than the pseudohexagonal Nb2O5 nanoparticles due to the different morphologies and phase structures. The T-Nb2O5-700 nanoparticles show the higher capacity (175 mAh/g) than that of TT-Nb2O5-500 nanosheets (127 mAh/g) and TT-Nb2O5-600 nanoparticles (39 mAh/g) at a current density of 50 mA/g and good rate performance with a capacity of 140 mAh/g at 1.0 A/g. The excellent rate capability and cycling stability of orthorhombic T-Nb2O5 may be ascribed to the dominant contribution of pseudocapacitive effect. This material has the great potential as a practical high-rate anode material for lithium-ion batteries.