Bi₂O₃ nanoparticles encapsulated by three-dimensional porous nitrogen-doped graphene for high-rate lithium ion batteries

A composite consisting of Bi₂O₃ nanoparticles encapsulated by three-dimensional (3D) porous nitrogen-doped graphene is reported. Due to the 3D porous structure, the composite has large specific surface area of 112 m² g⁻¹, which can increase the contact area between active material and electrolyte. In addition, the 3D porous conductive framework can not only facilitate the fast electron transport and Li⁺ diffusion but also enhance the electrical conductivity of the composite. As expected, the composite shows an outstanding rate capability of 273 mAh g⁻¹ at 10000 mA g⁻¹ and a capacity of 417 mAh g⁻¹ over 100 cycles at a current density of 200 mA g⁻¹. Therefore, the composite is a promising candidate as an anode material for high-rate lithium ion batteries.