Assembly of TiO2/graphene with macroporous 3D network framework as an advanced anode material for Li-ion batteries

Abstract

Three-dimensional (3D) TiO₂–graphene frameworks (TGFs) with macroporous architecture were fabricated through the in situ synthesis of TiO₂ with the participation of graphene oxide followed by hydrothermal assembly. TGFs exhibited a 3D hierarchical porous architecture with mesopores (2.4 nm), macropores (10–30 μm) and a large specific surface area (196 m² g⁻¹), which not only provided contacts between the electrode material and the electrolyte but also increased the mass transport of Li-ions in the charge/discharge process. When it was used as a cathode material in Li-ion batteries, TGFs presented an excellent reversible specific capacity of 210 mA h g⁻¹ at 100 mA g⁻¹ and an outstanding reversible cycling stability (111 mA h g⁻¹ after 500 cycles); even at the current density of 500 mA g⁻¹, TGF also performed very well. This excellent electrochemical performance was attributed to the unique 3D hierarchical porous architecture and the synergistic effects of TiO₂ and graphene in Li-ion storage and transport.