Temperature-Driven Synthesis of 1D Fe2O3@3D Graphene Composite Applies as Anode of Lithium-Ion Batteries

Abstract

A series of Fe2O3-anchored three-dimensional graphene (3DG) composites are synthesized via hydrothermal and annealing methods. The Fe2O3 nanocrystals in composites display nanocubes, one-dimensional (1D) nanorods and ellipsoids at hydrothermal temperatures of 120 °C, 150 °C and 180 °C, respectively. Notably, the composite synthesized at 150 °C shows 1D Fe2O3 uniformly embedded in 3DG, forming an interpenetrating 1D-3D (three-dimensional) structure. This combined structure is beneficial in improving the electrochemical stability and accelerating the Li+ diffusion rate. When used as anode for lithium-ion batteries (LIBs), the optimized 1D-3D Fe2O3@3DG composite delivers a reversible specific capacity of 1041 mAh g−1 at 0.1 A g−1 and maintains a high reversible specific capacity of 775 mAh g−1 after 200 cycles. The superior electrochemical properties of Fe2O3@3DG are a result of the stable interpenetrate structure, enhanced conductivity, and buffered volume change. These results suggest that Fe2O3@3DG composites have significant potential as advanced anode materials for LIBs and the combined 1D-3D structure also provides inspiration for other electrode material structure design.