One-step hydrothermal synthesis of 3D porous microspherical LiFePO4/graphene aerogel composite for lithium-ion batteries

Three-dimensional (3D) porous LiFePO4/graphene aerogel (LFP/GA) composite was successfully prepared by an in-situ hydrothermal process. In this composite, the LiFePO4 microspheres assembled by nanoparticles were embedded in a three-dimensional framework intertwined with the graphene sheets, which acts as a bridge for transfer of electron and diffusion of lithium ion. The large specific surface of the composite structure enables the increased infiltration area and utilization of the active material. The content of the graphene sheet is analyzed and is found important for the Li-storage characteristics of LiFePO4. An aerogel composite with 10% of graphene displays the best electrochemical performance, with the specific discharge capacities of 168 mAh g−1 and 155 mAh g−1 at respectively 0.1C and 1C, and the capacity retains 96.3% for up to 800 cycles. This novel 3D porous aerogel composite is identified as a promising cathode material for the rechargeable Li battery, and the simple strategy may be applied to construct other high performing composite structure and materials.