LiFe_0.95Mn_0.05PO₄@C film grown on multilayer graphene as a cathode material for lithium-ion batteries

Integrating nanostructured LiFePO₄ with carbon substrates is a feasible way to obtain high electrochemical performance for lithium-ion batteries (LIBs). The distribution uniformity of LiFePO₄ and contact surface area between LiFePO₄ and carbon substrates are crucial for the high electrode performance. In this work, LiFePO₄ thin film was synthesized on the flat surface of mechanically exfoliated multilayer graphene (MLG) via chemical deposition of Fe₂O₃ thin film on MLG and conversion to LiFePO₄ by solid phase reaction. To enhance the electrochemical performance, carbon coating and Mn doping were carried out to modify the LiFePO₄ thin film. LiFe_0.95Mn_0.05PO₄@C film on MLG (MLG/LiFe_0.95Mn_0.05PO₄@C) exhibits high electrochemical performance. Based on the total mass of the composite, specific discharge capacity of 62.5 mAh g⁻¹ is delivered at a high current density of 10 C. Specific discharge capacity of 126.8 mAh g⁻¹ is maintained after 100 cycles at 0.2 C, exhibiting a capacity retention of 97.5%. This method is suitable for large-scale synthesis of carbon-based LiFePO₄ composites at low cost.