Improved Li-storage performance of Mg²⁺-doped LiVPO₄F@C cathode material synthesized by a fast carbothermal reduction reaction

LiVPO₄F is a promising cathode material for lithium-ion batteries due to its advantages in safety, discharge potential and energy density. In this work, we report a fast carbothermal reduction reaction to synthesize the Mg²⁺-doped LiVPO₄F@C cathode materials with superior electrochemical performances. It indicates that Mg substitution of V can increase the pyrolytic temperature by 40 °C and improve the Li⁺diffusivity by two times at the discharge plateau. In particular, the LiV_0.97Mg_0.03PO₄F@C cathode material exhibits a high discharge capacity of 140.3 mA h/g at 1 C with a high discharge potential of 4.2 V and a prominent capacity retention of 88.2% after 500 cycles. The fast carbothermal reduction reaction and Mg doping strategies developed in this work may be promising to promote the practical application of LiVPO₄F for energy storage.