Dual strategy of La³⁺ doping and carbon coating enhancing the rate performance of NaTi₂(PO₄)₃ anode materials

NaTi₂(PO₄)₃ (NTP) is considered a promising anode material for sodium-ion batteries due to its open and stable framework structure. However, its poor conductivity prevents its direct application as an anode material. In this paper, a dual strategy of La³⁺ doping and carbon coating is proposed to improve the conductivity of NTP. The results show that the NTP-La_0.06@C electrode doped with 6.00% La and 5.00 wt% of carbon coating has excellent electrochemical performance, and the coulombic efficiency is up to 95.31% in the first cycle. The initial specific capacity is 103.05 mAh·g⁻¹ with a capacity retention of 97.30% after 1000 cycles at 10C rate. Even after 2000 cycles, there is still a specific capacity of 98.62 mAh·g⁻¹ with a capacity retention of 92.71%, and as well as the NTP-La_0.06@C has a higher Na⁺-insert diffusion coefficient of 3.19×10⁻¹¹ cm²·s⁻¹ than the pristine NTP@C of 2.35×10⁻¹¹ cm²·s⁻¹ during charging. Therefore, the La³⁺ doping and carbon coating strategy shows great potential in improving the performance of NaTi₂(PO₄)₃ anode materials.