NaSn 0.02 Ti 1.98 (PO 4 ) 3 /C as a promising anode material with high performance for sodium-ion batteries

In this paper, NaSn 0.02 Ti 1.98 (PO 4 ) 3 /C composite material was prepared by spray drying method combined with high-temperature calcination, which can improve the electrochemical performance of NaTi 2 (PO 4 ) 3 . The doping of Sn 4+ increases the lattice spacing of NaTi 2 (PO 4 ) 3 , thereby accelerating the diffusion coefficient of Na + . The carbon doped on NaTi 2 (PO 4 ) 3 reduces the charge transfer impedance and enhances the ion diffusion coefficient. As a result, NaSn 0.02 Ti 1.98 (PO 4 ) 3 /C exhibits improved electrochemical performance. The specific capacity for the initial discharge of NaSn 0.02 Ti 1.98 (PO 4 ) 3 /C at 1C, 5C, 10C and 20C rates are 108 mAh/g, 86 mAh/g, 76.3 mAh/g, and 71.4 mAh/g, respectively. After 1400 cycles at 10C, the capacity of the material decreases to 64.3 mAh/g, with a capacity retention rate of 84.2%. Therefore, NaSn 0.02 Ti 1.98 (PO 4 ) 3 /C exhibits fast charge/discharge performance as well as cycling stability.