TiN modified NaTi2(PO4)(3) as an anode material for aqueous sodium ion batteries

The TiN coated NaTi2(PO4)(3) with high electrochemical performance as anode materials for aqueous sodium-ion batteries were synthesized successfully by solvothermal routine and subsequent nitriding process in the presence of ammonia. The nitriding process would not change the crystal structure of NaTi2(PO4)(3). However, the Ti4+ in the material can be reduced to Ti3+, and the nitrogen atom can be doped into the material, forming a TiN layer on the surface of the material, which significantly increased the electronic conductivity of NaTi2(PO4)(3) material. By adjusting nitriding time, we have prepared the best nitriding material and the effect of nitriding on NaTi2(PO4)(3) materials has been clearly clarified. The rate capacity and cyclic performance of the TiN tailored NaTi2(PO4)(3) have been greatly improved, which is much better than the pristine phase. The initial capacity of the TiN tailored NaTi2(PO4)(3) can reach 131.9 mAh g(-1), and it can still keep 92 mAh g(-1) after 100 cycles at 2 C.