Improvement of sodium storage performance of N-doped carbon coated NaTi2(PO4)3 derived from polyvinyl pyrrolidone

Nitrogen incorporated carbon composite of Sodium titanium phosphate (NaTi2(PO4)(3)/NTP) can be deliberated as a proficient anode for sodium-ion battery application for its structural stability and good ionic mobility. Presence of nitrogen into the carbon moiety delaminate the problem of poor electronic conductivity and make it practically usable. The carbon composite properties play a crucial role on surface engineered active material, which control the electrochemical performance of an electrode. Here we have synthesized a N-doped carbon coated NTP composite using only ploy vinyl pyrrolidone as both nitrogen and carbon source by a simple sol-gel method. The as prepared NTP-N@C composite reveals excellent electrochemical properties including cycleability, rate performance and specific capacity. The hetero atom doping into carbon matrix enhances both the ionic and electronic conductivity. The structural and morphological study also shows that source of carbon and carbon matrix properties has significant effect on the electrochemical performance. Compare to citric acid derived NTP-C, NTP-N@C shows better performance by delivering a discharge capacity of 106.5 mAhg(-1) and 67 mAhg(-1) at a current density of 0.1 Ag-1 and 3 Ag-1. Again when the electrode is cycled at 1 Ag-1 for 500 cycle its capacity retention is 86.8% whereas for NTP-C it is only 58.2%. Results exposes the combination of carbon coating and nitrogen doping makes sodium titanium phosphate a promising anode for practical application in sodium-ion battery research.