Lithium storage performance improvement of NaTi2(PO4)3 with nitrogen-doped carbon derived from polyaniline

NASICON-type NaTi2(PO4)3 has been acknowledged as a promising anode for energy storage due to high ion conductivity and low cost. Nevertheless, intrinsic low electrical conductivity of NaTi2(PO4)3 and low stability in aqueous electrolyte limit its further applications in aqueous lithium rechargeable battery. In this paper, polyaniline as carbon and nitrogen sources was employed to synthesize nitrogen-doped carbon coated NaTi2(PO4)3 (NTP-P) composite by sol-gel approach and following calcination treatment. The loose and carbon-coated structure endows NTP-P with good structure stability and improved electrochemical kinetics. Compared with glucose-derived carbon-coated NaTi2(PO4)3 composite, NTP-P exhibits superior rate and cycling performance. NTP-P with proper carbon content delivers the discharge capacity of 119.4 and 83.4 mAh g−1 at rate of 0.2 and 15 C, and its capacity retention can maintain 85.8% after 1000 cycles at 5 C. This research reveals that the integration of carbon coating and nitrogen doping by using polyaniline give an excellent method to enhance the electrochemical properties of electrode materials.