Advanced LiTi2(PO4)3@N-doped carbon anode for aqueous lithium ion batteries

Abstract

In this paper, LiTi2(PO4)3@N-doped carbon anode has been synthesized by in situ carbon coating approach. The well-proportioned N-doped carbon layer and loose nanoporous structure was obtained by using urea as nitrogen source and pore former. LiTi2(PO4)3@N-doped carbon as anode demonstrates much better rate capability than LiTi2(PO4)3@carbon in ALIBs. The optimized anode delivers the discharge capacity of 93.7mAhg−1 and 74.2mAhg−1 at rates of 10C and 20C, 22.5mAhg−1 and 50.0mAhg−1 larger than that of LiTi2(PO4)3@carbon. Moreover, LiTi2(PO4)3@N-doped carbon exhibits excellent cycling performance with capacity retention of 84.3% at 5C after 1000 cycles. As verified, the well-proportioned N-doped carbon layer could reduce charge transfer resistance and improve electrical conductivity. The loose nanoporous structure could shorten pathway and facilitate diffusion for Li ion. Therefore, LiTi2(PO4)3@N-doped carbon gets the superior electrochemical properties benefiting from those two characteristics.