Core-Shell Structured LiTi2(PO4)3/C Anode for Aqueous Lithium-Ion Batteries

A simple high-temperature solid-state reaction route incorporating a polymerization-coating method is developed to prepare a core-shell structured LiTi2(PO4)(3)/C composite (PDA-cLTP), using polydopamine(PDA) as the carbon and nitrogen source. The PDA-cLTP shows an excellent discharge capacity of 117 mAh g(-1) at 1 C with a high retention of 91.4% for 200 cycles. Cycled at 10 C, a capacity of 80 mAh g(-1) and a retention of 76.0% for 1000 cycles are preserved. The high rate capability and cycling stability of PDA-cLTP are ascribed to the more homogeneous nitrogen-doped carbon coating on the surface of LiTi2(PO4)(3)/C composite compared to PAN-cLTP using polyacrylonitrile(PAN) as carbon and nitrogen sources. The reported PDA-cLTP synthesis and coating design strategies offer effective approaches to develop high electrochemical performance and long-life aqueous lithium-ion batteries for utility-scale/bulk-storage energy storage applications.