Enhanced High-Rate Capability of Aqueous Lithium Batteries with Multiple Effects of N-Doped Carbon Coating on the LiTi2(PO4)3 Interface

LiTi2(PO4)3 (LTP) is widely recognized as a promising anode material for aqueous lithium-ion batteries due to its stable three-dimensional framework structure and working potential within the aqueous electrolyte potential window. However, the low conductivity of pure-phase LTP poses a significant challenge that must be overcome for its practical application. In this work, N-doped carbon-coated LTP (NC@LTP) composites with a layered flower-like morphology were synthesized via an organic precipitation method. The N-doped carbon layer improved the conductivity and hydrophilicity of the anode and caused carbon defects that facilitated Li+ transport. The initial specific capacity at 10 C was enhanced from 39.4 to 81.5 mAh g–1 after N-doping. The pouch cells retained 92.7% of their capacity after 150 cycles at 1 C and demonstrated excellent safety in abuse tests. In addition, the modification mechanism of the N-doped carbon layer was verified through DFT calculations. This study provides references and ideas for the modification of high-performance aqueous lithium-ion battery electrode materials.