Rapid electron/ion transport in CNT/LiTi2(PO4)3@C–N electrodes for aqueous lithium-ion batteries with high stability, flexibility and safety

Abstract

Self-supporting and flexible carbon nanotube/carbon-coated nitrogen-doped LiTi₂(PO₄)₃ (CNT/LTP@C–N) hybrid films are manufactured via vacuum filtration. LTP@C–N is entangled into CNT networks to build a 3D conductive network. Such hybrid electrodes possess a large surface area, enhance the overall conductivity of these composite electrodes, and facilitate electrolyte infiltration, thereby resulting in advanced electrochemical properties. Typically, the CNT/LTP@C–N electrodes afford a high initial discharge capacity of 143 mA h g⁻¹ at 1 C, considerable rate property (85 mA h g⁻¹ at 30 C), and good cyclability (87.3% capacity retention after 1500 cycles at 5 C) in a non-aqueous electrolyte. When utilized as anodes for aqueous lithium-ion batteries (ARLBs), a high energy density (67 Wh kg⁻¹ calculated from the mass of anode and cathode active materials) and long term cycling stability (capacity retention of 70.2% after 1000 cycles at 3 C) can be achieved.