Hollow Ti₃C₂ MXene/Carbon Nanofibers as an Advanced Anode Material for Lithium-Ion Batteries

Lithium-ion batteries (LIBs) are rechargeable batteries that have attracted great interest as next-generation energy storage devices that will lead future energy technologies because of their various excellent advantages. Two-dimensional (2D) MXene-based LIBs have been actively investigated because of their high energy/power density and good performance at high charge/discharge rates. However, three major limitations of 2D MXene electrodes – self-stacking, low specific surface area, and disturbance of Li⁺ diffusion by surface terminations – have hindered the commercialization of MXene-based LIBs. Herein, we fabricate 1D hollow Ti₃C₂T_x MXene/carbon (MX/C) nanofibers via an electrospinning process and use them as anode materials in LIBs. Compared with the pristine 2D MXene (MX) paste electrode and MXene/carbon (MX/C) paste electrode, the hollow MX/C nanofibers electrode exhibits a greater specific surface area, less self-stacking of flakes, and surface functional groups tailored for LIBs. The LIBs based on the hollow electrode exhibit a higher energy density (306.5 mA h g⁻¹ at 40 mA g⁻¹) than those with the MX paste electrode (81.08 mA h g⁻¹ at 40 mA g⁻¹) and MX/C paste electrode (196.9 mA h g⁻¹ at 40 mA g⁻¹). In addition, the hollow MX/C nanofiber electrode shows a high reversible capacity, proving that it is a promising anode material for LIBs.