Mn2+ Pre-Embedded V2CTx MXene as a Negative Electrode for Lithium-Ion Batteries

V2CTx MXene is a promising anode material for lithium-ion batteries due to its high electrical conductivity and abundant active sites. However, the spatial environment within its layers restricts the function of its energy storage electrode. Herein, V2CTx MXene was synthesized via an NH4F–HCl-assisted hydrothermal etching method, followed by electrochemical pre-intercalation of Mn2+ using a three-electrode system. Structural characterizations confirm that Mn2+ pre-intercalation effectively modulates the interlayer environment, reduces surface F terminations, and maintains a stable layered structure. Electrochemical measurements demonstrate that the Mn2+-intercalated V2CTx MXene delivers an enhanced reversible capacity of 313.6 mAh·g−1 after 200 cycles, outperforming pristine V2CTx MXene. The improved rate capability and reduced charge transfer resistance indicate accelerated ion/electron transport kinetics. This study provides an effective interlayer engineering strategy for improving MXene-based lithium-ion storage performance.