Highly Enhanced Pseudocapacitive Performance of Vanadium‐Doped MXenes in Neutral Electrolytes

2D titanium carbide (Ti3C2Tx MXene) is recognized as a promising material for pseudocapacitor electrodes in acidic solutions, while the current studies in neutral electrolytes show much poorer performances. By a simple hydrothermal method, vanadium‐doped Ti3C2Tx 2D nanosheets are prepared to tune the interaction between MXene and alkali metal adsorbates (Li+, Na+, and K+) in the neutral electrolyte. Maintaining the 2D morphology of MXene, the coexisting V3+ and V4+ are confirmed to form surface V–C and V–O species. At a medium doping level of V:Ti = 0.17:1, the V‐doped MXene exhibits the highest capacitance of 365.9 F g−1 in 2 m KCl (10 mV s−1) and excellent stability (5% loss after 5000 cycles), compared to only 115.7 F g−1 of pristine MXene. Density functional theory calculations reveal the stronger alkali metal ion–O interaction on V‐doped MXene surface than unmodified MXene and a further capacitance boost to 404.9 F g−1 using Li+‐containing neutral electrolyte is reported, which is comparable to the performance under acidic conditions. Vanadium‐doped titanium carbide (Ti3C2Tx MXene) nanosheets are prepared via a simple hydrothermal method to tune the interaction between MXene and alkali metal adsorbates (Li+, Na+, and K+) in neutral electrolytes. The strong alkali metal ion–O interaction on the V‐doped MXene surface boosts the capacitance to 404.9 F g−1, which is comparable to the performance under acidic conditions.