2D MXene Anodes with Engineered Electrolyte for High‐Performing Lithium‐Ion Batteries in Extreme Cold

Abstract Lithium‐ion batteries (LIBs), while widely adopted, suffer from severe performance losses at subzero temperatures due to sluggish Li ⁺ ion diffusion, increased interfacial resistance, and electrolyte freezing. In this study, the use of titanium carbide (Ti ₃ C ₂ T _x ) MXene is investigated as an anode material to overcome these limitations with high electrical conductivity, large interlayer spacing, and pseudocapacitive charge storage enabling efficient lithium‐ion transport even at low temperatures. Electrochemical characterization demonstrates that Ti ₃ C ₂ T _x MXene electrodes provide significantly lower charge‐transfer resistance and superior low‐temperature performance than graphite, delivering 31.7 mAh g ⁻¹ at −70 °C (C/30 rate) while graphite exhibits negligible capacity even at −50 °C. These performance enhancements are enabled by the pseudocapacitive behavior of Ti ₃ C ₂ T _x MXene and its surface terminations, which facilitate rapid lithium‐ion transport—a mechanism confirmed by density functional theory (DFT) calculations. The combination of Ti ₃ C ₂ T _x MXene electrodes and dipropyl ether (DPE)‐based lithium bis(fluorosulfonyl)imide (LiFSI) electrolyte—which retains ≈67% of its room‐temperature ionic conductivity at −10 °C—enables stable electrochemical performance in extreme cold, surpassing the operational limits of conventional lithium‐ion batteries. To the best of this knowledge, this is the first report of functional lithium‐ion battery operation down to −70 °C using a Ti ₃ C ₂ T _x MXene anode and DPE‐based electrolyte, highlighting Ti ₃ C ₂ T _x MXene's promise as a next‐generation anode.