Electrochemically Intercalated Ti₃C₂ MXene Bulk for Expanding Interlayer Spacing and Enhancing Supercapacitor Performance

Tuning the interlayer spacing of 2D MXenes bulk mainly focuses on hydrothermal intercalation, physiotherapy intercalation, and ion exchange intercalation. Nevertheless, the feasibility of electrochemical intercalation technology for expanding the interlayer spacing of Ti₃C₂ MXene bulk is not yet clear, and further research is required to advance it. Here, we employed an electrochemical intercalation technology to successfully embed metal cations (K⁺ and Na⁺) into the interlayer structure of Ti₃C₂ MXene bulk, expanding the interlayer spacing from ∼10.50 to ∼13.10 Å by K⁺ intercalation, which can broaden electron/ion transport channels and enhance supercapacitor performance. Compared to the pristine Ti₃C₂ MXene bulk, the specific capacitance value increased by a factor of 2.8. Moreover, the intercalated MXene also exhibits excellent rate capability, with an increase from 47.32 to 70.20%. This work opens up a new path for the modification of Ti₃C₂ MXene bulk.