Electrochemical and in-situ X-ray diffraction studies of Ti3C2Tx MXene in ionic liquid electrolyte

摘要

2D titanium carbide (Ti3C2TxMXene) showed good capacitance in both organic and neat ionic liquid electrolytes,udbut its charge storage mechanism is still not fully understood. Here, electrochemical characteristics of Ti3C2Txudelectrode were studied in neat EMI-TFSI electrolyte. A capacitive behavior was observed within a large electrochemicaludpotential range (from −1.5 to 1.5 V vs. Ag). Intercalation and de-intercalation of EMI+ cations and/orudTFSI− anions were investigated by in-situ X-ray diffraction. Interlayer spacing of Ti3C2Tx flakes decreases duringudpositive polarization, which can be ascribed to either electrostatic attraction effect between intercalated TFSI−udanions and positively charged Ti3C2Tx nanosheets or steric effect caused by de-intercalation of EMI+ cations.udThe expansion of interlayer spacing when polarized to negative potentials is explained by steric effect of cationudintercalation.