LiF/HCl‐Etched Two‐Dimensional Ti 3 C 2 T x MXene Sheet Coated on Carbon Cloth for Flexible Supercapacitor Studies

Abstract This study demonstrates that an LiF/HCl‐etched two‐dimensional Ti carbide MXene (2D Ti 3 C 2 T x MXene@CC) achieves superior surface quality, with fewer defects, and enhanced functional group attachment and electrochemical performance, relative to the HF‐etched counterpart. The reported method demonstrates improved safety and environmental friendliness, avoiding the risks posed by HF while preserving the MXene's structural integrity, rendering the method ideal for advanced flexible energy storage applications. FESEM and HR‐TEM images confirmed the sheet‐like morphology of the MXene, and AFM revealed its thin‐layered structure. FESEM with EDS mapping confirmed the presence of Ti, C, O, and F in the MXenes. with atomic weight percentages of 65.48%, 16.13%, 9.60%, and 8.82%, respectively. XRD highlighted the octahedral crystalline phase, especially the (002) crystalline plane, within the MXene. The 2D Ti 3 C 2 T x MXene@CC was used as the working electrode in flexible supercapacitor studies, and a mixture of poly(vinyl alcohol) and KOH was used as an electrolyte; a specific capacitance, energy density, and power density of 360.4 F g −1 , 12 Wh kg −1 , and 123 W kg −1 , respectively, were obtained. Furthermore, this flexible supercapacitor exhibited 83.12% capacity retention and 99.42% Coulombic efficiency over 10,000 cycles.