Enhancing the ion accessibility of Ti3C2Tx MXene films by femtosecond laser ablation towards high-rate supercapacitors

Abstract

MXenes have attracted tremendous attention in the area of electrochemical energy-storage devices owing to their high electrical conductivity, pseudocapacitance and two-dimensional lamellar structure. Nevertheless, MXene flakes intrinsically tend to lie flat and restack, resulting in highly tortuous ion transport pathways and inferior ion accessibility. Herein, we develop a femtosecond laser ablation strategy to fabricate flexible and high-performance MXene ribbon supercapacitor electrodes. The fabricated MXene ribbons have porous edges with exposed continuous lamellar channels, which shortens the H+ transport pathways, impregnates with sufficient electrolyte, benefits for H+ intercalation and ion storage. The resultant MXene ribbons exhibit high specific capacitance (1308.3 mF/cm2), good rate capability and long cycling life (95% capacitance retention and 92% coulombic efficiency after 30,000 cycles). This work provides a new strategy for the rational structure design of high-rate MXene-based supercapacitor electrodes and lays the foundation for the next generation high-performance energy storage devices.