Antimonene Engineered Highly Deformable Freestanding Electrode with Extraordinarily Improved Energy Storage Performance

Advanced 2D materials have spurred great interest as a new paradigm in pursuing improved energy storage performance. Herein, for the first time, antimonene is utilized as an effective active component for constructing highly deformable and editable freestanding film electrodes, as the basis of a supercapacitor with record-breaking electrode performance. The insertion of antimonene is able to improve the environmental stability of the antimonene/MXene composite electrode and remarkably enhance the energy storage capability in both protic and neutral electrolytes. Notably, an ultrahigh specific volumetric capacitance of 4255 F cm(-3) is achieved by the electrode tested in a1 m H2SO4 electrolyte, which represents the state-of-the-art value reported to date for supercapacitor electrodes based on MXenes. The flexible supercapacitors constructed by the composite electrode, also demonstrate highly competitive energy and power densities: 459.75 mWh cm(-3) and 3.12 W cm(-3) for the asymmetrical one with a much widened potential window of 2 V in neutral electrolyte; 112.52 mWh cm(-3) and 1 W cm(-3) for the symmetrical configuration with an outstanding capacitance of 1265 F cm(-3) in acidic media. This work sheds new light on the fabrication of high-performance supercapacitor electrodes with functionalities in different electrolyte media and various device configurations.