Remarkable Conductivity Design of FeCo₂S₄/MXene 2D Membrane Electrodes for Advanced Pseudocapacitance Characteristic Behavior

Abstract

Supercapacitors (SCs) are promising energy supply systems for various electronics. In this work, we detailed the in situ growth of FeCo 2 S 4 on MXene for asymmetric SCs. Notably, the digital model was first built to explore the relationship between wt (FeCo 2 S 4 ) and capacitance performance, realizing the maximum theoretical capacity (3635.7 F g −1 ) prediction. Furthermore, it was discovered that the synergistic effect of the FeCo 2 S 4 /MXene heterojunction could dramatically improve conductivity and structural stability, which accelerated charge transmission at the electrode/electrolyte interface, resulting in a significant enhancement in electrochemical performance. The FeCo 2 S 4 /MXene electrode exhibited a higher capacitance of 2415.3 F g −1 and a prominent long-term stability of about 90.5%. And the FeCo 2 S 4 /MXene//AC declared an impressive energy density of 68.7 Wh kg −1 at a power density of 800 W kg −1 . The FeCo 2 S 4 /MXene composite systems have great potential for advanced SC systems due to their facile assembly and remarkable electrochemical performance.