Efficiently Designed Three-Dimensional Architecture of CoMn2O4 Decorated V2CT x MXene for Asymmetric Supercapacitors

The structure, morphology, stoichiometry, and chemical characterization of the V2CTx MXene, CoMn2O4, and V2C@CoMn2O4 nanocomposite, prepared by using a soft template method, have been studied. The electron microscopy studies reveal that the V2C@CoMn2O4 composite incorporates mesoporous spheres of CoMn2O4 within the 2D layered structure of MXene. The specific capacitance of the composite electrode is similar to 570 F g(-1) at 1 A g(-1), which is significantly higher than that of the sum of the individual components. It also exhibits great rate capability and a Coulombic efficiency of similar to 96.5% over 10000 cycles. An asymmetric supercapacitor prototype created with V2C@CoMn2O4//activated carbon outperformed other reported ASCs in terms of achieving a high energy density of 62 Wh kg(-1) at a power density of 440 W kg(-1). The improved response of V2C@CoMn2O4 and ASC is attributed to the enhanced active area available for charge transfer and the synergistic interaction between CoMn2O4 spherical particles and nanolayered MXene. Supporting density functional theory (DFT) calculations are performed to understand the impact of composite heterojunction formation on its detailed electronic structure. Our atomistic simulations reveal that by incorporating CoMn2O4 in V2C, the density of electronic states at the Fermi level increases, boosting the charge transfer characteristics. These modifications in turn enhance the charge storage capabilities of heterojunction. Finally, the merits of the V2C@CoMn2O4 composite electrode are discussed by comparing it with those of other existing high-performance MXene-based composite electrodes.