Manipulation of electrochemical properties of MXene electrodes for supercapacitor applications by chemical and magnetic disorder

Abstract

The potential of two-dimensional MXenes as electrodes in supercapacitor applications has been studied extensively. However, the role of chemical and magnetic disorder in their electrochemical parameters, e.g., capacitance, has not been explored yet. In this work, we have systematically addressed this for V_2−xMn_xCO₂ MXene solid solutions with an analysis based upon the results from first-principles electronic structure calculations. We find that the variations in the total capacitance over a voltage window depend on the degree of chemical and magnetic disorder. In the course of our investigation, it was also found that the magnetic structure on the surface can substantially influence the redox charge transfer, an as yet unexplored phenomenon. A significantly large charge transfer and thus a large capacitance can be obtained by manipulating the chemical composition and the magnetic order of the surfaces. These findings can be useful in designing operational supercapacitor electrodes with magnetic constituents.