Metal layer intercalation with Mxene to enhance the performance of supercapacitor: Using DFT approach

Supercapacitors have attracted significant attention as energy storage devices due to their large power efficiency. Sc-based Mxenes is a potential candidate for the electrode of supercapacitors (SC) because of its superior properties, such as extraordinary electronic characteristics and excellent carrier mobility . In this research work, Sc 2 CO 2 /Sc 2 CO 2 (M/M) homo-bilayer and Sc 2 CO 2 /X/Sc 2 CO 2 (X = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) hetero-trilayer structures are investigated using DFT. The structural properties, density of states , quantum capacitance, average quantum capacitance, surface charge density, work function , total interlayer charge transfer, integrated charge density, isosurface charge density difference, and bader charge analysis of homo-bilayer and hetero-trilayer are studied. The DFT-D3 method with the Becke-Johnson damping function is used a as dispersion correction factor for all the calculations for the bi- and tri-layers. Results revealed that the insertion of the transition metal layer as interfacial between the bilayer of Sc 2 CO 2 significantly enhanced the C Q and Q. For the aqueous system, all the bi- and tri-layer exhibited asymmetrical behavior except M/V/M, M/Fe/M, and M/Cu/M trilayer. The calculated results show that M/Zn/M (−906.75μC/cm 2 ) and M/Fe/M (925μC/cm 2 ) hetero-trilayer are the best cathode and anode respectively. In the case of an ionic/organic system, all the bilayers have asymmetrical behavior except the M/V/M hetero-trilayer. The calculated findings illustrate that M/Mn/M (1538.5μC/cm 2 ) and M/Fe/M (−1416.4μC/cm 2 ) hetero-trilayer is the best anode and cathode respectively. The findings reveal that hetero-trilayer structures give better results as compared to monolayer and homo-bilayer structures. • Hetro layers give better results as comapred mono and homo bilayers. • Interfacial layer between the bilayer of Sc 2 CO 2 that enhance the C Q and Q significantly. • M/Zn/M and M/Fe/M trilayer are best cathode and anode for aqueous system. • M/Mn/M and M/Fe/M trilayer is the best anode and cathode for ionic/organic system.