Computational Studies on the Electrochemical Performance of Doped and Substituted Ti3C2Tx (T = O, OH) MXene. Issue 9 (22nd September 2022)

• Record Type: Journal Article
• Authors: Das, Mandira; Ghosh, Subhradip
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 9(2022)
• Publication Date: 2022-09-22
• Subjects: Electrochemical Capacitors -- Energy Storage -- Pseudocapacitance -- Supercapacitors -- Theory and Modelling; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac91fd
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Using Density functional theory (DFT) in conjunction with a solvation model, we have investigated the phenomenon of electrode-electrolyte interaction at the electrode surface and its consequences on the electrochemical properties like the charge storage and total capacitance of doped and substituted functionalized Ti3 C2 T x (T = O, OH) supercapacitor electrode. We have studied nitrogen-doped, nitrogen substituted, and molybdenum substituted MXenes in acidic electrolyte H2 SO4 solution. By considering nitrogen doping at different sites, we found that the greatest capacitance is obtained for doping at functional sites. Our results agree well with the available experiment. We also found that the enhancement in capacitances due to nitrogen doping is due to amplifications in the pseudocapacitance. We propose that the primary mechanism leading to the enhanced value of the capacitances due to nitrogen doping is surface redox activity. The performances of substituted systems, on the other hand, are degraded compared to the pristine ones. This suggests that better storage capacities in Ti3 C2 T x electrode can be obtained by doping only. We provide insights into the reasons behind contrasting behavior in doped and substituted systems and suggest ways to further improve the capacitances in the doped system.