An evaluation of the capacitive behavior of supercapacitors as a function of the radius of cations using simulations with a constant potential method

Author(s)

Paulista Neto, Antenor J. ^[1] ; da Silva, Debora A. C. ^[1] ; Goncalves, Vanessa A. ^{[2, 3]} ; Zanin, Hudson ^[1] ; Freitas, Renato G. ^{[2, 3]} ; Fileti, Eudes E. ^[4]

Affiliation

^[1] Univ Estadual Campinas, Ctr Innovat New Energies, Sch Elect & Comp Engn, Adv Energy Storage Div, Carbon Sci Tech Labs, Av Albert Einstein 400, BR-13083852 Campinas, SP - Brazil

^[2] Univ Fed Mato Grosso, Inst Phys, BR-78060900 Cuiaba, MT - Brazil

^[3] Univ Fed Mato Grosso, Dept Chem, Lab Computat Mat, BR-78060900 Cuiaba, MT - Brazil

^[4] Univ Fed Sao Paulo, Inst Sci & Technol, BR-12247014 Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 24, n. 5, p. 3280-3288, FEB 2 2022.
• Web of Science Citations: 0

Abstract

We report on the atomistic molecular dynamics, applying the constant potential method to determine the structural and electrostatic interactions at the electrode-electrolyte interface of electrochemical supercapacitors as a function of the cation radius (Cs+, Rb+, K+, Na+, Li+). We find that the electrical double layer is susceptible to the size, hydration layer volume, and cations' mobility and analyzed them. Besides, the transient potential shows an increase in magnitude and length as a function of the monocation size, i.e., Cs+ > Rb+ > K+ > Na+ > Li+. On the other hand, the charge distribution along the electrode surface is less uniform for large monocations. Nonetheless, the difference is not observed as a function of the radius of the cation for the integral capacitance. Our results are comparable to studies that employed the fixed charge method for treating such systems. (AU)

• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 14/02163-7 - Development of supercapacitors devices from graphene, carbon nanotubes and diamonds
• Grantee: Hudson Giovani Zanin
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 17/11958-1 - CINE - Advanced Energy Storage Division
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Grants - Research Centers in Engineering Program