Salt-in-water and water-in-salt electrolytes: the effects of the asymmetry in cation and anion valence on their properties

Autor(es)

Messias, Andresa ^[1] ; da Silva, Debora A. C. ^[2] ; Fileti, Eudes E. ^[3]

Afiliação do(s) autor(es)

^[1] Fed Univ ABC, Ctr Nat & Human Sci, BR-09210170 Santo Andre, SP - Brazil

^[2] 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

^[3] Univ Fed Sao Paulo, Inst Sci & Technol, BR-12247014 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. 24, n. 1 NOV 2021.
• Citações Web of Science: 0

Resumo

We investigated the structural, dynamic, energetic, and electrostatic properties of electrolytes based on the ion pairs LiCl and Li2SO4. Atomistic molecular dynamics simulations were used to simulate these aqueous electrolytic solutions at two different concentrations 2 M (normal) and 21 M (superconcentrated, WiSE). The effects of the valence asymmetry of the Li2SO4 electrolyte were also discussed for both salt concentrations. Our results differ in the physical aspect of pure electrolytes, showing the drastic effect of high concentration, in particular on the viscosity, which is dramatically increased in WiSE. This is a consequence of their reduced ionic mobility and has a direct effect on ionic conductivity. Also, our results for graphene-based supercapacitors, as indicated by some experimental work, do not indicate any better performance of WiSEs over normal electrolytes. In fact, the differences in the total capacitance, due to the concentration of ions, presented by both electrolytes are negligible. The valence asymmetry can be clearly observed in some properties but for most of them its effects could not be quantified or isolated. (AU)

• Processo FAPESP: 17/11631-2 - CINE: desenvolvimento computacional de materiais utilizando simulações atomísticas, meso-escala, multi-física e inteligência artificial para aplicações energéticas
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia