Energy and power performances of binary mixtures of ionic liquids in planar and porous electrodes by molecular dynamics simulations

Autor(es)

Ferreira, Pedro H. L. ; Sampaio, Abner M. ; Siqueira, Leonardo J. A.

• Tipo de documento: Artigo Científico
• Fonte: Electrochimica Acta; v. 410, p. 11-pg., 2022-04-01.

Resumo

Binary mixtures of ionic liquids are interesting alternatives to tailor ionic liquids properties. Some of them have been proposed as electrolytes for supercapacitors. Herein, we performed molecular dynamics simulations of planar and porous electrodes with binar y mixtures of ionic liquids comprising the 1-ethyl-3-methyl-imidazoliumbis(trifluoromethane-sulfonyl)imide ([EMIM][NTf2]) and 1-ethyl-3-methyl-imidazoliumtetrafluoroborate ([EMIM] [BF4]), increasing the mole fraction of the latter (xBF4) from 0 to 1. The energy densities calculated from the simulations increase monotonically with x(BF4), accordingly with available experimental results [Angew. Chem. Int. Ed. 2015, 54, 1 - 5]. Considering that the electrode simulations were dealt with the constant potential model, the characteristic charging times were calculated for planar and porous electrodes. The devices containing only [EMIM] [NTf2] charge slower than electrolytes with x(BF4) > 0.0, and the fastest charging happens inx(BF4) = 1.0 V. These features are related to the higher [NTf2]-electrode interaction and also to the smaller size of [BF4](-). For porous electrode, the calculated Ragone plot indicates that [EMIM][BF4] outperforms a l l the other electrolytes with a voltage of 3.0 V in terms of energ y and power densities. In the system of best performance, there are considerable contributions of co-ion desorption and counter-ion adsorption mechanisms in the negative and positive electrodes, respectively. (AU)

• Processo FAPESP: 19/18125-0 - Estudo computacional de materiais com aplicação em armazenamento de energia
• Beneficiário: Leonardo José Amaral de Siqueira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• 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
• Processo FAPESP: 18/21401-7 - EMU concedido no processo 2017/11631-2: cluster computacional de alto desempenho - ENIAC
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários