Fluoroalkoxyaluminate-based ionic liquids as electrolytes for sodium-ion batteries

Author(s)

Fiates, Juliane ; Ratochinski, Rafael H. ; Lourenco, Tuanan C. ; Da Silva, Juarez L. F. ; Dias, Luis G.

• Document type: Journal article
• Source: JOURNAL OF MOLECULAR LIQUIDS; v. 369, p. 12-pg., 2023-01-01.

Abstract

Ionic liquids (ILs) are a promising class of materials because of their unique properties such as high elec-trochemical stability window and intrinsic conductive nature, which are desirable in the development of high-performance electrolytes for energy storage applications. However, the strong Coulombic interac-tions between cation and anion, which contributes to the high viscosity of the ILs, are the main bottleneck in their applications as electrolytes. Weakly coordinated anions-based ILs are a class of electrolytes with high degree of charge delocalization, which leads to weak ionic interactions and improves the ionic trans-port. Here, we have performed molecular dynamics simulations and density functional theory calcula-tions of imidazolium and ammonium-based ionic liquids in different Na' mole fractions comprising the weakly coordinated fluoroalkoxyaluminate anion ([Al(Ohfip)4]-). The results have shown that the 0.8-scaled OPLS-AA based force field predicted the transport properties of neat systems with good accu-racy. The Na'-[anion] pair structural and lifetime analysis suggest that the fluoroalkoxyaluminate pro-motes lower lifetimes and facilitates the mobility of Na' in these systems. Although the cations provided similar transport and structural results for Na', the theoretical electrochemical stability win-dows of the ammonium-derived ILs exhibited values above 5.0 eV, which indicates good performance for energy storage applications.(c) 2022 Elsevier B.V. All rights reserved. (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: 18/21401-7 - Multi-User Equipment approved in grant 2017/11631-2: cluster computational de alto desempenho - ENIAC
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 19/23681-0 - From ab initio to continuum methods to the screening of sodium-ion battery materials
• Grantee: Tuanan da Costa Lourenço
• Support Opportunities: Scholarships in Brazil - Post-Doctoral