Trends in Na-Ion Solvation with Alkyl-Carbonate Electrolytes for Sodium-Ion Batteries: Insights from First-Principles Calculations

• DOI: 10.1021/acs.jpcc.5b04706
• Publication Date: 2015-09-15T18:11:51Z
• Authors: Mehdi Shakourian-...; Ganesh Kamath; Kassiopeia Smith; Hui Xiong; Subramanian K. R....
• Keywords: Diethyl carbonate; Dimethyl carbonate; Propylene carbonate; Carbonate Ion

Classical molecular dynamics (MD) simulations and M06-2X hybrid density functional theory calculations have been performed to investigate the interaction of various nonaqueous organic electrolytes with Na+ ion in rechargeable Na-ion batteries. We evaluate trends solvation behavior seven common namely pure carbonate solvents (ethylene (EC), vinylene (VC), propylene (PC), butylene (BC), dimethyl (DMC), ethyl methyl (EMC), diethyl (DEC)) four binary mixtures carbonates (EC:PC, EC:DMC, EC:EMC, EC:DEC). Thermochemistry for ion, coordinated clusters obtained from simulations, show that formation Na-carbonate complexes is exothermic proceeds favorably. Based on highest binding energy (ΔEb), enthalpy (ΔH(sol)), Gibbs free (ΔG(sol)) values solvents, our results conclusively EC mixture (EC:PC) are best sodium-ion based Quantum chemical analyses understand observed solvation. atoms molecules (QTAIM) analysis shows interactions classified as a closed-shell (electrostatic) interaction. The localized orbital decomposition (LMO-EDA) also indicates electrostatic term (ΔEele) between has value confirms QTAIM about nature noncovalent (NCI) plots indicate responsible strong weak attractive interactions. Density state (DOS) HOMO–LUMO gap EC, VC, PC, BC, DMC, EMC, DEC increases they interact although decreases addition an electrolyte additive EMC. Calculated these quantum suggest EC:PC emerge batteries, which excellent agreement previously reported silico experimental results.