Density-Functional Tight-Binding Molecular Dynamics Simulation of Graphene Oxide-Ionic Liquid Electrolyte Interface in Sodium-Ion Batteries

Sodium-ion batteries present an attractive and abundant alternative to lithium-ion systems, utilizing ionic liquid electrolytes and carbon-based anodes to achieve high performance. Nonetheless, the stability can be influenced by interfacial chemical interactions. The present study employs a divide-and-conquer-type density-functional tight-binding molecular dynamics alongside Grimme’s DFT-D3 dispersion, to explore graphene oxide (GO) anodes in conjunction with NaFSA/[C3C1Pyr]FSA electrolytes. The level of concentration has a significant impact on the concentration, resulting in a decrease in the intensity of the RDF peaks. The hydroxyl-based GO demonstrates remarkable stability, as evidenced by the detection of only one new molecule at a concentration of 3 M. The interactions between sodium and FSA ions are predominant, with minor contributions from OH and H2O associated with hydroxyl-based GO. Sodium ions demonstrate significant diffusion across the graphene surface, where an epoxide-based GO reveals charge fluctuations while a hydroxide-based one exhibits charge delocalization.