(232e) Ester-Based Electrolytes for Na-Ion Battery

Sodium-ion batteries (SIBs) emerge as an alternative or complement to the prevailing lithium-ion batteries (LIBs), and it have attracted a decade of intensive research efforts. In the research of electrolyte design, non-aqueous carbonate solvents (the combination of cyclic and linear carbonate) have been the main choice for the SIBs. However, carbonated-based electrolyte has limitations in ionic transport and melting point, thus limit fast charge and low temperature performance. Esters with low viscosity and low melting point are usually used as co-solvent in carbonated-based electrolyte to enhance the fast charge and low temperature performance. However, the use of linear or cyclic esters as major solvent in SIBs have not been explored. There are several studies use linear esters as sole electrolyte solvents in LIBs, but the differences between sodium and lithium batterie in terms of their chemistry/electrochemistry properties open opportunities to apply esters in SIBs. In this project, we investigate the physical and electrochemical performance of a series of esters in the context of SIBs electrolytes, figure out the relationship between the chemical structure of solvent with the Li ion solvent shell, and provide strategies to optimize the electrolyte formulation.