Research progress in non-aqueous low-temperature electrolytes for sodium-based batteries

With the increasing demand and striking upsurge in the price of lithium carbonate, sodium-ion batteries (SIBs) have gained significant attentions due to their abundance over lithium-ion batteries (LIBs). Some prototype SIBs have achieved great progress in terms of energy densities. Although SIBs show a relatively higher tolerance at the low temperature than LIBs due to the weaker cation–solvent interaction, the low-temperature performance of SIBs remains a critical challenge restricted by the electrolyte solidification and sluggish interphasial kinetics. In this review, we briefly cover the latest research progress in usable low-temperature electrolytes for SIBs. In the meantime, the mitigating mechanism and low-temperature performance of the electrolytes in different SIB configurations are also discussed. The merits and demerits of ether-based and carbonate-based electrolytes are compared to demonstrate their potential and limitations, thus providing application principles for ether-based and carbonate-based electrolytes at low temperatures to maximize their advantages. Furthermore, mitigation strategies for low-temperature electrolytes are emphasized to guide the future electrolyte design. Finally, we provide some perspectives on the development of the low-temperature electrolytes for SIBs.