Achieving long-cycling sodium-ion full cells in ether-based electrolyte with vinylene carbonate additive

Abstract

The sodium-ion full cell can be employed in the ether-based electrolyte by the addition of VC and exhibits long term cycling stability and high capacity retention. • NaCF 3 SO 3 -DGM + 5wt% VC electrolyte could make sodium-ion full cells applicable. • The sodium-ion full cell with the electrolyte exhibits long term cycling stability. • VC can be synergistically oxidized with DGM to form integrity CEI layers. Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously. Ether-based electrolytes, preference of anode materials, cannot match with high-potential cathodes failing to apply in full cells. Herein, vinylene carbonate (VC) as an additive into NaCF 3 SO 3 -Diglyme (DGM) could make sodium-ion full cells applicable without pre-activation of cathode and anode. The assembled FeS@C || Na 3 V 2 (PO 4 ) 3 @C full cell with this electrolyte exhibits long term cycling stability and high capacity retention. The deduced reason is additive VC, whose HOMO level value is close to that of DGM, not only change the solvent sheath structure of Na + , but also is synergistically oxidized with DGM to form integrity and consecutive cathode electrolyte interphase on Na 3 V 2 (PO 4 ) 3 @C cathode, which could effectively improve the oxidative stability of electrolyte and prevent the electrolyte decomposition. This work displays a new way to optimize the sodium-ion full cells easily with bright practical application potential.