Sulfur-Containing Inorganic-Rich Interfacial Chemistry Empowers Advanced Sodium-Ion Full Batteries

Sodium-ion batteries (SIBs) with abundant sodium resources have been considered to be competitive candidates for large-scale energy storage systems. However, undesirable instability of the electrode/electrolyte interface (EEI) at the electrode surface in a commercial ester-based electrolyte results in the unsatisfactory electrochemical performance of SIBs. Herein, robust sulfur-containing inorganic-rich EEI is simultaneously constructed on both Prussian blue (PB) cathode and hard carbon (HC) anode via the film-forming additive, named sulfolane (SL). SL largely participates in the inner Na+ sheath, weakening the coordination of Na+-solvent with accelerated Na+ desolvation and inducing the additive-derived sulfur-containing inorganic-rich interfacial chemistry. These merit the improved reversible capacity, rate performance, and cycling stability of the HC||PB full cell with SL-containing electrolyte. More importantly, the HC||PB pouch cell delivers a high capacity retention of 78.3% after 500 cycles, demonstrating the feasibility of SL in SIBs. This work provides valuable guidance to develop sulfur-containing inorganic-rich interfacial chemistry for advanced SIBs.