Dipolar interaction-mediated molecular anchoring electrolyte enables wide-temperature sodium-ion batteries with enhanced safety and durability

Given intractable challenges faced by practical sodium-ion batteries (SIBs) in safety, ultralong lifespan and broad temperature adaptability with synergistic interfacial compatibility, persistent efforts in electrolyte engineering are imperative to expedite their commercialization. Here we design a molecular anchoring electrolyte with remarkable flame retardancy, oxidative/reductive reliability and electrochemical durability against both electrodes. Through multiple dipolar interactions (δ ⁺ H-δ ^- F, δ ⁺ H-δ ^- O and δ ⁺ H-δ ^- N), a dynamic hierarchical solvation network is constructed and its unique interface stabilization mechanism is revealed by multiscale characterizations and theoretical insights. The electrolyte endows high-voltage phosphate cathode with extraordinary electrochemical durability (87.6% of capacity retention after 5000 cycles) through constructing robust interphases enriched with F and N. Great compatibility with commercial layered oxide further indicates its versatility. Strikingly, the electrolyte also sustains stable operation under extreme temperatures (-60 ~ 70 °C). Our proposed dipolar interaction regulation mechanism provides a new paradigm for designing safe and durable electrolytes, stimulating practical application of wide-temperature SIBs in extreme environment energy storage.