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 in safety, 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 flame retardancy, oxidative/reductive reliability and electrochemical durability against various electrodes. Through multiple dipolar interactions (δ+H-δ-F and δ+H-δ-O), 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 positive electrodes with high electrochemical durability (for instance, 87.6% of capacity retention after 5000 cycles at 2 C) through constructing robust interphases containing fluorine and nitrogen elements. Good compatibility with commercial layered oxide positive electrodes further indicates its versatility. Strikingly, the electrolyte also makes it feasible to operate under wide temperature range (−60 ~ 70 °C). Our proposed dipolar interaction regulation mechanism provides an effective approach for designing safe and durable electrolytes, stimulating practical application of wide-temperature sodium-ion batteries in pursuit of sustainable energy storage. Different challenges in safety, lifespan and temperature adaptability with synergistic interfacial compatibility hinder the development of sodium batteries. Here, this work presents a dipolar interaction-mediated molecular anchoring electrolyte to construct robust interphases for durable wide-temperature (−60 ~ 70 °C) sodium batteries.