Reviving ether-based electrolytes for sodium-ion batteries

The development of ether-based electrolytes has significant challenges, primarily caused by the irreversible co-intercalation of ether and Li+ into commercial graphite, which excluded ether from use in commercial lithium-ion batteries (LIBs). However, the explosive development of sodium-ion batteries (SIBs) in recent years has driven a revival in ether-based electrolytes, due to their superior rate capability and low temperature suitability. In this review, we trace the evolution of ether-based electrolytes, from rise and subsequent decline to their current revival. We provide comprehensive analysis of the compatibility mechanisms between ether-based electrolytes and both anodes and cathodes in SIBs. Furthermore, we assess the feasibility of commercializing ether-based electrolytes, considering key factors such as electrochemical performance, safety and cost. Finally, we highlight critical challenges that must be overcome, from fundamental research to large-scale commercialization, and provide theoretical guidance for future development and innovation of ether-based electrolytes.