A Minimal Hybrid-chain Ether Electrolyte Enables Wide-Temperature Sodium-Ion Batteries

Abstract

A minimal hybrid-chain ether electrolyte enables wide-temperature sodium-ion batteries (SIBs) by combining short-chain dimethoxyethane (G1) and long-chain triglyme (G3) to balance Na+ solvation and interfacial chemistry. It lowers the freezing point to −60.6 °C, maintains 1.23 mS cm−1 conductivity at −40 °C, and induces a temperature-adaptive SEI, delivering 253.5 mAh g−1 at −40 °C and stable pouch-cell operation from −40 to 50 °C.