Sodium-ion batteries require electrolytes that withstand high voltages and low temperatures for commercial use. Here, authors design a non-flammable sulfonamide solvent with a melting point as low as −86 °C, enabling stable, conductive interphases on both electrodes. This electrolyte allows 1-Ah pouch cells to retain capacity at −60 °C/−70 °C and achieve long cycling stability (up to 81.6% after 1000 cycles at 4.2 V).
- Xinke Cui
- Qunfang Li
- Weijiang Xue