Weakly solvating electrolytes (WSE) can favor reversible Na batteries at -40 °C for some extreme applications because of the low desolvation energy. However, it is challenging to enable reversible Na batteries at lower temperatures. Herein, we uncover that the low ionic conductivity of WSE reduces reaction kinetics at -60 °C. Accordingly, a highly conductive weakly solvating electrolyte (HCWSE) is designed by introducing additives of strongly solvating solvents and the dilution of NaPF