Carbonate Ester‐Based Sodium Metal Battery with High‐Capacity Retention at −50 °C Enabled by Weak Solvents and Electrodeposited Anode

battery exhibited the highest capacity retention (compared to room-temperature capacity) in carbonate ester-based SMBs (98.05 % at -25 °C, 91.3 % at -40 °C, 87.9 % at -50 °C, respectively). The cyclic stability of 350 cycles at -25 °C with a high energy efficiency of 96.15 % and 70 cycles at -50 °C can be achieved. Even in chill atmospheric environment with the fluctuant temperature, the battery can still operate over one month. This work provides a new opportunity for the development of low-temperature carbonate ester-based SMBs.