Rechargeable Na–SO2Battery with Ethylenediamine Additive in Ether‐Based Electrolyte

Abstract

AbstractRechargeable metal–SO2batteries have drawn tremendous attention because it can accelerate SO2fixation/utilization and offer high energy density. Herein, a rechargeable Na–SO2battery based on an ether‐based liquid electrolyte with an ethylenediamine (EDA) additive is realized via the reversible formation/decomposition of Na2S2O4. Experimental investigations reveal that the EDA additive provides three benefits by simultaneously decreasing the overall electrode polarization, increasing the full discharge capacity, and improving battery cyclability. At a current density of 250 mA g−1, the full discharge capacity of the battery with the EDA additive is more than twice of a similar system in the absence of EDA. In addition to the significantly enhanced capacity, the as‐assembled Na–SO2battery demonstrates excellent cyclic stability after 200 cycles, which is equivalent to a total duration of 1600 h. Moreover, the corrosion resistance of Na anode is strengthened with the aid of EDA in the SO2‐containing liquid electrolyte. This work will pave the way for Na–SO2batteries as a promising battery technology toward both pollutant gas utilization and energy storage.