Turning on Lithium-Sulfur Full Batteries at -10 °C.

Lithium-sulfur (Li-S) batteries using LiS and Li-free anodes have emerged as a potential high-energy and safe battery technology. Although the operation of Li-S full batteries based on LiS has been demonstrated at room temperature, their effective use at a subzero temperature has not been realized due to the low electrochemical utilization of LiS. Here, ammonium nitrate (NHNO) is introduced as a functional additive that allows Li-S full batteries to operate at -10 °C. The polar N-H bonds in the additive alter the activation pathway of LiS by inducing the dissolution of the LiS surface. Then, LiS with an amorphized surface layer undergoes the modified activation process, which consists of the disproportionation and direct conversion reaction, through which LiS is efficiently converted into S. The Li-S full battery using NHNO delivers a reversible capacity and cycling stability over 400 cycles at -10 °C.