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

Lithium-sulfur (Li-S) batteries using Li 2 S 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 Li 2 S has been demonstrated at room temperature, their effective use at a subzero temperature has not been realized due to the low electrochemical utilization of Li 2 S. Here, ammonium nitrate (NH 4 NO 3 ) 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 Li 2 S by inducing the dissolution of the Li 2 S surface. Then, Li 2 S with an amorphized surface layer undergoes the modified activation process, which consists of the disproportionation and direct conversion reaction, through which Li 2 S is efficiently converted into S 8 . The Li-S full battery using NH 4 NO 3 delivers a reversible capacity and cycling stability over 400 cycles at -10 °C.