Turning on Lithium–Sulfur Full Batteries at −10 °C
Hun Kim, Jang‐Yeon Hwang, Young-Geun Ham, Ha‐Neul Choi, Muhammad Hilmy Alfaruqi, Jaekook Kim, Chong Seung Yoon, Yang‐Kook Sun
Abstract
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.