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

Abstract

Lithium-sulfur (Li-S) batteries using Li2S and Li-free anodes have emerged as a potential high-energyandsafe battery technology. Although the operation of Li-S fullbatteries based on Li2S has been demonstrated at room temperature,their effective use at a subzero temperature has not been realizeddue to the low electrochemical utilization of Li2S. Here,ammonium nitrate (NH4NO3) is introduced as afunctional additive that allows Li-S full batteries to operateat -10 & DEG;C. The polar N-H bonds in the additivealter the activation pathway of Li2S by inducing the dissolutionof the Li2S surface. Then, Li2S with an amorphizedsurface layer undergoes the modified activation process, which consistsof the disproportionation and direct conversion reaction, throughwhich Li2S is efficiently converted into S-8.The Li-S full battery using NH4NO3 deliversa reversible capacity and cycling stability over 400 cycles at −10 °C.