In situ/operando characterization techniques for rechargeable lithium–sulfur batteries: a review

Abstract

Rechargeable lithium–sulfur (Li–S) batteries have recently attracted global research interest due to their high theoretical specific capacity and energy density. To improve the performance and cycling stability of Li–S batteries, a clear understanding of the electrochemical reaction process and the degradation mechanisms of the sulfur redox chemistry are extremely important. In the past few decades, various advanced in situ/operando characterization tools have emerged, which have facilitated the understanding of the degradation mechanisms and the further development of high-performance Li–S batteries. In this review, we have summarized recent significant advances in in situ/operando characterization techniques for Li–S batteries. In particular, because of the existence of the soluble polysulfide species during the charge/discharge process, many creative ideas have been introduced into in situ/operando characterization of the electrochemical process in Li–S batteries.