Recent advances of metal phosphides for Li-S chemistry

Li-S batteries have been considered as one of advanced next-generation energy storage systems owing to their remarkable theoretical capacity (1672 mAh g(-1)) and high energy density (2600 Wh kg(-1)). However, critical issues, mainly pertaining to lithium polysulfide shuttle and slow sulfur reaction kinetics, have posed a fatal threat to the electrochemical performances of Li-S batteries. The situation is even worse for high sulfur-loaded and flexible cathodes, which are the essential components for practical Li-S batteries. In response, the use of metal compounds as electrocatalysts in Li-S systems have been confirmed as an effective strategy to date. Particularly, recent years have witnessed many progresses in phosphides-optimized Li-S chemistry. This has been motivated by the superior electron conductivity and high electrocatalytic activity of phosphides. In this tutorial review, we offer a systematic summary of active metal phosphides as promoters for Li-S chemistry, aiming at helping to understanding the working mechanism of phosphide electrocatalysts and guiding the construction of advanced Li-S batteries. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.