Unraveling Polysulfide's Adsorption and Electrocatalytic Conversion on Metal Oxides for Li-S Batteries

Lithium sulfur (Li-S) batteries possess high theoretical capacity and energy density, holding great promise for next generation electronics and electrical vehicles. However, the Li-S batteries development is hindered by the shuttle effect and sluggish conversion kinetics of lithium polysulfides (LiPSs). Designing highly polar materials such as metal oxides (MOs) with moderate adsorption and effective catalytic activity is essential to overcome the above issues. To design efficient MOs catalysts, it is critical and necessary to understand the adsorption mechanism and associated catalytic processes of LiPSs. However, most reviews still lack a comprehensive investigation of the basic mechanism and always ignore their in-depth relationship. In this review, a systematic analysis toward understanding the underlying adsorption and catalytic mechanism in Li-S chemistry as well as discussion of the typical works concerning MOs electrocatalysts are provided. Moreover, to improve the sluggish adsorption-diffusion-conversion process caused by the low conductive nature of MOs, oxygen vacancies and heterostructure engineering are elucidated as the two most effective strategies. The challenges and prospects of MOs electrocatalysts are also provided in the last section. The authors hope this review will provide instructive guidance to design effective catalyst materials and explore practical possibilities for the commercialization of Li-S batteries.

Automated summary

Lithium sulfur (Li-S) batteries hold great promise for next generation electronics and electrical vehicles due to their high theoretical capacity and energy density. However, the development of Li-S batteries is hindered by the shuttle effect and sluggish conversion kinetics of lithium polysulfides (LiPSs). This review provides a systematic analysis of the adsorption and catalytic mechanism in Li-S chemistry, discussing the role of metal oxides (MOs) as efficient catalysts and proposing oxygen vacancies and heterostructure engineering as effective strategies to improve the sluggish adsorption-diffusion-conversion process. The challenges and prospects of MOs electrocatalysts in Li-S batteries are also discussed.