MXenes in lithium–sulfur batteries: Scratching the surface of a complex 2D material – A minireview

Abstract

Lithium–sulfur (Li–S) batteries currently face the challenges of low active material utilization and poor cycling stability. A substantial forward leap in the commercialization of sulfur-based batteries can only be accomplished in tandem with the development of optimized materials with specific features capable to promote sulfur redox kinetics and to prevent polysulfide shuttle process. MXene family, a 2D material class derived from layered MAX phases, has a great potential to revolutionize the development of electrodes and chemically active separators for electrochemical energy storage devices due to their inherent high conductivity and self-functionalized surface. Herein, current research progress in the use of MXene materials for enhancing the performance and longevity of Li–S batteries is reviewed. Based on theoretical studies and experimental findings, the relationship between the MXene features and their chemical interaction with sulfur redox species to constrain the shuttling of soluble polysulfide intermediates and the subsequent influence on the cell performance is discussed. Accordingly, this review provides a comprehensive guideline for the rational design of MXene-comprised sulfur cathodes and functional hybrid separators for high-performance Li–S batteries. Finally, some valuable future research directions of MXenes in Li–S batteries are outlined.