Boosting electrochemical kinetics of S cathodes for room temperature Na/S batteries

Due to the low cost and high energy density, the room temperature (RT) Na/S battery system is deemed as one of the best potential energy-storage systems. However, various issues still severely hinder its practical applications, especially the shuttle effect caused by soluble sodium polysulfides (NaPSs) and the low conversion efficiency of S8 and Na2S2/Na2S in S cathodes. Recently, various strategies were adopted into RT-Na/S batteries to boost the electrochemical kinetics of S cathodes, which are capable of significantly accelerating (or altering) the redox process and mitigating the shuttle effect of S cathodes. Herein, the representative works have been systematically reviewed, with emphasis on the roles of carbon-based hosts, covalent S composites, catalytic metal-modified hosts, and other functional components. Furthermore, the future challenges and research directions for the S cathodes have also been prospected in detail to provide guideline for the development of RT-Na/S batteries.