A multifunctional gel coating design for simultaneous interface amelioration, polysulfide adsorption and redox regulation in lithium-sulfur batteries

A unique gel polymer coating strategy with multiple distinctive functions such as interface amelioration, polysulfide adsorption and redox regulation was proposed for developing advanced Li-S batteries. [Display omitted] •A polymer composite membrane with rapid gelation function was introduced on the sulfur cathode.•The novel gel coating design allows for facile ion transport and effective polysulfide entrapment.•The catalysis effect and electric activation deriving from PEOOT:PSS achieve redox regulation. Surface modification on the sulfur cathode by an extra coating design always helps to restrict the polysulfide immigration to the Li anode and offers good accommodation for the cathode volume change, in favor of improving sulfur utilization and cycle stability. This work aims to further develop the coating technology by introducing a unique polymer membrane with rapid gelation function on the top of sulfur cathode. The novel coating strategy combines the advantages of conventional solid coating and gel polymer electrolyte by integrating the two units, allowing for facile ion transport at the interface, flexible surface protection and effective polysulfide immobilization. Also, the catalysis effect and electric activation deriving from the conductive component in the gelled coating, further achieve the redox regulation for sulfur conversion. Finally, these factors make distinct contributions to the overall improvement of Li-S battery performance.