CommunicationAn in-plane heterostructure of graphene and titanium carbide for efficient polysulfide confinement

•An in-plane heterostructure constructed by graphene and conductive titanium carbide (TiC) is prepared.•A part of graphene was transformed into TiC using graphene as the template and carbon source.•The coating layer constructed by such heterostructures on separator effectively restrains the polysulfide shuttling.

Lithium polysulfide (LiPS) shuttling is one of the main obstacles hindering the practical use of lithium-sulfur (Li-S) batteries. Constructing an interlayer composed of carbon or noncarbon materials on separator is a promising way to restrain the LiPS shuttling, but such a layer always hinders the Li ion diffusion and is hard to realize the reuse of the captured LiPSs. In this study, an in-plane heterostructure constructed by graphene and titanium carbide (TiC) was prepared by directly using graphene as a template and the carbon source to react with TiCl4 under thermal treatment. In this process, graphene was partially transformed into TiC forming such a heterostructure, which is benefit to reducing the Li ion and electron diffusion barrier. Moreover, the TiC has strong affinity towards LiPSs and high conductivity. Thus, the in-plane heterostructures filtered on a separator as a coating layer effectively blocks the shuttle of LiPSs and greatly improves the sulfur utilization and cycling performance, indicating a promising way to promote the practical applications of high performance Li-S batteries.

Graphical abstractDownload high-res image (261KB)Download full-size image