Elevated polysulfide regulation by an ultralight all-CVD-built ReS2@N-Doped graphene heterostructure interlayer for lithium–sulfur batteries

Lithium–sulfur battery is amongst the most promising next-generation energy storage technology owing to their high theoretical capacity and energy density. Nevertheless, the notorious shuttle effect of lithium polysulfides (LiPSs) seriously impedes its practical applications. Here, we report an all-CVD approach to realize the direct growth of ReS2@N-doped graphene (NG) heterostructure, which serves as an ultralight high-performance interlayer for elevated LiPS regulation via easy transfer onto the commercial separator. In contrast to the traditional interlayers constructed via vacuum filtration of nanostructured materials that inevitably increase the thickness and weight of the separator, our all-CVD-enabled ReS2@NG film possesses an area of 15 mm × 100 mm, a thickness of ~0.5 μm and a negligible areal weight of 80–90 μg cm−2. Benefiting from the two-dimensional (2D) vertically-erected nanostructure, adsorptive ReS2-conductive NG interface, and favorable electrical conductivity, thus-derived ReS2@NG interlayer readily enhances reaction kinetics for LiPS conversion and boosts the reutilization of trapped LiPS whilst guaranteeing smooth transportation of lithium ions. Accordingly, an initial discharge capacity of 854 mAh g−1 with an average capacity decay of 0.064% per cycle after 800 cycles can be harvested at 2.0 C. Even at a high sulfur loading of 6.4 mg cm−2, an initial areal capacity of 6.1 mAh cm−2 can be gained, which still retains 5.8 mAh cm−2 after 40 cycles at 0.1 C. This work is anticipated to shed light upon the construction of CVD-enabled versatile 2D heterostructures for enriching the interlayer design with multifunctionality and cost-effectiveness.