Multifunctional reaction interfaces for capture and boost conversion of polysulfide in lithium-sulfur batteries

Lithium-sulfur batteries have gotten a growing number of investigations because of its overwhelming superiority in theoretical energy density and cost. Nevertheless, the application process of lithium-sulfur batteries is severely obstructed by disadvantageous shuttle effect, which arises from the dissolution and migration of intermediate polysulfides and its sluggish conversion kinetics. Herein, we design the conductivity-adsorption-catalysis reaction interface, which is constructed by growing NiCo2S4 nanoparticle on reduced graphene oxide (NiCo2S4@rGO), to afford chemical immobilization and conversion promotion of polysulfides. In this structure, rGO with excellent conductivity can ensure rapid electron transfer and well-distributed NiCo2S4 nanoparticles serve as high-efficiency active sites to anchor polysulfides and accelerate its conversion reaction. Thus, lithium-sulfur batteries with this multifunctional reaction interface deliver improved cycling stability with capacity retention rate of 76% after 500 cycles at 1 C. And a good initial capacity of 776 mAh g−1 is gained under high sulfur loading of 3.6 mg cm−2. This work supplies promising interface design strategies to enhance polysulfides redox kinetics and alleviate shuttle effect for high-performance lithium-sulfur batteries. [Display omitted] •A conductivity-adsorption-catalyze reaction interface is demonstrated.•The lyophilic property and polar surface is more conducive to the electrolyte infiltration and polysulfide adsorption.•NiCo2S4@rGO can effectively boost kinetics of polysulfide conversion reaction.•Using NiCo2S4@rGO in the interlayer exhibits excellent electrochemical performances especially under high sulfur loading.