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. (C) 2020 Elsevier Ltd. All rights reserved.