Universal interface and defect engineering dual-strategy for graphene-oxide heterostructures toward promoted Li–S chemistry

Abstract

Li–S battery is broadly regarded as one of the most promising energy storage systems due to its prominent merits in energy density and theoretical capacity. Nevertheless, existing challenges such as formidable shuttle effect and sluggish redox kinetics hinder its practical application. Herein, we propose a universal interface and defect engineering dual-strategy to design graphene-oxide (G-oxide) hybrids as heterostructured electrocatalysts targeting promoted Li–S chemistry. The employment of direct plasma-enhanced chemical vapor deposition technique allows the in situ formation of graphene over a suite of oxide powders. Benefiting from the creation of heterointerface and carbon/oxygen defects, G-oxide realizes balanced management of polysulfide adsorption, lithium-ion migration and electron transportation, accordingly rendering bi-directional electrocatalysis behaviors for the sulfur conversion. Thus-assembled S/G-oxide cathode affords stable cycling performances even under a sulfur loading of 8.1 mg cm−2 and an electrolyte usage of 4.0 μL mg–1S.