Multi-functional ZnS quantum Dots/Graphene aerogel modified separator for high performance lithium-sulfur batteries

Abstract

Lithium-sulfur (Li-S) batteries have been considered as a promising candidate for next-generation energy storage, yet their practical application is limited by the polysulfides (PS) shuttle effect and slow kinetics of sulfur redox reaction. Despite the progress in engineering the separator for Li-S batteries, the separator with the synergistic effect of efficient PS blockage and PS conversion catalysis has not been successfully explored. Here, a zinc sulfide quantum dots/reduced graphene aerogel (ZnS-RGA) modified separator is developed for Li-S batteries. ZnS quantum dots function as the chemically LiPS-anchoring and catalytic sites that can simultaneously accelerate the sulfur redox reaction (SRR) and suppress the shuttle effect, while the 3D porous RGA further physically blocks the migration of LiPS. As a consequence, the Li-S batteries with ZnS-RGA modified separator present a high initial discharge capacity of 1211 mAh g − 1 at 0.1 C and stable cycling performance over 500 cycles at 1 C. We believe the strategy incorporating the SRR catalysts with LiPS-immobilizing separator will be an appealing way for producing high-performance Li-S devices.