摘要
Designing advanced sulfur electrocatalysts has long been heralded as an efficient approach to settle the issues of the dreadful shuttle effect and sluggish reaction kinetics of the lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.Therefore,we designed a hierarchical bimetal defective MgCo LDH@rGO nanosphere as a sulfur electrocatalyst to regulate the LiPSs catalytic conversion behavior,which demonstrated efficient catalytic activity and robust structural stability.The introduction of etching Mg^(2+)formed a hollow structure and Lewis acid points in MgCo LDH@rGO,serving as active sites for effective LiPS immobilization.The excellent conductivity and larger specific surface area of reduced graphene oxide(rGO)levered the utilization of sulfur and alleviated volume expansion during lithiation,rendering enhanced stability.Meanwhile,the vibrant regulation of active sites in the MgCo LDH@rGO resulted in more effective LiPS catalytic conversion and completed Li_(2)S transformation,as revealed by ex-situ X-ray adsorption spectroscopy analysis.Attributed to these inimitable structural features,the Li-S batteries delivered excellent performance under a high areal capacity of over 7 mAh cm^(−2)and remarkable cyclic stability over 500 cycles.This structural design strategy endowed the sulfur cathode with superior LiPS catalytic activity,opening a new insight into high-performance Li-S batteries.
基金
supported by the Natural Sciences and Engineering Research Council of Canada,the University of Waterloo and Waterloo Institute for Nanotechnology,Canada,the Natural Science Foundation of Ningxia,China(grant no.2023AAC01003)
the Natural Science Foundation of China(grant no.22309179).
