The severe shuttle effect of polysulfides (LiPSs) and the slow liquid-solid phase conversion are the main obstacles hindering the practical application of lithium-sulfur (Li-S) batteries. Separator modification with a high-activity catalyst can boost LiPSs conversion and suppress their shuttle effect. In this work, multi-heterostructured MXene/NiS/CoS with rich S-vacancies was constructed facilely with a hydrothermal and high-temperature annealing strategy for separator modification.
View Article and Find Full Text PDFDue to the "shuttle effect" and low conversion kinetics of polysulfides, the cycle stability of lithium sulfur (Li-S) battery is unsatisfactory, which hinders its practical application. The Mott-Schottky heterostructures for Li-S batteries not only provide more catalytic/adsorption active sites, but also facilitate electrons transport by a built-in electric field, which are both beneficial for polysulfides conversion and long-term cycle stability. Here, MXene@WS heterostructure was constructed by in-situ hydrothermal growth for separator modification.
View Article and Find Full Text PDFTransition-metal compounds can be used as electrocatalysts to expedite polysulfide conversion effectively in lithium-sulfur batteries. However, insufficient conductivity and tedious preparation process still limit their practical applications. In this work, NiCo alloy nanoparticles embedded in hollow carbon spheres (NiCo@HCS) are fabricated via a facile, template-free strategy from the NiCo-metal-organic framework (MOF) precursor and used as electrocatalysts for separator modification.
View Article and Find Full Text PDFEfficient and durable electrocatalysts are important for polysulfide conversion in high-performance Li-S batteries. Herein, we report a sacrificial template strategy to synthesize a sulfur/nitrogen-codoped carbon-supported manganese (Mn) single-atom catalyst (Mn/SNC). The synthesis is enabled by fabricating a novel precursor, i.
View Article and Find Full Text PDFIn order to overcome the shuttling effect of soluble polysulfides in lithium-sulfur (Li-S) batteries, we have designed and synthesized a creative MoS-MoO/carbon shell (MoS-MoO/CS) composite by a HO-enabled oxidizing process under mild conditions, which is further used for separator modification. The MoS-MoO heterostructures can conform to the CS morphology, forming two-dimensional nanosheets, and thus shorten the transport path of lithium ion and electrons. Based on our theoretical calculations and experiments, the heterostructures show strong surface affinity toward polysulfides and good catalytic activity to accelerate polysulfide conversion.
View Article and Find Full Text PDFLithium-sulfur batteries (LSBs) have gained intense research enthusiasm due to their high energy density. Nevertheless, the 'shuttle effect' of soluble polysulfide (a discharge product) reduces their cycling stability and capacity, thus restricting their practical application. To tackle this challenging issue, we herein report a sulfonated covalent organic framework modified separator (SCOF-Celgard) that alleviates the shuttling of polysulfide anions and accelerates the migration of Liions.
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