Abstract
Owing to high aspect ratio of edge sites and superior catalytic activity, atomically thin transition metal dichalcogenides (TMDCs) show great promise to tailor the electrolyte/electrode interface properties for high performance lithium-sulfur battery (Li–S battery). However, the TMDCs that engineer the electrode/electrolyte interface are usually produced through chemical hydrothermal methods, which show low crystallinity and thick multilayer structure. Herein, a highly crystalline and atomically thin tungsten disulfides on carbon cloth (WS2@CC) was developed via chemical vapor deposition (CVD) and served as an effective electrode/electrolyte interface for Li–S battery. Our results demonstrate that the atomically thin WS2 with high crystal quality and abundant edges sites can effectively accelerates the redox kinetics of sulfur/lithium polysulfides and regulates the precipitation/decomposition of insoluble Li2S. More importantly, it was revealed that the hierarchical flower-stacked WS2 with excessive exposed catalytic edges shows extremely strong polysulfide adsorption, which causes the sulfur species aggregation and passivation on the WS2@CC surface, thus resulting in deformed rate performance and poor cycling stability as compared to the few-layer WS2@CC. Our work provides a new insight into the structural engineering of TMDCs by CVD for Li–S battery, and suggests the importance of rational chemisorption and catalysis of the interface to realize the high-performance Li–S battery.
[Display omitted]
•A highly crystalline and atomically thin tungsten disulfides on carbon cloth (WS2@CC) was developed.•Atomically thin WS2 with high crystal quality and abundant edges sites can effectively accelerates the redox kinetics.•The hierarchical flower-stacked WS2 shows extremely strong polysulfide adsorption for Li–S batteries.