Engineering Bi/V/Mo-Based Multicomponent Heterostructure Electrocatalyst Toward Robust Lithium-Sulfur Batteries and...

The sluggish reaction kinetics and formidable shuttle effect of soluble lithium polysulfides (LiPSs) are thorny problems for the future industrialization of lithium-sulfur (Li-S) batteries. Therefore, exploring efficient electrocatalysts to capture LiPSs and accelerate their conversion is highly desirable yet tremendously challenging. Herein, a high-efficiency Bi/Bi₂O₃/VMoN@rGO electrocatalyst with multifunctional active sites and multilevel heterointerfaces is elaborately designed for Li-S batteries. Noteworthy, the multilevel heterointerfaces can greatly modulate the electron distribution, facilitate the charge transfer, optimize the chemical absorption, and enhance the intrinsic activity, while rGO contributes to high electrical conductivity, sufficient active sites, and robust structural stability. Thanks to the synergy of different components, Li-S batteries employing the Bi/Bi₂O₃/VMoN@rGO functional separators exhibit impressive electrochemical performance and high sulfur utilization even under high sulfur loading. More importantly, it is discovered that Bi and Bi₂O₃ experience an electrochemical phase evolution to generate Bi₂S₃ with amorphous and crystalline phases, thereby bringing in unexpected performance enhancement. Furthermore, experimental results and theoretical calculations authenticate that a reduced Li₂S decomposition energy barrier is achieved after the in situ electrochemical reconstruction. This work not only provides new mechanistic insights into developing high-efficiency sulfur electrocatalysts but also sheds light on regulating the catalytic activity via self-reconstruction.