Stoichiometry engineering of high-entropy alloys regulates electronic configurations for Sabatier-balanced LiPSs adsorption and catalysis in LiS batteries

Stoichiometry engineering expands electronic tunability in Li S catalysts. • Composition tuning regulates charge redistribution and d-band centers in HEAs. • CF/HEA-1 enables Sabatier-balanced LiPSs adsorption and conversion. • CF/HEA-1 lowers polarization and accelerates bidirectional sulfur redox. • CF/HEA-1 enables 2000-cycle Li S cells with only 0.022% decay per cycle. Most existing studies on high-entropy alloy (HEA) sulfur electrocatalysts rely on changing elemental species to adjust their affinity for lithium polysulfides (LiPSs) and matching redox catalytic activity, so as to alleviate the intrinsic trade-off between LiPS adsorption and desorption. In this work, interconnected carbon fibers (CF) modified with CrMnFeCoNi HEA nanoparticles of tunable atomic ratios are synthesized to uncover the correlation between catalytic activity and surface electronic configuration toward efficient sulfur electrocatalysis. Combining density functional theory (DFT) calculations and systematic experimental characterizations, we demonstrate that tuning the atomic ratios of metallic elements within CrMnFeCoNi HEA can redistribute their surface charge, shift the positions of the d-band center, and ultimately regulate their adsorption affinity toward LiPSs. The optimized HEA catalyst achieves a favorable balance between adsorption and desorption, which drastically boosts the catalytic efficiency of LiPS conversion. Consequently, the cell based on the optimized CF/HEA-1 interlayer delivers a high reversible capacity of 938 mAh g −1 and maintains stable long-term cycling over 2000 cycles at 1.0C, corresponding to an ultralow capacity decay rate of 0.022% per cycle. This work proposes a feasible electronic modulation strategy to optimize HEA catalytic behavior, providing valuable guidance for the design of advanced lithium‑sulfur battery electrocatalysts. Download: Download high-res image (129KB) Download: Download full-size image