Asymmetric Polarization\nModulation of d–p Hybridization-Enhanced\nBidirectional Sulfur Redox Kinetics with Heteronuclear Dual-Atom Catalysts

Lithium sulfur batteries (LiSBs) represent a highly promising\navenue\nfor future energy storage systems, offering high energy density and\neco-friendliness. However, the sluggish kinetics of the sulfur redox\nreaction (SRR) poses a significant challenge to their widespread applications.\nTo tackle this challenge, we have developed an efficient heteronuclear\ndual-atom catalyst (hetero-DAC) that leverages surface charge polarization\nto enhance the asymmetric adsorption of sulfur intermediates. This\nstudy investigates how asymmetric electronic redistribution of CoFe\nDACs modulates the d–p orbital hybridization with sulfur intermediates,\nrevealing the mechanisms of moderate adsorption dynamics with enhanced\ncatalytic performance. The dynamic switching between mono and dual\nadsorption sites, enabled by the heteronuclear polarized configuration,\nfine-tunes the orbital hybridization, boosting the bidirectional rate-determining\nsteps, that is, the solid–solid conversion of Li<sub>2</sub>S<sub>2</sub> to Li<sub>2</sub>S and the reverse dissociation of\nLi<sub>2</sub>S. Consequently, the thus-designed CoFe DACs cathode\ndelivers impressive rate performance, achieving a high initial specific\ncapacity of 703.9 mA h g<sup>–1</sup> at 3 C, with a negligible\ndecay rate of only 0.031% over 1000 cycles, demonstrating sustained\nlong-term cycling stability. This work bridges geometric configurations\nand electronic structures, elucidating the mechanisms of asymmetric\ntrapping and conversion enabled by hetero-DACs and offering fresh\nperspectives for catalyst design in LiSBs and beyond.