School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA, 5005, Australia.
Australian Synchrotron, ANSTO, 800 Blackburn Rd., Clayton, VIC, 3168, Australia.
Angew Chem Int Ed Engl. 2023 May 22;62(22):e202301681. doi: 10.1002/anie.202301681. Epub 2023 Apr 20.
Improving kinetics of solid-state sulfide conversion in sulfur cathodes can enhance sulfur utilization of metal-sulfur batteries. However, fundamental understanding of the solid-state conversion remains to be achieved. Here, taking potassium-sulfur batteries as a model system, we for the first time report the reducing overpotential of solid-state sulfide conversion via the meta-stable S intermediates on transition metal single-atom sulfur hosts. The catalytic sulfur host containing Cu single atoms demonstrates high capacities of 1595 and 1226 mAh g at current densities of 335 and 1675 mA g , respectively, with stable Coulombic efficiency of ≈100 %. Combined spectroscopic characterizations and theoretical computations reveal that the relatively weak Cu-S bonding results in low overpotential of solid-state sulfide conversion and high sulfur utilization. The elucidation of solid-state sulfide conversion mechanism can direct the exploration of highly efficient metal-sulfur batteries.
提高硫正极中固态硫化物转化的动力学可以提高金属-硫电池的硫利用率。然而，固态转化的基础理解仍有待实现。在这里，我们首次以钾硫电池为模型体系，通过过渡金属单原子硫主体上的亚稳态 S 中间体报告了固态硫化物转化的还原过电势。含有 Cu 单原子的催化硫主体分别在 335 和 1675 mA g 的电流密度下表现出 1595 和 1226 mAh g 的高容量，且库仑效率≈100%稳定。结合光谱表征和理论计算揭示了相对较弱的 Cu-S 键导致固态硫化物转化的过电势较低和硫利用率较高。固态硫化物转化机制的阐明可以指导高效金属-硫电池的探索。
