Ye, C.Shan, J.Li, H.Kao, C.-C.Gu, Q.Qiao, S.2023-05-022023-05-022023Angewandte Chemie International Edition, 2023; 62(22):e202301681-1-e202301681-71433-78511521-3773https://hdl.handle.net/2440/138168Version of record online: April 20, 2023Improving kinetics of solid-state sulfide conversion in sulfur cathodes can enhance sulfur utilization and promote Coulombic efficiency of secondary metal-sulfur batteries. However, fundamental mechanisitic understanding of the solid-state conversion in metal-sulfur batteries 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 K2S3 to K2S conversion via the meta-stable S2-3 intermediates on a range of transition metal single-atom catalytic sulfur hosts. The resultant catalytic sulfur host containing Cu single atoms demonstrate high discharge capacities of 1,595 and 1226 mAh g-1 at specific current densitieis of 335 and 1675 mA g-1, respectively, with stable Coulombic efficiency of ~100% during cycling. Combined spectroscopic characterizations and density functional theory computations reveal that the Cu single atom catalyst exhibits a relatively weak Cu-S bonding during sulfur redox conversion, resulting in low overpotential of solid-state K2S3-K2S conversion and high sulfur utilization. The elucidation of reaction mechanism of solid-state sulfide conversion can direct the exploration of highly efficient metal-sulfur batteries.en© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.meta-stable intermediatesmetal-sulfur batteriessingle atom catalystsolid-state conversionsulfur hostJournal article10.1002/anie.2023016812023-05-02638416Shan, J. [0000-0003-4308-5027]Li, H. [0000-0003-0662-6939]Kao, C.-C. [0000-0002-4669-9924]Qiao, S. [0000-0002-1220-1761] [0000-0002-4568-8422]