Potassium ion batteries (PIBs) have attracted tremendous attentions based on the fact that lithium ion batteries have been increasingly challenged by the uneven distribution and ultralow reserve of lithium sources. Safety concern has raised requirement for acceptable anode materials with high capacity and favorable working-potential. Here, a 3D flower-like antimony oxychloride (Sb₄O₅Cl₂) that is synthesized via a mild hydrothermal method, is firstly employed as anode material for PIBs, where a high reversible capacity of 530 mAh g⁻¹ could be achieved at current density of 50 mA g⁻¹, with decent cycling performance and rate capability. Kinetic analyses based on electrochemical measurements evidence that the Sb₄O₅Cl₂ electrode could deliver high K⁺ ion diffusion coefficient, and density functional theory calculations are also conducted to probe the migration paths of K⁺ ion in Sb₄O₅Cl₂ and the electronic structure involved in the electrochemical kinetics behaviors. The K⁺ ion storage mechanism during potassiation/de-potassiation is investigated via ex-situ X-ray diffraction, high resolution transmission electron microscope and theoretical calculations, and a reversible process involving both conversion-type and alloy/de-alloy reactions is established.

由于锂离子电池越来越受到锂源分布不均和超低储量的挑战，钾离子电池（PIBs）引起了极大的关注。安全问题提高了对具有高容量和良好工作电位的可接受负极材料的要求。在这里，通过温和的水热法合成的 3D 花状三氯氧化锑 (Sb ₄ O ₅ Cl ₂ ) 首次用作 PIBs 的负极材料，其可逆容量可达 530 mAh g ^-1电流密度为 50 mA g ^-1，具有良好的循环性能和速率能力。基于电化学测量的动力学分析表明 Sb ₄ O ₅ Cl ₂电极可以提供高 K ⁺离子扩散系数，并且还进行了密度泛函理论计算以探索 K ⁺离子在 Sb ₄ O ₅ Cl ₂中的迁移路径和涉及电化学动力学行为的电子结构。K ⁺ 通过异位X射线衍射、高分辨率透射电子显微镜和理论计算研究了钾化/去钾化过程中的离子储存机理，并建立了一个涉及转化型和合金/去合金反应的可逆过程。