Deciphering the Sb₄O₅Cl₂–MXene Hybrid as a Potential Anode Material for Advanced Potassium-Ion Batteries

Potassium-ion batteries (PIBs) possess great potential in new-generation large-scale energy storage. However, their applications are plagued by large volume change and sluggish reaction kinetics of the electrode materials during the repeated charge/discharge processes. Guided by computerization modeling, we, herein, report the atomic-scale interfacial regulation of Sb₄O₅Cl₂ coupled with structural engineering for the robust anode material of PIBs via simple MXene hybridization using a microwave-assisted hydrothermal method. Benefiting from the ostensive interfacial interplay between Sb₄O₅Cl₂ and Ti₃C₂, MXene hybridization induces a favorable variation in spin polarization densities and the coordination of Sb atoms in Sb₄O₅Cl₂, which are effective in optimizing the K⁺ ion diffusion path, thus resulting in a significantly reduced K⁺ ion diffusion barrier and promoted K⁺ insertion/extraction kinetics. The as-prepared Sb₄O₅Cl₂–MXene anodes exhibit a highly reversible discharge capacity and decent cyclability, in addition to the low discharge plateau and promising full cell performance. This work is pivotal for not only paving the way for the exploration of anode materials for high-performance PIBs but also shedding light on the fundamental research on K⁺ ion storage in antimony oxychloride.