Sb2S3/Sb2O3@Inner Wrinkled Hollow Carbon for Stable Potassium-Ion Storage

Antimony-based materials have attracted extensive attention in the field of lithium-ion batteries and sodium-ion batteries due to their high theoretical specific capacity and have become a new generation of high-energy-density electrode materials. As anodes, antimony-based materials can efficiently store K+ ions through conversion and alloying reactions. However, antimony-based anodes face challenges in efficient potassium storage, such as insufficient structural stability, poor electrical conductivity, and slow electrochemical reaction kinetics. In this study, we assembled Sb2O3 and Sb2S3 nanoparticles on the surface of inner wrinkled hollow carbon (Sb2O3/Sb2S3@IWHC) by a one-step hydrothermal method. The obtained composite anodes integrate the advantages of different dimensions and phases of the respective components. IWHC is crucial in alleviating stress changes, reducing side reactions, and enhancing electrical conductivity and structural stability. The good dispersion of Sb2O3/Sb2S3 particles on the surface of IWHC and the combination of conversion and alloying reactions significantly increase the storage capacity. The obtained Sb2O3/Sb2S3@IWHC electrode demonstrates excellent electrochemical performance, delivering a high specific capacity (214.2 mAh g–1 at 0.2 A g–1), outstanding cycling stability (89.6% capacity retention after 200 cycles), and superior rate capability (115.6 mAh g–1 at 5 A g–1). This study indicates that the composites, including antimony-based compounds and IWHC, are promising anodes for high-performance K+ storage.