Nanodot‐in‐Nanofiber Structured Carbon‐Confined Sb₂Se₃ Crystallites for Fast and Durable Sodium Storage

Abstract Antimony‐based materials possess high specific capacity and appropriate redox potential for sodium storage, but they suffer from huge volume expansion/contraction when sodium ions insert/extract, which leads to inferior cycle life. Herein, a hierarchical nanodot‐in‐nanofiber structure is proposed to address this challenge, in which antimony selenide (Sb₂Se₃) nanocrystallites are confined by both 0D and 1D carbon layers. The multi‐pronged nanostructure reduces the size of active particles, alleviates the intrinsic volume change of Sb₂Se₃, and forms a stable transport network for charge carriers. Finally, the nanodot‐in‐nanofiber structured Sb₂Se₃ anode exhibits outstanding performance for sodium storage, such as high capacity and exceptional cycle lifespan for over 10 000 cycles at 2.0 A g⁻¹. Therefore, this work can be valuable for the rational design of ultra‐stable alloy and conversion‐type materials in the application of next‐generation batteries.