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

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.