Unlocking Exceptionally Fast and Large‐Capacity Na+ Storage of Fe2SSe via Coupling Multicore‐in‐Multishell Design and Vacancy Engineering

作者：Xu-Dong Zhao, Zicong Wang, Zhuoming Jia, Xianglong Kong, Ying Zhao, Tianhui Han, Fei He, Qi-Qi Sun, Dan Yang, Chengkai Yang, Piaoping Yang, Zhi-Liang Liu · 发表于：Advanced Functional Materials · 年份：2025 · DOI：10.1002/adfm.202518989 · 被引用次数：10

Achieving simultaneous high‐rate capability and large reversible capacity remains a core challenge for sodium‐ion battery (SIB) anodes. Herein, the rational design and synthesis of a multicore Fe2SSe architecture is reported, enriched with anion vacancies and confined within a multishell carbon matrix (V‐Fe2SSe@MC), to address this challenge. This tailored structure effectively accommodates volume fluctuations, maintains robust electrode‐electrolyte interfaces, and significantly accelerates Na+ and electron transport. The dense concentration of selenium/sulfur vacancies not only boosts intrinsic electrical conductivity but also generates abundant active sites while lowering the energy barrier for Na+ diffusion. Most critically, the coupling of the multicore‐in‐multishell architecture with the induced anion vacancies produces a synergistic effect that alleviates the conventional trade‐off between storage capacity and rate capability. As a result, the V‐Fe2SSe@MC anode unlocks exceptionally fast and large‐capacity Na+ storage, delivering a high specific capacity of 505 mAh g−1 even at 40C and maintaining 97% capacity over 3000 cycles at 20C. Comprehensive in situ characterizations elucidate the reversible cleavage and regeneration of Fe─S/Se bonds and excellent structural integrity during cycling. This work provides compelling insight into the rational design of high‐performance SIB anodes via the integrated approach combining multicore‐in‐multishell structural design with vaca...