Balancing Electronic Spin State via Atomically-Dispersed Heteronuclear Fe–Co Pairs for High-Performance Sodium–Sulfur Batteries

作者：Canhuang Li, Jing Bo Yu, Dawei Yang, Hao Li, Yapeng Cheng, Yuchuan Ren, Xiaoyu Bi, Jiachen Ma, Ruirui Zhao, Yingtang Zhou, Jian Wang, Chen Huang, Junshan Li, Ivan Pinto‐Huguet, Jordi Arbiol, Haining Zhang, Sen Xin, Andreu Cabot · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.4c15408 · 被引用次数：102 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Inorganic Chemistry and Materials

Room-temperature sodium–sulfur (Na–S) batteries are emerging as a promising next-generation energy storage technology, offering high energy densities at low cost and utilizing abundant elements. However, their practical application is hindered by the shuttle effect of sodium-polysulfides and the sluggish kinetics of sulfur redox reactions. In this study, we demonstrate a heteronuclear diatomic catalyst featuring Fe and Co bimetallic sites embedded in nitrogen-doped hollow carbon nanospheres (Fe–Co/NC) as an effective sulfur host at the cathode of Na–S batteries. Aberration-corrected high-angle annular dark field scanning transmission electron microscopy demonstrates the presence of isolated Fe–Co atomic pairs, while synchrotron radiation X-ray absorption fine structure analysis confirms the (Fe–Co–N 6 ) coordination structure. Density functional theory calculations show that the introduction of Fe atoms induces electron delocalization in Co(II), shifting the electronic configuration from a low-spin to a higher-spin state. This shift enhances the hybridization of the Co dz 2 orbitals with the antibonding π orbitals of sulfur atoms within the sodium sulfide species that accelerates their catalytic conversion. As a result, Fe–Co/NC-based cathodes exhibit excellent cycling stability (378 mAh g –1 after 2000 cycles) and impressive rate performance (341.1 mAh g –1 under 5 A g –1 ).