Patil Rahul, Pathak Prakash Kumar, Mishra Meemansha, Matsagar Babasaheb M, Mohini Antra, Chen Norman C-R, Wu Kevn C-W, Bano Amreen, Salunkhe Rahul R, Dutta Saikat
Electrochemical Energy & Sensor Research Laboratory, Amity Institute of Click Chemistry Research & Studies, Amity University Uttar Pradesh, Noida, 77282, India.
VSB Technical University of Ostrava, Centre for Energy and Environmental Technologies, Nanotechnology Centre, 17. listopadu 2172/15, Ostrava, 70800, Czech Republic.
Small. 2025 Aug 28:e07064. doi: 10.1002/smll.202507064.
Sluggish diffusion kinetics of Na drastically restrain the rate capability and capacitance of the anode for sodium-ion batteries (SIBs). Herein, a Fe single-atom strategy is employed to construct Fe─N─O active sites closely coupled with FeC species, establishing strong electronic interactions and, more importantly, an optimized coordination environment through precise tuning of their composition ratio with wood-derived nanoporous carbon (WNC) support. The charging Na through nanoporous carbon of Fe─N─O-WNC anode is revealed by electrochemical capacitive and charge-discharge studies to establish a reversible conversion and diffusion of Na supported by theoretical calculation of Na migration energy (eV) against the diffusion path. Fe─N─O-WNC anode, assembled with sodium foil as counter electrodes in a coin cell, exhibits a significant discharge-specific capacity of 318 mAh g at a current density of 50 mAg. The electrochemical analysis support the role of Fe─N bonding in modulating the electronic environment of Na diffusion sites. The incorporation of Fe─N─O in WNC results in 1) faster Na diffusion through hollow (H) sites, 2) stretching of the Fe─N bond during discharge cycles. In addition, Fe─N─O-WNC anode promises for the manufacturing of advanced SIBs from a renewable material and thereby enhancing the investigation of sodiophilic Fe─N sites.
钠离子在阳极的扩散动力学缓慢，极大地限制了钠离子电池（SIB）阳极的倍率性能和电容。在此，采用铁单原子策略构建与碳化铁物种紧密耦合的Fe─N─O活性位点，通过精确调节其与木质衍生纳米多孔碳（WNC）载体的组成比，建立强电子相互作用，更重要的是，建立优化的配位环境。通过电化学电容和充放电研究揭示了Fe─N─O-WNC阳极中钠离子通过纳米多孔碳的充电过程，通过钠离子迁移能（eV）对扩散路径的理论计算，证实了钠离子的可逆转化和扩散。以钠箔作为对电极组装在扣式电池中的Fe─N─O-WNC阳极，在电流密度为50 mAg时表现出318 mAh g的显著放电比容量。电化学分析支持了Fe─N键在调节钠离子扩散位点电子环境中的作用。在WNC中引入Fe─N─O导致：1）钠离子通过中空（H）位点的扩散更快；2）放电循环过程中Fe─N键的拉伸。此外，Fe─N─O-WNC阳极有望用可再生材料制造先进的SIB，从而加强对亲钠Fe─N位点的研究。
