MOF‐Derived Fe<sub>7</sub>S<sub>8</sub> Nanoparticles/N‐Doped Carbon Nanofibers as an Ultra‐Stable Anode for Sodium‐Ion Batteries
Yu Wang, Zi Wen, Chang Chun Wang, Chun Cheng Yang, Qing Jiang
Abstract
Abstract Sodium‐ion batteries (SIBs) have aroused wide concern due to their potential applications in large‐scale energy‐storage systems. In this work, a hybrid of Fe 7 S 8 nanoparticles/N‐doped carbon nanofibers (Fe 7 S 8 /N‐CNFs) is designed and synthesized via electrospinning. As an anode for SIBs, Fe 7 S 8 /N‐CNFs exhibit a high reversible capacity of 649.9 mAh g −1 at 0.2 A g −1 after 100 cycles, and superior cycling stability for 2000 cycles at 1 A g −1 with only 0.00302% capacity decay per cycle. Such excellent performance originates from: i) Fe 7 S 8 nanoparticles (average diameter of 17 nm), which shorten the Na + diffusion distance; ii) the unique 3D N‐CNFs, which enhance the conductivity, alleviate the self‐agglomeration and large volume change of Fe 7 S 8 nanoparticles, and offer numerous active sites for Na + adsorption and paths for electrolyte diffusion. The fascinating structure and superior electrochemical properties of Fe 7 S 8 /N‐CNFs shed light on developing high‐performance SIBs anode materials.