Multifunctional Heterostructured Fe3O4‐FeTe@MCM Electrocatalyst Enabling High‐Performance Practical Lithium‐Sulfur Batteries Via Built‐in Electric Field

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-08, Vol.20 (31), p.e2312288-n/a
• Main Authors: Gao, Yi‐bo, Liu, Guo‐qiang, Geng, Hai‐tao, He, Xin, Na, Xiang‐ming, Liu, Fu‐shuang, Li, Bao, Wang, Bao
• Format: Article
• Language: English
• Subjects: Battery cycles; built‐in electric field; Catalytic activity; Catalytic converters; Charge materials; Commercialization; Diffusion barriers; Electric fields; Electrocatalysts; Heterostructures; Iron oxides; Lithium; Lithium sulfur batteries; Microspheres; polysulfide conversion; Polysulfides; practical lithium–sulfur batteries; Sulfur; synergistic catalysis
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202312288

The development of capable of simultaneously modulating the sluggish electrochemical kinetics, shuttle effect, and lithium dendrite growth is a promising strategy for the commercialization of lithium‐sulfur batteries. Consequently, an elaborate preparation method is employed to create a host material consisting of multi‐channel carbon microspheres (MCM) containing highly dispersed heterostructure Fe3O4‐FeTe nanoparticles. The Fe3O4‐FeTe@MCM exhibits a spontaneous built‐in electric field (BIEF) and possesses both lithophilic and sulfophilic sites, rendering it an appropriate host material for both positive and negative electrodes. Experimental and theoretical results reveal that the existence of spontaneous BIEF leads to interfacial charge redistribution, resulting in moderate polysulfide adsorption which facilitates the transfer of polysulfides and diffusion of electrons at heterogeneous interfaces. Furthermore, the reduced conversion energy barriers enhanced the catalytic activity of Fe3O4‐FeTe@MCM for expediting the bidirectional sulfur conversion. Moreover, regulated Li deposition behavior is realized because of its high conductivity and remarkable lithiophilicity. Consequently, the battery exhibited long‐term stability for 500 cycles with 0.06% capacity decay per cycle at 5 C, and a large areal capacity of 7.3 mAh cm−2 (sulfur loading: 9.73 mg cm−2) at 0.1 C. This study provides a novel strategy for the rational fabrication of heterostructure hosts for practical Li‐S batteries. The elaborately prepared Fe3O4‐FeTe@MCM loaded the highly dispersed nanoparticles with built‐in electric field in the hollow multi‐channel nanospheres, which can regulate the bidirectional catalytic conversion of polysulfide through the lithophilic and sulfophilic sites at the heterogeneous interface and the charge redistribution to achieve high performance lithium‐sulfur batteries.