基于Fe/Fe_(3)O_(4)双相催化剂的高性能硫正极

Fe/Fe_(3)O_(4)-based Biphasic Catalysts for High Performance Sulfur Cathodes

针对锂硫电池中硫正极所面临的导电性差、体积膨胀、多硫化物穿梭和制备成本高等问题,利用绿色且低成本的重金属离子絮凝剂吸附金属离子来制备Fe/Fe_(3)O_(4)-C硫正极载体材料。形貌和结构分析表明,复合材料的三维碳结构上有Fe和Fe_(3)O_(4)均匀分布。负载硫后得到的Fe/Fe_(3)O_(4)-C-S电极具有优异的电化学反应动力学,在0.1C、0.2C、0.5C、1.0C倍率下分别表现出高达908、640、524、438 mAh·g^(-1)的比容量,在0.1C倍率下循环100圈后依然能够保持62.9%的初始容量。由此可见,Fe/Fe_(3)O_(4)-C复合材料中的三维碳结构既能提高导电性,也能缓解硫的体积膨胀,而Fe/Fe_(3)O_(4)双相催化剂可以高效地吸附多硫化物并促进其转化,从而抑制了穿梭效应。

To address the issues of poor conductivity,volume expansion,polysulfide shuttle,and high cost faced by sulfur cathodes in lithium-sulfur batteries,an eco-friendly and cost-effective flocculant was employed to adsorb heavy-metal ions fabricating Fe/Fe_(3)O_(4)-C composite for sulfur loading.Morphological and structural analysis revealed the uniform distribution of Fe and Fe_(3)O_(4) on 3D carbon skeletons.The Fe/Fe_(3)O_(4)-C-S electrode possessed excellent electrochemical reaction kinetics,delivering a specific ca-pacity of 908,640,524,438 mAh·g^(-1) at rates of 0.1C,0.2C,0.5C and 1.0C,respectively.After 100 cycles at 0.1C,62.9%of the initial capacity was retained.These results demonstrated that the 3D carbon skeleton in Fe/Fe_(3)O_(4)-C composites could enhance the electrical conductivity and alleviate the vol-ume expansion of sulfur.The Fe/Fe_(3)O_(4) biphasic catalysts were able to efficiently adsorb polysulfides and facilitate their conversion,thereby inhibiting the shuttle effects.