Increasing demands for lithium-ion batteries (LIBs) with high energy density and high power density require highly reversible electrochemical reactions to enhance the cyclability and capacities of electrodes. As the reversible formation/decomposition of the solid electrolyte interface (SEI) film during the lithiation/delithiation process of Fe₃S₄ could bring about a higher capacity than its theoretical value, in the present work, synthesized Fe₃S₄ nanoparticles are sandwich-wrapped with reduced graphene oxide (RGO) to fabricate highly reversible and long cycling life anode materials for high-performance LIBs. The micron-sized long slit between sandwiched RGO sheets effectively prevents the aggregation of intermediate phases during the discharge/charge process and thus increases cycling capacity because of the reversible formation/decomposition of the SEI film driven by Fe nanoparticles. Furthermore, the RGO sheets interconnect with each other by a face-to-face mode to construct a more efficiently conductive network, and the maximum interfacial oxygen bridge bonds benefit the fast electron hopping from RGO to Fe₃S₄, improving the depth of the electrochemical reactions and facilitating the highly reversible lithiation/delithiation of Fe₃S₄. Thus, the resultant Fe₃S₄/RGO hybrid shows a highly reversible charge capacity of 1324 mA h g^–1 over 275 cycles at a current density of 100 mA g^–1, even retains 480 mA h g^–1 over 500 cycles at 1000 mA g^–1, which are much higher than reported values.

中文翻译：

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高锂存储容量和长循环寿命的Fe ₃ S ₄阳极，带有可逆固体电解质界面膜和夹心的还原氧化石墨烯壳

对于具有高能量密度和高功率密度的锂离子电池（LIB）的日益增长的需求要求高度可逆的电化学反应以增强电极的可循环性和容量。由于在Fe ₃ S ₄的锂化/脱锂过程中固体电解质界面（SEI）膜的可逆形成/分解可能带来比其理论值更高的容量，因此在本工作中，合成的Fe ₃ S ₄纳米颗粒被还原的氧化石墨烯（RGO）夹在中间包裹，以制造用于高性能LIB的高度可逆且循环寿命长的阳极材料。夹在中间的RGO片之间的微米级长缝有效地防止了在放电/充电过程中中间相的聚集，并因此增加了循环容量，这是由于受Fe纳米粒子驱动的SEI膜的可逆形成/分解。此外，RGO片材通过面对面的方式相互连接以构建更有效的导电网络，并且最大的界面氧桥键有利于电子从RGO到Fe ₃ S ₄的快速跳变。，改善了电化学反应的深度，并促进了Fe ₃ S ₄的高度可逆的锂化/脱锂。因此，所得的Fe ₃ S ₄ / RGO杂化物在100 mA g ^–1的电流密度下，在275个循环中显示出1324 mA hg ^–1的高度可逆充电容量，甚至在1000 mA的500个循环中仍保持480 mA hg ^–1 g ^–1，比报告值高得多。