The use of inexpensive graphite oxide (GO) as a carbon source, instead of the expensive reduced graphene oxide (rGO), is essential to prepare metal oxide/rGO composites. In this work, we investigated the in situ reaction of GO and FeCl₃ to produce Fe₂O₃/rGO composites as anode materials for high‐energy lithium‐ion batteries (LIBs). In this reaction, iron ions combined with the oxygen‐containing functional groups of GO, which subsequently grew into Fe₂O₃ nanoparticles, whereas the GO transformed into rGO under hydrothermal conditions. In the composite Fe₂O₃−rGO_x samples, intergranular gaps in the Fe₂O₃ sub‐micron particles evidently increased the contact between the Fe₂O₃ active material and the electrolyte, which improved the Li‐ion conductivity and electrochemical performance of the Fe₂O₃−rGO_x composites. The Fe₂O₃−rGO₂ sample showed the best cyclic performance and delivered the highest capacity of all samples. The initial discharge and charge capacities of Fe₂O₃−rGO₂ were 1086.3 and 722.4 mAh g⁻¹, respectively. After 100 cycles, the discharge specific capacity of Fe₂O₃−rGO₂ was 653.2 mAh g⁻¹ and the coulombic efficiency was 98.4 %. We found that an appropriate weight ratio and composite morphology of Fe₂O₃−rGO_x were important in influencing the electrochemical properties of the composite anode materials for high‐energy LIBs.

中文翻译：

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廉价氧化石墨与FeCl3原位反应合成Fe2O3 /石墨烯复合材料的表征

廉价的氧化石墨（GO）代替昂贵的还原氧化石墨烯（rGO）用作碳源，对于制备金属氧化物/ rGO复合材料至关重要。在这项工作中，我们研究了GO和FeCl _3的原位反应以生产Fe ₂ O ₃ / rGO复合材料作为高能锂离子电池（LIBs）的负极材料。在该反应中，铁离子与GO的含氧官能团结合，随后长成Fe ₂ O ₃纳米颗粒，而GO在水热条件下转化为rGO。在复合Fe ₂ O ₃ -rGO _x样品中，Fe ₂ O中的晶间间隙_3个亚微米颗粒明显增加了Fe ₂ O ₃活性材料与电解质之间的接触，从而改善了Fe ₂ O ₃ -rGO _x复合材料的锂离子电导率和电化学性能。Fe ₂ O ₃ -rGO ₂样品显示出最佳的循环性能，并提供了所有样品中最高的容量。Fe ₂ O ₃ -rGO ₂的初始放电和充电容量分别为1086.3和722.4mAh g ^-1。100次循环后，Fe ₂ O ₃的放电比容量-rGO ₂为653.2mAh g ^-1，库仑效率为98.4％。我们发现适当的重量比和Fe ₂ O ₃ -rGO _x的复合形态对影响高能LIBs复合阳极材料的电化学性能很重要。