Uniform one-pot anchoring of Fe3O4 to defective reduced graphene oxide for enhanced lithium storage
Uniform one-pot anchoring of Fe3O4 to defective reduced graphene oxide for enhanced lithium storage
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DOI：
10.1016/j.cej.2017.02.108
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发表时间：
2017-06
影响因子：
15.1
通讯作者：
Dohyeon Yoon;J. Hwang;Wonyoung Chang;Jaehoon Kim
中科院分区：
文献类型：
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作者：
Dohyeon Yoon;J. Hwang;Wonyoung Chang;Jaehoon Kim
使用超临界异丙醇 (scIPA) 可以将 Fe3O4 纳米粒子高度均匀且紧密地锚定在有缺陷的还原氧化石墨烯 (DRGO) 表面。 DRGO 的缺陷和富氧位点有利于 Fe3O4 颗粒在其表面的异质成核和生长，而 scIPA 独特的还原能力有助于去除一些氧官能团。 Fe3O4-DRGO复合材料由于增强的异质成核而表现出良好剥离的介孔结构和高比表面积。当作为锂离子电池阳极进行测试时，Fe3O4-DRGO 复合材料在 50 mA g−1 倍率下表现出 1045 mAh g−1 的高可逆放电容量，并且在 2.5 A g−1 的高充放电倍率下经过 1000 次循环后，具有 96% 的优异循环容量保持率和几乎 100% 的库伦效率。 Fe3O4-DRGO 与传统 Fe3O4-RGO 复合材料的物理化学和电化学性能的比较表明，超细 Fe3O4 颗粒沉积、高表面积和容易的锂离子传输到活性相解释了 Fe3O4-DRGO 复合材料的高电化学性能。
Highly uniform and tight anchoring of Fe3O4nanoparticles on the surface of defective reduced graphene oxide (DRGO) is achieved using supercritical isopropanol (scIPA). The defect- and oxygen-rich sites of DRGO favor the heterogeneous nucleation and growth of Fe3O4particles on its surface, while the unique reduction ability of scIPA helps remove some of the oxygen functionalities. The Fe3O4-DRGO composite exhibits a well-exfoliated mesoporous structure with a high specific surface area owing to the enhanced heterogeneous nucleation. When tested as an anode in Li-ion batteries, the Fe3O4-DRGO composite exhibits a high reversible discharge capacity of 1045 mAh g−1at a rate of 50 mA g−1and an excellent cycling capacity retention of 96% with almost 100% coulombic efficiency after 1000 cycles under a high charge–discharge rate of 2.5 A g−1. The comparison of physicochemical and electrochemical properties of Fe3O4-DRGO with those of the conventional Fe3O4-RGO composite revealed that the ultrafine Fe3O4particle deposition, high surface area, and facile Li-ion transport to the active phase account for the high electrochemical performance of the Fe3O4-DRGO composite.