Porous Fe2O3 Nanoframeworks Encapsulated within Three-Dimensional Graphene as High-Performance Flexible Anode for Lithium-Ion Battery
Porous Fe2O3 Nanoframeworks Encapsulated within Three-Dimensional Graphene as High-Performance Flexible Anode for Lithium-Ion Battery
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封装在三维石墨烯内的多孔 Fe2O3 纳米框架作为锂离子电池的高性能柔性阳极
DOI：
10.1021/acsnano.7b02198
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发表时间：
2017-05-01
期刊：
影响因子：
17.1
通讯作者：
Xu, Yuxi
中科院分区：
文献类型：
--
作者：
Jiang, Tiancai;Bu, Fanxing;Xu, Yuxi
将纳米多孔金属氧化物集成到具有封装结构的三维石墨烯（3DG）中是一条很有前途的路线，但开发高性能锂离子电池电极仍然具有挑战性。在此，我们设计了3DG/金属有机骨架复合材料，通过过量的金属离子诱导的组合和空间限制的奥斯特瓦尔德熟化策略，它可以转化为3DG/Fe 2 O3气凝胶与多孔Fe 2 O3纳米骨架很好地封装在石墨烯中。分级结构提供了高度互穿的多孔导电网络和石墨烯与多孔Fe 2 O3之间的紧密接触，以及丰富的应力缓冲纳米空间，用于在电化学过程中有效的电荷传输和稳健的结构稳定性。所得的自支撑3DG/Fe 2 O3气凝胶在机械压制时直接用作锂离子电池的高柔性阳极，并且在0.2A/g下在130次循环后显示出1129 mAh/g的比容量，并且在5A/g下在1200次循环后显示出优异的循环稳定性，容量保持率为98%，这是迄今为止报道的最好结果。这项研究提供了一个有前途的路线，大大提高了金属氧化物的电化学性能，并为开发高性能的电化学储能电极材料提供了启发性的见解。
Integrating nanoscale porous metal oxides into three-dimensional graphene (3DG) with encapsulated structure is a promising route but remains challenging to develop high-performance electrodes for lithium-ion battery. Herein, we design 3DG/metal organic framework composite by an excessive metal-ion-induced combination and spatially confined Ostwald ripening strategy, which can be transformed into 3DG/Fe2O3 aerogel with porous Fe2O3 nanoframeworks well encapsulated within graphene. The hierarchical structure offers highly interpenetrated porous conductive network and intimate contact between graphene and porous Fe2O3 as well as abundant stress buffer nanospace for effective charge transport and robust structural stability during electrochemical processes. The obtained free-standing 3DG/Fe2O3 aerogel was directly used as highly flexible anode upon mechanical pressing for lithium-ion battery and showed an ultrahigh capacity of 1129 mAh/g at 0.2 A/g after 130 cycles and outstanding cycling stability with a capacity retention of 98% after 1200 cycles at 5 A/g, which is the best results that have been reported so far. This study offers a promising route to greatly enhance the electrochemical properties of metal oxides and provides suggestive insights for developing high-performance electrode materials for electrochemical energy storage.