Enhanced Cyclic Performance and Lithium Storage Capacity of SnO2/Graphene Nanoporous Electrodes with Three-Dimensionally Delaminated Flexible Structure
Enhanced Cyclic Performance and Lithium Storage Capacity of SnO2/Graphene Nanoporous Electrodes with Three-Dimensionally Delaminated Flexible Structure
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DOI：
10.1021/nl802484w
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发表时间：
2009-01-01
期刊：
影响因子：
10.8
通讯作者：
Honma, Itaru
中科院分区：
文献类型：
--
作者：
Paek, Seung-Min;Yoo, EunJoo;Honma, Itaru
为了制备具有分层结构的纳米多孔电极材料，在金红石型SnO 2纳米颗粒存在下，在乙二醇溶液中重新组装石墨烯纳米片（GNS）。根据TEM分析，石墨烯纳米片均匀地分布在松散堆积的SnO 2纳米颗粒之间，从而可以制备具有大量空隙空间的纳米多孔结构。所得SnO/GNS具有810 mAh/g的可逆容量;此外，其循环性能与裸SnO 2纳米粒子相比显著增强。30次循环后，SnO 2/GNS的充电容量仍保持在570 mAh/g，即可逆容量保持率约为70%;而裸SnO 2纳米粒子首次充电时的比容量为550 mAh/g，仅在15次循环后迅速下降至60 mAh/g。GNS对SnO 2纳米粒子的尺寸限制限制了嵌锂时的体积膨胀，而SnO 2和GNS之间形成的孔隙可作为充放电过程中的缓冲空间，从而获得上级循环性能。
To fabricate nanoporous electrode materials with delaminated structure, the graphene nanosheets (GNS) in the ethylene glycol solution were reassembled in the presence of rutile SnO2 nanoparticles. According to the TEM analysis, the graphene nanosheets are homogeneously distributed between the loosely packed SnO2 nanoparticles in such a way that the nanoporous structure with a large amount of void spaces could be prepared. The obtained SnO/GNS exhibits a reversible capacity of 810 mAh/g; furthermore, its cycling performance is drastically enhanced in comparison with that of the bare SnO2 nanoparticle. After 30 cycles, the charge capacity of SnO2/GNS still remained 570 mAh/g, that is, about 70% retention of the reversible capacity, while the specific capacity of the bare SnO2 nanoparticle on the first charge was 550 mAh/g, dropping rapidly to 60 mAh/g only after 15 cycles. The dimensional confinement of tin oxide nanoparticles by the surrounding GNS limits the volume expansion upon lithium insertion, and the developed pores between SnO2 and GNS could be used as buffered spaces during charge/discharge, resulting in the superior cyclic performances.