Flexible nitrogen-doped graphene/SnO2 foams promise kinetically stable lithium storage
Flexible nitrogen-doped graphene/SnO2 foams promise kinetically stable lithium storage
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柔性氮掺杂石墨烯/SnO2泡沫有望实现动力学稳定的锂存储
DOI：
10.1016/j.nanoen.2015.03.016
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发表时间：
2015-04-01
期刊：
影响因子：
17.6
通讯作者：
Yu, Shu-Hong
中科院分区：
文献类型：
--
作者：
Cong, Huai-Ping;Xin, Sen;Yu, Shu-Hong
在开发锂离子电池的高性能电极材料时，构建动力学稳定的石墨烯-SnO2 阳极很有吸引力，但仍然具有挑战性。在这里，我们展示了石墨烯-SnO2复合材料的平衡设计，即具有集成宏观薄膜和互连微/纳米泡沫结构的柔性氮掺杂石墨烯/SnO2（NG-SnO2）泡沫。有利的结构和成分相结合，提高了 Li+ 的可及性和电子传输，同时防止与电解质和 SnO2 发生副反应。值得注意的是，一种新颖的电化学是由 SnO2 和石墨烯之间的协同效应引发的，即 SnO2 的不可逆转化反应在循环时变得可逆。这些努力导致容量增加>1000 mA h g(-1)。该复合泡沫在0.1 A g(-1)倍率下经过8.5个月的循环后，可以保留超过81%的初始容量，达到1678 mAh g(-1)，表现出动力学稳定的电化学性能。 (C) 2015 Elsevier Ltd. 保留所有权利。
In developing high-performance electrode materials for lithium-ion batteries, building kinetically stable graphene-SnO2 anode is appealing yet remains challenging. Here we demonstrate a balanced design of graphene-SnO2 composite, i.e., a flexible nitrogen-doped graphene/SnO2 (NG-SnO2) foam with an integrated macroscale film and interconnected micro-/nano-foam architecture. The combined favorable structure and components improve the Li+ accessibility and electron transmission, while prevent side reactions with the electrolyte and SnO2. Notably, a novel electrochemistry is triggered by the synergistic effect between SnO2 and graphene, i.e., irreversible conversion reaction of SnO2 becomes reversible upon cycling. These efforts lead to an ascending capacity with the increment of >1000 mA h g(-1). The composite foam can retain more than 81% of its initial capacity to 1678 mA h g(-1) over cycles of 8.5 months at a rate of 0.1 A g(-1), exhibiting kinetically-stable electrochemical performances. (C) 2015 Elsevier Ltd. All rights reserved.