Indirect growth of mesoporous Bi@C core-shell nanowires for enhanced lithium-ion storage
Indirect growth of mesoporous Bi@C core-shell nanowires for enhanced lithium-ion storage
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间接生长介孔Bi@C核壳纳米线以增强锂离子存储
DOI：
10.1039/c4nr04378b
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发表时间：
2014-01-01
期刊：
影响因子：
6.7
通讯作者：
Zheng, Gengfeng
中科院分区：
文献类型：
--
作者：
Dai, Rui;Wang, Yuhang;Zheng, Gengfeng
在本文中，我们提出了一种简单的合成策略，通过在惰性气氛下控制Bi2S3@葡萄糖衍生的富碳多糖（GCP）纳米线的热解来制备均匀的铋@碳（Bi@C）核-壳纳米线。GCP的碳化和Bi 2S 3到Bi的热解分别发生在500 ℃和600 ℃，这增加了纳米线的比表面积和孔体积，从而允许容纳更多的锂离子。同时，碳壳层作为缓冲层缓解了电化学合金形成过程中的大体积膨胀-收缩，也能有效地减少纳米线的聚集。作为概念验证，Bi@C核-壳纳米线阳极表现出增强的循环稳定性（在100 mA g（-1）的电流密度下100次循环后为408 mA h g（-1））和额定容量（在1 A g（-1）的电流密度下为240 mA h g（-1）），远高于纯铋微粒和相应的Bi2S3@C纳米线。
In this paper, we propose a facile synthetic strategy for uniform bismuth@carbon (Bi@C) core-shell nanowires, which are prepared via controlled pyrolysis of Bi2S3@ glucose-derived carbon-rich polysaccharide (GCP) nanowires under an inert atmosphere. Carbonization of GCP and pyrolysis of Bi2S3 into Bi occur at 500 degrees C and 600 degrees C, respectively, which increase the specific surface area and the pore volume of the nanowires, thus allowing accommodation of more lithium ions. Meanwhile, the carbon shell serves as a buffer layer to relieve large volume expansion-contraction during the electrochemical alloy formation, and can also efficiently reduce the aggregation of the nanowires. As a proof-of-concept, the Bi@C core-shell nanowire anodes manifest enhanced cycling stability (408 mA h g(-1) after 100 cycles at a current density of 100 mA g(-1)) and rate capacity (240 mA h g(-1) at a current density of 1 A g(-1)), much higher than pure bismuth microparticles and corresponding Bi2S3@C nanowires.