Hollow Silicon Nanospheres Encapsulated with a Thin Carbon Shell: An Electrochemical Study
Hollow Silicon Nanospheres Encapsulated with a Thin Carbon Shell: An Electrochemical Study
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DOI：
10.1016/j.electacta.2016.08.059
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发表时间：
2016-10-01
影响因子：
6.6
通讯作者：
Shaw, Leon L.
中科院分区：
文献类型：
--
作者：
Ashuri, Maziar;He, Qianran;Shaw, Leon L.
在这项研究中，我们研究了用薄碳壳封装的空心硅纳米球 HSi@C 的电化学性能，作为锂离子电池阳极的潜在候选材料。使用模板法形成空心硅纳米球，然后通过吡咯前体的碳化进行碳涂覆以形成HSi@C。对HSi@C的合成条件和所得结构进行了详细研究，以获得碳壳封装的空心硅纳米球的目标设计。所获得的HSi@C表现出比微米和纳米尺寸硅阳极更好的电化学循环稳定性，在2 A g(-1)电流密度下循环100次后稳定比容量为700 mAh g(-1)，在1 A g(-1)电流密度下循环120次后稳定比容量为800 mAh g(-1)。 HSi@C 的优越性能归因于纳米结构材料、增强的电导率以及用于 Si 膨胀的中心空隙空间的存在的协同组合，而整个 HSi@C 颗粒的体积几乎没有变化或没有变化。这项研究是对获得具有导电碳壳的空心硅核所需结构的合成条件的首次详细研究。这项研究还为未来进一步提高HSi@C阳极的比容量提供了指导。 (C) 2016 Elsevier Ltd. 保留所有权利。
In this study we have investigated the electrochemical properties of hollow silicon nanospheres encapsulated with a thin carbon shell, HSi@C, as a potential candidate for lithium-ion battery anodes. Hollow Si nanospheres are formed using a templating method which is followed by carbon coating via carbonization of a pyrrole precursor to form HSi@C. The synthesis conditions and the resulting structure of HSi@C have been studied in detail to obtain the target design of hollow Si nanospheres encapsulated with a carbon shell. The HSi@C obtained exhibits much better electrochemical cycle stability than both micro-and nano-size silicon anodes and deliver a stable specific capacity of 700 mA h g(-1) after 100 cycles at a current density of 2 A g(-1) and 800 mA h g(-1) after 120 cycles at a current density of 1 A g(-1). The superior performance of HSi@C is attributed to the synergistic combination of the nanostructured material, the enhanced conductivity, and the presence of the central void space for Si expansion with little or no change in the volume of the entire HSi@C particle. This study is the first detailed investigation of the synthesis conditions to attain the desired structure of a hollow Si core with a conductive carbon shell. This study also offers guidelines to further enhance the specific capacity of HSi@C anodes in the future. (C) 2016 Elsevier Ltd. All rights reserved.