Largely Improved Battery Performance Using Micro-Sized Silicon Skeleton Caged By Polypyrrole As Anode.
Largely Improved Battery Performance Using Micro-Sized Silicon Skeleton Caged By Polypyrrole As Anode.
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DOI：
10.1021/acsnano.9b06301
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发表时间：
2019-09
期刊：
影响因子：
17.1
通讯作者：
Yingying Lv;Mingwei Shang;Xi Chen;Parisa Shabani Nezhad;J. Niu
中科院分区：
文献类型：
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作者：
Yingying Lv;Mingwei Shang;Xi Chen;Parisa Shabani Nezhad;J. Niu
具有纳米结构硅的各种架构已经证明了有前途的电池性能，同时在工业生产中提出了挑战。作为阳极的石墨中硅的电流比小于5wt%，这极大地限制了电池的能量密度。在这篇文章中，我们报告了一个大的硅笼复合材料（微米），是由一个硅骨架和超薄（<5 nm）介孔聚吡咯（PPy）皮肤通过一个简单的湿化学方法的可扩展的合成。工业上可获得的微米尺寸的AlSi合金被用作前驱体。中空骨架构造提供足够的空间以适应充电/放电时剧烈的体积膨胀/收缩，同时导电聚合物用作Li+/e-传输的保护层和快速通道。以微硅笼为阳极的电池在高充放电速率和高材料负载下具有良好的长循环容量保持率。在0.2C下，在3 mg/cm 2负载下500次循环和4.4mg/cm 2负载下400次循环后，分别实现了~1660 mAh/g的比容量和~99.8%和99.4%的库仑效率（CE）。在1.0 C下，在如此高的负载下，在500次循环后仍保持高达1149 mAh/g的容量。获得了高达6.4 mAh/cm 2的面积容量，4.4 mg/cm 2的负载，这确保了为电动汽车等大型设备供电的高电池能量密度。
Various architectures with nano-structured silicon have demonstrated promising battery performance while posing a challenge in industrial production. The current ratio of silicon in graphite as anode is less than 5 wt%, which greatly limits the battery energy density. In this article, we report a scalable synthesis of large silicon cage composite (micrometers) that is composed of a silicon skeleton and an ultra-thin (<5 nm) mesoporous polypyrrole (PPy) skin via a facile wet-chemical method. The industry available, micro-sized AlSi alloy was used as precursor. The hollow skeleton configuration provides sufficient spaces to accommodate the drastic volume expansion/shrinkage upon charging/discharging while the conductive polymer serves as a protective layer and fast channel for Li+/e- transport. The battery with the micro-silicon (μ-Si) cage as anode displays an excellent capacity retention upon long cycling at high charge/discharge rates and high material loadings. At 0.2 C, the specific capacity of ~1660 mAh/g with Coulombic efficiency (CE) of ~99.8% and 99.4 % were achieved after 500 cycles at 3 mg/cm2 loading and 400 cycles at 4.4 mg/cm2 loading, respectively. At 1.0 C, a capacity as high as 1149 mAh/g was remained after 500 cycles with such high loading. The areal capacity of as high as 6.4 mAh/cm2 with 4.4 mg/cm2 loading was obtained, which ensures a high battery energy density in powering large devices such as electric vehicles.