Scalable synthesis of silicon-nanolayer-embedded graphite for high-energy lithium-ion batteries
Scalable synthesis of silicon-nanolayer-embedded graphite for high-energy lithium-ion batteries
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DOI：
10.1038/nenergy.2016.113
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发表时间：
2016-08-08
期刊：
影响因子：
56.7
通讯作者：
Cho, Jaephil
中科院分区：
文献类型：
--
作者：
Ko, Minseong;Chae, Sujong;Cho, Jaephil
现有的阳极技术正在接近它们的极限，硅因其高比容量和丰度而被认为是一种潜在的替代品。然而，到目前为止，硅的商业应用还不能满足电极压延的需要，粘结剂含量有限，可与商业石墨阳极媲美，以获得高能量密度。在这里，我们论证了使用硅纳米层嵌入石墨/碳的下一代混合阳极的可行性。这种结构允许硅和天然石墨之间的兼容性，并解决了传统机械球磨中粉碎的石墨粉尘和未结合的硅颗粒的结构失效导致的严重副反应问题。这种结构具有很高的首次循环库仑效率(92%)，仅6次循环库仑效率迅速提高到99.5%，100次循环后容量保持率为96%，工业电极密度为1.6g cm(-3)，面容量负载为3.3mAhcm(-2)，浆料中的粘结剂为4wt；因此，使用LiCoO2的全电池表现出比使用标准商业石墨电极更高的能量密度(1,043WH L(-1))。
Existing anode technologies are approaching their limits, and silicon is recognized as a potential alternative due to its high specific capacity and abundance. However, to date the commercial use of silicon has not satisfied electrode calendering with limited binder content comparable to commercial graphite anodes for high energy density. Here we demonstrate the feasibility of a next-generation hybrid anode using silicon-nanolayer-embedded graphite/carbon. This architecture allows compatibility between silicon and natural graphite and addresses the issues of severe side reactions caused by structural failure of crumbled graphite dust and uncombined residue of silicon particles by conventional mechanical milling. This structure shows a high first-cycle Coulombic effciency (92%) and a rapid increase of the Coulombic effciency to 99.5% after only 6 cycles with a capacity retention of 96% after 100 cycles, with an industrial electrode density of >1.6 g cm(-3), areal capacity loading of >3.3 mAh cm(-2), and < 4 wt% binding materials in a slurry. As a result, a full cell using LiCoO2 has demonstrated a higher energy density (1,043 Wh l(-1)) than with standard commercial graphite electrodes.