Controlled Prelithiation of Silicon Monoxide for High Performance Lithium-Ion Rechargeable Full Cells

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• 作者：Hye Jin Kim ; Sunghun Choi ; Seung Jong Lee ; Myung Won Seo ; Jae Goo Lee ; Erhan Deniz ; Yong Ju Lee ; Eun Kyung Kim ; Jang Wook Choi
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：January 13, 2016
• 年：2016
• 卷：16
• 期：1
• 页码：282-288
• 全文大小：544K
• ISSN：1530-6992

文摘

Despite the recent considerable progress, the reversibility and cycle life of silicon anodes in lithium-ion batteries are yet to be improved further to meet the commercial standards. The current major industry, instead, adopts silicon monoxide (SiO_x, x ≈ 1), as this phase can accommodate the volume change of embedded Si nanodomains via the silicon oxide matrix. However, the poor Coulombic efficiencies (CEs) in the early period of cycling limit the content of SiO_x, usually below 10 wt % in a composite electrode with graphite. Here, we introduce a scalable but delicate prelithiation scheme based on electrical shorting with lithium metal foil. The accurate shorting time and voltage monitoring allow a fine-tuning on the degree of prelithiation without lithium plating, to a level that the CEs in the first three cycles reach 94.9%, 95.7%, and 97.2%. The excellent reversibility enables robust full-cell operations in pairing with an emerging nickel-rich layered cathode, Li[Ni_0.8Co_0.15Al_0.05]O₂, even at a commercial level of initial areal capacity of 2.4 mAh cm^–2, leading to a full cell energy density 1.5-times as high as that of graphite-LiCoO₂ counterpart in terms of the active material weight.