材料科学
阳极
纳米线
电解质
硅
基质(水族馆)
纳米材料
离子
纳米技术
电池(电)
光电子学
化学工程
电极
功率(物理)
化学
海洋学
物理
物理化学
量子力学
地质学
工程类
作者
Hung Tran Nguyen,Fei Yao,Mihai Robert Zamfir,Chandan Biswas,Kyeong A So,Young Hee Lee,Sang Woo Kim,Seung Nam,Jong Min Kim,Didier Pribat
标识
DOI:10.1002/aenm.201100259
摘要
Abstract Silicon exhibits the largest known capacity for Li insertion in anodes of Li‐ion batteries. However, because of large volume expansion/phase changes upon alloying, Si becomes powder‐like after a few charge‐discharge cycles. Various approaches have been explored in the past to circumvent this problem, including the use of nanomaterials, particularly Si nanowires. However, even though nanowires resist cracking very well, anodes based on Si nanowires still see their original capacity fade away upon cycling, because of wire detachment from the substrate, due to the stress generated at their roots upon alloying with Li. Here, we present a silicon nanowire growth strategy yielding highly interconnected specimens, which prevents them from being individually detached from the substrate. We report a ∼100% charge retention after 40 cycles at C/2 rate, without charging voltage limitation. We also show that our anodes can be cycled at 8C rates without damage and we grow nanowires with a density of 1.2 mg/cm 2 , yielding anodes delivering a 4.2 mAh/cm 2 charge density. Finally, we point out that a better understanding of the interactions of silicon with electrolytes is needed if the field is to progress in the future.
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