Electrochemical properties of core–shell nano-Si@carbon composites as superior anode materials for high-performance Li-ion batteries

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• 作者：Hedong Chen ; Xianhua Hou ; Lina Qu…
• 刊名：Journal of Materials Science: Materials in Electronics
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：28
• 期：1
• 页码：250-258
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Optical and Electronic Materials; Characterization and Evaluation of Materials;
• 出版者：Springer US
• ISSN：1573-482X
• 卷排序：28

文摘

Si@carbon composites have been successfully prepared via spray drying and subsequent calcination using PSA microspheres, nano-silicon and natural graphite as raw materials. Nano-silicon with a 20–100 nm particle size is prepared by radio-frequency electromagnetic induction. Such small nano-silicon particles can effectively accommodate the volume expansion of the Si@carbon anode. Additionally, the unique core–shell structure of Si@carbon composites can effectively alleviate the agglomeration of nano-silicon particles. Electrochemical tests show that the Si/carbon electrode delivers a high initial discharge capacity of approximately 1404.27 mAh g−1 with an initial coulombic efficiency of 82.4 %. The discharge specific capacity remains as high as 73.6 % after 100 charging-discharging cycles, demonstrating the electrode material’s good cycle stability. In addition, the corresponding specific capacity of the Si@carbon composites electrode remains at around 1150 mAh g−1 at a current density of 1 A g−1. And when the current density is 0.1 A g−1, its specific capacity can still remain at around 920 mAh g−1, indicating excellent capacity reversibility. Therefore, Si@carbon composites are superior anode materials for high-performance Li-ion batteries.