Silicon-based anode materials are considered as the most attractive alternatives to traditional graphite anodes, thereby advancing the evolution of new-generation lithium-ion battery technology. However, the inadequate electrical conduction of silicon-based materials, along with severe volume expansion during charging and discharging processes, limits their further technological applications. Herein, a dual-layer carbon shell configuration is designed to efficiently alleviate the substantial volumetric expansion of silicon during cycles, while simultaneously improving the efficiency of both electron and lithium ions. The effectiveness of this layered buffering approach is credited to the networked structure of outer single-walled carbon nanotubes (SWCNTs) layer, which is firmly attached to the inner carbon shell's surface. The modified structure not only elevates the level of electrical conduction, but also significantly reduces the internal stress due to silicon's expansion. The developed Si@C@SWCNT electrode materials exhibit high capacity of 1267.3 mA h g after 500 cycles at 1 A g, and sustains an elevated rate capacity of 863 mA h g at 8 A g. This study highlights the enormous potential of Si@C@SWCNT composites for use in lithium-ion batteries and provides new perspectives for further exploration and utilization of silicon-carbon anodes.

中文翻译：

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通过碳涂层和薄层单壁碳纳米管网提高商用硅纳米颗粒的循环稳定性

硅基负极材料被认为是传统石墨负极最具吸引力的替代品，从而推动了新一代锂离子电池技术的发展。然而，硅基材料的导电性不足以及充放电过程中严重的体积膨胀限制了其进一步的技术应用。在此，双层碳壳结构被设计为有效减轻循环过程中硅的大幅体积膨胀，同时提高电子和锂离子的效率。这种分层缓冲方法的有效性归功于外单壁碳纳米管（SWCNT）层的网络结构，该结构牢固地附着在内碳壳表面上。改进的结构不仅提高了导电水平，而且还显着降低了由于硅膨胀而产生的内应力。所开发的Si@C@SWCNT电极材料在1 A g-1下循环500次后表现出1267.3 mAh g-1的高容量，并在8 A g-1下维持863 mAh g-1的高倍率容量。该研究凸显了Si@C@SWCNT复合材料在锂离子电池中的巨大潜力，为硅碳负极的进一步探索和利用提供了新的视角。