Abstract Nano-Si/MWCNTs composite was a representative solution to improve Si-based anode material’s rate performance in lithium-ion batteries (LIBs). However, the problems of easy agglomeration of silicon nanoparticles and carbon nanotubes hindered Si/MWCNT’s further development. In this study, we combine silicon nanoparticles with MWCNTs cleverly by utilizing freeze-drying method to solve the problems and enhance silicon-based material’s rate performance. Compared with Si-MWCNTs composite treated by electric blast-drying method, the rate performance of Si-MWCNTs treated by freeze-drying is significantly improved, especially at different current densities. When Si-MWCNTs are encapsulated in FPC (flour-derived porous carbon, FPC), the as-obtained Si-MWCNTs-PVPC-FPC-SC-1 (sucrose-derived carbon, SC) prepared by freeze-drying method delivers a reversible capacity of 1347.5 mAh g-1 at 0.1 A g-1 after cycling at 5 A g-1 and a reversible capacity of 501 mAh g-1 at 1 A g-1 after 500 cycles. Our study demonstrates that the freeze-drying method can solve the problems of easy agglomeration of silicon nanoparticles and MWCNTs as well as improve Si-based anode’s rate performance for LIBs. The synthetic route presented in this paper is low-cost and easy to scale up for silicon-carbon (Si/C) composites with high rate performance and long cycle life.

中文翻译：

---

用于锂存储的 Si/MWCNTs 复合材料的策略和详细解释

摘要 Nano-Si/MWCNTs 复合材料是提高锂离子电池（LIBs）中硅基负极材料倍率性能的代表性解决方案。然而，硅纳米颗粒和碳纳米管容易团聚的问题阻碍了Si/MWCNT的进一步发展。在这项研究中，我们通过利用冷冻干燥方法将硅纳米颗粒与多壁碳纳米管巧妙地结合来解决问题并提高硅基材料的倍率性能。与电鼓风干燥法处理的Si-MWCNTs复合材料相比，冷冻干燥法处理的Si-MWCNTs的倍率性能显着提高，尤其是在不同电流密度下。当 Si-MWCNTs 被封装在 FPC（面粉衍生的多孔碳，FPC）中时，所获得的 Si-MWCNTs-PVPC-FPC-SC-1（蔗糖衍生的碳，SC) 在 5 A g-1 下循环后在 0.1 A g-1 下的可逆容量为 1347.5 mAh g-1，在 1 A g-1 下在 500 次循环后的可逆容量为 501 mAh g-1循环。我们的研究表明，冷冻干燥方法可以解决硅纳米颗粒和多壁碳纳米管容易团聚的问题，并提高硅基负极对锂离子电池的倍率性能。本文提出的合成路线成本低，易于放大，具有高倍率性能和长循环寿命的硅碳 (Si/C) 复合材料。我们的研究表明，冷冻干燥方法可以解决硅纳米颗粒和多壁碳纳米管容易团聚的问题，并提高硅基负极对锂离子电池的倍率性能。本文提出的合成路线成本低，易于放大，具有高倍率性能和长循环寿命的硅碳 (Si/C) 复合材料。我们的研究表明，冷冻干燥方法可以解决硅纳米颗粒和多壁碳纳米管容易团聚的问题，并提高硅基负极对锂离子电池的倍率性能。本文提出的合成路线成本低，易于放大，具有高倍率性能和长循环寿命的硅碳 (Si/C) 复合材料。