Abstract Nanoporous silicon @ graphitized carbon (NPSi@C) composites have been reasonably designed and synthesized via one-step magnesiothermic co-reduction using rice husks as the silicon source and CO2 as the carbon source. In the self-assembly process, the nano-silicon prepared from rice husk-derived SiO2 is made into a porous structure and uniformly recombined with graphitized carbon formed by CO2 reduction at low temperature (680 °C). The nanoporous structure has contributed to accommodate the large volume effect of activated silicon and provides sufficient channels for the transfer of lithium ions. Furthermore, the graphitized carbon layers effectively enhance the electrical conductivity and coulombic efficiency of the composites, which is conducive to the improvement of electrochemical performance. The optimized NPSi@C composite exhibits superior lithium storage properties with the initial coulombic efficiency of 41.0% and the reversible specific capacity of 681.8 mA h g−1 after 100 cycles at 0.2 A g−1. This study suggests a simple, low-cost, and scalable strategy, which maximizes the advantages of traditional magnesiothermic reduction, to the preparation of Si/C composites as the most promising alternative anode materials for lithium ion batteries.

中文翻译：

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纳米多孔硅@石墨化碳复合材料的一步合成及其优越的储锂性能

摘要 以稻壳为硅源，CO2为碳源，通过一步镁热共还原，合理设计并合成了纳米多孔硅@石墨化碳（NPSi@C）复合材料。在自组装过程中，将稻壳衍生的 SiO2 制备的纳米硅制成多孔结构，并在低温（680°C）下与 CO2 还原形成的石墨化碳均匀复合。纳米多孔结构有助于适应活化硅的大体积效应，并为锂离子的转移提供足够的通道。此外，石墨化碳层有效地提高了复合材料的电导率和库仑效率，有利于电化学性能的提高。优化的 NPSi@C 复合材料表现出优异的锂存储性能，初始库仑效率为 41.0%，在 0.2 A g-1 下循环 100 次后可逆比容量为 681.8 mA hg-1。该研究提出了一种简单、低成本和可扩展的策略，最大限度地发挥传统镁热还原的优势，制备 Si/C 复合材料作为最有前途的锂离子电池替代负极材料。