Silicon (Si) is a promising anode material for next‐generation lithium‐ion batteries (LIBs) due to its high specific capacity and abundance. However, challenges such as significant volume expansion during cycling and poor electrical conductivity hinder its large‐scale application. In this study, the multifunction of sodium polyacrylate (PAAS) utilized to develop a hierarchical porous silicon–carbon anode (Si/SiOx@C) through a simple and efficient method. The hierarchical porous structure successively consists of nano‐silicon cores, SiOx encapsulating layers, surrounding space, and phenolic resin‐derived carbon shells with carbon chains connecting the SiOx layers and carbon shells in the space. The SiOx nanolayers promote Li⁺ transport, while excess PAAS, removed by washing, generates space for volume expansion, improving cycling performance. Residual carbon chains of PAAS and carbon shells form a conducting carbon network, enhancing electron transport and rate performance. As an anode for LIBs, the composite delivers a high reversible capacity of 685.3 mAh g⁻¹ after 1000 cycles at 1 C with a capacity retention rate of 54.7%. Full cells with the Si/SiOx@C anode and LiNi0.8Co0.1Mn0.1O2 cathode exhibit an excellent capacity retention rate of 96.8% after 200 cycles at 1 C. This work provides a novel approach for the rational design and engineering of advanced LIBs.

中文翻译：

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用于锂离子电池的多级多孔结构 Si/C 负极材料，通过双封装层提高锂离子和电子传输速率


硅 （Si） 因其高比容量和丰度而成为下一代锂离子电池 （LIB） 的一种很有前途的负极材料。然而，循环过程中体积的显著膨胀和导电性差等挑战阻碍了其大规模应用。在本研究中，聚丙烯酸钠 （PAAS） 的多功能通过一种简单有效的方法开发了多级多孔硅-碳阳极 （Si/SiOx@C）。多级多孔结构依次由纳米硅核、SiOx 包封层、周围空间和酚醛树脂衍生的碳壳组成，碳链连接空间中的 SiOx 层和碳壳。SiOx 纳米层促进 Li⁺ 传输，而通过洗涤去除多余的 PAAS 为体积膨胀产生空间，从而提高循环性能。PAAS 和碳壳的残余碳链形成导电碳网络，增强了电子传输和速率性能。作为锂离子电池的负极，该复合材料在 1 C 下循环 1000 次后可提供 685.3 mAh g⁻¹ 的高可逆容量，容量保持率为 54.7%。采用 Si/SiOx@C 负极和 LiNi0.8Co0.1Mn0.1O2 阴极的全电池在 1 C 下循环 200 次后表现出 96.8% 的优异容量保持率。这项工作为先进 LIB 的合理设计和工程提供了一种新的方法。