Jang Seunghyeok, Kim Jae-Hun
School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea.
Materials (Basel). 2025 Jul 11;18(14):3272. doi: 10.3390/ma18143272.
Silicon alloy-based materials are widely studied as high-capacity anode materials to replace commercial graphite in lithium-ion batteries (LIBs). Among these, silicon suboxide (SiO) offers superior cycling performance compared to pure Si-based materials. However, achieving a high initial Coulombic efficiency (ICE) remains a key challenge. To address this, previous studies have explored SiO composites (x ≈ 1, 2), where nano-Si is uniformly dispersed within a Si suboxide matrix to enhance ICE. While this approach improves reversible capacity and ICE compared to conventional SiO, it still falls short of the capacity achieved with pure Si. This study employs a high-energy mechanical milling approach with increased Si content to achieve higher reversible capacity and further enhance the ICE while also examining the effects of trace oxygen uniformly distributed within the Si suboxide matrix. Structural characterization via X-ray diffraction, Raman spectroscopy, and electron microscopy confirm that Si crystallites (<10 nm) are homogeneously embedded within the SiO matrix, reducing crystalline Si size and inducing partial amorphization. Electrochemical analysis demonstrates an ICE of 89% and a reversible capacity of 2558 mAh g, indicating significant performance improvements. Furthermore, carbon incorporation enhances cycling stability, underscoring the material's potential for commercial applications.
硅基合金材料作为高容量负极材料被广泛研究，以取代锂离子电池（LIBs）中的商用石墨。其中，一氧化硅（SiO）与纯硅基材料相比具有卓越的循环性能。然而，实现高初始库仑效率（ICE）仍然是一个关键挑战。为解决这一问题，先前的研究探索了SiO复合材料（x≈1, 2），其中纳米硅均匀分散在一氧化硅基体中以提高ICE。虽然这种方法与传统SiO相比提高了可逆容量和ICE，但仍低于纯硅的容量。本研究采用高能机械球磨法增加硅含量，以实现更高的可逆容量并进一步提高ICE，同时研究一氧化硅基体中均匀分布的微量氧的影响。通过X射线衍射、拉曼光谱和电子显微镜进行的结构表征证实，硅微晶（<10 nm）均匀嵌入SiO基体中，减小了结晶硅尺寸并诱导了部分非晶化。电化学分析表明ICE为89%，可逆容量为2558 mAh g，表明性能有显著改善。此外，碳的掺入增强了循环稳定性，突出了该材料的商业应用潜力。
