The severe volumetric changes occur during the lithiation/de-lithiation of silicon materials, which are the main cause of battery capacity failure. In this study, the expansion behavior of a cell composed of a silicon-carbon anode and Li(NiCoMn)O (NCM523) was measured using the electrochemical dilatometry, and the contributions of different silicon and carbon components to the expansion were analyzed, along with factors affecting the cyclic stability of the silicon carbon anode. The results indicate that amorphous carbon can inhibit the volume expansion of monocrystalline silicon in the late stage of lithiation, thereby ensuring the cyclic stability of silicon. The cyclic stability of silicon-carbon composites is affected by irreversible expansion and expansion variation, and these two factors are negatively correlated. This research provides insights and guidance for the design of silicon carbon electrodes with superior electrochemical performance.

中文翻译：

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通过电化学膨胀法研究硅和碳成分对硅碳电极厚度演变和性能退化的影响


硅材料在锂化/脱锂过程中发生严重的体积变化，是电池容量失效的主要原因。在这项研究中，使用电化学膨胀法测量了由硅碳阳极和Li(NiCoMn)O (NCM523)组成的电池的膨胀行为，并分析了不同硅和碳组分对膨胀的贡献，以及影响硅碳负极循环稳定性的因素结果表明，非晶碳可以抑制单晶硅在锂化后期的体积膨胀，从而保证硅的循环稳定性。硅碳复合材料的循环稳定性受不可逆膨胀和膨胀变化的影响，且这两个因素呈负相关。该研究为具有优异电化学性能的硅碳电极的设计提供了见解和指导。