Capacity fade in lithium-ion batteries largely originates from the undesired electrolyte decomposition, which results in the formation of solid electrolyte interphase (SEI) and the anode surface passivation. In this work, a mesoscale interfacial modeling approach is developed to investigate the formation and growth of the SEI film on a typical graphite based anode over several cycles. It is found that lithium diffusion kinetics in the SEI film significantly affects the SEI growth rate. A lower lithium diffusion barrier leads to a higher growth rate. The present model demonstrates that the SEI thickness is a linear function of the square root of the charging time over long-time cycling. Growth of multicomponent SEI film is also elucidated. It is found that the heterogeneity of the SEI film may lead to instability in lithium ion concentration distribution.

中文翻译：

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锂离子电池阳极中固体电解质中间层形成的中尺度解释

锂离子电池的容量衰减主要源于不希望的电解质分解，从而导致形成固态电解质中间相（SEI）和阳极表面钝化。在这项工作中，开发了一种中尺度界面建模方法，以研究在几个周期内典型的石墨基阳极上SEI膜的形成和生长。发现锂在SEI膜中的扩散动力学显着影响SEI的生长速率。较低的锂扩散势垒导致较高的生长速率。本模型表明，在长时间循环中，SEI厚度是充电时间平方根的线性函数。还阐明了多组分SEI膜的生长。