The capacity fade of modern lithium ion batteries is mainly caused by the formation and growth of the solid–electrolyte interphase (SEI). Numerous continuum models support its understanding and mitigation by studying SEI growth during battery storage. However, only a few electrochemical models discuss SEI growth during battery operation. In this article, a continuum model is developed that consistently captures the influence of open‐circuit potential, current direction, current magnitude, and cycle number on the growth of the SEI. The model is based on the formation and diffusion of neutral lithium atoms, which carry electrons through the SEI. Recent short‐ and long‐term experiments provide validation for our model. SEI growth is limited by either reaction, diffusion, or migration. For the first time, the transition between these mechanisms is modelled. Thereby, an explanation is provided for the fading of capacity with time t of the form t ^β with the scaling coefficent β , 0≤β ≤1. Based on the model, critical operation conditions accelerating SEI growth are identified.

中文翻译：

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电池循环期间的固体电解质界面：生长机制理论。

现代锂离子电池的容量衰减主要是由固体电解质界面（SEI）的形成和生长引起的。许多连续模型通过研究电池存储期间 SEI 的增长来支持对其的理解和缓解。然而，只有少数电化学模型讨论了电池运行期间 SEI 的增长。在本文中，开发了一个连续模型，该模型能够一致地捕捉开路电位、电流方向、电流幅度和循环次数对 SEI 增长的影响。该模型基于中性锂原子的形成和扩散，中性锂原子通过 SEI 携带电子。最近的短期和长期实验为我们的模型提供了验证。SEI 的生长受到反应、扩散或迁移的限制。首次对这些机制之间的转换进行了建模。由此，解释了容量随时间t的衰减，其形式为t ^β，缩放系数为β，0≤β ≤1。根据该模型，确定了加速 SEI 增长的关键操作条件。