Transition metal dissolution from high-voltage Li-ion battery cathodes disrupts the formation and performance of the solid-electrolyte interphase (SEI). SEI contamination by transition metals results in continual Li loss and severe capacity fade. Fundamental understanding of how metals undermine SEI passivation is necessary to mitigate this degradation. This two-part study interrogates the mechanisms by which transition metals facilitate through-film charge-transfer and SEI failure. Part I presents experimental results in which we intentionally contaminate SEIs with Mn, Ni, and Co. Rotating disk electrode voltammetry of a redox mediator quantifies how each metal impacts the charge-transfer characteristics of the SEI. A physics-based model finds that all three metals disrupt the electronic properties of the SEI more than the morphology. Surprisingly, the Butler-Volmer kinetics of charge-transfer through a Mn-contaminated SEI are an order of magnitude faster than for a Co-contaminated SEI, even with similar embedded metal concentrations. Such trends between metals are inconsistent with bandgap predictions from density functional theory, implying an alternative redox-cycling mechanism, which is mathematically developed and compared to experiment in Part II.

中文翻译：

---

过渡金属如何通过SEI进行电子转移：第一部分：实验和巴特勒-沃尔默模型

来自高压锂离子电池阴极的过渡金属溶解破坏了固体电解质中间相（SEI）的形成和性能。过渡金属对SEI的污染会导致锂的连续损失和严重的容量衰减。对金属如何破坏SEI钝化的基本理解对于减轻这种退化是必要的。这项由两部分组成的研究探讨了过渡金属促进薄膜电荷转移和SEI失效的机制。第一部分介绍了实验结果，其中我们故意用Mn，Ni和Co污染SEI。氧化还原介体的转盘电极伏安法量化了每种金属如何影响SEI的电荷转移特性。基于物理学的模型发现，所有三种金属对SEI的电子特性的破坏都比形态更为严重。出人意料的是，即使有相似的嵌入金属浓度，通过Mn污染的SEI进行电荷转移的Butler-Volmer动力学也比被Co污染的SEI快一个数量级。金属之间的这种趋势与密度泛函理论的带隙预测不一致，这暗示了另一种氧化还原循环机制，该机制是通过数学方法开发的，并与第二部分中的实验进行了比较。