Li-ion battery degradation and safety events are often attributed to undesirable metallic lithium plating. Since their release, Li-ion battery electrodes have been made progressively thicker to provide a higher energy density. However, the propensity for plating in these thicker pairings is not well understood. Herein, we combine an experimental plating-prone condition with robust mesoscale modeling to examine electrode pairings with capacities ranging from 2.5 to 6 mAh/cm² and negative to positive (N/P) electrode areal capacity ratio from 0.9 to 1.8 without the need for extensive aging tests. Using both experimentation and a mesoscale model, we identify a shift from conventional high state-of-charge (SOC) type plating to high overpotential (OP) type plating as electrode thickness increases. These two plating modes have distinct morphologies, identified by optical microscopy and electrochemical signatures. We demonstrate that under operating conditions where these plating modes converge, a high propensity of plating exists, revealing the importance of predicting and avoiding this overlap for a given electrode pairing. Further, we identify that thicker electrodes, beyond a capacity of 3 mAh/cm² or thickness >75 μm, are prone to high OP, limiting negative electrode (NE) utilization and preventing cross-sectional oversizing the NE from mitigating plating. Here, it simply contributes to added mass and volume. The experimental thermal gradient and mesoscale model either combined or independently provide techniques capable of probing performance and safety implications of mild changes to electrode design features.

中文翻译：

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高面积容量锂离子电池电极的锂镀特性


锂离子电池的退化和安全事件通常归因于不良的金属锂镀层。自发布以来，锂离子电池电极已逐渐​​变得更厚，以提供更高的能量密度。然而，这些较厚配对的电镀倾向尚不清楚。在这里，我们将实验性电镀条件与稳健的介观模型相结合，以检查容量范围为 2.5 至 6 mAh/cm ² 以及负极与正极 (N/P) 电极面积容量比为 0.9 的电极配对。至 1.8，无需进行大量老化测试。通过实验和介观模型，我们发现随着电极厚度的增加，从传统的高荷电状态（SOC）型电镀向高过电位（OP）型电镀的转变。这两种电镀模式具有不同的形态，可通过光学显微镜和电化学特征来识别。我们证明，在这些电镀模式聚合的操作条件下，存在较高的电镀倾向，揭示了预测和避免给定电极配对的这种重叠的重要性。此外，我们还发现，容量超过 3 mAh/cm ² 或厚度 >75 μm 的较厚电极容易出现高 OP，限制负极 (NE) 利用率并防止 NE 横截面尺寸过大减轻电镀。在这里，它只是增加了质量和体积。实验热梯度和介观模型组合或独立提供了能够探测电极设计特征轻微变化的性能和安全影响的技术。