捕捉锂离子电极热导率中的压延 U 形
Capturing the calendering U-shape in lithium-ion electrode thermal conductivity
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中文总结 AI 辅助
研究锂离子电极压延对热导率的非单调影响，开发 Zehner--Bauer--Schlünder 模型的压延感知扩展，结合多孔介质基线与接触贡献，该模型在多种电极材料和压延状态下降低了预测误差，强调纳入微观结构演化的必要性。
中文摘要 AI 辅助
压延是锂离子电极生产中的关键制造步骤，通过降低电极孔隙率提高体积能量密度。然而，其对平面有效热导率的影响可能是非单调的：基于石墨的阳极测量显示，在早期压延过程中热导率最初下降，随后在更高压实度下恢复。传统的基于孔隙率的有效介质闭合模型无法再现这种 U 形行为。我们开发了 Zehner--Bauer--Schlünder 模型的压延感知扩展，将克努森校正的多孔介质基线与压缩指数接触贡献相结合。对于石墨电极，该模型表示增加颗粒接触和压延诱导的各向异性石墨颗粒重新定向的竞争效应，这最初减少了有利的平面热传输路径。对于准各向同性的 NMC 阴极，观察到的响应通过与过程相关的接触网络演化来捕捉。在跨越薄和厚石墨阳极以及 NMC622 和 NMC811 阴极的 27 种压延状态下，所提出的闭合模型将平均绝对百分比误差从零拟合参考模型的 31.1%降低到 4.5%。结果表明，纳入与过程相关的微观结构演化对于捕捉测量到的电导率最小值是必要的。跨额外电极配方、厚度和化学组成的验证对于评估可转移性仍然是必要的。
英文摘要
Calendering is a key manufacturing step in lithium-ion electrode production, increasing volumetric energy density by reducing electrode porosity. Its effect on through-plane effective thermal conductivity, however, can be non-monotonic: measurements of graphite-based anodes show an initial decrease in thermal conductivity during early calendering followed by recovery at higher compaction. Conventional porosity-based effective-medium closures cannot reproduce this U-shaped behaviour. We develop a calendering-aware extension of the Zehner--Bauer--Schlünder model that combines a Knudsen-corrected porous-medium baseline with a compression-indexed contact contribution. For graphite electrodes, the model represents the competing effects of increasing particle contact and calendering-induced reorientation of anisotropic graphite particles, which initially reduces favourable through-plane heat-transport pathways. For quasi-isotropic NMC cathodes, the observed response is instead captured through process-dependent contact-network evolution. Across 27 calendering states spanning thin and thick graphite anodes and NMC622 and NMC811 cathodes, the proposed closure reduces the mean absolute percentage error from 31.1% for the zero-fit reference model to 4.5%. The result shows that incorporating process-dependent microstructural evolution is necessary to capture the measured conductivity minimum. Validation across additional electrode formulations, thicknesses, and chemistries remains necessary to assess transferability.
