The intercalation and aging induced volume changes of lithium-ion battery electrodes lead to significant mechanical pressure or volume changes on cell and module level. As the correlation between electrochemical and mechanical performance of lithium ion batteries at nano and macro scale requires a comprehensive and multidisciplinary approach, physical modeling accounting for chemical and mechanical phenomena during operation is very useful for the battery design. Since the introduced fully-coupled physical model requires proper parameterization, this work also focuses on identifying appropriate mathematical representation of compressibility as well as the ionic transport in the porous electrodes and the separator. The ionic transport is characterized by electrochemical impedance spectroscopy (EIS) using symmetric pouch cells comprising LiNi_1/3Mn_1/3Co_1/3O₂ (NMC) cathode, graphite anode and polyethylene separator. The EIS measurements are carried out at various mechanical loads. The observed decrease of the ionic conductivity reveals a significant transport limitation at high pressures. The experimentally obtained data are applied as input to the electrochemical-mechanical model of a prismatic 10 Ah cell. Our computational approach accounts intercalation induced electrode expansion, stress generation caused by mechanical boundaries, compression of the electrodes and the separator, outer expansion of the cell and finally the influence of the ionic transport within the electrolyte.

锂离子电池电极的嵌入和老化引起的体积变化会导致电池和模块水平上的显着机械压力或体积变化。由于锂离子电池在纳米和宏观尺度上的电化学性能和机械性能之间的相关性需要全面和多学科的方法，因此在操作过程中考虑化学和机械现象的物理建模对于电池设计非常有用。由于引入的完全耦合的物理模型需要适当的参数设置，因此这项工作还着重于确定可压缩性以及多孔电极和隔板中离子迁移的适当数学表示。离子传输的特征在于使用包含LiNi的对称袋式电池的电化学阻抗谱（EIS）_1/3 Mn _1/3 Co _1/3 O ₂（NMC）阴极，石墨阳极和聚乙烯隔膜。EIS测量是在各种机械负载下进行的。所观察到的离子电导率的降低揭示了在高压下的显着运输限制。将实验获得的数据作为输入，应用到棱柱形10 Ah电池的电化学力学模型中。我们的计算方法考虑了插层引起的电极膨胀，由机械边界引起的应力产生，电极和隔板的压缩，电池的外部膨胀以及最终电解质中离子迁移的影响。