For an electrode of lithium-ion batteries (LiBs), packing active particles yields a very complex microstructure that largely affects the battery performance. This work develops and validates a 3D microstructure-resolved model to study the influence of the active particle size distribution, particle shape, and particle packing configuration. The results show that mixing large and small particles in a random manner can increase the volume fraction of active materials, leading to the highest energy density when the diffusion limitation in the electrolyte is weak. A layered manner with small particles near the separator gives the highest energy density when the diffusion limitation in the electrolyte is severe. A wide particle size distribution deteriorates the performance of LiBs, as the number of large particles increases, and these particles are difficult for the intercalation of lithium. The effects of particle size distribution would not be qualitatively but quantitatively changed by the diffusion limitation in the electrolyte. Besides, the particle shape with a small sphericity is beneficial for improving energy density due to the shorter diffusion path. These results should serve to guide the optimal design of LiB electrodes with high performance.

中文翻译：

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通过微观结构解析模型探讨活性颗粒对锂离子电池的影响


对于锂离子电池（LiB）的电极，活性颗粒的堆积会产生非常复杂的微观结构，在很大程度上影响电池的性能。这项工作开发并验证了 3D 微观结构解析模型，以研究活性颗粒尺寸分布、颗粒形状和颗粒堆积结构的影响。结果表明，以随机方式混合大小颗粒可以增加活性材料的体积分数，从而在电解质中的扩散限制较弱时获得最高的能量密度。当电解质中的扩散限制严重时，隔膜附近具有小颗粒的分层方式可提供最高的能量密度。宽的粒径分布会降低LiB的性能，因为大颗粒的数量增加，并且这些颗粒难以嵌入锂。粒度分布的影响不会因电解质中的扩散限制而发生质的改变，而是数量的改变。此外，球形度小的颗粒形状由于扩散路径较短，有利于提高能量密度。这些结果应有助于指导高性能LiB电极的优化设计。