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| 基于力平衡颗粒堆积法的多晶颗粒微结构建模 |
| Microstructure modeling of polycrystalline particles based on force-equilibrium packing methods |
| 投稿时间：2024-01-01 修订日期：2024-02-20 |
| DOI： |
| 中文关键词: 粒子填充 力平衡 韦布尔分布 多晶颗粒微结构 |
| 英文关键词:particle packing force-equilibrium Weibull distribution particle microstructure |
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| 中文摘要: |
| 锂离子电池正极的活性材料通常由多晶结构的颗粒构成，且构成多晶颗粒的单晶晶粒的大小、形状和取向存在极大的随机性。简单高效地针对不同活性材料多晶颗粒的微结构进行客观科学的拓扑描述，是实现合理可靠锂电池力化学建模仿真，为多晶颗粒微结构设计提供优化策略的前提。传统的晶粒建模方法通常存在计算效率底或适配程度差等问题，本文基于一种等效桁架结构和力平衡原理的颗粒堆积方法，获得稳定的粒子堆积结构，并根据粒子镶嵌的拓扑结构对多晶颗粒进行网格剖分，获得多晶颗粒的微结构模型，在保证单晶颗粒粒径分布规律的同时提高了计算效率。基于力平衡原理的颗粒堆积法根据力学原理修正每个粒子向平衡态演化时的位移，从而以更自然且更快的方式收敛到稳定的粒子堆积结构。在此基础上，利用颗粒的镶嵌拓扑结构对每个球体完成网格划分，最终完成多晶颗粒微结构的建模。最后，考虑了圆形边界下二维和三维两种计算模型，分析了不同粒径分布的颗粒堆积与多边形晶格的物理结构之间的关系。 |
| 英文摘要: |
| The active material of lithium-ion battery cathode usually consists of particles with polycrystalline structure. The constituents are primary grains whose size, shape and orientation have great randomness. Thus, it is essential to effectively complete an objective topological description of active particle microstructures, in order to conduct a reliable chemo-mechanical simulation of lithium-ion batteries and to provide guidelines for microstructure optimization. The traditional grain modeling methods usually suffer from the problems of low computational efficiency or poor fitness with real microstructure in terms of size distribution. In this work, a random packing method based on equivalent truss structure and force equilibrium is proposed to update the displacement of each particle according to physical principles, thus providing a more natural and faster route towards a stable particle packing structure. In addition, the paper utilizes the tessellation topology of the particles to draw the grain boundaries of the particles and finally to construct the particle microstructure. Both two-dimensional and three-dimensional models under respective spherical and circular boundaries are considered in the paper, and the relationship between particle packing with different size distributions and the physical microstructure of the particle is analyzed. |
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