在离子电池的硬碳电极中进行了全面的扩散诱导应力合多尺度建模和分析
P Pavan Kumar1, Asutosh Agrawal1,2, Debasis Nayak1,2
1Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur-721302, West Bengal, India. tkkundu@metal.iitkgp.ernet.in.
Physical chemistry chemical physics : PCCP
|June 20, 2023
概括
在离子电池 (LIB) 中优化硬碳颗粒大小可以防止故障. 这项研究使用多尺度建模来找到最佳尺寸,减少扩散诱导应激 (DIS) 和容量色.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 计算机建模 计算建模
背景情况:
- 由扩散诱导应力 (DIS) 引起的颗粒断裂是导致离子电池 (LIB) 故障的主要原因.
- 优化基于电荷状态 (SOC) 依存性质的电极粒子大小和充/放电率 (C-rates) 是减轻DIS的有希望的策略.
研究的目的:
- 开发和应用全面的多尺度建模方法,以确定高能LIB中硬碳 (HC) 阳极材料的最佳颗粒大小.
- 为了研究在各种C率的化过程中HC粒子内DIS的演变.
主要方法:
- 密度函数理论 (DFT) 用于计算体积膨胀 (CVE) 的SOC依赖系数.
- 分子动力学 (MD) 模拟确定了SOC依赖的扩散性和弹性模量.
- 一个连续模型整合了DFT和MD的结果,以模拟不同C率 (1C-10C) 的HC粒子 (100-1000nm半径) 中的Li+度和DIS演变.
主要成果:
- 多尺度模型成功地结合了Li+扩散率和弹性模块的SOC依赖变化.
- 模拟追踪了在化过程中HC粒子内的应力放松和体积膨胀.
- 确定了HC阳极的优化颗粒大小,平衡了不同C率的DIS.
结论:
- 拟议的多尺度建模框架为优化LIB电极中的DIS提供了一个现实的方法.
- 这项研究为选择最佳颗粒大小提供了指导,以防止颗粒裂纹引起的容量色.
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