储能科学与技术 ›› 2024, Vol. 13 ›› Issue (10): 3622-3629.doi: 10.19799/j.cnki.2095-4239.2024.0318

• 储能测试与评价 • 上一篇    下一篇

锂离子电池均质化电化学模型的电极颗粒半径分布拓展

曹昕1(), 李棉刚2(), 侯宇程1, 贡晓旭2, 李香龙1, 周奎2, 梁惠施2, 杨清华1   

  1. 1.国网北京市电力公司电力科学研究院,北京 100075
    2.清华四川能源互联网研究院,四川 成都 610213
  • 收稿日期:2024-04-11 修回日期:2024-04-24 出版日期:2024-10-28 发布日期:2024-10-30
  • 通讯作者: 李棉刚 E-mail:caoxin_ncepu_16@163.com;limiangang@tsinghua-eiri.org
  • 作者简介:曹昕(1994—),男,博士,工程师,研究方向为新型电力系统,E-mail:caoxin_ncepu_16@163.com
  • 基金资助:
    国网北京市电力公司科技项目(520223230011)

Expansion of the homogeneous electrochemical model for lithium-ion batteries to incorporate electrode particle radius distribution

Xin CAO1(), Miangang LI2(), Yucheng HOU1, Xiaoxu GONE2, Xianglong LI1, Kui ZHOU2, Huishi LIANG2, Qinghua YANG1   

  1. 1.Beijing Electric Power Economic and Technical Research Institute, Beijing 100075, China
    2.Sichuan Energy Internet Research Institute, Tsinghua University, Chengdu 610213, Sichuan, China
  • Received:2024-04-11 Revised:2024-04-24 Online:2024-10-28 Published:2024-10-30
  • Contact: Miangang LI E-mail:caoxin_ncepu_16@163.com;limiangang@tsinghua-eiri.org

摘要:

锂离子电池的仿真对电池研发和评估具有重要作用。当前锂离子电池仿真所使用的经典伪二维模型采用恒定电极颗粒半径假设,无法满足对仿真精度的需求。本工作通过对电极颗粒半径分布的累积分布函数进行逆变换采样,并开展电极颗粒活性比表面积校正,在维持伪二维模型均质化特性的基础上成功引入了电极颗粒半径分布,从而提升了仿真精度。首先,从数学上推导了在伪二维模型中引入电极颗粒半径分布的理论方法,将由伪随机函数生成的关联电极空间坐标的均匀分布数代入电极颗粒半径分布的累积分布函数中,以逆变换采样获得不同电极空间坐标的电极颗粒半径。然后,推导和论证了在引入电极颗粒半径分布后电极颗粒活性比表面积的校正方式,并给出了常见电极颗粒半径分布在伪二维模型中的拓展方程。最后,通过对正极和负极是否进行电极颗粒半径分布拓展的四种组合建立的伪二维模型进行了相同条件的仿真对比,并基于实验数据对无拓展的和含电极颗粒半径分布拓展的伪二维模型开展仿真验证,结果表明本工作提出的电极颗粒半径分布拓展方法能够更准确地仿真电池内部的极化变化,尤其是对弛豫过程的仿真结果更接近实际电池表现,因而具有更高的仿真精度。

关键词: 锂离子电池, 电化学模型, 电极颗粒半径分布, 仿真

Abstract:

Simulation of lithium-ion batteries plays an important role in battery research and evaluation. The classical pseudo-two-dimensional model used in battery simulations typically assumes a constant electrode particle radius, which limits simulation accuracy. In this study, we enhance the pseudo-two-dimensional model by integrating the cumulative distribution function of electrode particle radius distribution through inverse transformation sampling. This process corrects the active specific surface area of the electrode particles, effectively incorporating the electrode particle radius distribution while maintaining the homogeneity characteristics of the pseudo-two-dimensional model, thereby improving simulation accuracy. Firstly, we derive a theoretical method to incorporate the electrode particle radius distribution into the pseudo-two-dimensional model. We use a pseudo-random function to generate uniform distribution numbers based on electrode spatial coordinates, which are then substituted into the cumulative distribution function to determine the electrode particle radius at different electrode spatial coordinates through inverse transformation sampling. Then, we present a method for correcting the active specific surface area of the electrode particles after introducing the radius distribution, along with expansion equations for common electrode particle radius distributions within the pseudo-two-dimensional model, each with different combinations of expanded radius distribution for the positive and negative electrodes, under the same conditions. Simulations comparing the pseudo-two-dimensional model with and without the expanded radius distribution are conducted and validated against experimental data. The results show that incorporating the radius distribution significantly improves the simulation of polarization changes inside the battery, especially during the relaxation process, leading to enhanced simulation accuracy.

Key words: lithium-ion batteries, electrochemical model, electrode particle radius distribution, simulation

中图分类号: