CIESC Journal ›› 2022, Vol. 73 ›› Issue (6): 2529-2542.DOI: 10.11949/0438-1157.20220135

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Heat-mass transfer in real porous electrode based on simulated annealing algorithm

Pan HUANG1(),Cheng LIAN1,2(),Honglai LIU1,2()   

  1. 1.School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
    2.School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2022-01-25 Revised:2022-03-22 Online:2022-06-30 Published:2022-06-05
  • Contact: Cheng LIAN,Honglai LIU

基于模拟退火算法的真实多孔电极中热-质传递的研究

黄盼1(),练成1,2(),刘洪来1,2()   

  1. 1.华东理工大学化工学院,上海 200237
    2.华东理工大学化学与分子工程学院,上海 200237
  • 通讯作者: 练成,刘洪来
  • 作者简介:黄盼(1997—),男,博士研究生,panhuang@mail.ecust.edu.cn
  • 基金资助:
    国家自然科学基金项目(91834301);国家自然科学基金创新群体项目(51621002);上海市青年科技启明星计划项目(21QA1401900);能源清洁利用国家重点实验室开放基金(ZJUCEU2021005)

Abstract:

The ion-electron transfer and heat transfer in the electrode significantly affect the electrochemical energy storage performance. The study of heat - mass transfer in porous electrodes, as a typical mesoscale problem, is of great significance to the design of high-performance electrochemical energy storage devices. At present, the simplified model of porous electrode can only approximate the real pore size distribution to a certain extent, and it is difficult to represent the diversified surface morphology and the complex distribution of catalytic active sites, which limits the in-depth study of heat-mass transfer in porous electrode. Therefore, a simulated annealing algorithm based on improved state updating random reconstruction method and dynamic annealing coefficient was used to reconstruct the two-dimensional SEM image after image segmentation into a real three-dimensional porous electrode. Then, the ion transport and electrode heat conduction models in real porous electrodes were established by reconstructing the PNP equation and Fourier law. The results show that when the charging time is 0.1 plate charging relaxation time, the ions mainly adsorb on the contact surface between the skeleton phase of the porous electrode and bulk phase, and the ions tend to migrate from the edge of the cross section to the center. In addition, since the actual thermal conduction distance is much smaller than the thickness of the porous electrode, the thermal relaxation time in the porous electrode is much smaller than that of the flat plate.

Key words: porous electrode, heat-mass transfer, simulated annealing algorithm, ion transport, electrode heat conduction

摘要:

电极中的离子-电子传递和传热显著影响着电化学储能性能。深入研究多孔电极中的热-质传递现象这一典型的介尺度问题,对高性能电化学储能器件的设计具有重要意义。采用一种基于改进的状态更新的随机重建方法和动态退火系数相结合的模拟退火算法,将图像分割后的二维SEM图重构为真实的三维多孔电极。通过重构多孔电极和PNP方程与傅里叶定律,建立真实多孔电极中的离子传递和电极导热模型。结果表明,当充电时间为0.1个平板充电弛豫时间时,离子主要吸附在多孔电极骨架相与体相的接触面上,且离子倾向于从截面边缘往中心迁移。由于实际的导热距离远小于多孔电极厚度,多孔电极中的热弛豫时间远小于平板的热弛豫时间。

关键词: 多孔电极, 热-质传递, 模拟退火算法, 离子传递, 电极导热

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