Simulation of heat generation in a reconstructed LiCoO2 cathode during galvanostatic discharge

Abstract

A three dimensional numerical framework with finite volume method was employed to simulate heat generation of a semi lithium ion battery (LIB) cell during isothermal galvanostatic discharge processes. The microstructure of the LIB cathode electrode was experimentally determined using X-ray nano computed tomography technology. Heat generation in the semi LIB cell during galvanostatic discharge processes from different mechanisms, such as electronic resistive heat, ionic resistive heat, contact resistive heat, reaction heat, entropic heat and heat of mixing, was investigated. The spatial distribution of heat generation rates from different mechanisms was also studied. The simulation results demonstrate that the magnitude of heat generation rates spans a wide range in the electrode due to structural inhomogeneity. The simulation results of heat generation from the three dimensional model and the porous-electrode theory model were compared in this study. It is found that the typical Bruggeman coefficient, 1.5, underestimated ionic resistance in the electrolyte and overestimated electronic resistance in the cathode particles. In general, the three dimensional model predicted more heat generation than the porous-electrode theory model at large discharge rates due to the wider distribution of physical and electrochemical properties.

Experimental and numerical investigation of the application of phase change materials in a simulative power batteries thermal management system

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Thermal characterization of Li-ion cell electrodes by photothermal deflection spectroscopy

“…However, detailed numerical modelling of electrode structures [26] or multi-dimensional approaches [12,14e15] require single electrode properties. Data of single electrodes or electrode coatings additionally facilitate analysis of structure-property correlations to predict thermal conductivities of electrodes.…”

Analysis of Polarization in Realistic Li Ion Battery Electrode Microstructure Using Numerical Simulation

“…They concluded that the high surface roughness of realistic microstructure favored high instantaneous power performance but accelerated side reactions which have a negative impact on power performance. Based on X-ray nano-computed tomography (nano-CT) images, Yan et al reconstructed the electrode microstructure and developed a FVM framework to conduct 3D simulation of a half cell with LiCoO 2 cathode [15,16]. They found that the physical and electrochemical variables were distributed in a wider range than that from the pseudo 2D model due to the microstructural inhomogeneity.…”