Session: K6-03: HEAT TRANSFER IN ENERGY SYSTEMS - ENERGY STORAGE I

Paper Number: 130166

130166 - Advancement in Lithium-Ion Battery Pack Thermal Modeling Based on Electrochemical Principles 

Abstract: 

A lithium-ion battery pack, employed in diverse applications like electric vehicles, comprises individual modules, each
housing collections of cells. These cells, functioning as singular units, convert chemical reactions into electric power. This
study presents an advanced thermal model for lithium-ion battery packs, considering both cell-level and module-level analysis.

The heat generated within each cell arises from the complex electrochemical reactions within the cell, governed by Fick’s
second law of diffusion. Based on the assumption that each electrode particle can be simplified as a single sphere, the Single
Particle Model (SPM) consisting of two Partial Differential Equations (PDEs) is employed, one for each electrode dynamics.
Ohm’s law is then applied to compute electric power, and subsequently, Joule’s effect is used to calculate heat generated
from electric power. Additionally, heat from conduction interactions among internal cell components and the battery casing is
assessed using the classical thermal resistance model. Convective heat generated within the liquid electrolyte is also considered in the overall heat analysis within a cell.

The aforementioned heat generated inside a cell from Joule’s effect, conduction, and convection effects is treated as the
averaged heat source per cell within a module. Determining the total heat of each module in the pack based on the sum of battery cell heat sources, the model employs a PDE as the transient heat equation to analyze internal temperature in each module of a battery pack. Heat exchanges between modules, crucial for safety and heat dissipation, are incorporated as boundary conditions, resulting in a cascaded system of PDEs. Model validation can be achieved through comparative experimental results, providing a solid foundation for the proposed coupled electrochemical-thermal system for thermal modeling purpose. This accurate model will help prevent issues such as overheating and thermal runaway that reduce battery life, pose safety hazards, and lead to catastrophic failures.

The main novelty of this study lies in: (1) In contrast to prevailing heat transfer studies that treat the battery pack as a whole,
often relying on computational fluid dynamics (CFD), this study begins by modeling the heat in each cell through PDEs derived from the electrochemical model and subsequently, extends this model to encompass the heat in each module. Furthermore, by incorporating heat exchanges as boundary conditions, a system of PDEs for each module is established, enhancing the model accuracy for the battery pack. (2) In contrast to prevailing control engineering studies that focus on battery cells using PDE models, this study uses systems of multiple PDEs to model the temperature in the module within the battery pack.

Presenting Author: Shuxia Tang Texas Tech University

Presenting Author Biography: Shu-Xia Tang received the Ph.D. degree in mechanical engineering from the Department of Mechanical and
Aerospace Engineering, University of California, San Diego, La Jolla, CA, USA, in 2016. She is currently an Assistant Professor with the Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, USA. Her research interests include stability analysis, estimation, and control design of distributed parameter systems.

Dr. Tang is a Senior Member of IEEE, the Senior Associate Editor for the ASME DSCC (Dynamic Systems and Control Division) Newsletter and an Editorial Board Member of the IEEE Control Systems Society and ASME Dynamic Systems and Control Division. She is a Member of the Technical Committee on Distributed Parameter Systems of the IEEE Control Systems Society, the IFAC Technical Committee on Distributed Parameter Systems, and the ASME Techinical Committee on Energy
Systems.

Authors:

Patryck Ferreira Texas Tech University
Shuxia Tang Texas Tech University