Electro-Thermal Equivalent Circuit of Lithium-Ion Battery Using COMSOL

Abstract

In this paper, the significance of electro-thermal equivalent circuits in enhancing the performance and safety of lithium-ion batteries is discussed. The electro-thermal equivalent circuit effectively models battery behavior by incorporating temperature distribution and internal resistances. The methodology for generating the equivalent circuit is described, employing physical analogies and establishing an analogy between electrical and thermal variables. The equivalent circuit represents the battery as a network of nodes and resistors, with voltage symbolizing temperature and current symbolizing heat flow. Additionally, the paper elucidates the process of simulation and data acquisition using COMSOL software, enabling the retrieval of temperature and heat flux values under various boundary conditions. The obtained data is utilized to construct the equivalent circuit and determine its parameters. The paper concludes with the testing and evaluation of the equivalent circuit's accuracy in predicting temperature values. The conducted tests demonstrate an accuracy exceeding 90%, affirming the reliability of the proposed approach.