Development of robust and accurate thermo-electrochemical models for Lithium-ion batteries

Abstract

Integrating lithium-ion batteries (LIBs) as an energy storage system in electronic devices, including electric vehicles (EVs), creates new challenges. LIB design must be optimized according to the specifications of each application to improve battery performance and safety in each application while avoiding rapid battery degradation. Therefore, accurate models that can forecast the performance of LIBs under various operating conditions are required. Consequently, the primary purpose of this study is to establish a battery model that accounts for the correct thermal heating of large prismatic batteries (PBs) used in EVs. Due to large fluctuations in the space current and Temp (Temp) of PCs (PCs), one-dimensional (1D) models cannot be used to model these PCs. This work combines a 1D model into a three-dimensional multilayer model by the resistive network method. The established model was validated by evaluating the simulated surface Temp of a PB (containing LFP as the positive (+ve) electrode and graphite as the negative (-ve) electrode) with experimental data at different charge (CH)/ discharge (DISCH) rates (1C, 2C, 3C, and 5C). Application of the model utilized effect size, location, and thickness of current collector sheets on the electrochemical (electrochem) properties of large cells is evaluated. Moving the bumps from the edge and one side (a standard commercial design) to the center and the other side of the cell and maximizing their width have been shown to reduce the change in imbalance caused by electrochem current flow.