Accelerated 3D Simulation for Analyzing Electrochemical and Thermal Distribution in Lithium-Ion Batteries

Abstract

Understanding the spatial and temporal internal behavior of lithium-ion batteries (LIBs) is crucial for ensuring safe operation and preventing unexpected faults during manufacturing and diagnosis processes. Traditional approaches, such as the pseudo-two-dimensional (P2D) model, provide a simplified representation of LIBs but limit the analysis of continuum-scale electrochemical distribution inside the cell.This study proposes an accelerated three-dimensional (3D) simulation methodology, expanding the conventional P2D model into a pseudo-four-dimensional (P4D) model, including three dimensions of cell structure and a pseudo-dimension inside electrode particles based on the porous electrode theory. In this study, the electrochemical model in the pseudo-four-dimension is combined with a thermal model, considering energy balance with ohmic heat, reaction heat, entropic heat, and internal short circuit (ISC) heat generation.To analyze the P4D model, we apply the following numerical strategies: 1) Elimination of nonlinearity inside model equations using Taylor series expansion, 2) Separation of electrochemical and thermal model variables using a staggered time-stepping method, and 3) Determination of time step size based on the gradient of model output. The proposed method is validated by comparing simulation results for an LFP cell with experimental results and a commercial software under constant current discharge operations (1C, 2C, 3C, and 5C).The accelerated 3D simulation methodology offers significant advantages for exploring internal inhomogeneous properties under different materials operating conditions, ensuring battery safety and reliability under various scenarios. We demonstrate that the proposed method enables the investigation of internal distributions of concentration, potential, and temperature inside battery cells, paving the way for designing and managing batteries with various materials. Figure 1