A comprehensive numerical approach for solving heterogeneous electrochemical-thermal model of lithium-ion battery

Numerical simulation of lithium-ion battery heterogeneous model faces significant challenges due to multiscale geometric complexity and strongly coupled multiphysics behavior. This study develops a numerical computational framework based on open-source platform OpenFOAM. To address the complex structure of the heterogeneous model, the framework employs local homogenization for cross-scale spatial discretization and domain decomposition with customized governing equations and boundary conditions. Furthermore, to handle the multiphysics coupling and strong nonlinearity of the equations, a segregated nested iterative algorithm is implemented. This approach incorporates outer-loop current density optimization with inner-loop potential equation relaxation to effectively resolve matrix stiffness and convergence difficulties. The accuracy of this framework is rigorously validated through dual verification against experimental data and COMSOL simulations. Results show excellent agreement, with terminal voltage predictions maintaining under 2% average relative difference across three C-rates. Featuring parallel architecture, it achieves less than 0.5 h simulation time for typical battery systems with remarkable 50$\times$ speedup at 64-core parallelization. Extensive numerical tests across various material systems under diverse conditions demonstrate exceptional robustness. This study establishes a foundational framework for developing electrochemical numerical simulation tools specifically for battery applications, facilitating the design of next-generation ultra-high-performance batteries.