Numerical study of the electrochemical–thermal–mechanical coupled mechanisms of the Li-ion batteries

Lithium-ion batteries constitute a complex multiscale system, integrating physical phenomena across particle, electrode, and cell levels. The development of porous electrode models that bridge microstructural characteristics with macroscopic performance provides a computational foundation for intelligent battery design. Mechanochemical interactions arising during cycling affect the electrochemical processes and significantly influence rate capability and degradation behavior. This study introduces ETMbatteryFoam, a multi-scale simulation framework developed in OpenFOAM, resolving coupled electrochemical–thermal–mechanical phenomena across particle, electrode, and cell scales. By extending traditional concentrated solution theory with small-strain continuum mechanics, the solver formulates a system of partial differential equations describing mass transport, charge conservation, interfacial reaction kinetics, and stress evolution. A segregated iterative algorithm enables full multi-physics simulations of 1C charge/discharge within 1.5 min. Validation against in situ swelling experiments shows less than 8% deformation prediction error for lithium nickel cobalt manganese oxide/graphite systems. The modular and extensible framework provides high-fidelity resolution of electrochemical–mechanical coupling, thereby directly supporting the development of next-generation high-power batteries.