Modeling the powder plasticity of porous electrodes for the prediction of battery breathing and swelling prior to degradation

Porous electrodes in lithium-ion batteries undergo cyclic mechanical deformation during operation, yet predictive models in the small-to-medium strain regime under functional pressure conditions remain scarce. This work develops and calibrates a constitutive model for porous electrode materials by integrating systematic low-pressure triaxial and uniaxial compression tests with the Drucker–Prager/Cap (DPC) plasticity framework, grounded in traditional powder mechanics. The calibrated model captures particle sliding and porous consolidation via the Drucker–Prager envelope and Deshpande–Fleck cap, respectively, and is readily implementable in commercial finite element platforms. Coupled with reduced-order electrochemical models, it enables accurate prediction of reversible “breathing” and irreversible “swelling” during cycling. Discussion highlights the model’s sensitivity to electrochemical inputs, the amplification of small prediction errors in mechanical response, and the practical treatment of diffusion-induced strain as a tunable fitting parameter for industrial use. The approach balances experimental simplicity, computational efficiency, and predictive fidelity, offering a practical tool for battery manufacturing, structural design, and life-cycle management.