Microscale diffusion-mechanics model for a polymer-based solid-state battery cathode

A non-linear microscale diffusion-mechanics model combining mass transport and linear momentum balance equations, with elasto-viscoplastic polymer constitutive law interfacial traction-separation is proposed to provide a new insight into the effects of viscoplasticity damage on in situ diffusive-mechanical behaviour polymer-based cathode for solid-state battery (SSB). Diffusion mechanics are coupled through two mechanisms: (1) active particle (AP) volumetric change dependence Li concentration, (2) flux mechanical opening. The resolved simple microstructure using an axisymmetric unit cell concept, integrated finite-element solver ABAQUS help its user subroutines (UMAT UINTER). Finite-element simulations reveal that plastic deformations due changes AP reduce value opening displacement, which desirable maintaining flux. results also demonstrate slower charging rates may lead softer response, thus smaller gap. Moreover, comparison between elastic current models electrolyte shows even 5% shrinkage leads overprediction material law, limits validity modelling SSBs.