A phase field model for coupling diffusion-deformation-fracture multi-physics in porous electrodes

With the rapid advancements in electric vehicles and renewable energy technologies, Li-ion batteries (LIBs) play a crucial role as primary energy storage devices. However, as battery sizes increase and performance demands rise, the reliability and durability of battery components become paramount. In this investigation, a phase field model coupling diffusion-deformation-fracture multi-physics in porous electrodes is developed and implemented numerically through secondary development based on the Uer-defined element (UEL) subroutine of the commercial software ABAQUS. The model without pre-existing crack is capable of simulating efficiently the behaviors of crack initiation, propagation, and crack merging of porous electrodes coupled Li-ion diffusion-induced stress, enabling the complex crack propagation mechanism of coupling chemical and mechanical phenomena due to the presence of pores. The research findings reveal that both hydrostatic stress and the resultant concentration variations significantly influence crack propagation in porous electrodes. Concurrently, the crack width broadens with increasing crack length scale parameter. Lower critical energy release rates induce earlier crack initiation and accelerate crack propagation velocity in porous electrodes. These results contribute to a deeper understanding of the structural integrity and performance of porous electrodes in LIBs, and have implications for enhancing their reliability and performance in the design and optimization of LIBs.