Modeling, validation, and analysis of swelling behaviors of lithium-ion batteries

The swelling of lithium-ion batteries (LIBs) is one of the responsible reasons to cause capacity degradation and safety problems. Quantification of the swelling force and the corresponding strain is a critical problem in exploring the complex electro-mechanical behaviors in batteries. Though in the current open literature, a few models are available to describe the swelling of the component materials in a battery. A physics-based detailed model linking the component material scale to the cell scale is still lacking. Herein, we develop a fully detailed three-dimensional swelling mechanical model considering the actual structure of the battery. After rigorous validation by the experiment, we leverage the model to investigate a complicated coupled boundary, i.e., plate-constrained swelling. The swelling force and uneven stress distribution of each component are analyzed among various influential factors. The results provide fundamental insights into the application of LIB.