Mechanism of Mechanics Evolution of Li-ion Battery Separator

For the problem of separator microstructure quantitative evolution under different loads, a simulation study based on images reconstruction is carried out. Aiming at the complex image structure problem of the amorphous fiber region of the SEM image, the binary processing and threshold segmentation methods were developed to efficiently identify and extract the pore phase and solid phase of the membrane. Based on the image finite element method, the simulations result of the evolution of the microstructures have found that the internal deformation of the separator shows the features of local stress concentration, local instability, and non-uniform mechanical characteristics. Microscopic information, such as porosity under different loads was quantitatively obtained. The characterization of separator microstructure evolution under different mechanical loads was also quantitatively analyzed in the modeling.