3D simulation of all-solid-state batteries with real electrode structures derived from X-ray computed tomography

To enhance all-solid-state battery performance, optimization of the electrode structure through highly accurate simulations is essential. However, conventional pseudo-two-dimensional simulations are limited in accuracy, and three-dimensional (3D) simulations have rarely been studied owing to the computational cost and challenges in reproducing the actual electrode structure. In this study, we perform 3D simulations using a finite element method that incorporates the actual electrode structure obtained from X-ray computed tomography images. The 3D simulation reproduced experimental results more accurately than the pseudo-two-dimensional simulation, particularly in capturing the gradient of discharge curves associated with lithium diffusion in the active material (AM), especially at high C-rates. This improvement is attributed to the 3D simulation's ability to account for the AM particle size distribution. Moreover, results from the 3D simulations show that relatively smaller AM particles exhibit higher lithium diffusion efficiency, enabling higher capacity among these particles. Conversely, relatively larger AM particles accumulate high lithium concentrations only on the particle surface, thereby reducing cell performance. These findings reveal that the AM particle size and particle size distribution are key factors in battery performance. Moreover, our approach is expected to accelerate the development of high-performance batteries leveraging 3D simulations.