2018/05/23 by Marie Francine Lagadec, Lagadec, Marie Francine, Raphael Zahn +5
Computer Science · Engineering · #Advanced Battery Technologies Research #Advancements in Battery Materials #Applied Physics (physics.app-ph) #FOS: Electrical engineering #FOS: Physical sciences #Image and Video Processing (eess.IV) #Interconnection Networks and Systems #Materials Science (cond-mat.mtrl-sci) #electronic engineering #information engineering
paper · pdf · doi:10.48550/arxiv.1806.00083
openalex publication_date 2018/05/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The structure of lithium ion battery components, such as electrodes and\nseparators, are commonly characterised in terms of their porosity and\ntortuosity. The ratio of these values gives the effective transport of lithium\nions in the electrolyte-filled pore spaces, which can be used to determine the\nionic resistivity and corresponding voltage losses. Here, we show that these\nmicrostructural characteristics are not sufficient. Analysis of tomographic\ndata of commercial separators reveals that different polyolefin separators have\nsimilar porosity and through-plane tortuosity, which, in the homogenised\npicture of lithium ion cell operation, would imply that these different\nseparators exhibit similar performance. However, numerical diffusion\nsimulations indicate that this is not the case. We demonstrate that the extent\nto which lithium ion concentration gradients are induced or smoothed by the\nseparator structure is linked to pore space connectivity, a parameter that can\nbe determined by topological or network based analysis of separators. These\nfindings enable us to propose how to design separator microstructures that are\nsafer and accommodate fast charge and discharge.\n