caa a22 4500 52878532X 20200808031353.0 cr unu---uuuuu 180924e20181101xx s 000 0 eng 10.3929/ethz-b-000287867 doi 10.1039/c8ee00875b doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/287867 Topological and network analysis of lithium ion battery components: the importance of pore space connectivity for cell operation [Elektronische Daten] [Marie Francine Lagadec, id_orcid 0000-0002-6214-5171, Raphael; id_orcid 0000-0003-0223-0697 Zahn, Simon; id_orcid 0000-0001-5885-121X Müller, Vanessa; id_orcid 0000-0001-6435-0227 Wood] Energy Environ. Sci. Open access ethresearch The structure of lithium ion battery components, such as electrodes and separators, are commonly characterised in terms of their porosity and tortuosity. The ratio of these values gives the effective transport coefficient of lithium ions in the electrolyte-filled pore spaces, which can be used to determine the ionic resistivity and corresponding voltage losses. Here, we show that these microstructural characteristics are not sufficient. Analysis of tomographic data of commercial separators reveals that different polyolefin separators have similar porosity and through-plane tortuosity, which, in the homogenised picture of lithium ion cell operation, would imply that these different separators exhibit similar performance. However, numerical diffusion simulations indicate that this is not the case. We demonstrate that the extent to which lithium ion concentration gradients are induced or smoothed by the separator structure is linked to pore space connectivity, a parameter that can be determined by topological or network based analysis of separators. These findings enable us to propose how to design separator microstructures that are safer and accommodate fast charge and discharge. Creative Commons Attribution-NonCommercial 3.0 Unported http://creativecommons.org/licenses/by-nc/3.0 ethresearch Lagadec Marie Francine joint author id_orcid 0000-0002-6214-5171 joint author Zahn Raphael; id_orcid 0000-0003-0223-0697 joint author Müller Simon; id_orcid 0000-0001-5885-121X joint author Wood Vanessa; id_orcid 0000-0001-6435-0227 joint author Energy & Environmental Science London : Royal Society of Chemistry 11 (11), pp. 3194-3200 1754-5692 http://hdl.handle.net/20.500.11850/287867 text/html WWW-Backlink auf das Repository (Open access) BK010053 XK010053 XK010000 1 Journal Article ethresearch ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/287867 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Lagadec Marie Francine joint author ETHRESEARCH 700 -- id_orcid 0000-0002-6214-5171 joint author ETHRESEARCH 700 1- Zahn Raphael; id_orcid 0000-0003-0223-0697 joint author ETHRESEARCH 700 1- Müller Simon; id_orcid 0000-0001-5885-121X joint author ETHRESEARCH 700 1- Wood Vanessa; id_orcid 0000-0001-6435-0227 joint author ETHRESEARCH 773 0- Energy & Environmental Science London : Royal Society of Chemistry 11 (11), pp. 3194-3200 1754-5692