title: Comparison of three-dimensional analysis and stereological techniques for quantifying lithium-ion battery electrode microstructures.
abstract: Lithium-ion battery performance is intrinsically linked to electrode microstructure. Quantitative measurement of key structural parameters of lithium-ion battery electrode microstructures will enable optimization as well as motivate systematic numerical studies for the improvement of battery performance. With the rapid development of 3-D imaging techniques, quantitative assessment of 3-D microstructures from 2-D image sections by stereological methods appears outmoded; however, in spite of the proliferation of tomographic imaging techniques, it remains significantly easier to obtain two-dimensional (2-D) data sets. In this study, stereological prediction and three-dimensional (3-D) analysis techniques for quantitative assessment of key geometric parameters for characterizing battery electrode microstructures are examined and compared. Lithium-ion battery electrodes were imaged using synchrotron-based X-ray tomographic microscopy. For each electrode sample investigated, stereological analysis was performed on reconstructed 2-D image sections generated from tomographic imaging, whereas direct 3-D analysis was performed on reconstructed image volumes. The analysis showed that geometric parameter estimation using 2-D image sections is bound to be associated with ambiguity and that volume-based 3-D characterization of nonconvex, irregular and interconnected particles can be used to more accurately quantify spatially-dependent parameters, such as tortuosity and pore-phase connectivity.
authors.affiliation: The Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
authors.forename: Oluwadamilola O
authors.initials: OO
authors.lastname: Taiwo
authors.affiliation: The Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
authors.forename: Donal P
authors.initials: DP
authors.lastname: Finegan
authors.affiliation: Manchester X-Ray Imaging Facility, School of Materials, University of Manchester, Manchester M13 9PL, U.K.
authors.forename: David S
authors.initials: DS
authors.lastname: Eastwood
authors.affiliation: Swiss Light Source, Paul Scherrer Institut, 5232 Villigen, PSI, Switzerland.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Fife
authors.affiliation: The Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
authors.forename: Leon D
authors.initials: LD
authors.lastname: Brown
authors.affiliation: Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, U.K.
authors.forename: Jawwad A
authors.initials: JA
authors.lastname: Darr
authors.affiliation: Manchester X-Ray Imaging Facility, School of Materials, University of Manchester, Manchester M13 9PL, U.K.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Lee
authors.affiliation: The Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
authors.forename: Daniel J L
authors.initials: DJ
authors.lastname: Brett
authors.affiliation: The Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London, WC1E 7JE, U.K.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Shearing
keywords: 3-D image analysis; Image quantification; X-ray tomography; lithium-ion battery; microstructural characterization; stereology