Three‐Phase Multiscale Modeling of a LiCoO2 Cathode: Combining the Advantages of FIB–SEM Imaging and X‐Ray Tomography. Issue 5 (22nd November 2014)

• Record Type: Journal Article
• Authors: Zielke, Lukas; Hutzenlaub, Tobias; Wheeler, Dean R.; Chao, Chien‐Wei; Manke, Ingo; Hilger, André; Paust, Nils; Zengerle, Roland; Thiele, Simon
• Is Part Of: Advanced energy materials. Volume 5:Issue 5(2015:Mar.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2014-11-22
• Subjects: Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201401612
• Languages: English
• ISSNs: 1614-6832

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>LiCoO₂ electrodes contain three phases, or domains, each having specific‐intended functions: ion‐conducting pore space, lithium‐ion‐reacting active material, and electron conducting carbon‐binder domain (CBD). Transport processes take place in all domains on different characteristic length scales: from the micrometer scale in the active material grains through to the nanopores in the carbon‐binder phase. Consequently, more than one imaging approach must be utilized to obtain a hierarchical geometric representation of the electrode. An approach incorporating information from the micro‐ and nanoscale to calculate 3D transport‐relevant properties in a large‐reconstructed active domain is presented. Advantages of focused ion beam/scanning electron microscopy imaging and X‐ray tomography combined by a spatial stochastic model, validated with an artificially produced reference structure are used. This novel approach leads to significantly different transport relevant properties compared with previous tomographic approaches: nanoporosity of the CBD leads to up to 42% additional contact area between active material and pore space and increases ionic conduction by a factor of up to 3.6. The results show that nanoporosity within the CBD cannot be neglected.</p> </abstract>