Quantification of Microstructural and Transport Properties of Solid Oxide Fuel Cells From Three-Dimensional Physically Realistic Network Structures

Author(s):  
Naga Siva Kumar Gunda ◽  
Sushanta K. Mitra

The present work investigated a new method of calculating effective transport properties of solid oxide fuel cell (SOFC) electrodes from three-dimensional (3D) physically realistic network structures. These physically realistic network structures are topological equivalent representations of reconstructed microstructures in the form of spheres (nodes or bodies) and cylinders (segments or throats). Maximal ball algorithm is used to extract these physically realistic network structures from the series of two-dimensional (2D) cross-sectional images of SOFC electrodes. Dual-beam focused ion beam - scanning electron microscopy (FIB-SEM) is performed on SOFC electrodes to acquire series of 2D cross-sectional images. Finite element method is implemented to compute the effective transport properties from the network structures. As an example, we applied this method to calculate the effective gas diffusivity of lanthanum strontium manganite (LSM) of SOFC. The results obtained from physically realistic network structures are compared with reconstructed 3D microstructures.

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5127
Author(s):  
Tomasz A. Prokop ◽  
Grzegorz Brus ◽  
Shinji Kimijima ◽  
Janusz S. Szmyd

In this work, a three-dimensional microstructure-scale model of a Solid Oxide Fuel Cell’s Positive-Electrolyte-Negative assembly is applied for the purpose of investigating the impact of decreasing the electrolyte thickness on the magnitude, and the composition of electrochemical losses generated within the cell. Focused-Ion-Beam Scanning Electron Microscopy reconstructions are used to construct a computational domain, in which charge transport equations are solved. Butler–Volmer model is used to compute local reaction rates, and empirical relationships are used to obtain local conductivities. The results point towards three-dimensional nature of transport phenomena in thin electrolytes, and electrode-electrolyte interfaces.


2009 ◽  
Vol 15 (1) ◽  
pp. 71-77 ◽  
Author(s):  
James R. Wilson ◽  
Marcio Gameiro ◽  
Konstantin Mischaikow ◽  
William Kalies ◽  
Peter W. Voorhees ◽  
...  

AbstractA method is described for quantitatively analyzing the level of interconnectivity of solid-oxide fuel cell electrode phases. The method was applied to the three-dimensional microstructure of a Ni–Y2O3-stabilized ZrO2 (Ni-YSZ) anode active layer measured by focused ion beam scanning electron microscopy. Each individual contiguous network of Ni, YSZ, and porosity was identified and labeled according to whether it was contiguous with the rest of the electrode. It was determined that the YSZ phase was 100% connected, whereas at least 86% of the Ni and 96% of the pores were connected. Triple-phase boundary (TPB) segments were identified and evaluated with respect to the contiguity of each of the three phases at their locations. It was found that 11.6% of the TPB length was on one or more isolated phases and hence was not electrochemically active.


2019 ◽  
Vol 7 (1) ◽  
pp. 1879-1887 ◽  
Author(s):  
James Wilson ◽  
Worawarit Kobsiriphat ◽  
Roberto Mendoza ◽  
Hsun-Yi Chen ◽  
Tom Hines ◽  
...  

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