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Title: Geometric sensitivity of electrochemical fin shape on three dimensional microstructure network conductivity analysis

A rapid microstructural assessment tool has previously been developed to support electrode design efforts by modeling charge transport and surface electrochemistry through networks of transport channels represented by ideal axisymmetric electrochemical fins. Analytical solutions have allowed these fins to take the form of a positive curvature sphere, a neutral curvature conical frustum, and a negative curvature smooth exponential profile. Our paper aims to enhance the geometric sensitivity of the network modeling tool by fitting ideal fin shapes to individual channels within the microstructure via dimensionless parameters describing channel morphology. The tool is used to directly compute effective transport properties of a range of microstructures, including artificial packed sphere structures and real solid oxide fuel cell electrode and gas membrane material microstructures imaged by X-ray nanotomography. The results we obtained are compared with detailed finite element analyses and predictions from percolation theory. It is shown that the model can capture transport losses associated with microstructure on the particle scale, highlighting its potential as a less computationally demanding complement to detailed numerical models such as finite element or lattice Boltzmann methods for preliminary electrode design screening. Results also emphasize the importance of capturing local microstructural effects of specific transport networks, as electrochemicalmore » fin results provide more accurate performance predictions than percolation theory for structures near their percolation threshold.« less
 [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [1]
  1. Univ. of Connecticut, Storrs, CT (United States)
  2. Univ. of Alabama, Huntsville, AL (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 0378-7753
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Power Sources; Journal Volume: 291; Journal Issue: C
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
42 ENGINEERING electrode; three-dimensional; modeling; electrochemical fin; microstructure; design