Impact of particle size ratio and volume fraction on effective material parameters and performance in solid oxide fuel cell electrodes

Robert M. McMeeking, Benjamin Völker

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Optimization of the microstructure of porous electrodes plays an important role in the enhancement of the performance of solidoxidefuelcells. For this, microstructural models based on percolation theory have proven useful for the estimation of the effectivematerial properties of the electrodematerial, assumed to consist of a binary mixture of spherical electron and ion conducting particles. In this work, we propose an extension of prior approaches for calculating the effectivesize of the three-phase boundary, which we judge to be physically more sound and, in particular, well suited for characterizing mixtures of particles of different sizes. This approach is then employed in a one-dimensional cell level model encompassing the entire set of processes of gas transport, electronic and ionic conduction as well as the electrochemical reactions. The impact of the electron and ion conducting particlesizes, their volumefraction and their sizeratio on the performance of the fuelcell are investigated in a parametric study. Under certain conditions, cathode microstructures having electronic conducting particles of size different from that of the ionic conducting particles become preferable and yield a higher maximum power density when compared to the best possible configuration of monodisperse particles.
Original languageEnglish
Pages (from-to)199-215
Number of pages17
JournalJournal of Power Sources
Volume215
Early online date16 May 2012
DOIs
Publication statusPublished - 1 Oct 2012

Fingerprint

solid oxide fuel cells
Solid oxide fuel cells (SOFC)
Volume fraction
Particle size
Ions
Ionic conduction
conduction
Microstructure
Electrodes
electrodes
Electrons
Phase boundaries
Binary mixtures
Cathodes
Gases
Acoustic waves
gas transport
microstructure
electronics
binary mixtures

Keywords

  • solid oxide fuel cells (SOFC)
  • three-phase boundary
  • percolation theory
  • microstructure
  • composite electrode
  • multi-physics modeling

Cite this

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title = "Impact of particle size ratio and volume fraction on effective material parameters and performance in solid oxide fuel cell electrodes",
abstract = "Optimization of the microstructure of porous electrodes plays an important role in the enhancement of the performance of solidoxidefuelcells. For this, microstructural models based on percolation theory have proven useful for the estimation of the effectivematerial properties of the electrodematerial, assumed to consist of a binary mixture of spherical electron and ion conducting particles. In this work, we propose an extension of prior approaches for calculating the effectivesize of the three-phase boundary, which we judge to be physically more sound and, in particular, well suited for characterizing mixtures of particles of different sizes. This approach is then employed in a one-dimensional cell level model encompassing the entire set of processes of gas transport, electronic and ionic conduction as well as the electrochemical reactions. The impact of the electron and ion conducting particlesizes, their volumefraction and their sizeratio on the performance of the fuelcell are investigated in a parametric study. Under certain conditions, cathode microstructures having electronic conducting particles of size different from that of the ionic conducting particles become preferable and yield a higher maximum power density when compared to the best possible configuration of monodisperse particles.",
keywords = "solid oxide fuel cells (SOFC), three-phase boundary, percolation theory, microstructure, composite electrode, multi-physics modeling",
author = "McMeeking, {Robert M.} and Benjamin V{\"o}lker",
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AU - McMeeking, Robert M.

AU - Völker , Benjamin

PY - 2012/10/1

Y1 - 2012/10/1

N2 - Optimization of the microstructure of porous electrodes plays an important role in the enhancement of the performance of solidoxidefuelcells. For this, microstructural models based on percolation theory have proven useful for the estimation of the effectivematerial properties of the electrodematerial, assumed to consist of a binary mixture of spherical electron and ion conducting particles. In this work, we propose an extension of prior approaches for calculating the effectivesize of the three-phase boundary, which we judge to be physically more sound and, in particular, well suited for characterizing mixtures of particles of different sizes. This approach is then employed in a one-dimensional cell level model encompassing the entire set of processes of gas transport, electronic and ionic conduction as well as the electrochemical reactions. The impact of the electron and ion conducting particlesizes, their volumefraction and their sizeratio on the performance of the fuelcell are investigated in a parametric study. Under certain conditions, cathode microstructures having electronic conducting particles of size different from that of the ionic conducting particles become preferable and yield a higher maximum power density when compared to the best possible configuration of monodisperse particles.

AB - Optimization of the microstructure of porous electrodes plays an important role in the enhancement of the performance of solidoxidefuelcells. For this, microstructural models based on percolation theory have proven useful for the estimation of the effectivematerial properties of the electrodematerial, assumed to consist of a binary mixture of spherical electron and ion conducting particles. In this work, we propose an extension of prior approaches for calculating the effectivesize of the three-phase boundary, which we judge to be physically more sound and, in particular, well suited for characterizing mixtures of particles of different sizes. This approach is then employed in a one-dimensional cell level model encompassing the entire set of processes of gas transport, electronic and ionic conduction as well as the electrochemical reactions. The impact of the electron and ion conducting particlesizes, their volumefraction and their sizeratio on the performance of the fuelcell are investigated in a parametric study. Under certain conditions, cathode microstructures having electronic conducting particles of size different from that of the ionic conducting particles become preferable and yield a higher maximum power density when compared to the best possible configuration of monodisperse particles.

KW - solid oxide fuel cells (SOFC)

KW - three-phase boundary

KW - percolation theory

KW - microstructure

KW - composite electrode

KW - multi-physics modeling

U2 - 10.1016/j.jpowsour.2012.05.014

DO - 10.1016/j.jpowsour.2012.05.014

M3 - Article

VL - 215

SP - 199

EP - 215

JO - Journal of Power Sources

JF - Journal of Power Sources

SN - 0378-7753

ER -