Journal article

Three-dimensional pore structure and ion conductivity of porous ceramic diaphragms

  • Wiedenmann, Daniel Dept. of Geosciences and FRIMAT, University of Fribourg, Switzerland
  • Keller, Lukas EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Holzer, Lorenz ZHAW, Institute of Computational Physics ICP, Zurich University of Applied Sciences, Winterthur, Switzerland
  • Stojadinović, Jelena EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Münch, Beat EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Suarez, Laura EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Fumey, Benjamin EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Hagendorfer, Harald EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Brönnimann, Rolf EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Modregger, Peter Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland - School of Biology and Medicine, University of Lausanne, Switzerland
  • Gorbar, Michal EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Vogt, Ulrich F. EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Züttel, Andreas EMPA, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf, Switzerland
  • Mantia, Fabio La CES, Center for Electrochemical Sciences, Ruhr-University Bochum, Germany
  • Wepf, Roger ETH, Centre EMEZ, Zurich, Switzerland
  • Grobéty, Bernard Dept. of Geosciences and FRIMAT, University of Fribourg, Switzerland
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    2013
Published in:
  • AIChE Journal. - 2013, vol. 59, no. 5, p. 1446–1457
English The ion conductivity of two series of porous ceramic diaphragms impregnated with caustic potash was investigated by electrochemical impedance spectroscopy. To understand the impact of the pore structure on ion conductivity, the three-dimensional (3-D) pore geometry of the diaphragms was characterized with synchrotron x-ray absorption tomography. Ion migration was calculated based on an extended pore structure model, which includes the electrolyte conductivity and geometric pore parameters, for example, tortuosity (τ) and constriction factor (β), but no fitting parameters. The calculated ion conductivities are in agreement with the data obtained from electrochemical measurements on the diaphragms. The geometric tortuosity was found to be nearly independent of porosity. Pore path constrictions diminish with increasing porosity. The lower constrictivity provides more pore space that can effectively be used for mass transport. Direct measurements from tomographs of tortuosity and constrictivity opens new possibilities to study pore structures and transport properties of porous materials.
Faculty
Faculté des sciences et de médecine
Department
Département de Géosciences
Language
  • English
Classification
Mineralogy
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/302893
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