Simulation of the diffusional impedance and application to the characterization of electrodes with complex microstructures

Hui Chia Yu, Stuart B. Adler, Scott A. Barnett, K. Thornton*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Electrochemical impedance spectroscopy (EIS) has been widely employed to probe material properties in energy materials. One important aspect of EIS is the diffusional impedance. To date, the diffusional impedance behavior is understood based on the analytical solutions of the one-dimensional (1D) diffusion equation. However, transport in materials is strongly influenced by the materials’ three-dimensional (3D) microstructures that often possess complex geometries that are unlike the simplified 1D domains. In this work, we simulate the concentration response driven by oscillating loads by solving the diffusion equation in complex, experimentally determined 3D microstructures obtained from solid oxide fuel cell cathode and lithium-ion battery cathode. The simulation results demonstrate that the diffusional impedance can serve as a new technique for the evaluation of microstructural characteristics of porous media, including the tortuosity, the porosity, and the area of the loading boundary. Our findings open a new array of applications for diffusional impedance measurements.

Original languageEnglish (US)
Article number136534
JournalElectrochimica Acta
Volume354
DOIs
StatePublished - Sep 10 2020

Keywords

  • Electrode microstructure
  • Impedance spectroscopy
  • Smoothed boundary method
  • Three-dimensional simulations
  • Tortuosity

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

Fingerprint

Dive into the research topics of 'Simulation of the diffusional impedance and application to the characterization of electrodes with complex microstructures'. Together they form a unique fingerprint.

Cite this