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Author
Hsieh, G. | Mason, T. O. | Garboczi, E. J. | Pederson, L. R.
Title
Experimental Limitations in Impedance Spectroscopy. Part 3. Effect of Reference Electrode Geometry/Position.
Coporate
Northwestern Univ., Evanston, IL National Institute of Standards and Technology, Gaithersburg, MD Pacific Northwest Laboratory, Richland, WA
Journal
Solid State Ionics, Vol. 96, 153-182, 1997
Keywords
impedance spectroscopy | building technology | counter | electrodes | electrolyte | pseudoreference | reference | simulation | working
Abstract
Experiments and computer simulations on Pt/YSZ specimens in various electrode configurations were performed to investigate the effect of reference electrode geometry/position on the accuracy of impedance measurements. The internal, Luggin probe-type, geometry is the preferred reference electrode configuration as it accurately measures both electrolyte and electrode impedances. External, 'pseudoreference', electrodes sample an averaged effective potential and can register inaccurate electrolyte resistances, sometimes with distorted electrode arcs. A symmetric configuration can accurately measure the impedance of an electrode; however, the electrolyte resistance will not scale linearly according to sample dimensions, as one might exptect. An asymmetric configuration exhibits both non-linear partitioning of electrolyte resistance and distortions in the electrode impedance arc under certain circumstances. The reliability of three-electrode measurements is very sensitive to aspect ratio and electrode configuration.