Microstructure characterisation of solid oxide electrolysis cells operated at high current density

Jacob R. Bowen (Invited author), Janet Jonna Bentzen, Ming Chen, Sune Dalgaard Ebbesen, Ghislaine Ehora, Anne Hauch, Peter Vang Hendriksen, Yi-Lin Liu, Xiufu Sun, Wei Zhang

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

Abstract

High temperature solid oxide cells can be operated either as fuel cells or electrolysis cells for efficient power generation or production of hydrogen from steam or synthesis gas (H2 + CO) from steam and CO2 respectively. When operated under harsh conditions, they often exhibit microstructural degradation of cell components in relation to the loss of electrochemical performance specific to the mode of operation. Thus descriptive microstructure characterization methods are required in combination with electrochemical characterization methods to decipher degradation mechanisms.
In the present work, microstructure evolution of the Ni-yttria stabilized zirconia (YSZ) is followed as a function of galvanostatic steam electrolysis testing at current densities between -0.5 and -1.0 A cm-2 for periods of up to 750 hours at 800 °C. The volume fraction and size of the percolating Ni particles was statistically quantified using the mean linear intercept method as a function of current density and correlated to increases in serial resistance.
The above structural changes are then compared in terms of electrode degradation observed during the co-electrolysis of steam and CO2 at current densities up to -1.5 A cm-2. In this study, the formation of ZrO2 based nano particles at the Ni-pore interface is responsible for the loss of Ni-YSZ particle contact and thus loss of triple phase boundary. Formation of similar nano particles at Ni internal grain boundaries is also thought to be responsible for loss of Ni percolation.
Original languageEnglish
Publication date2013
Publication statusPublished - 2013
EventThermec 2013 - International Conference on Processing & Manufacturing of Advanced Materials: Processing, Fabrication, Properties, Application - Las Vegas, United States
Duration: 2 Dec 20136 Dec 2013
http://www.thermec.org/template3s/index-org.php

Conference

ConferenceThermec 2013 - International Conference on Processing & Manufacturing of Advanced Materials
CountryUnited States
CityLas Vegas
Period02/12/201306/12/2013
Internet address

Cite this

Bowen, J. R., Bentzen, J. J., Chen, M., Ebbesen, S. D., Ehora, G., Hauch, A., Hendriksen, P. V., Liu, Y-L., Sun, X., & Zhang, W. (2013). Microstructure characterisation of solid oxide electrolysis cells operated at high current density. Abstract from Thermec 2013 - International Conference on Processing & Manufacturing of Advanced Materials, Las Vegas, United States.