Effect of Leaks in Solid Oxide Electrolysis Cells Tested for Durability under Co-Electrolysis Conditions
Solid oxide electrolysis cells have an immense potential in converting CO2 and H2O into syngas during co-electrolysis operation. The produced syngas can be further converted into hydrocarbons. This kind of technology is called power-to-gas or power-to-liquid. To produce hydrocarbons via this route, durability of the cells is still a challenge, which needs to be further investigated in order to improve the cells. In this work, various nickel-yttria stabilized zirconia (Ni-YSZ) fuel electrode supported or YSZ electrolyte supported cells, cerium gadolinium oxide (CGO) barrier layer, and an oxygen electrode are investigated for durability under co-electrolysis conditions in both galvanostatic and potentiostatic conditions. While changing the gas on the oxygen electrode, keeping the fuel electrode gas composition constant, a change in the gas concentration arc was observed by impedance spectroscopy. Measurements of open circuit potential revealed the presence of leaks in the setup. It is speculated that the change in concentration impedance may be related to the leaks. Furthermore, the cells were also tested under pressurized conditions to find an inter-play between the leak rate and the pressure. A mathematical modeling together with electrochemical and microscopy analysis is presented.
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 European Commission, “Roadmap 2050,” Policy, no. April, pp. 1–9, 2012.
 S. Mesfun, D. L. Sanchez, S. Leduc, E. Wetterlund, J. Lundgren, M. Biberacher, F. Kraxner, “Power-to-gas and power-to-liquid for managing renewable electricity intermittency in the Alpine Region,” Renew. Energy, vol. 107, pp. 361–372, July 2017.
 X. Sun, M. Chen, Y.-L. Liu, P. Hjalmarsson, S.D. Ebbesen, S.H. Jensen, M. B. Mogensen, P. V. Hendriksen, “Durability of Solid Oxide Electrolysis Cells for Syngas Production,” J. Electrochem. Soc., vol. 160, no. 9, pp. F1074–F1080, July 2013.
 S. H. Jensen, H. Langnickel, N. Hintzen, M. Chen, X. Sun, A. Hauch, G. Butera, L. R. Clausen, "Pressurized reversible operation of a 30-cell solid oxide cell stack using carbonaceous gases,", Proc. of EFC 2017.
 A. Hauch, K. Brodersen, M. Chen, and M. B. Mogensen, “Ni/YSZ electrodes structures optimized for increased electrolysis performance and durability,” Solid State Ionics, vol. 293, pp. 27–36, Oct. 2016.
 M. Chen, Y. L.Liu, J. J. Bentzen, W. Zhang, X.Sun, A. Hauch, Y. Tao, J. R. Bowen, P. V. Hendriksen, “Microstructural Degradation of Ni/YSZ Electrodes in Solid Oxide Electrolysis Cells under High Current,” J. Electrochem. Soc., vol. 160, no. 8, pp. F883–F891, May 2013.
 A. Hauch, S. D. Ebbesen, S. H. Jensen, and M. Mogensen, “Solid Oxide Electrolysis Cells : Microstructure and Degradation of the Ni / Yttria-Stabilized Zirconia Electrode,” pp. 1184–1193, Sep 2008.
 S. D. Ebbesen, C. Graves, A. Hauch, S. H. Jensen, and M. Mogensen, “Poisoning of Solid Oxide Electrolysis Cells by Impurities,” J. Electrochem. Soc., vol. 157, no. 10, p. B1419, Aug 2010.
 P. Hjalmarsson, X. Sun, Y. L. Liu, and M. Chen, “Influence of the oxygen electrode and inter-diffusion barrier on the degradation of solid oxide electrolysis cells,” J. Power Sources, vol. 223, pp. 349–357, Feb 2013.
 V. Gil, K. K. Hansen, “High Performance Infiltrated Backbones for Cathode-Supported SOFC’s,” ECS Tans., 2014.
 M. Rao, X. Sun, and A. Hagen, “A Comparative Study of Durability of Solid Oxide Electrolysis Cells Tested for Co-Electrolysis under Galvanostatic and Potentiostatic Conditions,” J. Electrochem. Soc., vol. 165, no. 10, pp. 748–755, June 2018.
 S. H. Jensen, A. Hauch, P. V. Hendriksen, and M. Mogensen, “Advanced Test Method of Solid Oxide Cells in a Plug-Flow Setup,” J. Electrochem. Soc., vol. 156, no. 6, p. B757, Apr. 2009.
 C. Graves, “Ravdav.” Department of Energy Conversion and Storage, Technical University of Denmark, 2012.
 S. H. Jensen, J. Hjelm, A. Hagen, and M. Mogensen, “Electrochemical impedance spectroscopy as diagnostic tool," in Handb. Fuel Cells., vol. 6, John Wiley & Sons, 2009.
 S. H. Jensen, A. Hauch, P. V. Hendriksen, M. Mogensen, N. Bonanos, and T. Jacobsen, “A Method to Separate Process Contributions in Impedance Spectra by Variation of Test Conditions,” J. Electrochem. Soc., vol. 154, no. 12, p. B1325, Oct. 2007.
 S. Primdahl, M. Mogensen, “Gas Conversion Impedance: A Test Geometry Effect in Characterization of Solid Oxide Fuel Cell Anodes,” vol. 145, no. 7, pp. 2431–2438, Mar. 1998.
 M. García-Camprubí, N. Fueyo, V. Novaresio, P. Asinari, and S. Izquierdo, “An open-source library for the numerical modeling of mass-transfer in solid oxide fuel cells,” Comput. Phys. Commun., vol. 183, no. 1, pp. 125–146, Aug, 2011.
 E. Hernández-Pacheco, D. Singh, P. N. Hutton, N. Patel, and M. D. Mann, “A macro-level model for determining the performance characteristics of solid oxide fuel cells,” J. Power Sources, vol. 138, no. 1–2, pp. 174–186, Aug. 2004.
 J. Dragsbæk Duhn, A. Degn Jensen, S. Wedel, and C. Wix, “Modeling of Gas Diffusion in Ni/YSZ Electrodes in CO2 and Co-electrolysis,” Fuel Cells, vol. 17, no. 4, pp. 442–456, July 2017.
 S. H. Jensen, X. Sun, S. D. Ebbesen, and M. Chen, “Pressurized Operation of a Planar Solid Oxide Cell Stack,” Fuel Cells, vol. 16, no. 2, pp. 205–218, Feb. 2016.