CFY-Stack Technology: The Next Design

Thursday, 30 July 2015: 09:00
Lomond Auditorium (Scottish Exhibition and Conference Centre)
C. Bienert, M. Brandner, S. Skrabs, A. Venskutonis, L. S. Sigl (PLANSEE SE), S. Megel, W. Becker, N. Trofimenko, M. Kusnezoff, and A. Michaelis (Fraunhofer IKTS)
The stack concept of electrolyte supported cells (ESC) is applicable for both, solid oxide fuel cells as well as solid oxide electrolysis cells. High power densities and efficiencies comparable to anode supported cells (ASC) can be achieved, however, for the stack design presented in this paper, in unison with high robustness. Incorporating an electrolyte made of fully scandia stabilized zirconia paired with chromium-based CFY (Cr5FeY) interconnects of matched CTE (coefficient of thermal expansion), a feasible stack concept was created with the focus on long-term stability in regard to high temperature corrosion and thermal cycling. Stack data of more than 20.000 hours of a single stack is presented in addition to industrial onward development of the stack design. Using the same material combinations and the same footprint as for the MK351-design, the newly developed MK352-design was simulated, drafted and produced and allows for easier stack setup and system integration. Minor changes in interconnect (IC) design enable lower pressure drops over the stack, which, paired with enhanced tolerance chains lead to enhanced stack performance, especially in regard to thermal cycling. Cross-checked, test results for the MK352-stack are in good agreement with the simulation.