Red-Ox Robust SOFC Stacks for Affordable, Reliable Distributed Generation Power Systems

Technical Report · Sun Aug 21 04:00:00 EDT 2022

DOI:https://doi.org/10.2172/1882509· OSTI ID:1882509

Blackburn, Bryan M. ^[1]; Deaconu, Stelu ^[2]; Wang, Lei ^[2]; Doherty, Kevin ^[2]; Li, Yue ^[2]

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1. Redox Power Systems, Beltsville, MD (United States); Redox Power Systems, LLC; Redox Power Systems, LLC
2. Redox Power Systems, Beltsville, MD (United States)

While SOFC systems are expected to operate reliably and with limited degradation in steady state or transient performance, SOFC stacks may ultimately fail due to the loss of structural integrity of one or several of the cells as a result of the weakening of the materials and interfaces due to physico-chemical changes that occur during continuous operation as a result of plastic and creep deformations, modification of the temperature profile, and/or degradation of the electrochemical performance of the cells. Degradation mechanisms originating from the cell components include coarsening of the microstructure over time; decomposition of materials; chemical reaction of electrode materials with electrolyte at the interface; delamination from each other; and for the anode, coking and sulfur poisoning. Of all the reliability issues that may occur for SOFCs, the main limitation for Ni-based cermet anodes (e.g., NiO-YSZ) is the poor stability during reduction-oxidation (red-ox) cycling. This project was aimed at the development of ceramic anode SOFCs based on SFCM (SrFe0.2Co0.4Mo0.4O3), which is a conductive perovskite that is red-ox stable. Additionally, the project involved the development of a red-ox robust stack. Scale up of SFCM-based cells to a large format (10 cm by 10 cm) cell size was achieved as well as a maximum power density of 0.9 W/cm² at 600 °C (>0.6 W/cm² at 0.6 V). Up to a 10-cell stack was successfully assembled and demonstrated, and cells showed similar performance in reformed, pipeline natural gas as in hydrogen. Finally, a 3-cell stack was red-ox cycled without degradation for 40 cycles at ~600 °C.

• Research Organization: Redox Power Systems, Beltsville, MD (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• Contributing Organization: University of Maryland
• DOE Contract Number: FE0027897
• OSTI ID: 1882509
• Report Number(s): DOE-REDOX-0027897
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
08 HYDROGEN
20 FOSSIL-FUELED POWER PLANTS
30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
42 ENGINEERING
ceramic anode
distributed generation
red-ox cycling
reduction-oxidation stable
reforming
solid oxide fuel cell
stack
natural gas