Efficient, High Performance Solid Oxide Electrolysis Cell for Hydrogen Production

The objectives of the proposed work are to increase efficiency, specific power, and specific volume of solid oxide electrolysis cells (SOEC) via performance improvements. Two approaches are proposed: (1) reducing the electrolyte thickness, and (2) using a rapid prototyping technology to create and validate optimal microstructures and compositional grading previously identified, via modeling and experimental work, to show a reduction in electrode resistance. The project goal is to improve SOEC current density at a given voltage by over 60%, which enables technological advances in electrolysis that enhance ISRU capabilities to produce power and propulsion consumables from lunar and martian carbon- or hydrogen-containing resources. For terrestrial applications, the project addresses climate concerns by enabling commercial deployment of hydrogen and synthesis gas generation using renewable energy and CO2. The OxEon team designed, constructed, and delivered a SOEC stack for the Mars In-Situ Resource Utilization Experiment (MOXIE) project for NASA’s Mars 2020 mission that produced propellant grade oxygen by electrolyzing Mars atmosphere CO2. Two paths will be evaluated to decrease electrolyte thickness while retaining the robustness of the electrolyte-supported cell structure proven on MOXIE and further developed to meet redox and thermal cycle tolerance requirements in a NASA SBIR Phase II program. Air electrode supported design development will continue, and > 60% thinner electrolytes will be evaluated for electrolyte supported cells. The proposed effort uses aerosol jet printing (AJ) as a rapid prototyping approach to precisely control electrode deposition to achieve functionally and microstructurally graded compositions. Optimal electrode microstructures produced via AJ printing will be evaluated in Phase I and transferred to a screen-printing manufacturing process in Phase II.