Optimizing Solid Oxide Fuel Cell Performance to Re-evaluate Its Role in the Mobility Sector.

Area of Science:

• Energy Science and Engineering
• Materials Science
• Electrochemistry

Background:

• Hydrogen is key to sustainable energy networks and decarbonizing the mobility sector.
• Solid oxide fuel cells (SOFCs) offer high efficiency and impurity tolerance, making them suitable for transportation applications.

Purpose of the Study:

• To develop a multiscale modeling methodology to assess the impact of materials and morphology on SOFC system performance.
• To identify optimal electrode combinations and membrane electrode assembly (MEA) designs for commercial-scale SOFC systems.

Main Methods:

• Utilized a half-cell model to determine intrinsic electrokinetics of anode and cathode materials.
• Employed a full cell model to select promising electrode combinations.
• Scaled up to a 3-D kW-stack model coupled with balance of plant components, focusing on MEA morphological optimization.

Main Results:

• An optimized MEA design with a Ni fiber-CGO anode and LSCF-infiltrated CGO cathode achieved a stack power density of 1.85 kW L^-1.
• A net system efficiency of 52.2% was demonstrated at operating temperatures below 700 °C.
• Manageable stack temperature gradients (<14 K cm^-1) and power density exceeding commercial targets were achieved.

Conclusions:

• The multiscale modeling approach successfully identified pathways to significantly boost SOFC performance.
• Optimized SOFCs have the potential to serve as prime movers in large transport applications beyond range extenders.
• Further development targeting performance-limiting processes can accelerate commercialization of SOFCs for trucks, trains, and ships.