Fivefold power-to-weight gain in lightweight hydrogen engines using Lithoz ceramic 3D printing
Monolithic zirconia gyroid geometry replaces conventional planar stacking in hydrogen propulsion research at the Technical University of Denmark
Researchers at the Technical University of Denmark’s Department of Energy Conversion and Storage (DTU Energy) have demonstrated a new architectural approach to solid oxide fuel cell (SOFC) design, producing monolithic ceramic fuel cells with nature-inspired gyroid geometries that deliver power-to-weight ratios approximately five times higher than those of conventional planar SOFC architectures.
The research team, led by Professor Vincenzo Esposito, printed single three-dimensional fuel cell structures using Lithoz yttria-stabilized zirconia (8YSZ) on a Lithoz CeraFab system via lithography-based ceramic manufacturing (LCM).
The resulting devices achieved power-to-weight ratios approaching around 1 W g⁻¹ at the device level, compared to around 0.2 W g⁻¹ typical of conventional planar configurations.
Structural assessment was contributed by Associate Professor Venkata Karthik Nadimpalli of DTU Construct, whose expertise covered the mechanical behavior and structural optimization of architected ceramic materials under thermal and operational conditions.
Eliminating interconnects and sealants
The monolithic gyroid design removes the interconnects and sealants that are standard components in stacked planar SOFC architectures, reducing weight, lowering thermal mismatch, and decreasing mechanical stress while improving volumetric utilization.
“Our motto ‘Escaping Flatland’ sounds like a logical step, but it has long been impossible to achieve,” said Esposito, Professor at DTU Energy. “The particular arrangement of materials and microstructures requires a significantly elevated level of complexity – but until recently, we simply lacked the tool to make this concept a reality.
“8YSZ remains one of the most widely used and technologically mature electrolyte materials for SOFCs. With its mature precision and scalability, Lithoz LCM technology has demonstrated the highest repeatability for these bio-inspired TPMS geometries with the thinnest possible inner walls, which inherently meet the gas supply requirements.
“The monolithic concept could only be achieved by precisely replicating those gyroid units and adding a sealed shell frame to maintain gastight conditions.”
Industrial scale-up planned
Johannes Homa, Chief Executive Officer at Lithoz, stated: “By realizing 8YSZ monolithic fuel cells with intricate gyroid geometries on their Lithoz CeraFab printer, DTU was able to reduce the dependence on conventional interconnect and sealing architectures inherent to stacked flat items.
“These elements have traditionally been the Achilles heel in the search for better power density in commercial planar SOFC stacks and, therefore, the traditional focus of attention in the quest for a more advantageous power-to-weight ratio.
“With their revolutionary monolithic concept, these elements eliminate the need to gradually optimize exit points, paving the way for a complete rethinking of fuel cell design. Of course, we are extremely excited about the impact this will have on the worldwide hydrogen-based industry.”
Professor Esposito’s team now plans to scale the project to an industrial level.
