Technology

SAFC’s technology offers the potential for lower cost combined with faster thermal cycling times and increased durability. This is achieved though a patented architecture that combines the best features of both planar and tubular SOFCs. Its cells are shaped from ceramic ‘clays’ whilst they are still pliable and then fired to produce the final rigid product, much as high-quality porcelain or many electronic components are manufactured.

The cell topology improves durability compared to existing planar architectures by reducing stress and avoiding any thermal expansion mismatch with metal supports to each layer. Unlike existing architectures, it also allows a single firing cycle to be used, which, together with a smaller component count and simplified gas supplies and sealing, reduces the cost of manufacture.

In use, a fuel, such as hydrogen or methane, is supplied to the anode side of the cell and oxygen or air is supplied to the cathode side. Each of these gases flows around the spiral of the cell, through voids in the electrodes, and is consumed in an electrochemical reaction across the electrolyte layer that produces electricity (and heat).

The formed and sintered fuel cell is rigid and strong enough to support itself and neither metal supports nor thicker ceramic layers are required. This reduces stress and cost. Costs are also reduced compared to both other topologies because a single firing can be used.

SAFC has developed and evaluated individual prototype cells producing 2W output. It has constructed modules containing up to 30 cells and thereby understood the gas flow and integration issues involved. Having proven the cell technology, SAFC is now focusing its development efforts on continued cost reduction, manufacturing process improvement, stack integration and demonstrating durability.