Ceramic interface and multilayer technology for micro fuel cells

Planar fuel cells typically consist of several functional layers stacked on top of each other. We have extended the concepts of multilayer ceramics and thick film technology to provide novel approaches for the design of extremely compact and cost efficient micro fuel cells, either for the high temperature operation (SOFC) or for near ambient operation (PEMFC). Solid oxide fuel cells (SOFCs) operate at temperatures as high as 850°C. Several ceramic technologies were developed to facilitate mechanical integrity and good electrical contact to the cell at these high operating temperatures and upon rapid thermal cycling. Ceramic interconnector plates can be manufactured by adapting the multilayer / thick film / via approach known from LTCC to HTCC multilayers such as zirconia. The result is a 3D shaped SOFC interconnector plate with an unparalleled thermomechanical stability and rigidity for special applications like military. Extending that HTCC functionalisation approach further led us to the manufacturing of other multilayer ceramic based micro-reactors, namely micro-reformers for hydrogen production on a pocket size scale. We have combined several high throughput 3D shaping technologies with novel catalyst coating approaches to yield micro-reactors that are cost efficient to manufacture and that expose a high inner catalytically active surface at a low pressure drop. We have also applied thick film technologies to incorporate additional functions such as sensors or heaters right into the multilayer. The contribution is concluded with a summary of the crucial shaping and coating technologies and an outlook on how these can be applied to future compact SOFC and PEMFC fuel cells.