Enhancing the Robustness of Brittle Solid Oxide Cell Stack Components

For long-term durability and robustness to withstand thermal cycles, the planar solid oxide cell (SOC) stack technologies are challenged by the use of brittle components. With the current trend of increasing the footprint of the SOC stacks, even larger thermal gradients and thermal stresses can be expected. In this overview paper, we present recent advances from our group on improving the fracture energy of three critical materials/interfaces. The fracture energy of the fuel electrode support is increased by ~50 % by tailoring composition and further optimizing the phase transformation toughening. The fracture energy of the air-side contact layer is increased by a factor of ~10 by using metallic pre-cursors that are transformed to spinels through in-situ reactive oxidative bonding. Finally, the fracture energy of the seal-interconnect interface is improved by a factor of 5 by combining an optimized sealing glass with aluminum based coatings for the interconnect.