Residual Stresses and Failure Probability of Solid Oxide Fuel Cells Due to the Sintering Process

F. Greco[1], J. van Herle[1], A. Nakajo[1]
[1]FUELMAT Group, Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
Published in 2013

A solid oxide fuel cell (SOFC) is composed of four layers (anode, electrolyte compatibility layer and cathode) of different ceramic materials. The anode layer is produced by tape casting, the remaining layers are deposited by screen-printing. The layers are sintered together at high temperatures. During heating up and cooling down (manufacturing process), stresses are generated in the layers due to the different thermal expansion coefficients. These stresses generate the bending of the cell as well as influence the failure probability of the anode. It has been found that the presence of creep and a counter-bending pressure on the anode can make the completed cell flat, and at the same time keep the electrolyte and compatibility layer in beneficial compressive stress.

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