Reduction of residual thermal stress on anode-supported SOFCs using porous aid layers

Abstract

After the fabrication of anode-supported planar solid oxide fuel cells (SOFCs), the mismatch of the thermal expansion coefficients (TECs) between the anode and the electrolyte introduces residual thermal stress in the cells. This residual stress on the electrolyte limits reliable cell operation in practice, and it often results in the failure of the cells. To alleviate the residual thermal stress of the cell, especially on the surface of the electrolyte, we propose to use an additional stress relieving porous layer between the electrolyte and the cathode. To analyze the stress reducing effect of the additional layer, several numerical calculations were carried out using various designs of the aid layer. In our simulation, the residual stress in the electrolyte was significantly reduced in the aided cell structures.