Characterization of electrolyte layers of plasma-sprayed metal supported solid oxide fuel cells

Kurzfassung

To increase the performance and durability ofmetal-supported solid oxide fuel cells it is important to understand the stresses occurring during manufacturing and operation of cells. In this work, the electrolyte layers of plasmasprayedmetal supported solid oxide fuel cellswere analyzed bymeans of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy in different stages of their fabrication (as powder, as sprayed material and as a reduced layer in the fuel cell system). It has been found that the determinant process for the gas permeability and performance of the cell is the reduction of the anode. During this process a tensile stress of 300 MPa is induced in the electrolyte material, generating crack networkswith undesired gas permeation in the cell. Furthermore, the reduction reaction, fromnickel oxide to pure nickel, produces 40% volume shrinkage. Texture and chemical homogeneity analyses of nano-powder material for functional layers are also presented. Finally, anode optimization strategies for metal supported solid oxide cells are discussed.