Evaluations of the residual strains in the plasma sprayed multi-layer electrodes of the solid oxide fuel cell

Abstract

We investigated the residual strain of each membrane electrodes in plasma-sprayed solid oxide fuel cell (SOFC), which are under the cyclic redox treatments. The results show that all of the components of SOFC reveal compressive residual stress after plasma spraying. However, the stress states of these components become complicated and irregular after the redox treatments. The strain state of both LSCM (La0.75Sr0.25Cr0.5Mn0.5O3−δ) buffer layer and anode was changed from compressive to tensile. We also found that the original stress state was changed when the upper component was deposited. For example, the original stress state was 0.78% in compressive; after the NiO/LDC (Ce0.55La0.45O3−δ) anode deposited on the LSCM buffer, the anode side of LSCM revealed the compressive strain with 3.34% and the matrix side of LSCM revealed the tensile strain with 10.65%. Two kinds of strain states coexisted in an electrode coating resulted in the electrode failure occurred in the reverse position of stress states. Therefore, the redox treatments indeed affect the strain state of the SOFC components and the influences on the cell durability should not be ignored. The more research results will be described in detail.