A study on sintering inhibition of La_0.8Sr_0.2 MnO_3-∂ cathode material for cathode-supported fuel cells

In this work, the effects of different sintering inhibitors added to La_0.8Sr_0.2MnO_3-∂ (LSM) were studied to obtain an optimum cathode material for cathode-supported type of Solid oxide fuel cell (SOFC) in terms of phase stability, mechanical strength, electric conductivity and porosity. Four different sintering inhibitors of Al₂O₃, CeO₂, NiO and gadolinium doped ceria (GDC) were mixed with LSM powder, sintered at 1300°C and then they were evaluated. The phase stability, sintering behavior, electrical conductivity, mechanical strength and microstructure were evaluated in order to assess the performance of the mixture powder as cathode support material. It has been found that the addition of Al₂O₃ undesirably decreased the electrical conductivity of LSM; other sintering inhibitors, however, showed sufficient levels of electrical conductivity. GDC and NiO addition showed a promising increase in mechanical strength of the LSM material, which is one of the basic requirements in cathode-supported designs of fuel cells. However, NiO showed a high reactivity with LSM during high temperature (1300oC) sintering. So, this study concluded that GDC is a potential candidate for use as a sintering inhibitor for high temperature sintering of cathode materials.