Effect of glass contents on the electrical and sintering property of La0.8Ca0.2CrO3/glass composite interconnects for solid oxide fuel cells

In order to improve the sintering ability and electrical conductivity of La0.8Ca0.2CrO3 (LCC), LCC/glass composite interconnect materials for high temperature solid oxide fuel cells (SOFCs) were studied in this paper. Glass is known as a sintering aid for improving sintering ability. It promotes liquid phase sintering and improves densification during the sintering process. The components of the glass used in this study are B2O3, SrO, La2O3, SiO2 and Al2O3.The phase stability, microstructure, electrical conductivity and thermal expansion coefficient (TEC) were measured to determine the optimal glass content in the composite materials. All of the tested composite materials showed perovskite structures and dense microstructures. It was found that the addition of up to 5 wt.% glass increased the sintering ability and the electrical conductivity in both air and hydrogen atmospheres. The glass powder enhances the sintering behavior because it acts as a liquid phase sintering aid and the Sr2+ ion in glass powder generates [SrLa′] and [CrCr•]. These lead to improvement in the electrical conductivity of the material. The TEC of the composites indicated compatibility with other cell components. The above results present that LCC/glass composite materials are suitable to be used as interconnects for SOFCs.

► We developed La0.8Ca0.2CrO3/glass composite interconnects for solid oxide fuel cells with different glass contents. ► We elucidated the effect of glass contents on the electrical and sintering property of La0.8Ca0.2CrO3/Glass Composite. ► The composite interconnect with 5 wt.% of glass showed the maximum electrical conductivity. ► The TEC values of all composites in this study were compatible with other cell components.