1. Ca and Pr substitution promoted the cell performance in LnSr3Fe3O10-δ cathode for solid oxide fuel cells
- Author
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Sato Kazunori, Soamwadee Chaianansutcharit, Jinda Yeyongchaiwat, Rojana Pornprasertsuk, and Nicharee Wongsawatgul
- Subjects
Materials science ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,Electrochemistry ,01 natural sciences ,Oxygen ,law.invention ,Oxygen permeability ,chemistry.chemical_compound ,law ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,Perovskite (structure) ,010302 applied physics ,Process Chemistry and Technology ,021001 nanoscience & nanotechnology ,Microstructure ,Cathode ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Chemical engineering ,chemistry ,Ceramics and Composites ,0210 nano-technology - Abstract
The substitution of Ca for Sr in the LnSr3-xCaxFe3O10-δ (x = 0–1.5, Ln = La, Pr, and Sm), Ruddlesden-Popper (RP) intergrowth structure was investigated to determine how the physical and electrochemical properties of this potential cathode material in solid oxide fuel cells (SOFCs) are impacted. A small amount of Ca incorporated into the structure reduced the thermal expansion coefficient, improved the electrical conductivity, and increased power density by up to 30% of a La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte-supported single cell. The microstructure and oxygen permeability of the materials were independent of Ca substitution. A phase transformation of LaSr3-xCaxFe3O10-δ to perovskite was observed when the Ca composition of x > 1.0. Among the substitution of Pr and Sm for La in LaSr2.7Ca0.3Fe3O10-δ, only PrSr2.7Ca0.3Fe3O10-δ was pure with no phase transformation found. The co-substitution of Pr and Ca promoted the reduction of Fe, enhanced the oxygen permeation and active surface, and diminished the contact resistance at the cathode-electrolyte interlayer. The co-substitution of Ca and Pr delivered good electrochemical performance of approximately 354 mWcm−2 at 800 °C on a 0.3 mm thick La0.8Sr0.2Ga0.8Mg0.2O3 electrolyte-supported cell and the lowest area specific resistance (ASR).
- Published
- 2020