Preparation and performance of PrLaNiO4 and (La0.75Sr0.2 Ba0.05)0.175Ce0.825O1.891 composite cathode material by solid state reaction for IT-SOFCs

• Published in: Ceramics international Vol. 43; pp. S700 - S704
• Main Authors: Chiu, Te-Wei, Lin, Ming-Xian, Shih, Heng-Yi, Hwang, Bae-yinn, Chang, Horng-Yi, Wang, Yao-Ming
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2017
• Subjects: Composites; Fuel cells; Impedance; Solid state reaction; Composites; Impedance; Solid state reaction; Fuel cells
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2017.05.269

Pr2NiO4 is one of the compounds in the Ln2NiO4 (Ln=Pr, La and Nd) group that exhibits the Ruddlesden-Poppor structure. The present research substituted this compound by lanthanum (La) to enhance chemical stability, because of the decomposition reaction of Pr2NiO4 for long-term operation. PrLaNiO4 powders were then synthesized using a solid state reaction method for the application of cathode materials in an intermediate-temperature solid oxide fuel cell (IT-SOFC); these material properties were then examined by XRD, SEM, thermomechanical analysis, alternating current impedance spectroscopy, and electrochemical analysis. The crystallization of the as-prepared PrLaNiO4 was obtained after heat-treatment at 1200°C for 6h. Moreover, PrLaNiO4 cathode material demonstrated favorable chemical stability with the electrolyte of (La0.75Sr0.2Ba0.05)0.175Ce0.825O1.891 (LSBC) under 1200°C for 6h. The determined thermal expansion coefficient of PrLaNiO4 was 14.1 × 10−6 K−1. Furthermore, to reduce their resistance the PrLaNiO4 powders were mixed with various wt% of LSBC. The maximal power density of PrLaNiO4−5wt% LSBC is 606mW/cm2 operated at 800°C in air, which also exhibited lower area-specific resistance of 0.202Ωcm2. The study concludes that the PrLaNiO4−5wt% LSBC is a better choice than Pr2NiO4 in cathode material for IT-SOFCs.