Thermal plasma synthesis of (La,Sr)CoO3-(La,Sr)2CoO4 composite cathodes for intermediate temperature solid oxide fuel cells (IT-SOFC)

• Published in: International journal of hydrogen energy 2024-01, Vol.51, p.1477-1486
• Main Authors: Aysal, Havva Eda, Kılıç, Fahrettin, Çakmak, Gülhan, Öztürk, Tayfur
• Format: Article
• Language: English
• Subjects: Composite cathode; Dual phase cathode; Plasma processing
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.07.031

(La,Sr)CoO3 and (La,Sr)2CoO4 dual phase powders were synthesized via thermal plasma to be used as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFC). This covered pure (La,Sr)CoO3 as well as the composites where the fraction of (La,Sr)2CoO4 was gradually increased reaching the mid-composition. Powders, all synthesized in the same condition, were extremely small in size, especially at mid-composition where they were close to 30 nm in size. Area specific resistance (ASR) determined from the symmetric cell imply improved cathodic performance at the mid-composition. Taking ASR = 0.15 Ω∗cm2 as benchmark, it was found that the (La,Sr)CoO3: (La,Sr)2CoO4 = 0.53:0.47 cathode may be used at temperatures close 750 °C. Measurements taken from several runs however imply that the cathode performance was not stable and ASR values increases with cycling. This was attributed to the powder form of the cathode which would be expected to coarsen rapidly due to accelerated surface diffusion. •(La,Sr)CoO3-(La,Sr)2CoO4 composite cathodes are synthesized via thermal plasma.•Particle size was smaller in cathodes with equimolar or near compositions.•Equimolar composite cathodes may be used at temperatures near 750 °C.•Less stable performance was assigned to non-layer nature of the cathode.