Abstract
Reducing the operating temperature of solid oxide fuel cells (SOFCs) to intermediate (650–850 °C) or even lower levels (400–650 °C) is an important practical requirement. However, the main obstacle to lowering the operating temperature is the poor oxygen reduction reaction (ORR) activity on the cathode side and, therefore, it is essential to explore cathode materials with good ORR activity in these temperature ranges. In this work, we investigated the possibility of using Sr2Sc0.1Nb0.1Co1.5Fe0.3O6−2δ (SSNCF) as a suitable intermediate temperature cathode material. SSNCF thin films with different orientations were prepared using the pulsed laser deposition technique, and the relationship of the surface chemical states and ORR activity was discussed in terms of crystallographic orientation. The results showed that the SSNCF/YSZ grown along the [110] direction exhibited superior ORR activity compared to the SSNCF/SDC/YSZ thin film electrode grown along the [100] direction. This was explained by the variation in the Sr-surface enrichment and cobalt ion oxidation state using X-ray photoemission spectroscopy.
Highlights
Solid oxide fuel cells (SOFCs) are a type of device that converts the chemical energy from fuel directly into electrical energy without the need for combustion
When the temperature is below 650 ◦ C, the polarization resistance (Rp) of the oxygen reduction reaction (ORR) (O2 + 4e− →2O2− ) on the cathode increases significantly, due to the sluggish reaction kinetics that occur at lower temperatures [2,3]
The SDC buffer layer proved to be valid for adjusting the growth direction of the SSNCF thin film
Summary
Solid oxide fuel cells (SOFCs) are a type of device that converts the chemical energy from fuel directly into electrical energy without the need for combustion. SOFCs have been continuously investigated for their simple structure, high energy conversion efficiency, fuel flexibility, and zero exhaust gas emission (i.e., SO2 , NO). The high operating temperature (>850 ◦ C) results in high maintenance costs and material compatibility issues. Significant progress has been made to bring the operating temperature down to the intermediate (650–850 ◦ C) and even lower ranges (400–650 ◦ C) [1]. When the temperature is below 650 ◦ C, the polarization resistance (Rp) of the oxygen reduction reaction (ORR) (O2 + 4e− →2O2− ) on the cathode increases significantly, due to the sluggish reaction kinetics that occur at lower temperatures [2,3]. Continuous improvements to cathode materials have been made, mixed ionic and electronic conducting (MIEC)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
