Facile and low-temperature synthesis approach to fabricate Sm_0.5Sr_0.5CoO_3−δ cathode material for solid oxide fuel cell

Herein, we report a facilely synthesized Sm_0.5Sr_0.5CoO₃ (SSC) nano-catalyst as a cathode material for the solid oxide fuel cell (SOFC). The SSC nano-catalyst was synthesized by a sol–gel process using citric acid and metal nitrates and calcination was performed at a relatively low temperature of 1250 ℃. The crystallinity and morphology of the catalyst were observed by the X-ray diffraction and scanning electron microscope. The average particle size of the SSC powder was 100 nm after calcination at 1250 °C. The resulting SSC material was employed as a cathode for the SOFC. The SOFC cell with highly active SSC showed a peak power density of 900 mWcm⁻² at 700 °C. The single cell with an SSC cathode showed excellent stability under the accelerated operating conditions of 0.5A/cm² and 650 °C for 1250 min. The cell performance was enhanced during the initial hours of the long-term operation which is attributed to the cathode activation process and improved cathode/buffer layer interface contact. This work features a cost-effective, scalable, and reproducible method for the production of highly robust SSC cathode material for the SOFC under relatively low calcination temperatures.