Solvothermal Synthesis of PtNi Nanoparticle Thin Film Cathode with Superior Thermal Stability for Low Temperature Solid Oxide Fuel Cells

This work adopts solvothermal synthesis to fabricate PtNi nanoparticles as thin film cathodes with superior resistance against thermally driven agglomeration for low temperature solid oxide fuel cells (LT-SOFCs) operating at 450 ºC. Metal-based porous electrodes are common choices for thin film LT-SOFCs, but pure metals with high density nanoscale porosities are vulnerable to thermal agglomeration, which imposes challenges to maintaining high performance with long-term stability. Typical Pt-based thin film cathodes are previously reported to sustain a record high 600 ºC of thermal annealing with acceptable morphological stability, but the temperature is still too low for practical LT-SOFC application. In this work, the solvothermal synthesized PtNi nanoparticle thin films show superior thermal stability, sustaining 10 h of annealing at 800 ºC without significant agglomeration observed. By controlling the length of synthesis time, the particle sizes and Pt loading ratio can be varied. The cost-effective solvothermal synthesis process for the fabrication of PtNi thin film cathode is a promising way for LT-SOFC manufacturing in scale as it involves no vacuum process like typical sputtering.