Suspension plasma spraying of La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes: Influence of carbon black pore former on performance and degradation

• Porous LSCF cathodes were made by suspension plasma spraying with carbon pore former.
• Best LSCF cathodes obtained a polarization resistance of 0.062 Ωcm2 at 744 °C.
• Adding a ceria-based interlayer improved kinetics-related cell degradation.
• Coating the metal substrate with La2O3 improved diffusion-related degradation.

Suspension plasma spray deposition is utilized to fabricate solid oxide fuel cell cathodes with minimal material decomposition. Adding carbon black as a pore former to the feedstock suspension results in smoother and more porous coatings, but over the range of carbon black concentrations studied, has little impact on the overall symmetrical cell performance. The cathode made with a suspension containing 25 wt% carbon has the highest deposition efficiency and a polarization resistance of 0.062 Ωcm2 at 744 °C. This cathode is tested for 500 h, and it is observed that adding an SDC interlayer between the YSZ electrolyte and the cathode(s) and/or coating the metal substrate with lanthanum chromite decrease the rate of performance degradation.