Alternative production route for supporting La0.8Sr0.2MnO3−δ-Ce0.8Gd0.2O2−δ (LSM-GDC)

Tape casting is a widely used ceramic process that generally makes use of pore former agents to produce elements with engineered porosity for SOFC applications. In this work, porous La0.8Sr0.2MnO3−δ-Ce0.8Gd0.2O2−δ (LSM-GDC) supporting cathode of suitable porosity was produced using the reactive sintering approach without using of pore forming agent. The reactive sintering approach was considered in order to exploit the porosity induced by the precursor decomposition during a single thermal treatment of calcining-debonding-sintering. A stable tape casting slurry of lanthanum, strontium and manganite precursors and GDC powder was used in order to obtain large-area, crack-free green tapes. This process allowed to obtain 10 × 10 cm2 LSM-GDC sintered tapes of thickness 600 μm with values of porosity and mechanical strength suitable for fuel cells applications, starting from the precursor mixture without the addition of pore former and avoiding any calcination step. Preliminary results show that the same conditions can be used to produce a LSM-GDC/GDC half-cell by co-firing this tape with on the top a screen-printed GDC layer. To the author knowledge this is the first time that the reactive sintering approach has been used to produce a large-area supporting cathode suitable for SOFC applications.

► We report an alternative production route for large-area supporting cathode for SOFC.
► Reactive sintering approach was used to produce cathode in a single thermal step.
► Suitable level of porosity has been reached exploiting precursors decomposition.
► We avoid any calcining step of the precursor powder and the use pore formers.
► Cathode shows air permeability and flexural strength suitable for SOFC application.