Effect of enhanced reaction area in double layered Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode for intermediate temperature solid oxide fuel cells

To optimize the microstructure of cathode for IT-SOFCs, double layered Ba0.5Sr0.5Co0.8Fe0.2O3-δ was fabricated and its performances were evaluated. Two types of symmetric cell with BSCF cathodes were prepared on Ce0.8G0.2O1.9 electrolyte pellets using a single continuous process, electrostatic slurry spray deposition. Single layered BSCF cathode was fabricated with a porous layer only, while double layered one was fabricated with a porous layer over a thin dense layer. The polarization resistances at 500 °C and the activation energy of double layered BSCF were about 61% and 22% lower than single layered BSCF, respectively. The exchange current density of double layered BSCF was also higher than that of single layered BSCF, suggesting that the larger active area of double layered BSCF cathode is effective in the increase of oxygen reduction reaction rates.