Tuning Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode to high stability and activity via Ce-doping for ceramic fuel cells

Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) fuel-cell cathode stands out because of its ultrahigh ionic conductivity and excellent electrocatalytic activity, but it is still very subject to instability. Here, a new strategy of Ce doping is proposed to boost the stability and activity of the BSCF cathode. A one-pot combustion method is employed to synthesize (Ba0.5Sr0.5)1-xCexCo0.8Fe0.2O3-delta (x=0-0.2) cathodes. Both BSCF and (Ba0.5Sr0.5)0.9Ce0.1Co0.8Fe0.2O3-delta have a cubic perovskite structure. (Ba0.5Sr0.5)0.8Ce0.2Co0.8Fe0.2O3-delta shows two phases of cubic perovskite and fluorite ceria. Proper Ce doping can boost the electrical conductivity of BSCF, and can dramatically reduce the polarization resistance of BSCF cathode. Ce doping significantly improved BSCF cathode long-term stability by 160 h. Moreover, ten-percent Ce doping in BSCF highly improves single-cell output performance from 516.33 mW cm-2 to 629.75 mW cm-2 at 750 degrees C. The results reveal that Ce doping as a potential strategy for enhancing the stability and activity of BSCF cathode is promising.

Automated summary

This study proposes a new strategy of Ce doping to enhance the stability and activity of BSCF fuel-cell cathode, and verifies its effectiveness through experiments. Ce doping can significantly increase the electrical conductivity of BSCF and reduce the polarization resistance, thereby improving the long-term stability of the cathode and the output performance of the cell.