Study on the ORR Mechanism and CO2-poisoning Resistance of La0.8Sr0.2MnO3-δ-coated Ba0.5Sr0.5Co0.8Fe0.2O3-δ Cathode for Intermediate Temperature Solid Oxide Fuel Cells

LSM-coated BSCF cathode with 3D core-shell architecture has been fabricated by the solution impregnation technology. On the basis of previous research, the synthesis process is improved in order to promote the perovskite degree of BSCF. In this paper, the ORR mechanism of LSM-coated BSCF is studied in detail. As the intervention of LSM shell, the LSM-coated BSCF presents different ORR rate-determining step compared with the BSCF cathode. The formation of lattice oxygen is the rate-determining step for the LSM-coated BSCF cathode, while the molecular oxygen surface adsorption is for the BSCF cathode. In the single cell tests, the LSM-coated BSCF cell shows higher maximum power density than the uncoated cell. The remarkable CO2-poisoning resistant performance of LSM-coated BSCF is verified by the CO2-TPD test and the single cell potentiostatic test. The excellent electrochemical performance and CO2-poisoning resistance indicate that LSM-coated BSCF is a promising cathode for IT-SOFCs.