Enhanced Reliability of Ni-Fe Alloys Supported SOFCs with Ex-Situ Sintered La0.8Sr0.2MnO3−δ Coated Ba0.5Sr0.5Co0.8Fe0.2O3–δ Cathode

A critical issue for massive production of metal-supported solid oxide fuel cell is cathode processing due to the contradicting of the metal support and the cathode with regard to the sintering atmosphere. Herein, LSM-BSCF (La0.8Sr0.2MnO3-δ coated Ba0.5Sr0.5Co0.8Fe0.2O3-δ) cathodes on Ni-Fe alloys supported SOFCs (NF-SOFCs) are fabricated by an ex situ sintering approach and electrochemical evaluation in humidified H2 fuel. The ex situ sintering of cathodes on NF-SOFCs are performed at 1050 °C in air with metal oxide support consisted of NiO and 10 at% Fe2O3, and then the oxide support is reduced in situ into Ni-Fe alloys during testing. Cross-section microstructure analysis shows clear evidence that each layer is well adhered to each other after reduction and the suitable microstructure of ex situ sintered cathode is observed after sintering at 1050 °C. In the single-cell test, a higher peak power density is achieved for NF-SOFC with ex situ sintered LSM-BSCF in comparison with in situ sintered cells, revealing a beneficial effect of ex situ sintered cathode on cell performance. The durability measurement and post-test analysis confirm the sufficient adherence and mechanical stability between ex situ sintered LSM-BSCF cathode and GDC (Ce0.9Gd0.1O1.95) electrolyte. The successful electrochemical characterizations of NF-SOFCs with ex situ sintered LSM-BSCF cathode confirm the applicability of the novel sintering procedure.