Co-Sintering of Spinel-Based Coating/Contact Dual-Layer Structure for Solid Oxide Fuel Cell Cathode-Side Application

A coating/contact dual-layer structure is fabricated via co-sintering in simulated interconnect/coating/contact/cathode test cells. Two different precursors are utilized to form Mn1.25Co1.75O4 and Ce-doped Mn1.25Co1.75O4 spinel coatings, while a mixture of Mn oxide and Co metal powders is employed as the contact material. After thermal conversion into a dense coating and a porous contact layer at 900 degrees C in air simultaneously, both test cells exhibit excellent electrical performance during the 1500-h area-specific resistance (ASR) measurement at 800 degrees C, due to the unique dual-layer structure via co-sintering. The cell with Ce-containing coating precursor shows better cell ASR behavior and lower degradation rate. Cross-sectional observation of the tested cells is conducted to assess the compatibility of the dual-layer structure with adjacent components as well as its effectiveness in inhibiting chromia scale growth and blocking Cr migration from the interconnect to the cathode.