Thermally sprayed MCO/FeCr24 interconnector with improved stability for tubular segmented-in-series SOFCs

Abstract

The present work aims to evaluate the feasibility of thermally sprayed Mn1.5Co1.5O4/FeCr24 interconnect under real operating environment of tubular solid oxide fuel cells (SOFC). Different from the planar SOFC, further practical application of ferritic stainless steels interconnector is still limited in tubular SOFC, mainly due to the special construction and complex operating environment. Investigating the stability of interconnector under reducing-oxidizing (redox) atmosphere is an important issue towards practical applications of tubular SOFC. In this work, thermal spraying was applied as a cost-effective method to prepare the segmented-in-series SOFCs based on Mn1.5Co1.5O4/FeCr24 interconnector. The detailed heating and deposition process for different Mn1.5Co1.5O4 particles, quantitative relationship between the Mn1.5Co1.5O4 coating thickness (δ0) and microstructure homogenization rate (dδ/dt) during oxidizing treatment, as well as the feasibility of thermally-sprayed Mn1.5Co1.5O4/FeCr24 interconnect for tubular SOFC applications in range of 600–800 °C were thoroughly evaluated.