Fabrication and operating characteristics of a flat tubular segmented-in-series solid oxide fuel cell unit bundle

A unit bundle of a flat tubular segmented-in-series (SIS)-solid oxide fuel cell (SOFC) for intermediate temperature (650–800 °C) operation was fabricated and operated in this study. We fabricated flat tubular ceramic supports through an extrusion process and analyzed the basic properties of the flat tubular ceramic support: the visible microstructure, porosity, mechanical strength, and pore size distribution. After that, we manufactured a flat tubular SIS-SOFC single cell using screen printing and a vacuum slurry dip-coating method for the electrode/interconnect and electrolyte. In addition, to make a unit bundle for a flat tubular SIS-SOFC, five SIS-SOFC single cells with an effective electrode area of 0.8 cm2 were coated onto the surface of the prepared ceramic support and were connected in series using an Ag + glass interconnect between each single SIS-SOFC cell. The performance of the 5-cell unit bundle for a flat tubular SIS-SOFC in 3% humidified H2 and air at 800 °C had a maximum power of 2.5 W. •The unit bundle for flat tubular segmented-in-series (SIS)-SOFC is presented.•The SOFC behavior with the basic operating variables showed stable performance.•The performance of the 5-cell unit bundle had a maximum power density of 0.62 W/cm2 at 800 °C.