Fabrication and characterization of microtubular and flattened ribbed SOFCs prepared by the multi-dip coating and co-firing

Presently, solid oxide fuel cells (SOFCs) are among the most efficient type of fuel cells and are expected to play a significant role in the next generation of energy conversion systems. Many types of SOFCs have been investigated in an effort to improve operational temperature tolerance. One particularly unique configuration is the microtubular cell, which has a large specific surface area per unit volume and can improve cell performance if integrated into stacks. In this paper, ceramic microtubular cells of diameter less than 1 mm were prepared via a multi-dip coating method. Steel wire was coated with polystyrene to make microtubular and flattened ribbed cells (FRCs). Green microtubular cells were separated from the wire by dissolving the polystyrene layer and co-firing at 1350 °C. These tubular cells show good linearity and a maximum power density of 0.14 W/cm2 at 550 °C. This coating process can be easily automated in comparison to the conventional extrusion process.