Novel concept of bolt-microtubular geometry for solid oxide fuel cells

Abstract

This study introduces a proof of concept for a novel solid oxide fuel cell geometry called bolt-microtubular. Bolt-microtubular anode supports are formed by winding tape cast anode support strip on a threaded rod followed by isostatic pressing. Bolt-microtubular cells are built by dip coating other cell layers on these supports. Conventional microtubular anode supports and cells are also fabricated similarly for comparison and, microstructural, mechanical and electrochemical investigations are carried out. Different anode current collection strategies are also examined. The results indicate that with the proposed methods thread patterns can be successfully created on the anode supports and bolt-microtubular anode supports without any structural damages can be obtained after sintering. Although three point bending tests show ∼27% decrease in the fracture strength of the anode supports with bolt-microtubular design for the wall thickness studied, bolt-microtubular cells outperform microtubular ones due to enhanced electrolyte-electrode interfaces and effective current collection. The highest peak electrochemical performance of 0.293 Wcm−2 at 800 °C is obtained from the bolt-microtubular cell with external current collection, whereas the maximum power density of classical microtubular cell under the same operating conditions is 0.227 Wcm−2. The overall results reveal that bolt-microtubular design is promising and deserves further investigations.