Novel microtubular solid oxide fuel cells with mesoscale surface patterns

In this study, a novel approach for fabricating microtubular solid oxide fuel cells (SOFCs) with mesoscale surface patterns is developed to enhance electrochemical performance via interface engineering. Various patterned anode supports are produced by wrapping the corresponding tape-cast green films onto water-soluble 3D-printed sacrificial rods featuring a range of surface dimple geometries, followed by isostatic pressing and mold removal. Complete patterned cells are further constructed on these supports through dip-coating and sintering processes. While microscopic analyses confirm successful transfer of surface features to both inner and outer surfaces of the anode support microtubes, mechanical testing reveals a reduction in flexural strength of the anode supports, attributed to localized thinning and stress concentrations induced by the patterned geometry. Electrochemical tests show significant improvements in power output, up to ∼85 %, for all patterned cells compared to the unpatterned reference cell, with the highest peak power density reaching 0.421 Wcm −2 at 800 °C. Impedance analysis indicates that reduced charge transfer and gas diffusion resistances are responsible for the improved performance. These findings demonstrate that morphological patterning of microtubular SOFCs is a promising route for enhancing performance without compromising structural integrity, offering new opportunities for compact and high-efficiency microtubular SOFC stack design. • 3D-printed water-soluble molds enable inner and outer surface pattern transfer. • Surface features increase TPB density and improved charge/gas transport. • Mesoscale-patterned microtubular SOFCs show up to 85 % power enhancement. • Low-cost fabrication enables compact, high-efficiency microtubular SOFCs.