Fabrication and Characterization of High Performance Intermediate Temperature Micro-Tubular Solid Oxide Fuel Cells

Abstract

A phase inversion-based dual-layer co-extrusion approach was advanced to fabricate micro-channel array structured micro-tubular solid oxide fuel cells (MT-SOFCs). The inner graphite layer was used as a sacrificial layer to eliminate the middle sponge-like layer and inner surface dense skin layer, which were normally formed using the single layer extrusion method. As a result, the micro-channel array generated in the outer layer was a more open structure and facile fuel/gas diffusion was obtained. The fuel/gas permeability of such an anode substrate Ni-Ce0.8Sm0.2O1.9 (Ni-SDC) was ∼9 times that of an anode substrate fabricated using the phase inversion-based single layer extrusion method. The open circuit voltages (OCVs) of the corresponding cell Ni-SDC/SDC/PrBaCo2O5+δ were 0.89 V–0.85 V at 500–600°C, much higher than those of other SDC electrolyte based MT-SOFCs. The peak power density of the cell was ∼1484 mW cm−2 at 600°C, approximately 1.5 times that of a similar cell with an anode substrate fabricated from the single layer extrusion method. This is also the highest performance among the SOFCs with the same material system in open literature. The fuel utilization rate was also significantly improved in different degrees depending on the supplied inlet fuel flow rates.