Co-Extruded Triple-Layer Micro-Tubular Solid Oxide Fuel Cell: The Influence of Cathode Extrusion Rate on the Fuel Cell Properties and Performance

A sufficient volume fraction for pore development is provided by an appropriate cathode thickness, while its solid volume fraction for cathode reaction sites is preserved. As this study involves a simplified fabrication technique, adjusting the cathode extrusion rate could influence the anode and electrolyte layers since they are co-extruded and co-sintered. Thus, the effect of cathode extrusion rates (between 3 ml min-1 to 6 ml min-1) on the triple layer anode/electrolyte/cathode MT-SOFC developed via phase inversion-based co-extrusion/co-sintering is examined in this study. The cathode suspension is subjected to large forces to be extruded using a high cathode extrusion rate of 6 ml min-1, which indirectly pushes the electrolyte layer to a thinner state, promoting better ions' hopping efficiency by reducing the pathway between the cathode and anode. Additionally, the anode thickness increased with increasing cathode extrusion rate, providing ample electrode reaction sites and thereby enhancing the gas diffusion process. Accordingly, the C6 sample achieves a maximum power density of 1.46 W cm-2 with 1.08 V OCV at an optimum operating temperature of 800 °C, which is high for MT-SOFCs in high-temperature applications. Hence, the optimal cathode extrusion rate for the MT-SOFC fabricated using this simplified method was 6 ml min-1.