Enhanced electrochemical performance by structural design of electrolyte surface combining 3D printing technology with multi-physical modelling

Patterned electrolyte surfaces are considered an effective strategy to enhance the cell performance of solid oxide fuel cells by increasing the contact area between the electrode and electrolyte, and subsequently reducing the area specific resistance. In this study, the patterning of an 8 mol% yttria stabilised zirconia (8YSZ) electrolyte surface tailored using the stereolithography (SLA) 3D printing technology and the effects of the electrolyte surface geometry on the cell performance were investigated using multi-physical field simulation and quantitative analysis. Defect-free densified planar and concavo–convex electrolytes were successfully prepared by applying SLA, and the concavo–convex cell yielded a maximum output power density of 288.9 mW cm−2 at 850 °C, which was 46.2 % higher than that of the planar cell. The simulation results revealed significant consumption of reactants and strong electrochemical reactions at the concave surface. Moreover, the hydrogen and oxygen consumptions at the edges were greater than those at the centre of both the concave and convex surfaces, whereas the edges of the concavo–convex structure were more conducive to the electrochemical reaction. Finally, the quantitative correlation between cell performance and the influencing factors was obtained by conducting stepwise linear regression analysis. Reducing the ion transfer path length and providing a sufficiently large effective contact area proved to be a productive strategy for improving cell output performance.