Fabrication of protonic ceramic fuel cells via infiltration with Ni nanoparticles: A new strategy to suppress NiO diffusion & increase open circuit voltage

Presently, most of the cells using BaZr0.8Y0.2O3-δ (BZY20) electrolyte were prepared by a co-sintering process performed between 1400 and 1600 °C. However, during the co-sintering process, Ni diffuses from the anode substrate into the BZY20 electrolyte layer, resulting in the decrease in both the proton conductivity and transport number of proton conduction. Furthermore, second phases like BaY2NiO5 form in the electrolyte, and the Y content decreases dramatically to about 5-6 at.%. All these issues indicate that the co-sintering process will restrict the further development of the BZY20 electrolyte-based cells, and some new method is necessary. In this work, we report a new cell fabrication method by infiltrating ink containing Ni nanoparticles into preliminarily sintered BZY20 cell with a porous layer, to suppress the unfavorable Ni diffusion and Y loss in the BZY20 electrolyte, which are problems in the conventional co-sintering process. This process is easy in manipulation and low in cost, and most importantly, makes the cell using the pristine BZY20 electrolyte possible. However, this approach needs to be improved or optimized by thinning the electrolyte, improving the adhesion between the electrolyte and electrode, and optimizing the anode structure. •Unfavorable diffusion of Ni and loss of Y in BZY20 electrolyte due to co-sintering•New anode structure by infiltrating Ni nanoparticles into porous BZY20 scaffold•Suppression of Ni diffusion and Y loss in BZ20 electrolyte by infiltration process•Improvement in open circuit voltage by infiltration process