Systematic analysis on the effect of sintering temperature for optimized performance of li_0.15ni_0.45zn_0.4o₂-gd_0.2ce_0.8o₂-li₂co₃-na₂co₃-k₂co₃ based 3d printed single-layer ceramic fuel cell

Single-layer ceramic fuel cells consisting of Li_0.15Ni_0.45Zn_0.4O₂, Gd_0.2Ce_0.8O₂ and a eutectic mixture of Li₂CO₃, Na₂CO₃ and K₂CO₃, were fabricated through extrusion-based 3D printing. The sintering temperature of the printed cells was varied from 700^◦C to 1000^◦C to identify the optimal thermal treatment to maximize the cell performance. It was found that the 3D printed single-layer cell sintered at 900^◦C produced the highest power density (230 mW/cm² ) at 550^◦C, which is quite close to the performance (240 mW/cm²) of the single-layer cell fabricated through a conventional pressing method. The best printed cell still had high ohmic (0.46 Ω·cm² ) and polarization losses (0.32 Ω·cm² ) based on EIS measurements conducted in an open-circuit condition. The XRD spectra showed the characteristic peaks of the crystalline structures in the composite material. HR-TEM, SEM and EDS measurements revealed the morphological information of the composite materials and the distribution of the elements, respectively. The BET surface area of the single-layer cells was found to decrease from 2.93 m²/g to 0.18 m²/g as the sintering temperature increased from 700^◦C to 1000^◦C. The printed cell sintered at 900^◦C had a BET surface area of 0.34 m²/g. The fabrication of single-layer ceramic cells through up-scalable 3D technology could facilitate the scaling up and commercialization of this promising fuel cell technology.