Study of Ba(Zr _0.9-x Ce _x )Y _0.1 O _3-δ Compositions on the Performance and Stability of Fuel-Flexible Proton-Conducting Ceramic Fuel Cells

Proton-conducting ceramic fuel cells (PCFCs) are emerging as a key technology in the realm of energy conversion, attracting widespread attention due to their ability to operate reversibly and utilize a diverse array of fuels, including hydrogen, methane, ammonia, and syngas. Recent work by Duan et al. 1 demonstrates remarkable stability of BaZrO 3-δ -based materials in both cermet fuel electrodes and electrolytes when used under a range of fuels such as hydrogen, methane, domestic natural gas (with and without hydrogen sulfide), propane, n-butane, i-butane, iso-octane, methanol, ethanol, and ammonia. However, while BaZrO 3-δ -based materials offer excellent chemical stability, they inherently suffer from low performance. On the other hand, BaCeO 3-δ -based materials offer superior proton conductivity but suffer from poor chemical stability. This study investigates Ba(Zr 0.9-x Ce x )Y 0.1 O 3-δ (x=0, 0.2, 0.5, 0.7,and 0.9) compositions to optimize both PCFC performance and stability. Fuel electrodes (60% NiO-40% Ba(Zr 0.9-x Ce x )Y 0.1 O 3-δ ) are prepared through uniaxial pressing and pre-sintered at 1300 °C, followed by the application of a thin (<10 μm) Ba(Zr 0.9-x Ce x )Y 0.1 O 3-δ electrolyte layer via dip coating, with subsequent sintering at 1400–1500 °C to ensure structural integrity. Ba(Co,Fe,Zr,Y)O 3-δ is employed as the air electrode material. Fabricated cells are studied by carrying out a detailed microstructural analysis of button cell cross-sections to evaluate material distribution, porosity, and interfacial integrity. This analysis will provide critical insights into the structural characteristics that influence performance and stability, alongside follow-up electrochemical long-term performance tests. This study paves the way for the advancement and potential of PCFC as high-performance, stable and fuel-flexible energy conversion devices. References: (1) Duan, C.; Kee, R. J.; Zhu, H.; Karakaya, C.; Chen, Y.; Ricote, S.; Jarry, A.; Crumlin, E. J.; Hook, D.; Braun, R. Highly durable, coking and sulfur tolerant, fuel-flexible protonic ceramic fuel cells. Nature 2018, 557 (7704), 217-222.