High-performance thin-film protonic ceramic fuel cells fabricated on anode supports with a non-proton-conducting ceramic matrix

A novel strategy to fabricate high-performance thin-film protonic ceramic fuel cells (PCFCs) is introduced by building thin-film PCFC components, including BaCe_0.55Zr_0.3Y_0.15O_3-δ (BCZY) electrolytes (1.5 μm) over anode supports consisting of non-proton-conducting ceramic and metal catalytic phases. Ni-yttria-stabilized zirconia (YSZ) was used as supports in this study, which is superior in terms of its well-established facile fabrication process, along with physical and chemical stability, compared to proton-conducting materials. The Ni-YSZ supports provided a flat and smooth deposition surface that facilitates the deposition of the thin film components. A Ni-BCZY anode (∼3 μm), a dense BCZY electrolyte layer (∼1.5 μm), and a porous Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ cathode (∼2 μm) were sequentially fabricated over the Ni-YSZ substrates using pulsed laser deposition, followed by post-annealing, and the process was optimized for each component. A fully integrated thin-film PCFC microstructure was confirmed, resulting in high open circuit voltages exceeding 1 V at operating temperatures in the range of 450-650 °C. A promising fuel cell performance was obtained using the proposed fuel cell configuration, reaching a peak power density of 742 mW cm^-2 at 650 °C.