Microstructure tailoring of the BaCe0.7Zr0.1Y0.2O3-?(BCZY)/Ni-BCZY dual-layer hollow fibers by co-spinning/co-sintering for high performance micro-tubular protonic ceramic fuel cells (MT-PCFCs)

Micro-tubular protonic ceramic fuel cells (MT-PCFCs) exhibit substantial advantages such as high energy con-version efficiency, large volumetric power density, and intermediate operating temperature. The performance of MT-PCFCs is highly dependent on the microstructure of the microtubes. In this study, BaCe0.7Zr0.1Y0.2O3-delta(BCZY)/Ni-BCZY (electrolyte/anode) dual-layer hollow fibers (DLHFs) are fabricated in a single step by co-spinning/co-sintering technique, which significantly reduces manufacturing time and cost. The relationship between the MT-PCFCs performance and the microstructure of the DLHFs is investigated. By adjusting the cermet powder content and the spinning rate, the microstructure of DLHFs is tailored and optimized to achieve the best performance for the MT-PCFCs. Experimental results indicate that the anode structure with thick finger-like voids inside and thin sponge-like interlayer closely attached to the thin electrolyte film is favorable to obtain high performance MT-PCFCs. A maximum power density of 554.5 mW cm-2 for the optimal MT-PCFC is achieved at 700 degrees C.