An anode-supported micro-tubular solid oxide fuel cell with redox stable composite cathode

A NiO-YSZ anode-supported hollow fiber solid oxide fuel cell (HF-SOFC) has been fabricated with redox stable (La_0.75Sr_0.25) _0.95Cr_0.5Mn_0.5O_3-δ-Sm _0.2Ce_0.8O_1.9-YSZ (LSCM-SDC-YSZ) composite cathode. The characterization of NiO-YSZ hollow fibers prepared by the phase inversion method is focused on the microstructure, porosity, bending strength and electrical conductivity. A thin YSZ electrolyte membrane (about 10 μm) can be prepared by a vacuum-assisted dip-coating process and is characterized in terms of microstructure and gas-tightness. The performance of the as-prepared HF-SOFC is investigated at 750-850 °C with humidified H₂ as fuel and ambient air as the oxidant. The peak power densities of 513, 408 and 278 mW cm^-2 can be obtained at 850, 800 and 750 °C, respectively, and the corresponding interfacial polarization resistances are 0.14, 0.29 and 0.59 Ω cm². The high performance at intermediate-to-high temperatures could be attributed to thin electrolyte and proper composite cathode with low interfacial polarization resistance. The low interfacial polarization resistance suggests potential applications of LSCM-SDC-YSZ composite oxides as the redox stable cathode. This investigation indicates that the redox stable LSCM-SDC-YSZ is a promising cathode material system for the next generation YSZ-based HF-SOFC. The results will be expected to open up a new phase of the research on the micro-tubular SOFCs.