High-performance and durable alcohol-fueled symmetrical solid oxide fuel cell based on ferrite perovskite electrode

Abstract

A solid oxide fuel cell utilizing bio-fuels such as methanol and ethanol could provide a carbon–neutral electricity generation and facilitate its applications in transport or stationary power unit. Herein, Ce4+ doping in SrFe0.95Ni0.05O3 imparts FeNi3 exsolution and CeO2 precipitation in a reducing condition, contributing to the fuel reforming, C-C bond cleavage and coke consumption in the anode chamber. The ferrite perovskites are stable in ethanol/steam at 800 °C, whereas they are unstable in ethanol vapor with the high C fugacity inducing the formation of Fe0 and carbides. However, the Ce0.2Sr0.8Fe0.95Ni0.05O3 anode maintains mostly the perovskite and is free from coke after the 300 h’ operation under C2H5OH fuel at 0.5 V or 0.7 V because of the dynamic balance between the carbon deposition and consumption since an operation for 10 h shows a clear carbon deposition. A maximum power density of 0.58 W cm−2 and a polarization resistance of 0.21 Ω cm2 at 800 °C can be obtained for the symmetrical solid oxide fuel cell with identical Ce0.2Sr0.8Fe0.95Ni0.05O3 cathode and anode under an ethanol fuel. The results demonstrate that the reversible and stable SrFeO3 with Ce/Ni co-doping has a bright prospect for alcohol fuel oxidation.