A high power density solid oxide fuel cell based on nano-structured La0.8Sr0.2Cr0.5Fe0.5O3-δ anode

Solid oxide fuel cell (SOFC) that is capable to operate on both hydrogen and methane as fuels is desired and its anode receives particular attention since it is the cell component directly converting fuels. (La,Sr)CrFeO3-δ is regarded as a candidate anode material but its electrochemical performance has been unsatisfactory. In this study, we improved the performance of an SOFC based exclusively on a La0.8Sr0.2Cr0.5Fe0.5O3-δ anode by means of impregnation. At 800 °C, the maximum power densities of such a cell reach 846 mWcm−2 with hydrogen as fuel, and 117 mW cm−2 when methane is fed. The anode polarization resistances are 0.06 ohm cm2 in hydrogen and 0.57 ohm cm2 in methane, estimated from impedance spectra fitting results. During a stability test of 100 h in hydrogen under a current loading of 850 mAcm−2, a conditioning period of ca. 50 h is seen during which the power density decreases moderately, and afterward the power density becomes gradually stable at around 490mW cm−2.

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