Different layered perovskite-related oxides are known to exhibit important electronic, magnetic and electrochemical properties. Owing to their excellent mixed-ionic and electronic conductivity and fast oxygen kinetics, cation layered double perovskite oxides such as PrBaCo2O5 in particular have exhibited excellent properties as solid oxide fuel cell oxygen electrodes. Here, we show for the first time that related layered materials can be used as high-performance fuel electrodes. Good redox stability with tolerance to coking and sulphur contamination from hydrocarbon fuels is demonstrated for the layered perovskite anode PrBaMn2O5+δ (PBMO). The PBMO anode is fabricated by in situ annealing of Pr0.5Ba0.5MnO3-δ in fuel conditions and actual fuel cell operation is demonstrated. At 800 °C, layered PBMO shows high electrical conductivity of 8.16 S cm(-1) in 5% H2 and demonstrates peak power densities of 1.7 and 1.3 W cm(-2) at 850 °C using humidified hydrogen and propane fuels, respectively.

Direct utilization of hydrocarbon and other renewable fuels is one of the most important issues concerning solid oxide fuel cells (SOFCs). Mixed ionic and electronic conductors (MIECs) have been explored as anode materials for direct hydrocarbon-type SOFCs. However, electrical conductivity of the most often reported MIEC oxide electrodes is still not satisfactory. As a result, mixed-conducting oxides with high electrical conductivity and catalytic activity are attracting considerable interest as an alternative anode material for noncoke depositing anodes. In this study, we examine the oxide composite Ce(Mn,Fe)O(2)-La(Sr)Fe(Mn)O(3) for use as an oxide anode in direct hydrocarbon-type SOFCs. High performance was demonstrated for this composite oxide anode in direct hydrocarbon-type SOFCs, showing high maximum power density of approximately 1 W cm(-2) at 1073 K when propane and butane were used as fuel. The high power density of the cell results from the high electrical conductivity of the composite oxide in hydrocarbon and the high surface activity in relation to direct hydrocarbon oxidation.

Inorganic perovskites exhibit many important physical properties such as ferroelectricity, magnetoresistance and superconductivity as well their importance as energy materials. Many of the most important energy materials are inorganic perovskites and find application in batteries, fuel cells, photocatalysts, catalysis, thermoelectrics and solar thermal. In all these applications, perovskite oxides, or their derivatives offer highly competitive performance, often state of the art and so tend to dominate research into energy material. In the following sections, we review these functionalities in turn seeking to facilitate the interchange of ideas between domains. The potential for improvement is explored and we highlight the importance of both detailed modelling and in situ and operando studies in taking these materials forward.

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Self-recovery is one of the most-desirable properties for functional materials. Recently, oxide anodes have attracted significant attention as alternative anode materials for solid-oxide fuel cells (SOFCs) that can overcome reoxidation, deactivation, and coke-deposition. However, the electrical conductivity and surface activity of the most-widely used oxide anodes remain unsatisfactory. Herein, we report the synthesis of an "intelligent oxide anode" that exhibits self-recovery from power-density degradation in the redox cycle by using a Pd-doped La(Sr)Fe-(Mn)O(3) cell as an oxide anode for the SOFCs. We investigated the anodic performance and oxidation-tolerance of the cell by using Pd-doped perovskite as an anode and fairly high maximum power densities of 0.5 and 0.1 W cm(-2) were achieved at 1073 and 873 K, respectively, despite using a 0.3 mm-thick electrolyte. Long-term stability was also examined and the power density was recovered upon exposure of the anode to air. This recovery of the power density can be explained by the formation of Pd nanoparticles, which were self-recovered through reoxidation and reduction. In addition, the self-recovery of the anode by oxidation was confirmed by XRD and SEM and this process was effective for improving the durability of SOFC systems when they were exposed to severe operating conditions.