Effect of sintering temperature on electrochemical performance of porous SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) oxygen electrodes for solid oxide cells

Abstract

This work evaluates the effects of the sintering temperature (800°C, 900°C, 1000°C) of SrTi 1-x Fe x O 3-δ (x = 0.35, 0.5, 0.7) porous electrodes on their electrochemical performance as potential oxygen electrode materials of solid oxide cells. The materials were prepared by a solid-state reaction method and revealed the expected cubic perovskite structure. After milling, the powders were characterised by a sub-micrometre particle size with high sinter-activity. It was shown that the lowest area specific resistance was achieved after sintering SrTi 0.65 Fe 0.35 O 3 electrodes at 1000°C, and SrTi 0.5 Fe 0.5 O 3 and SrTi 0.30 Fe 0.70 O 3 electrodes at 800°C, which can be considered to be a relatively low temperature. In general, EIS measurements showed that increasing the Fe content results in lowered electrode polarisation and a decrease of the series resistance. Even though the studied materials have much lower total conductivities than state-of-the-art electrode materials (e.g. (La,Sr)(Co,Fe)O 3 ), the polarisation resistances obtained in this work can be considered low.

Structure and transport properties of triple-conducting BaxSr1−xTi1−yFeyO3−δoxides

“…It should be also noted that the iron content increases the sinterability of these perovskites. 42 To analyse whether the proton conduction is possible in the barium-substituted strontium titanate-ferrite solid solutions, proton defects formation should be discussed. In the air, in acceptor-doped SrTiO 3 , the concentration of oxygen vacancies is much lower than that of electronic holes.…”

Electrochemical Oxidative Coupling of Methane: Deciphering the Exceptional Properties of BaMg0.33Nb0.67–xFexO3−δ for Enhanced Electrocatalysis and Durable Operation

“…However, with the inclusion of extra peaks around the 2θ angles of 43°, 62°and some smaller peaks at angles >70°, there may be a hexagonal phase formed, 40 characteristic of perovskites with Goldschmidt tolerance factors >1. Singlephase formation may require higher sintering temperatures (which may also affect electrochemical properties 44 ) or other methods of synthesis. 45,46 Dense, sintered pellets were prepared at 1400 °C with pellet densities being noted in Table S2 where increased iron incorporation led to less dense pellets.…”

Properties of Oxygen Vacancy and Hydrogen Interstitial Defects in Strontium Titanate: DFT + Ud,p Calculations

“…In recent years, STO has also become the subject of an increased interest in electrochemistry, as it has been demonstrated to be a good base material for the fabrication of the so-called triple-conducting oxides (TCOs). ,, These materials are capable of conducting oxygen (O 2– ) and hydrogen (H + ) ions, and electrons or holes, and are therefore considered promising for use as novel cathodes in proton-conducting fuel cells. , One of the examples of promising STO-based TCO is SrTi x Fe 1– x O 3−δ , which was found to be electrochemically stable, offering high ionic conductivity and good ion surface exchange rates. ,− …”