Performance modulation through selective, homogenous surface doping of lanthanum strontium ferrite electrodes revealed by <i>in situ</i> PLD impedance measurements

Riedl, Christoph; Siebenhofer, Matthäus; Nenning, Andreas; Friedbacher, Gernot; Weiß, Maximilian; Rameshan, Christoph; Bernardi, Johannes; Limbeck, Andreas; Kubicek, Markus; Opitz, Alexander Karl; Fleig, Jürgen

doi:10.1039/d1ta08634k

Cited by 8 publications

(6 citation statements)

References 101 publications

(159 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indicated by the formation of a positive surface charge for basic decorations (negative for acidic decorations), we can further assume that basic decorations promote the formation of positively charged oxygen vacancies, which have been proposed to be a decisive factor for fast oxygen exchange kinetics. − This hypothesis is also supported by the lower binding energy O 1s species measured on SrO-decorated PCO10 (and vice versa for SnO 2 -decorated PCO10, see Figure C). Nevertheless, independent of the exact nature of charge redistribution processes, it is evident that defect concentrations in the surface and subsurface will change upon decoration, altering oxygen exchange reaction rates, which contain contributions of both vacancy and electron concentrations.…”

Section: Mechanistic Discussionmentioning

confidence: 56%

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics

Riedl

Siebenhofer

Nenning

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

The oxygen exchange kinetics of epitaxial Pr 0.1 Ce 0.9 O 2−δ electrodes was modified by decoration with submonolayer amounts of different basic (SrO, CaO) and acidic (SnO 2 , TiO 2 ) binary oxides. The oxygen exchange reaction (OER) rate and the total conductivity were measured by in situ PLD impedance spectroscopy (i-PLD), which allows to directly track changes of electrochemical properties after each deposited pulse of surface decoration. The surface chemistry of the electrodes was investigated by near-ambient pressure XPS measurements (NAP-XPS) at elevated temperatures and by low-energy ion scattering (LEIS). While a significant alteration of the OER rate was observed after decoration with binary oxides, the pO 2 dependence of the surface exchange resistance and its activation energy were not affected, suggesting that surface decorations do not alter the fundamental OER mechanism. Furthermore, the total conductivity of the thin films does not change upon decoration, indicating that defect concentration changes are limited to the surface layer. This is confirmed by NAP-XPS measurements which find only minor changes of the Pr-oxidation state upon decoration. NAP-XPS was further employed to investigate changes of the surface potential step on decorated surfaces. From a mechanistic point of view, our results indicate a correlation between the surface potential and the altered oxygen exchange activity. Oxidic decorations induce a surface charge which depends on their acidity (acidic oxides lead to a negative surface charge), affecting surface defect concentrations, any existing surface potential step, potentially adsorption dynamics, and consequently also the OER kinetics.

show abstract

Section: Mechanistic Discussionmentioning

confidence: 56%

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics

Riedl

Siebenhofer

Nenning

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…1. While for the perovskite based substrate LSGM (orthorombic, Imma), epitaxial growth of LSF is not surprising and was already shown in a previous study, 48 it is not obvious that LSF can grow epitaxially on GDC. However, studies in literature have already shown the epitaxial growth of the structurally similar LSC on a GDC buffer layer 42,49,50 with a 451 in-plane rotation.…”

Section: Structural Characterization and Surface Morphologymentioning

confidence: 71%

In situ electrochemical observation of anisotropic lattice contraction of La_0.6Sr_0.4FeO_3−δ electrodes during pulsed laser deposition

Riedl

Siebenhofer

Ražnjević

et al. 2023

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The PLD has been utilized to deposit porous perovskite electrodes, 157‐160 electrolytes layers such as CGO, 161,162 YSZ, 163 and SDC/LSGM bilayers 164 so far. The exact transfer of the composition of LSGM was not possible through PLD 165 .…”

Section: Fabrication Techniques For Sofcsmentioning

confidence: 99%

A review on materials, advantages, and challenges in thin film based solid oxide fuel cells

Chasta

Himanshu

Dhaka

2022

Intl J of Energy Research

View full text Add to dashboard Cite

Summary In accomplishment of massive energy demand, the solid oxide fuel cells (SOFCs) have proven as apotheosis candidates due to their high energy conversion efficiencies, low pollution exhaust, fuel flexibility, and environmental friendliness which make these the most promising alternatives to conventional electricity generators. Despite numerous advantages of SOFCs, large‐scale industrial applications are yet to be realized owing to their high operating temperatures (800°C‐1000°C). To lower the operating temperature, it is crucial to minimize ionic resistances which can be accomplished by reducing the electrolyte thickness to lesser than 5 μm. Therefore, present article embraces a concise review on conventional materials, designs, and generations of SOFCs with their compatibility and drawbacks. The strengths and limitations of conventional and advanced tools for fabricating thin film based SOFCs (TF‐SOFCs) as well as the associated properties of electrolytes and electrodes are thoroughly examined, and further route cast is provided to attain better performance. The present review encourages the development of TF‐SOFCs using advanced techniques employing ultrathin single and bilayer electrolytes which can have potential to reduce the operating temperature of SOFCs from 450°C to 600°C region and pave the way for global commercialization.

show abstract

Performance modulation through selective, homogenous surface doping of lanthanum strontium ferrite electrodes revealed by in situ PLD impedance measurements

Abstract: Accelerating the oxygen reduction kinetics of solid oxide fuel cell (SOFC) cathodes is crucial to improve their efficiency and thus to provide the basis for an economically feasible application of...

Cited by 8 publications

References 101 publications

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics

In situ electrochemical observation of anisotropic lattice contraction of La_0.6Sr_0.4FeO_3−δ electrodes during pulsed laser deposition

A review on materials, advantages, and challenges in thin film based solid oxide fuel cells

Contact Info

Product

Resources

About

Performance modulation through selective, homogenous surface doping of lanthanum strontium ferrite electrodes revealed by in situ PLD impedance measurements

Abstract: Accelerating the oxygen reduction kinetics of solid oxide fuel cell (SOFC) cathodes is crucial to improve their efficiency and thus to provide the basis for an economically feasible application of...

Cited by 8 publications

References 101 publications

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics

Surface Decorations on Mixed Ionic and Electronic Conductors: Effects on Surface Potential, Defects, and the Oxygen Exchange Kinetics

In situ electrochemical observation of anisotropic lattice contraction of La0.6Sr0.4FeO3−δ electrodes during pulsed laser deposition

A review on materials, advantages, and challenges in thin film based solid oxide fuel cells

Contact Info

Product

Resources

About

In situ electrochemical observation of anisotropic lattice contraction of La_0.6Sr_0.4FeO_3−δ electrodes during pulsed laser deposition