Suppression of Sr surface segregation in La0.8Sr0.2Co0.2Fe0.8O3-δ via Nb doping in B-site
Source abstract
Abstract
Abstract Sr surface segregation has been one of the main reasons for the cathode performance degradation during the long-term operation of solid oxide fuel cells (SOFC). Investigation on Sr segregation mechanism and proposing strategies on suppressing the Sr surface segregation are significant for SOFC development. In this paper, La0.8Sr0.2Co0.2Fe0.8-xNbxO3-δ (LSCFNb, x = 0, 0.02, 0.04, 0.06, 0.08 and 0.1) are prepared via sol-gel method. The electrochemical performance and long-term stability are tested through electrochemical impedance spectroscopy (EIS) and constant current polarization. The results show that the long-term stability of LSCFNb cathodes are strongly affected by Nb content. Combining the results of ICP and XPS, it's revealed that the Sr surface segregation can be effectively suppressed with the increase of Nb content. The LSCFNb cathodes gain the optimal electrochemical performance when x = 0.04, with minimum polarization resistance of 0.27 Ω cm2 at 750 °C and oxygen reduction reaction activation energy of 1.54 eV. After cathodic polarization for 144 h, the polarization resistance and activation energy of LSCFNb4 cathode increase slightly, revealing it a promising cathode material for SOFC research.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Advancements in Solid Oxide Fuel Cells · Electronic and Structural Properties of Oxides · Magnetic and transport properties of perovskites and related materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (40)
Show source-provided references
1. Lowering the temperature of solid oxide fuel cells10.1126/science.1204090 ↗
2. Solid oxide fuel cell commercialization, research and challenges
3. Solid oxide fuel cells10.1039/b105764m ↗
4. A high-performance cathode for the next generation of solid-oxide fuel cells10.1038/nature02863 ↗
5. Nb and Pd co-doped La0.57Sr0.38Co0.19Fe0.665Nb0.095Pd0.05O3-δ as a stable, high performance electrode for barrier-layer-free Y2O3-ZrO2 electrolyte of solid oxide fuel cells10.1016/j.jpowsour.2017.12.066 ↗
6. High temperature properties of La0.6Sr0.4Co0.8Fe0.2O3−δ phase structure and electrical conductivity10.1016/S0167-2738(03)00027-4 ↗
7. Performance of La0.6Sr0.4Co1−yFeyO3 (y= 0.2, 0.5 and 0.8) nanostructured cathodes for intermediate-temperature solid-oxide fuel cells: influence of microstructure and composition10.1016/j.ceramint.2015.10.104 ↗
8. Development of lanthanum strontium cobalt ferrite perovskite electrodes of solid oxide fuel cells-A review10.1016/j.ijhydene.2019.01.212 ↗
9. Correlation of time-dependent oxygen surface exchange kinetics with surface chemistry of La0.6Sr0.4Co0.2Fe0.8O3−δ catalysts10.1021/acsami.9b06569 ↗
10. Degradation factors in (La, Sr)(Co, Fe) O3-δ cathode/Sm2O3–CeO2 interlayer/Y2O3–ZrO2 electrolyte system during operation of solid oxide fuel cells10.1016/j.jpowsour.2016.02.052 ↗
11. Chromium poisoning effects on surface exchange kinetics of La0.6Sr0.4Co0.2Fe0.8O3−δ10.1021/acsami.7b02762 ↗
12. Sulfur poisoning on La0.6Sr0.4Co0.2Fe0.8O3 cathode for SOFCs10.1149/2.059111jes ↗
13. Performance stability and degradation mechanism of La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes under solid oxide fuel cells operation conditions10.1016/j.ijhydene.2014.03.077 ↗
14. Time-dependent performance changes in LSCF-infiltrated SOFC cathodes: the role of nano-particle coarsening10.1016/j.ssi.2011.02.003 ↗
15. Surface segregation in solid oxide cell oxygen electrodes: phenomena, mitigation strategies and electrochemical properties10.1007/s41918-020-00078-z ↗
16. Degradation mechanisms of porous La0.6Sr0.4Co0.2Fe0.8O3-δ solid oxide fuel cell cathodes10.1149/2.1211807jes ↗
17. Insight into surface segregation and chromium deposition on La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes of solid oxide fuel cells10.1039/C4TA01426J ↗
18. In situ study of activation and de-activation of LSM fuel cell cathodes–Electrochemistry and surface analysis of thin-film electrodes10.1016/j.jcat.2012.07.010 ↗
19. Surface termination and subsurface restructuring of perovskite-based solid oxide electrode materials10.1039/C4EE01497A ↗
20. In situ high temperature X-ray photoelectron spectroscopy study of barium strontium iron cobalt oxide10.1016/j.memsci.2011.08.006 ↗
21. Segregated chemistry and structure on (001) and (100) surfaces of (La1–xSrx)2CoO4 override the crystal anisotropy in oxygen exchange kinetics10.1021/acs.chemmater.5b02292 ↗
22. Surface segregation and restructuring of colossal-magnetoresistant manganese perovskites La0.65Sr0.35MnO310.1103/PhysRevB.62.R14629 ↗
23. Cation size mismatch and charge interactions drive dopant segregation at the surfaces of manganite perovskites10.1021/ja3125349 ↗
24. Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides[J]10.1107/S0567739476001551 ↗
25. A density functional theory study of self-regenerating catalysts LaFe1–xMxO3–y (M= Pd, Rh, Pt)10.1021/ja110302t ↗
26. Origin of Sr segregation at La1−xSrxMnO3 surfaces10.1103/PhysRevB.83.155437 ↗
27. Stability of La0.6Sr0.4Co0.2Fe0.8O3-δ as SOFC cathode10.1149/2.063210jes ↗
28. Investigation of surface Sr segregation in model thin film solid oxide fuel cell perovskite electrodes10.1039/C1EE02762J ↗
29. Mechanistic understanding of Cr poisoning on La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF)10.1149/1.3205852 ↗
30. Study on durability of novel core-shell-structured La0.8Sr0.2Co0.2Fe0.8O3-δ@Gd0.2Ce0.8O1.9 composite materials for solid oxide fuel cell cathodes10.1016/j.ijhydene.2021.06.031 ↗
31. Effect of optimal GDC loading on long-term stability of La0.8Sr0.2Co0.2Fe0.8O3-δ/Gd0.2Ce0.8O1.9 composite cathodes10.1016/j.ceramint.2020.10.248 ↗
32. Relationship between cation substitution and stability of perovskite structure in SrCoO3–δ-based mixed conductors10.1016/j.ssi.2006.10.022 ↗
33. Die strukturen von Verbindungen ABO310.1007/BF01468312 ↗
34. R factors in Rietveld analysis: how good is good enough?[J]10.1154/1.2179804 ↗
35. Effect of Sr content and strain on Sr surface segregation of La1–xSrxCo0.2Fe0.8O3−δ as cathode material for solid oxide fuel cells10.1021/acsami.6b07118 ↗
36. Novel SrCo1−yNbyO3−δ cathodes for intermediate-temperature solid oxide fuel cells10.1016/j.jpowsour.2009.12.081 ↗
37. Comparative studies of SrCo1−xTaxO3−δ (x= 0.05–0.4) oxides as cathodes for low-temperature solid-oxide fuel cells10.1002/celc.201500157 ↗
38. A comparative study of SrCo0.8Nb 0.2O3−δ and SrCo0.8Ta0.2O3−δ as low-temperature solid oxide fuel cell cathodes: effect of non-geometry factors on the oxygen reduction reaction10.1039/C5TA07178J ↗
39. Suppression of Sr surface segregation in La1−xSrxCo1−yFeyO3−δ: a first principles study10.1039/C2CP43148C ↗
40. Improved chemical and electrochemical stability of perovskite oxides with less reducible cations at the surface10.1038/nmat4659 ↗