The influence of discharge operation on the microstructure of strontium-doped lanthanum manganite cathode for solid oxide fuel cells

Yang, Jun; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

doi:10.1016/j.jpowsour.2011.12.049

Cited by 14 publications

(10 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: 12mentioning

confidence: 99%

“…1,13 Due to its unique positions in the fundamental understanding of the kinetics and mechanism of O 2 reduction reaction, the interface between LSM electrode and YSZ electrolyte has being attracted significant attention in recent years. 12,[20][21][22] Early studies show that polarization, either anodic or cathodic, can significantly alter/modify the interface, i.e., the coarsening of the contact rings on the YSZ electrolyte surface.23 Matsui et al quantitatively studied the microstructural change at the LSM/YSZ interface under polarization by focused ion beam-scanning electron microscopy technique and observed the increased roughness of YSZ surface and the formation of closed pores at the LSM/YSZ interface, after cathodic current treatment at 300 mA z E-mail: s.jiang@curtin.edu.au cm −2 . 24 Further study showed that polarization at a much high current density (e.g., 1.2 A cm −2 ) can cause the densification of LSM and formation of nanopores at the interface region.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Thermally and Electrochemically Induced Electrode/Electrolyte Interfaces in Solid Oxide Fuel Cells: An AFM and EIS Study

Jiang

2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

In high temperature solid oxide fuel cells (SOFCs), electrode/electrolyte interfaces play a critical role in the electrocatalytic activity and durability of the cells. In this study, thermally and electrochemically induced electrode/electrolyte interfaces were investigated on pre-sintered and in situ assembled (La 0.8 Sr 0.2 ) 0.90 MnO 3 (LSM) and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) electrodes on Y 2 O 3 -ZrO 2 (YSZ) and Gd 0.2 Ce 0.8 O 2 (GDC) electrolytes, using atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). The results indicate that thermally induced interface is characterized by convex contact rings with depth of 100-400 nm and diameter in agreement with the particle size of pre-sintered LSM and LSCF electrodes, while the electrochemically induced interfaces under cathodic polarization conditions on in situ assembled electrodes are characterized by particle-shaped contact marks or clusters (50-100 nm in diameter). The number and distribution of contact clusters depend on the cathodic current density as well as the electrode and electrolyte materials. The contact clusters on the in situ assembled LSCF/GDC interface are substantially smaller than that on the in situ assembled LSM/GDC interface likely due to the high mixed ionic and electronic conductivities of LSCF materials. The results show that the electrochemically induced interface is most likely resulting from the incorporation of oxygen species and cation interdiffusion under cathodic polarization conditions. However, the electrocatalytic activity of electrochemically induced electrode/electrolyte interfaces is comparable to the thermally induced interfaces for the O 2 reduction reaction under SOFC operation conditions. © The Author Solid oxide fuel cell (SOFC) is one of the most efficient technologies for the conversion of chemical energy of fuels such as hydrogen and natural gas directly into electrical power. It employs a solid oxide electrolyte such as yttria-stabilized zirconia (YSZ) that serves as an ionic conductor in the temperature range between 600• C to 1000• C. The electrolyte separates the cathode from the anode and conducts oxygen ions from the cathode to the anode where they react electrochemically with the fuel. Electrons are then released to an external circuit, which provides a useful source of electrical power. The electrochemical reactions such as O 2 reduction at the cathode and H 2 oxidation at the anodes occur at the electrode/electrolyte interface regions.1-3 Thus, in SOFCs, electrode/electrolyte interfaces play a vital role in the mechanism and kinetics of the electrochemical reactions and in the fundamental understanding of the relationship between the electrochemical processes and microstructure.4-10 The cell performance and durability also depend strongly on the microstructural change at the interface under SOFC operation conditions. 11,12Lanthanum strontium manganite (LSM) is one of the most common cathode materials for SOFCs because of high electrical conductivity, good thermal and chem...

show abstract

Section: 12mentioning

confidence: 99%

mentioning

confidence: 99%

Thermally and Electrochemically Induced Electrode/Electrolyte Interfaces in Solid Oxide Fuel Cells: An AFM and EIS Study

Jiang

2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Solid oxide fuel cells (SOFCs) have attracted significant attention as they are capable of producing electricity efficiently with low pollutant emission 1–6. Owing to the use of solid oxide electrolyte, SOFCs are usually operated at high temperatures of 600–800 °C, which allows favorable fuel flexibility.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Influence of Oxide Component in Ni‐Based Cermet Anodes for Ammonia‐Fueled Solid Oxide Fuel Cells

et al. 2015

View full text Add to dashboard Cite

Recently, the promising prospect of ammonia as a hydrogen carrier for solid oxide fuel cells (SOFCs) has attracted significant interests. In this work, the effects of temperature, fuel content, and total flow rate of anode gas on the performance of Ni/yttria‐stabilized zirconia (Ni/YSZ) anode for ammonia‐fueled SOFCs were investigated. Based on obtained results, the utilization route of ammonia on Ni/YSZ anode was discussed; the results of electrochemical experiments were related with the catalytic decomposition bahavior of ammonia over Ni/YSZ. Moreover, the catalytic activity for ammonia decomposition and anode performance of Ni/samarium‐doped ceria (Ni/SDC) and Ni/yttrium‐doped barium cerate (Ni/BCY) were also investigated. Among these anode materials, Ni/BCY exhibited the highest ammonia decomposition activity and anode performance for ammonia‐fueled SOFCs at intermediate temperatures.

show abstract

“…Before current passage, most TPBs were ascribable to active sites and located in the edges of LSM/SDC contact domain, as is observed in Figure 3a. In the case of LSM/YSZ system, the dense LSM layer was formed over YSZ electrolyte upon cathodic current passage [10,32]. At higher overpotential, inactive TPBs appear to be newly formed at the two phase boundary of LSM/YSZ due to the formation of closed pores.…”

Section: Resultsmentioning

confidence: 99%

“…These phenomena indicate the sintering and/or densification of LSM particles, which will be related to the reduction in active TPB length. In the case of LSM/YSZ system, the dense LSM layer was formed over YSZ electrolyte upon cathodic current passage [10,32]. The thickness of this layer was dependent on the chemical composition of LSM, operating time as well as overpotential.…”

Section: Resultsmentioning

confidence: 99%

Interfacial Stability between Air Electrode and Ceria‐Based Electrolyte under Cathodic Polarization in Solid Oxide Fuel Cells

Matsui¹,

Komoto²,

Muroyama³

et al. 2014

Fuel Cells

View full text Add to dashboard Cite

The stability of interfacial structure between air electrode and ceria‐based electrolyte (Sm2O3–CeO2, SDC) was evaluated under various polarization conditions at 1,000 °C. This is because the structural change at the interface is strongly related to the diffusion of constituent elements and has the potential to affect the long‐term stability. In this study, (La,Sr)MnO3 (LSM) and (La,Sr)(Co,Fe)O3 (LSCF) were applied as air electrodes. The cell with LSM/SDC interface showed the performance enhancement after cathodic polarization for 5 h, accompanied with the change in interfacial structure. The magnitude of the microstructural change as well as activation was dependent on the current density and the oxygen partial pressure. However, the active triple phase boundary (TPB)‐length decreased at every condition studied. On the other hand, no appreciable change in interfacial structure was confirmed for the LSCF/SDC system regardless of polarization conditions. In response to this phenomenon, the total TPB‐length was almost identical to the active one. The difference in morphological evolution at the interface depending on the electrode material was discussed.

show abstract

The influence of discharge operation on the microstructure of strontium-doped lanthanum manganite cathode for solid oxide fuel cells

Cited by 14 publications

References 15 publications

Thermally and Electrochemically Induced Electrode/Electrolyte Interfaces in Solid Oxide Fuel Cells: An AFM and EIS Study

Thermally and Electrochemically Induced Electrode/Electrolyte Interfaces in Solid Oxide Fuel Cells: An AFM and EIS Study

Catalytic Influence of Oxide Component in Ni‐Based Cermet Anodes for Ammonia‐Fueled Solid Oxide Fuel Cells

Interfacial Stability between Air Electrode and Ceria‐Based Electrolyte under Cathodic Polarization in Solid Oxide Fuel Cells

Contact Info

Product

Resources

About