Wettability and interfacial reactions in the systems and Ni/Ti-TiO2/YSZ

Tsoga, A.; Naoumidis, A.; Nikolopoulos, P.

doi:10.1016/1359-6454(96)00019-5

Cited by 118 publications

(62 citation statements)

References 2 publications

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“…In fact, examination of coatings carried out with 100 g/l YSZ bath loading, which showed a thickness of only about 2 µm, is evidence that the YSZ powder formed an almost complete barrier to nickel adsorption on the surface. Sheela and Pushpavanam [5] who studied electroless nickel-diamond coatings and Balaraju, et al [22] who investigated electroless Ni-P composite coatings also observed a similar trend. The latter suggests that the emergent pattern could be ascribed to the possibility of grouping or agglomeration of second phase particles resulting from a decrease in the mean distance between them.…”

Section: Sample Preparation and Characterisationsupporting

confidence: 49%

“…Besides being noted to have a characteristic property of reducing the anode/cell performance [20,21], phosphorus has a tendency to form a liquid phase with nickel at temperatures above 850˚C which thereafter precipitation hardens to yield an undesired material, nickel phosphide (Ni 3 P). Alternatives such as hydrazine (N 2 H 4 )-probably with less deleterious effects-do exist, but have considerable cost implications.…”

Section: Methodsmentioning

confidence: 99%

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Effect of Sodium Dodecyl Sulphate on the Composition of Electroless Nickel – Yttria Stabilized Zirconia Coatings

Nwosu¹,

Davidson²,

Hindle

2011

ACES

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The influence of a surfactant on the composition of nickel-yttria stabilised zirconia (YSZ) cermet coatings, applied by electroless nickel plating technique was examined. The amphiphilic characteristics of anionic surfactant sodium dodecyl sulphate (SDS), was relied upon for enhanced dispersion of YSZ particles co-deposited for use as anodes in solid oxide fuel cell technology and potential heat absorbing layers in thermal barrier coatings. Optical microscopy was employed to study the correlation between the plating thickness, level of ceramic loading and SDS concentration while the effect of the surfactant and fineness of YSZ particles on the as-deposited coating's ceramic to metal ratio, was analysed using energy dispersive X-ray analysis (EDXA) characterisation technique.

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Section: Sample Preparation and Characterisationsupporting

confidence: 49%

Section: Methodsmentioning

confidence: 99%

Effect of Sodium Dodecyl Sulphate on the Composition of Electroless Nickel – Yttria Stabilized Zirconia Coatings

Nwosu¹,

Davidson²,

Hindle

2011

ACES

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“…34,35 The results in this work are remarkable as the Ni/YSZbased (i.e. Sc-free) cell used for YSZ-Low, seems equally long-term stable during H 2 S poisoning when compared to the Ni/ScYSZ-based cell in the ScYSZ-Low test when the two cells are tested at similar low overpotential.…”

Section: Low Overpotential H 2 S Test -Eis-mentioning

confidence: 52%

Sulfur Poisoning of SOFC Anodes: Effect of Overpotential on Long-Term Degradation

Hauch

Hagen

Hjelm

et al. 2014

J. Electrochem. Soc.

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Sulfur impurities in carbon containing fuels for solid oxide fuel cells (SOFC), e.g. natural gas and biogas, typically lead to significant losses in performance due to the sulfur sensitivity of Ni/yttria-stabilized-zirconia (YSZ) anodes for SOFC. Full cells having Ni/YSZ anodes have been characterized during long-term galvanostatic operation in internal reforming gas mixture (CH 4 /H 2 O/H 2 :30/60/10), with 2 ppm H 2 S exposure to the anode for 500 hours at 850 • C, at different current densities. This work focus on the long-term effect of H 2 S exposure over a few hundreds of hours; and describes and correlates the observed evolution of anode performance, over hundreds of hours, with sulfur exposure at low cell overpotential (low current density) and at high overpotential (high current density) with and without H 2 S exposure. For tests at low overpotential with H 2 S exposure only a reversible loss in performance was observed and post-mortem SEM analysis showed an intact Ni/YSZ anode microstructure. For tests at high cell overpotential the H 2 S exposure caused both a reversible loss in performance and an irreversible long-term degradation. Post-mortem SEM analysis of the Ni/YSZ anode from this tests showed increased porosity and lack of percolating Ni in the few microns of the anode closest to the anode/electrolyte interface. Fuel flexibility is an attractive characteristic of solid oxide fuel cells (SOFC). They can for instance be fuelled with carbon containing fuels such as natural gas or fuels derived from biomass. A well-known drawback for the use of carbon containing fuels is the fact that they contain varying amounts of sulfur, which poisons Ni-based SOFC anodes.1-8 Therefore, it is important to investigate the SOFC tolerance toward sulfur poisoning and how it is affected by operating parameters.There are many studies concerning the initial, and mainly reversible, loss in performance occurring at SOFC anodes upon sulfur poisoning as a function of different operating conditions. 4,7-9 Fewer results are reported on the long-term, and often irreversible, loss of performance due to sulfur poisoning, 5,8,10 even though this will inevitably be of high importance for SOFC as an emerging energy conversion technology. In order to establish the acceptable limits for sulfur impurities in carbon containing fuels in order to avoid longterm, irreversible degradation, 5,11 it is necessary to understand how the sulfur impurity tolerance correlate to operating parameters such as gas mixtures, temperature and current density, and indirectly to the cell overpotential.It has been suggested that Ni-zirconia based SOFC anodes containing Sc are more tolerant toward H 2 S poisoning than Ni/YSZ based anodes 5,7 and in this work both short and long term tests were performed to investigate this hypothesis. Tests were mainly carried out at the same set of test conditions (e.g. temperature, current density, fuel) in order to compare Sc-Y co-doped (ScYSZ) and Y doped zirconia (YSZ) Ni cermet SOFC anodes. There are several studies s...

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“…Using the results from this study along with the experimental measurements, which report that the Ni-YSZ equilibrium contact angle is at least 117 [8,12], we can make predictions as to the performance of SOFC anodes. As observed, materials with low contact angles result in a metallic coating type of microstructure that has high active TPB density and benefits from the high contiguity of its ceramic substrate.…”

Section: Discussionmentioning

confidence: 99%

“…Employing alternative materials affects changes in both the electrochemical properties and microstructural features of the anode. For example, a change in the materials used within the SOFC anode brings about a concomitant change in interfacial properties [12,13], and, correspondingly, the potential to increase cell performance. In particular, experimental findings by Ringuedé et al [14] suggest that alloying Ni with various amounts of Co results in an extension of the triple-phase boundary and a significant increase in fuel cell performance.…”

Section: Introductionmentioning

confidence: 99%

Phase wettability and microstructural evolution in solid oxide fuel cell anode materials

et al. 2014

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Recent experimental and theoretical findings suggest that high-temperature solid oxide fuel cells (SOFCs) often suffer from performance degradation due to coarsening of the metallic-phase particles within the anode. In this study, we explore the feasibility of improving the microstructural stability of SOFC anode materials by tuning the contact angle between the metallic phase and electrolyte particles. To this end, a continuum diffuse-interface model is employed to capture the coarsening behavior of the metallic phase and simulate a range of equilibrium contact angles. The evolution of performance-critical, microstructural features is presented for varying degrees of phase wettability. It is found that both the density of electrochemically active triple-phase regions and contiguity of the electron-conducting phase display undesirable minima near the contact angle of conventional SOFC materials. Our results suggest that tailoring the interfacial properties of the constituent phases could lead to a significant increase in the performance and lifetime of SOFCs.

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Wettability and interfacial reactions in the systems and Ni/Ti-TiO2/YSZ

Cited by 118 publications

References 2 publications

Effect of Sodium Dodecyl Sulphate on the Composition of Electroless Nickel – Yttria Stabilized Zirconia Coatings

Effect of Sodium Dodecyl Sulphate on the Composition of Electroless Nickel – Yttria Stabilized Zirconia Coatings

Sulfur Poisoning of SOFC Anodes: Effect of Overpotential on Long-Term Degradation

Phase wettability and microstructural evolution in solid oxide fuel cell anode materials

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