Effect of microstructure refinement on performance of Ni/Ce0.8Gd0.2O1.9 anodes for low temperature solid oxide fuel cell

Torknik, Fatemeh Sadat; Keyanpour-Rad, Mansoor; Maghsoudipour, Amir; Choi, Gyeong Man

doi:10.1016/j.ceramint.2013.07.015

Cited by 34 publications

(16 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is well-known that reduction of NiO to Ni is followed by a significant volume contraction (up to ca. 70%) [58], [59]. On the contrary, reduction of CeO2 to CeO1.5…”

Section: Simulation Of the Xps Ni/ce Armentioning

confidence: 96%

Operando observation of nickel/ceria electrode surfaces during intermediate temperature steam electrolysis

Papaefthimiou

Niakolas

Paloukis

et al. 2017

Journal of Catalysis

View full text Add to dashboard Cite

The solid oxide electrolysis cell (SOEC) technology has a huge potential for future mass production of hydrogen, mainly due to its high electrical-to-chemical energy conversion efficiency. However, the durability and the performance of SOEC devices are inferior to that of other competitive electrolysis technologies inhibiting the commercialization of SOECs. Despite the fact that Ni-based cermets are currently the most widely used cathode materials for SOEC, change of the nickel oxidation state has been accused as a major issue limiting the performance of these devices. In this work we provide operando experimental evidence of the active surface oxidation state and composition of nickel/doped-ceria cermets under water electrolysis conditions using ambient pressure X-ray photoelectron and near edge X-ray absorption fine structure spectroscopies, combined with quantitative spectra simulation. Remarkably under specific operational conditions, nickel is maintained in a partially oxidized state which, counterintuitive to the expected behavior, can be beneficial to the cell performance. This finding may initiate new improvement strategies for SOEC electrodes based on thorough optimization of the operational conditions, in order to engineer in situ the most propitious electrode configuration

show abstract

“…It is well-known that reduction of NiO to Ni is followed by a significant volume contraction (up to ca. 70%) [58], [59]. On the contrary, reduction of CeO2 to CeO1.5…”

Section: Simulation Of the Xps Ni/ce Armentioning

confidence: 96%

Operando observation of nickel/ceria electrode surfaces during intermediate temperature steam electrolysis

Papaefthimiou

Niakolas

Paloukis

et al. 2017

Journal of Catalysis

View full text Add to dashboard Cite

show abstract

“…Currently, composite anode materials with ceriabased electrolytes such as Ni-SDC and Ni-GDC only exhibit promising cell performance that is limited to intermediate-temperature applications (600 -800°C) [8,[12][13][14]. Doped ceria electrolytes have been shown to cause performance degradation due to chemical and mechanical instabilities in the LT region [15].…”

Section: Introductionmentioning

confidence: 99%

EFFECTS OF NiO LOADING AND PRE-CALCINATION TEMPERATURE ON NiO-SDCC COMPOSITE ANODE POWDER FOR LOW-TEMPERATURE SOLID OXIDE FUEL CELLS

Hoa

Rahman

Somalu³

2017

Ceramics - Silikaty

View full text Add to dashboard Cite

The microstructural and thermal characteristics of NiO-samarium-doped ceria carbonate (NiO-DCC) composite powders have been explored in terms of NiO loading and pre-calcination temperature. NiO-SDCC composite powders were intimately mixed via fast ball-milling using different NiO loadings (50-70 wt. %) and subjected to various pre-calcination temperatures (600-800°C). Subsequently, the pre-calcined powders were then used to fabricate composite pellets using a uniaxial press and sintered at a low temperature of 600°C. The crystalline phase, carbonate bonding, microstructure and thermal behaviour of the composite anode powders were investigated. The microstructure, porosity, and hardness of sintered composite pellets were also evaluated. All samples maintained their chemical compatibility and carbonate bonding after various processes. The findings indicated that the pre-calcination factor was more important than NiO loading in terms of powder and pellet morphologies as well as the thermal expansion behaviour. Moreover, the composite pellets prepared with composite powders pre-calcined at increasing temperatures exhibited an increase in porosity, but within an acceptable range (30-40 %). Overall, composite pellets fabricated with 50 wt. % NiO exhibited the optimum hardness values of 21-31 HV and the lowest thermal expansion of 12.2-12.7 × 10-6 K-1 .

show abstract

“…Indeed, theses lanthanide mixed‐oxides exhibit good performances (high ionic conductivity, long term thermal stability, etc.) when used as electrolytes . In order to avoid gas permeation and to limit extrinsic resistive contribution due to the presence of residual closed porosity or high density of grain boundaries, dense (low limit around 95% of the theoretical density) anionic conductor membrane are required to avoid gas permeation.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the sintering mechanisms of GDC pellets obtained by the compaction of nanostructured oxide microspheres

et al. 2017

View full text Add to dashboard Cite

International audienceThe sintering behavior of green pellets obtained from nanostructured Ce0.8Gd0.2O1.9 submillimetric microspheres is studied in the present paper. Corresponding shrinkage rate curve shows a two-step densification in dynamic conditions, with the presence of two successive extrema, at 1200 K and 1500 K. To fully understand this non-common densification behavior, an iterative study was performed. Multiple characterizations point out multiscale organization of the matter with temperature giving rise to differential sintering stages of two different particle size classes. Concerning 1200 K-first shrinkage rate maximum, it corresponds to the densification of nanometric aggregates of crystallites into submicrometric pre-sintered aggregates, resulting in a specific porous microstructure with residual open porosity. As-generated porosity combined with submicron size of pre-sintered aggregates thus prevent from a homogeneous sintering illustrated by a single maximum shrinkage rate. Finally, the second maximum shrinkage rate at 1500 K can then be associated to optimal temperature for submicrometric particles sintering

show abstract

Effect of microstructure refinement on performance of Ni/Ce0.8Gd0.2O1.9 anodes for low temperature solid oxide fuel cell

Cited by 34 publications

References 39 publications

Operando observation of nickel/ceria electrode surfaces during intermediate temperature steam electrolysis

Operando observation of nickel/ceria electrode surfaces during intermediate temperature steam electrolysis

EFFECTS OF NiO LOADING AND PRE-CALCINATION TEMPERATURE ON NiO-SDCC COMPOSITE ANODE POWDER FOR LOW-TEMPERATURE SOLID OXIDE FUEL CELLS

Investigation of the sintering mechanisms of GDC pellets obtained by the compaction of nanostructured oxide microspheres

Contact Info

Product

Resources

About