A novel approach to preparing nano-size Co3O4-coated Ni powder by the Pechini method for MCFC cathodes

Lee, Deokjung; Hong, Mingzi; Bae, Seungchul; Lee, Heung Chan; Park, Eunjoo; Kim, Keon

doi:10.1039/b303980c

Cited by 42 publications

(9 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, a fast decomposition of the precursors brought about formation of Ni/NiO nanocomposite with subsequent carbon formation. Similar studies were observed with different systems [31][32][33][34][35]. Results of these studies have been suggested Ni formation as a result of both the decomposition of the precursors and the protection of Ni by graphite.…”

Section: Structural Analysissupporting

confidence: 83%

Incandescent combustion synthesis of nanomagnetic Ni/NiO composites

Deraz

2021

SCI SINTER

View full text Add to dashboard Cite

This study is the first attempt to large-scale energy-efficient production of nanomagnetic Ni/NiO composites by using the autocombustion based on leaves or extract of corchorus olitorius. The as synthesized product can be characterized by using XRD, SEM, TEM and EDX techniques. The results confirm that the as synthesized materials consisted entirely of well crystalline Ni and NiO phases. The crystallinity of both Ni and NiO enhanced by increasing amount of the corchorus olitorius. However, the corchorus olitorius - treatment resulted in an increase in the crystallite size and lattice constant. The SEM analysis confirms formation of fragile, fluffy and spongy networks. The average of grain size for the as prepared particles was found to be 45 nm in agreement with the trend of the crystallite size calculated by using XRD technique. Furthermore, changing of nature and content of the corchorus olitorius brought about progressive modifications in the magnetic properties, namely, Ms, Mr, Mr/Ms, Hc and Ka, of the fabricated Ni/NiO nanocomposite according to the structural, morphological as well as microstructural variation. The saturation magnetization (Ms) of the sample with corchorus olitorius leaves was found to be 0.2383 emu/g while the Ms with corchorus olitorius extract was found to 6.977 emu/g. This was discussed in the light of finite size, surface and interface effects. Thus, we unveil a new approach for incandescent combustion synthesis via an innate approach for corchorus olitorius leaves in the directly fabrication for different nanocomposites.

show abstract

Section: Structural Analysissupporting

confidence: 83%

Incandescent combustion synthesis of nanomagnetic Ni/NiO composites

Deraz

2021

SCI SINTER

View full text Add to dashboard Cite

show abstract

“…In this study, we evaluated the effect of the large specific surface area of nanosized ceria-based oxides such as CeO 2 and SDC prepared by the Pechini method, which is a complex polymerization methods. 20,21,27,28 We then compared the results to the electrical conduction on the surface of the solid phase for systems using other oxides such as α-Al 2 O 3 and γ-LiAlO 2 . 11 29,30 These carbonates are abbreviated as "LN" and "LNK" hereinafter.…”

mentioning

confidence: 99%

Electrical Conductivity of Ceria-Based Oxides/Alkali Carbonate Eutectic Nanocomposites

Mizuhata

Kubo

Ichikawa

et al. 2021

J. Electrochem. Soc.

View full text Add to dashboard Cite

Differential thermal analysis (DTA) and electrical conductivity calculated from AC impedance measurements are discussed for binary and ternary eutectics: (Li 0.52 Na 0.48 ) 2 CO 3 (LN) and (Li 0.435 Na 0.315 K 0.25 ) 2 CO 3 (LNK), coexisting with nanosized CeO 2 and ceria-based oxides such as CeO 2 :Sm 3+ (samarium doped ceria: SDC) particles prepared by the Pechini method. The influence of the surface properties of oxides with smooth surfaces, narrow particle size distributions, and large specific surface areas near the eutectic point is presented. The obtained DTA spectra indicate that the melting enthalpy disappeared in systems with a melt containing less than 30 vol% and 45 vol% LN and LNK eutectics, respectively. Sm 3+ doping contributes to an increase in the electrical conductivity of the composites below the eutectic points of molten carbonate. The temperature dependence of the electrical conductivity for both binary and ternary eutectic carbonates coexisting with CeO 2 and SDC at melt contents less than ca. 15 vol% does not indicate a remarkable change in conductivity in the temperature range near each eutectic point of molten carbonate. The low-temperature characteristics are significantly improved using nanosized ceria-based oxides because of nonfrozen eutectics with a low molar enthalpy of fusion and limited solid-phase influence on ionic conduction.

show abstract

“…Minimal voltage degradation effects were found during a period of 5,000 h testing at 650 • C in comparison to cells using uncoated NiO electrodes (Okawa et al, 2004). Alternative methods for synthesis of core/shell electrodes have been also investigated by Korean researchers (Lee et al, 2003(Lee et al, , 2004Park et al, 2005;Kim et al, 2006Kim et al, , 2011. The solubility of Co/Ce coated Ni powders prepared by a sol-gel Pechini process has been reported to be about 80% lower in comparison to a routine NiO cathode under 67CO 2 -33O 2 atmosphere at 650 • C (Kim et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Degradation of MCFC Materials in a 81 cm2 Single Cell Operated Under Alternated Fuel Cell/Electrolysis Mode

et al. 2021

View full text Add to dashboard Cite

The possibility of producing hydrogen from molten carbonate steam electrolysis using the well-established Molten Carbonate Fuel Cell (MCFC) technology was explored in this work. For this purpose, a 81 cm2 MCFC single cell assembled with conventional cell materials was operated under alternated fuel cell/electrolysis conditions at 650°C in a binary eutectic Li2CO3-K2CO3 electrolyte for about 400 h after an initial period of 650 h in which the cell worked only in the usual MCFC mode. A rapid cell performance loss in terms of cell internal resistance and electrode polarization was observed as soon as the cell started to work in the alternated fuel cell/electrolysis mode. After test completion, a post-mortem analysis was conducted to correlate the electrochemical response with cell materials degradation. Cell materials of the reverse cell were compared against a reference single cell that was assembled with the same materials and operated only in the fuel cell mode under comparable experimental conditions. Post-mortem analysis allowed to identify several serious stability issues of conventional MCFC materials when used in alternated operation modes. Thus, although the electrolyte matrix appeared almost unaffected, a significant amount of dissolved nickel was found in the matrix indicating that electrolysis operations promote an increasing chemical instability of the NiO oxygen electrode. A serious reduction of electrode porosity was also observed in both NiO oxygen and Ni metal fuel electrodes, which could explain the higher polarization resistance of the reversible cell in comparison to the reference MCFC cell. Furthermore, the oxygen current collector made with conventional 316L stainless steel was found to be seriously corroded under the alternated operation modes. Thus, the observed rapid increase in internal resistance in the reverse cell could be caused, at least in part, by an increased contact resistance between the oxygen electrode and the corroding current collector structure. Possible solutions for improving stability of electrodes and of the oxygen current collector in reverse MCFC cells were proposed and discussed in the final part of the work.

show abstract

A novel approach to preparing nano-size Co3O4-coated Ni powder by the Pechini method for MCFC cathodes

Cited by 42 publications

References 20 publications

Incandescent combustion synthesis of nanomagnetic Ni/NiO composites

Incandescent combustion synthesis of nanomagnetic Ni/NiO composites

Electrical Conductivity of Ceria-Based Oxides/Alkali Carbonate Eutectic Nanocomposites

Degradation of MCFC Materials in a 81 cm2 Single Cell Operated Under Alternated Fuel Cell/Electrolysis Mode

Contact Info

Product

Resources

About