Thermoelectric Properties of NaCo2–x Fe x O y

Dutta, Biprodas; Battogtokh, Jugdersuren; Mckewon, David; Vidensky, Igor; Dutta, N. P.; Pegg, Ian L.

doi:10.1007/s11664-007-0158-9

Cited by 8 publications

(5 citation statements)

References 9 publications

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“…[1][2][3][4] Since Terasaki et al found the high thermopower and conductivity of NaCo 2 O 4 single crystals at 300 K in 1997, 5 the sodium cobalt oxides Na x Co 2 O 4 have been widely studied for thermoelectric applications. [6][7][8][9][10][11] It was verified that the thermoelectric properties of a Na x Co 2 O 4 polycrystalline sintered body could be improved by obtaining high crystallographic orientation using special technology such as hot-pressing, 6 cold high-pressure, 7 spark plasma sintering, 8 and reactive templated grain growth method. 9 Biomacromolecules such as lipids, 12 proteins, 13 and polysaccharides 14 can exquisitely control the inorganic crystal type and hierarchical material self-assembly.…”

Section: Introductionmentioning

confidence: 96%

Preparation of Well-Tiled γ-Na x Co2O4 by a Novel and Simple Sodium Alginate Gel Method and Its Electrical Properties

Zhang

Tang

Gao

2009

Journal of Elec Materi

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In this paper, a novel and simple sodium alginate (SA) gel method was developed to prepare c-Na x Co 2 O 4 . This method involved the chemical gelling of SA in the presence of Co 2+ ions by cross-linking. After calcining at 700°C to 800°C, single-phase c-Na x Co 2 O 4 crystals were obtained. The arrangement of about 1 lm to 4 lm flaky particles exhibited a well-tiled structure along the plane direction of the flaky particles. SA not only acted as the control agent for crystal growth, but also provided a Na source for the c-Na x Co 2 O 4 crystals. The electrical properties of c-Na x Co 2 O 4 ceramics prepared via ordinary sintering after cold isostatic pressing were investigated. The Seebeck coefficient and power factor of the bulk material were 177 lV K À1 and 4.3 9 10 À4 W m À1 K À2 at 850 K, respectively.

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Section: Introductionmentioning

confidence: 96%

Preparation of Well-Tiled γ-Na x Co2O4 by a Novel and Simple Sodium Alginate Gel Method and Its Electrical Properties

Zhang

Tang

Gao

2009

Journal of Elec Materi

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“…The valence state moves toward a higher valence, indicating a chemical environment change of the Co element after F doping. A recent study revealed that the roles played by the different valence states of cobalt in its oxides are different, and a higher state of cobalt oxide exhibits higher conductivity, − which is in favor of improving the battery performances as shown later.…”

Section: Resultsmentioning

confidence: 83%

Enhanced Structural and Electrochemical Stability of Self-Similar Rice-Shaped SnO₂ Nanoparticles

Wan

Ren

et al. 2017

ACS Appl. Mater. Interfaces

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A facile one-pot hydrothermal strategy is applied to prepare Co and F codoped SnO (Co-F/SnO) nanoparticles, which exhibit a unique rice-shaped self-similar structure. Compared with the pristine and Co-doped counterparts (SnO and Co/SnO), the Co-F/SnO electrode demonstrates higher capacity, better cyclability, and rate capability as anode material for lithium ion batteries (LIBs). A high charge capacity of 800 mAh g can be successfully delivered after 50 cycles at 0.1 C, and a high reversible capacity of 700 mAh g could be retained after 100 cycles at 5 C. The excellent lithium storage performances of the Co-F/SnO nanoparticles could be attributed to the synergetic effects of the doped Co and F, as well as the unique hierarchical self-similar structure with moderate oxygen defect and inactive pillars, which not only facilitates the fast diffusion of Li ions, but also stabilizes the structure during the electrochemical cycling.

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“…At the present stage, it is not clear how the Na and K interact with the cathodes. However, Na and K tend to form solid solutions with B, Mn, Co and/or Fe, [53][54][55] which is detrimental to the microstructure stability of the cathode materials. 8 The BSD and XRD analysis of the bar samples heat-treated in the presence of glass for 7 and 30 days appear to indicate that major phase of Layer 1 is lanthanum and strontium borate and the ones in Layer 2 are the decomposed phases of LSM or LSCF, eg., Mn 2 O 3 for LSM and Fe 2 O 3 /CoFe 2 O 4 for LSCF.…”

Section: Resultsmentioning

confidence: 99%

Effect of Volatile Boron Species on the Microstructure and Composition of (La,Sr)MnO₃and (La,Sr)(Co,Fe)O₃Cathode Materials of Solid Oxide Fuel Cells

Chen¹,

Hyodo²,

Zhao³

et al. 2013

J. Electrochem. Soc.

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Effect of volatile boron species on the microstructure and composition of dense La 0.8 Sr 0.2 MnO 3 (LSM) and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF) bar samples is studied in detail using secondary ion mass spectroscopy (SIMS) technique. Prior to the characterization, the bar samples were heat-treated at 800 • C in air in the presence of borosilicate glass for 7 and 30 days. SIMS detected the deposition of boron as well as sodium and potassium on the surface and in the bulk of the bar samples. The boron deposition results in significant microstructure and composition changes. SIMS, EDS and XRD confirm that Sr in the form of SrB 2 O 4 is enriched on the outmost surface, leading to the Sr-deficient in the adjacent layer in the bulk. In the case of LSM bar samples, the interaction between boron and LSM leads to the formation of LaBO 3 and consequently the decomposition of the LSM perovskite structure. The present study demonstrates the remarkable detrimental effect of volatile boron species on the microstructure of the LSM and LSCF cathode materials of solid oxide fuel cells, and LSCF is more reactive with boron as compared to LSM.In planar solid oxide fuel cells (SOFCs), use of a reliable hermetic seal such as glass and glass-ceramics is essential to separate the fuels supplied to the anode and the air to the cathode. 1-3 On the other hand, the volatility of the components of glass and glass-ceramic such as silica, boron and alkaline elements and their interaction with other cell components cannot be neglected under the operation conditions of SOFCs. 4-8 Loss of boron in the glass seals and its detrimental effect on the SOFC performance are of a great concern. 9-11 Studies have shown that the volatile boron species from glass sealants can degrade the cathodes of SOFCs. [12][13][14][15] Our recent studies on the boron deposition and poisoning processes have demonstrated that the volatile boron species are chemically reactive with the (La,Sr)MnO 3 (LSM) and (La,Sr)(Co,Fe)O 3 (LSCF) cathodes, and the activity is dependent on the cathode materials as well as the surface area or particle size of the cathodes. 16,17 Deposition and poisoning of glass sealant components also occurs under solid oxide electrolysis cell (SOEC) operation conditions. For example, Hauch et al observed the deposition of Si from the glass seals at the electrolyte/electrode interface of Ni-based fuel electrodes of SOEC. 18 Therefore, it is necessary to investigate in detail the interaction between volatile boron species and common cathode materials of SOFCs such as LSM and LSCF to provide insights of the mechanism of boron deposition and poisoning. Fundamental understanding of the effect of impurities such as boron on the performance degradation is essential for the design and development of advanced cathodes with high tolerance toward impurities.LSM is the most studied electronically conducting material with negligible ionic conductivity. 19-21 Compared to LSM, mixed ionicelectronic conducting (MIEC) materials such as LSCF exhibits much better ele...

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Thermoelectric Properties of NaCo2–x Fe x O y

Cited by 8 publications

References 9 publications

Preparation of Well-Tiled γ-Na x Co2O4 by a Novel and Simple Sodium Alginate Gel Method and Its Electrical Properties

Preparation of Well-Tiled γ-Na x Co2O4 by a Novel and Simple Sodium Alginate Gel Method and Its Electrical Properties

Enhanced Structural and Electrochemical Stability of Self-Similar Rice-Shaped SnO₂ Nanoparticles

Effect of Volatile Boron Species on the Microstructure and Composition of (La,Sr)MnO₃and (La,Sr)(Co,Fe)O₃Cathode Materials of Solid Oxide Fuel Cells

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Thermoelectric Properties of NaCo2–x Fe x O y

Cited by 8 publications

References 9 publications

Preparation of Well-Tiled γ-Na x Co2O4 by a Novel and Simple Sodium Alginate Gel Method and Its Electrical Properties

Preparation of Well-Tiled γ-Na x Co2O4 by a Novel and Simple Sodium Alginate Gel Method and Its Electrical Properties

Enhanced Structural and Electrochemical Stability of Self-Similar Rice-Shaped SnO2 Nanoparticles

Effect of Volatile Boron Species on the Microstructure and Composition of (La,Sr)MnO3and (La,Sr)(Co,Fe)O3Cathode Materials of Solid Oxide Fuel Cells

Contact Info

Product

Resources

About

Enhanced Structural and Electrochemical Stability of Self-Similar Rice-Shaped SnO₂ Nanoparticles

Effect of Volatile Boron Species on the Microstructure and Composition of (La,Sr)MnO₃and (La,Sr)(Co,Fe)O₃Cathode Materials of Solid Oxide Fuel Cells