scholarly journals Electrochemical properties of La9.33Si6O26(LSO)-La0.8Sr0.2Ga0.8Mg0.2O2.55(LSGM) electrolyte over NiO and La0.1Ca0.9MnO3(LCM) electrodes

2021 ◽  
Author(s):  
Atiek Rostika Noviyanti ◽  
Yoga Trianzar Malik ◽  
Iman Rahayu ◽  
Diana Rakhmawaty Eddy ◽  
Uji Pratomo
Keyword(s):  
Activation Energy ◽  
Electrochemical Properties ◽  
Arrhenius Plot ◽  
Specific Resistance ◽  
Nyquist Plot ◽  
Electrical Circuit ◽  
Electrolyte System ◽  
Excellent Performance ◽  
Area Specific Resistance

Abstract The electrochemical properties of La9.33Si6O26(LSO)-La0.8Sr0.2Ga0.8Mg0.2O2.55(LSGM) electrolyte composites have been evaluated over NiO and La0.1Ca0.9MnO3 (LCM) electrodes using symmetric and asymmetrical cells of NiO/LSO-LSGM/NiO and NiO/LSO-LSGM/LCM, respectively. The Nyquist plot obtained from this study suggested that the new electrolyte system exhibits excellent performance over the NiO and LCM electrodes and shows an ideal Randel cell electrical circuit characteristic in both NiO/LSO-LSGM/NiO and NiO/LSO-LSGM/LCM cells. The area-specific resistance (ASR) and, the activation energy (Ea) of NiO/LSO-LSGM/NiO from the Arrhenius plot are lower than the NiO/LSO-LSGM/LCM, which is 0.30 Ω cm-2 and of 0.74 eV versus 0.40 Ω cm-2 with Ea of 0.76 eV, respectively.

Influence of Partial Substitution of Ba2+ for Sm3+ on the Structure and Electrochemical Properties of Sm 0.5-xBaxSr0.5Co0.8Fe 0.2O3-δPerovskite

2011 ◽  
Vol 239-242 ◽  
pp. 552-557
Author(s):  
Yan Hua Wang ◽  
Xi Wen Song ◽  
Fen Zhou ◽  
Jian Quan Gao ◽  
Sheng Li An
Keyword(s):  
Thermal Expansion ◽  
Electrochemical Properties ◽  
Specific Resistance ◽  
Sol Gel ◽  
Partial Substitution ◽  
Impedance Method ◽  
Orthorhombic Symmetry ◽  
Expansion Behavior ◽  
Composite Cathodes ◽  
Area Specific Resistance

Sm0.5-xBaxSr0.5Co0.8Fe0.2O3-δpowders were synthesized by a sol-gel method. The crystal structure and thermal expansion coefficient of Sm0.5-xBaxSr0.5Co0.8Fe0.2O3-δ(SBSCF,x=0.00, 0.05, 0.10) were investigated. All samples were the perovskite structure with an orthorhombic symmetry and exhibited a similar thermal expansion behavior. The electrochemical properties of SBSCF-SDC composite cathodes were studied using A.C. impedance method. The substitution of Ba2+for Sm3+had a significant effect on the area specific resistance of the composite cathodes. The area specific resistance (ASR) decreased with the increase of Ba2+substitution. This result suggested that the electrochemical performance of Sm0.5Sr0.5Co0.8Fe0.2O3-δbased cathode improved as Sm3+is partially substituted by Ba2+.

ON THE DIELECTRIC BEHAVIOR OF LiCo3/5Fe2/5VO4 CERAMICS

2010 ◽  
Vol 24 (07) ◽  
pp. 665-670
Author(s):  
MOTI RAM
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Frequency Dependence ◽  
Chemical Method ◽  
Arrhenius Plot ◽  
Dielectric Behavior ◽  
Tangent Loss ◽  
Low Frequencies ◽  
Different Temperatures ◽  
Tan Δ

The LiCo 3/5 Fe 2/5 VO 4 ceramics has been fabricated by solution-based chemical method. Frequency dependence of the dielectric constant (εr) at different temperatures exhibits a dispersive behavior at low frequencies. Temperature dependence of εr at different frequencies indicates the dielectric anomalies in εr at Tc (transition temperature) = 190°C, 223°C, 263°C and 283°C with (εr) max ~ 5370, 1976, 690 and 429 for 1, 10, 50 and 100 kHz, respectively. Frequency dependence of tangent loss ( tan δ) at different temperatures indicates the presence of dielectric relaxation in the material. The value of activation energy estimated from the Arrhenius plot of log (τd) with 103/T is ~(0.396 ± 0.012) eV.

scholarly journals Ba0.5Sr0.5Co0.8Fe0.2O3–δ–La0.6Sr0.4Co0.8Fe0.2O3–δ Composite Cathode for Solid Oxide Fuel Cell

2016 ◽  
Vol 61 (3) ◽  
pp. 1483-1488 ◽  
Author(s):  
M. Mosiałek ◽  
A. Kędra ◽  
M. Krzan ◽  
E. Bielańska ◽  
M. Tatko
Keyword(s):  
Electrochemical Impedance ◽  
Specific Resistance ◽  
Weight Ratio ◽  
Composite Cathode ◽  
Solid Oxide ◽  
Doped Ceria ◽  
Oxide Fuel ◽  
Composite Cathodes ◽  
Area Specific Resistance ◽  
Ceria Electrolyte

Abstract Composite cathodes contain Ba0.5Sr0.5Co0.8Fe0.2O3–δ and La0.6Sr0.4Co0.8Fe0.2O3–δ were tested in different configuration for achieving cathode of area specific resistance lower than Ba0.5Sr0.5Co0.8Fe0.2O3–δ and La0.6Sr0.4Co0.8Fe0.2O3–δ cathodes. Electrodes were screen printed on samaria-doped ceria electrolyte half-discs and tested in the three electrode setup by the electrochemical impedance spectroscopy. Microstructure was observed by scanning electron microscopy. The lowest area specific resistance 0.46 and 2.77 Ω cm−2 at 700 °C and 600 °C respectively revealed composite cathode contain Ba0.5Sr0.5Co0.8Fe0.2O3–δ and La0.6Sr0.4Co0.8Fe0.2O3–δ in 1:1 weight ratio. The area specific resistance of this cathode is characterized by the lowest activation energy among tested cathodes.

scholarly journals Method to Measure Area Specific Resistance and Chromium Migration Simultaneously from Solid Oxide Fuel Cell Interconnect Materials

Fuel Cells ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 570-577 ◽  
Author(s):  
J. Tallgren ◽  
O. Himanen ◽  
M. Bianco ◽  
J. Mikkola ◽  
O. Thomann ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Specific Resistance ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Area Specific Resistance

scholarly journals Pyrolysis Kinetic Parameters of Omari Oil Shale Using Thermogravimetric Analysis

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4060
Author(s):  
Ziad Abu El-Rub ◽  
Joanna Kujawa ◽  
Samer Al-Gharabli
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Kinetic Parameters ◽  
Oil Shale ◽  
Arrhenius Plot ◽  
Frequency Factor ◽  
Coefficient Of Determination ◽  
Assay Method ◽  
Temperature Integral ◽  
Integral Approximation

Oil shale is one of the alternative energies and fuel solutions in Jordan because of the scarcity of conventional sources, such as petroleum, coal, and gas. Oil from oil shale reservoirs can be produced commercially by pyrolysis technology. To optimize the process, mechanisms and rates of reactions need to be investigated. Omari oil shale formation in Jordan was selected as a case study, for which no kinetic models are available in the literature. Oil shale was analyzed using the Fischer assay method, proximate analysis (moisture, volatile, and ash), gross calorific value, elemental analysis (CHNS), and X-ray fluorescence (XRF) measurements. Non-isothermal thermogravimetric analysis was applied to study the kinetic parameters (activation energy and frequency factor) at four selected heating rates (5, 10, 15, and 20 °C/min). When oil shale was heated from room temperature to 1100 °C, the weight loss profile exhibited three different zones: drying (devolatilization), pyrolysis, and mineral decomposition. For each zone, the kinetic parameters were calculated using three selected methods: integral, temperature integral approximation, and direct Arrhenius plot. Furthermore, the activation energy in the pyrolysis zone was 112–116 kJ/mol, while the frequency factor was 2.0 × 107 − 1.5 × 109 min−1. Moreover, the heating rate has a directly proportional relationship with the rate constant at each zone. The three different methods gave comparable results for the kinetic parameters with a higher coefficient of determination (R2) for the integral and temperature integral approximation compared with the direct Arrhenius plot. The determined kinetic parameters for Omari formation can be employed in developing pyrolysis reactor models.

From theory to experiment: BaFe0.125Co0.125Zr0.75O3−δ, a highly promising cathode for intermediate temperature SOFCs

2020 ◽  
Vol 8 (6) ◽  
pp. 3413-3420 ◽  
Author(s):  
Elena Sánchez-Ahijón ◽  
Rafael Marín-Gamero ◽  
Beatriz Molero-Sánchez ◽  
David Ávila-Brande ◽  
Alicia Manjón-Sanz ◽  
...  
Keyword(s):  
Specific Resistance ◽  
Intermediate Temperature ◽  
Area Specific Resistance

BaFe0.125Co0.125Zr0.75O3−δ perovskite is a novel and efficient MIEC electrode for IT-SOFCs. Symmetrical cells with an area-specific resistance of 0.13 Ω cm2 at 700 °C and 0.05 Ω cm2 at 800 °C have been prepared.

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