Maximum power density analyses of a novel hybrid system based upon solid oxide fuel cells, vacuum thermionic generators and thermoelectric generators

ABSTRACTMicro-solid oxide fuel cells (Micro-SOFCs) with yttrium-doped barium zirconate (BZY) and strontium and cobalt-doped lanthanum scandate (LSScCo) electrolytes were fabricated for low-temperature operation at 300 °C. The micro-SOFC with a BZY electrolyte could operate at 300 °C with an open circuit voltage (OCV) of 1.08 V and a maximum power density of 2.8 mW/cm2. The micro-SOFC with a LSScCo electrolyte could operate at 370 °C; its OCV was about 0.8 V, and its maximum power density was 0.6 mW/cm2. Electrochemical impedance spectroscopy revealed that the electrolyte resistance in both the micro-SOFCs was lower than 0.1 Ωcm2, and almost all of the resistance was due to anode and cathode reactions. Although the obtained maximum power density was not sufficient for practical applications, improvement of electrodes will make these micro-SOFCs promising candidates for power sources of mobile electronic devices.

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Strontium And Iron Substituted Lanthanum Nickelate As Cathode Material In Solid Oxide Fuel Cells

KnE Materials Science ◽

10.18502/kms.v1i1.564 ◽

2016 ◽

Vol 1 (1) ◽

pp. 64 ◽

Cited By ~ 2

Author(s):

A.R. Gilev ◽

E.A. Kiselev ◽

V.A. Cherepanov

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Oxygen Nonstoichiometry ◽

Solid Oxide ◽

Maximum Power ◽

Total Conductivity ◽

Oxide Fuel ◽

Maximum Power Density ◽

Lanthanum Nickelate ◽

Power Densities

The MIEC La1.5Sr0.5Ni1-yFeyO4 (y=0.1-0.4) oxides have been studied as cathode materials with La0.88Sr0.12Ga0.82Mg0.18O3-δ (LSGM) electrolyte. Total conductivity, thermal expansion, oxygen nonstoichiometry, and chemical compatibility with LSGM and Ce0.8Sm0.2O1.9 (SDC) were determined. The following fuel cells were tested: La1.5Sr0.5Ni1-yFeyO4 (y=0.1, 0.2, 0.3, 0.4)/SDC/LSGM/Sr2N0.75Mg0.25MoO6 (SNMM) and La1.5Sr0.5Ni0.6Fe0.4O4/SDC/LSGM/SDC/NiO-SDC. For the former, the maximum power densities were 218, 274, 222, and 390 mW/cm2 at 850 °C in case of y equal to 0.1, 0.2, 0.3, and 0.4, respectively. The latter cell showed maximum power density of 341 mW/cm2 at 850°C.

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Performance of Two-Dimensional Functionally Graded Anode Supported Solid-Oxide Fuel Cells

ASME 2021 15th International Conference on Energy Sustainability ◽

10.1115/es2021-63582 ◽

2021 ◽

Author(s):

Sameer Osman ◽

Khaled Ahmed ◽

Mahmoud Ahmed

Keyword(s):

Fuel Cells ◽

High Temperature ◽

Solid Oxide Fuel Cells ◽

Power Density ◽

Thermal Stresses ◽

Functionally Graded ◽

Solid Oxide ◽

Oxide Fuel ◽

Maximum Power Density ◽

Two Dimensional

Abstract High-temperature ceramic materials used in solid-oxide fuel cells (SOFCs) are subject to high thermal stresses during operation due to the unequal thermal expansion between different layers. As a result, solid oxide fuel cells are prone to mechanical failure at elevated temperatures, limiting the maximum operating temperature and, therefore, limiting the maximum power density obtained from the fuel cell. Fuel cells with graded electrodes in the thickness direction have been used and extensively investigated to reduce the effect of non-uniform thermal expansion. In this study, two dimensional functionally graded electrodes are proposed for the first time. Thus, a comprehensive theoretical model is developed for a high-temperature SOFCs that includes the charge, species, energy, and momentum transport equations. Also, the bilinear elastoplastic material model is used to calculate thermal stresses and failure in solid materials. The model is used to study two-dimensional functionally graded electrodes introduced to investigate their effect on thermal stresses. The material grading will be implemented in two directions for each layer; thickness and length. Results indicate that using the two-dimensional grading reduced thermal stresses by over 40 % for a specific grading scheme compared to the conventional case. Grading the electrodes also positively affects the electrochemical performance, as the cell’s maximum power density was increased by over 60 %. These results prove that two-dimensional graded SOFCs can achieve much higher operating temperatures with safe thermal stresses, creating a potential for compact, high-temperature SOFCs designed for high power density applications.

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Influence of Composition of Gd-Doped Ceria Electrolyte on Performance of Solid Oxide Fuel Cell

Materials Science Forum ◽

10.4028/www.scientific.net/msf.724.389 ◽

2012 ◽

Vol 724 ◽

pp. 389-392 ◽

Cited By ~ 3

Author(s):

Yuta Ibusuki ◽

Yoshihiro Hirata ◽

Soichiro Sameshima ◽

Naoki Matsunaga

Keyword(s):

Power Density ◽

Open Circuit ◽

Solid Oxide ◽

Maximum Power ◽

Cell Performance ◽

Excess Oxygen ◽

Doped Ceria ◽

Oxide Fuel ◽

Maximum Power Density ◽

Oxide Ion Conductivity

Cell performance was measured for four types of Ni (40 vol%)-Gd-doped ceria (GDC) anode-supported solid oxide fuel cells with GDC electrolyte (40-120 μm thickness) of Ce1-xGdxO2-x/2 compositions (x = 0.05, 0.1, 0.15 and 0.2) at 773-1073 K using a H2 fuel. (La0.8Sr0.2)(Co0.8Fe0.2)O3 cathode was printed on the GDC films. The open circuit voltage and maximum power density at 873-1073 K showed a maximum at x = 0.1. The maximum power density at x = 0.1 was 166 and 506 mW/cm2 at 873 and 1073 K, respectively. The excess oxygen vacancy at x = 0.1-0.2, which does not contribute to the oxide ion conductivity, reacts with a H2 fuel to form electrons (H2 + VO 2H+ + VO×, VO× VO + 2e-). This reaction reduces the cell performance.

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Concepts for Ultra-High Power Density Solid Oxide Fuel Cells (SOFC)

ECS Transactions ◽

10.1149/06101.0177ecst ◽

2014 ◽

Vol 61 (1) ◽

pp. 177-190

Author(s):

L. Zhu ◽

L. Zhang ◽

F. Zhao ◽

A. V. Virkar

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Power Density ◽

High Power ◽

Solid Oxide ◽

High Power Density ◽

Oxide Fuel

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Design and Off-Design Analysis of a MW Hybrid System Based on Rolls-Royce Integrated Planar Solid Oxide Fuel Cells

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1839917 ◽

2007 ◽

Vol 129 (3) ◽

pp. 792-797 ◽

Cited By ~ 13

Author(s):

Loredana Magistri ◽

Michele Bozzolo ◽

Olivier Tarnowski ◽

Gerry Agnew ◽

Aristide F. Massardo

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Hybrid System ◽

System Size ◽

Solid Oxide ◽

Oxide Fuel ◽

Ambient Conditions ◽

Detailed Model ◽

Design Point ◽

Turbine Speed

In this paper the design point definition of a pressurised hybrid system based on the Rolls-Royce Integrated Planar-Solid Oxide Fuel Cells (IP-SOFCs) is presented and discussed. The hybrid system size is about 2 MWe and the design point analysis has been carried out using two different IP-SOFC models developed by Thermochemical Power Group (TPG) at the University of Genoa: (i) a generic one, where the transport and balance equations of the mass, energy and electrical charges are solved in a lumped volume at constant temperature; (ii) a detailed model where all the equations are solved in a finite difference approach inside the single cell. The first model has been used to define the hybrid system lay out and the characteristics of the main devices of the plant such as the recuperator, the compressor, the expander, etc. The second model has been used to verify the design point defined in the previous step, taking into account that the stack internal temperature behavior are now available and must be carefully considered. Apt modifications of the preliminary design point have been suggested using the detailed IP-SOFC system to obtain a feasible solution. In the second part of the paper some off-design performance of the Hybrid System carried out using detailed SOFC model are presented and discussed. In particular the influence of ambient conditions is shown, together with the possible part load operations at fixed and variable gas turbine speed. Some considerations on the compressor surge margin modification are reported.

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Geometrical scale dependency of thin film solid oxide fuel cells

Modern Physics Letters B ◽

10.1142/s0217984920400382 ◽

2020 ◽

Vol 34 (07n09) ◽

pp. 2040038

Author(s):

Yeageun Lee ◽

Jianhuang Zeng ◽

Chunhua Zheng ◽

Wonjong Yu ◽

Suk Won Cha ◽

...

Keyword(s):

Thin Film ◽

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Power Density ◽

Solid Oxide ◽

Scale Dependency ◽

Oxide Fuel ◽

Cross Sectional ◽

Ohmic Losses ◽

Geometrical Scale

To study the geometrical scale dependency of thin film solid oxide fuel cells (SOFCs), we fabricated three thin films SOFCs which have the same cross-sectional structure but different electrode areas of 1 mm2, 4 mm2 and 9 mm2. Since the activation and ohmic losses of SOFCs depend on their active region, we examined the variations of the power density of the cells with a Pt/YSZ/Pt structure and simulated the power density variations using the COMSOL software package.

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Microstructure optimization of nickel/gadolinium-doped ceria anodes as key to significantly increasing power density of metal-supported solid oxide fuel cells

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2019.10.010 ◽

2019 ◽

Vol 44 (59) ◽

pp. 31475-31487 ◽

Cited By ~ 4

Author(s):

Cornelia Bischof ◽

Andreas Nenning ◽

Andreas Malleier ◽

Lukas Martetschläger ◽

Andre Gladbach ◽

...

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Power Density ◽

Solid Oxide ◽

Doped Ceria ◽

Oxide Fuel ◽

Gadolinium Doped Ceria

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SFA-SDC Composite Cathodes Fabricated with Glycine-Nitrate Process for Intermediate-Temperature Solid Oxide Fuel Cells

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1070-1072.488 ◽

2014 ◽

Vol 1070-1072 ◽

pp. 488-491

Author(s):

Xiu Ling Yu ◽

Ming Fei Shi

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Power Density ◽

Peak Power ◽

Solid Oxide ◽

Intermediate Temperature ◽

Oxide Fuel ◽

Reaction Products ◽

Mass Content ◽

Composite Cathodes

SrFe0.9Al0.1O3-δ(SFA) powder was mixed with a different mass content of SDC 10, 20 and 30 wt.% to form SFA-SDC composite cathodes subsequently investigated as potential IT-SOFC cathodes on LSGM electrolytes. No obvious reaction products between SDC (or LSGM) and SFA occur under test for the cathode of SOFCs. As SOFC cathodes, the area-specific resistances of the SFA-SDC cathodes on the LSGM electrolyte with SDC 10, 20 and 30 wt.% at 800 oC are 0.089, 0.068 and 0.087 Ω cm2, respectively. The peak power density of the SFA-SDC20 on a 300 μm-thick LSGM electrolyte reach 512 mW cm−2 at 800 °C.

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