An Electricity and Value-Added Gases Co-Generation via Solid Oxide Fuel Cells

2013 ◽  
Author(s):  
Kang Wang ◽  
Pingying Zeng ◽  
Jeongmin Ahn
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Value Added ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Energy Field ◽  
New Frontier ◽  
Cogeneration System ◽  
Novel Strategy

In this study, an electricity and value-added chemicals cogeneration system using methane-fueled single chamber solid oxide fuel cells (SC-SOFCs) was successfully developed and investigated. The SC-SOFCs, which operated on methane/oxygen gas mixture with a ratio of 2:1, achieved an open-circuit voltage of 1.0 V and a maximum peak power density of ∼ 840 mW.cm-2 at 700 °C. By passing the exhaust gas of the fuel cell through a Ru/Al2O3 catalyst at 700 °C, the synthesis gas is obtained with a methane conversion of higher than 95%, while CO and H2 selectivity is higher than 92%. This study provides a novel strategy for energy conversion which is one of the major concerns in energy field and a new frontier for improving the energy efficiency of SOFCs.

scholarly journals Remarkable Ionic Conductivity in a LZO-SDC Composite for Low-Temperature Solid Oxide Fuel Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2277
Author(s):  
Zhengwen Tu ◽  
Yuanyuan Tian ◽  
Mingyang Liu ◽  
Bin Jin ◽  
Muhammad Akbar ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Ionic Conductivity ◽  
Low Temperature ◽  
Solid Oxide Fuel Cells ◽  
Ionic Conduction ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Open Circuit Voltages ◽  
Composite Samples

Recently, appreciable ionic conduction has been frequently observed in multifunctional semiconductors, pointing out an unconventional way to develop electrolytes for solid oxide fuel cells (SOFCs). Among them, ZnO and Li-doped ZnO (LZO) have shown great potential. In this study, to further improve the electrolyte capability of LZO, a typical ionic conductor Sm0.2Ce0.8O1.9 (SDC) is introduced to form semiconductor-ionic composites with LZO. The designed LZO-SDC composites with various mass ratios are successfully demonstrated in SOFCs at low operating temperatures, exhibiting a peak power density of 713 mW cm−2 and high open circuit voltages (OCVs) of 1.04 V at 550 °C by the best-performing sample 5LZO-5SDC, which is superior to that of simplex LZO electrolyte SOFC. Our electrochemical and electrical analysis reveals that the composite samples have attained enhanced ionic conduction as compared to pure LZO and SDC, reaching a remarkable ionic conductivity of 0.16 S cm−1 at 550 °C, and shows hybrid H+/O2− conducting capability with predominant H+ conduction. Further investigation in terms of interface inspection manifests that oxygen vacancies are enriched at the hetero-interface between LZO and SDC, which gives rise to the high ionic conductivity of 5LZO-5SDC. Our study thus suggests the tremendous potentials of semiconductor ionic materials and indicates an effective way to develop fast ionic transport in electrolytes for low-temperature SOFCs.

Measurements of Lateral Impedance and Local Characteristics of Solid Oxide Fuel Cells

2012 ◽  
Vol 9 (4) ◽  
Author(s):  
Shih-Wei Cheng ◽  
Yaw-Hwa Shui ◽  
Yung-Neng Cheng ◽  
Ruey-Yi Lee
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Local Characteristics ◽  
Eis Measurements ◽  
Original Cell ◽  
Lower Impedance

Lateral impedance and local characteristics of anode-supported solid oxide fuel cells (SOFCs) are studied in this paper. The testing device, which combines the original cell housing with a four-point probe equipment, is set for measuring SOFC single cell. The current collectors on anode and cathode in the original cell housing are, respectively, replaced by four independent probe units. They are not only to collect current, but also become measuring probes. Therefore, the lateral impedance of anode and cathode can be measured. Furthermore, the local characteristics are examined by open circuit voltage (OCV), I-V curve, and electrochemical impedance spectroscopy (EIS) measurements. The results show that the lateral impedance is substantially varied with temperature, the OCV at the center of the cell are higher than the edge, the central location on cell have better performance and lower impedance than the marginal location.

scholarly journals Fabrication and Electrochemical Performance of Zn-Doped La0.2Sr0.25Ca0.45TiO3 Infiltrated with Nickel-CGO, Iron, and Cobalt as an Alternative Anode Material for Solid Oxide Fuel Cells

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 269 ◽  
Author(s):  
Nazan Muzaffar ◽  
Nasima Arshad ◽  
Daniel Drasbæk ◽  
Bhaskar Sudireddy ◽  
Peter Holtappels
Keyword(s):  
Fuel Cells ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cells ◽  
Polarization Resistance ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Sulphur Poisoning ◽  
Operating Temperatures

In solid oxide fuel cells, doped strontium titinates have been widely studied as anode materials due to their high n-type conductivity. They are used as current conducting backbones as an alternative to nickel-cermets, which suffer degradation due to coking, sulphur poisoning, and low tolerance to redox cycling. In this work, anode backbone materials were synthesized from La0.2Sr0.25Ca0.45TiO3−δ (LSCTA-), modified with 5 wt.% Zn, and infiltrated with nickel (Ni)/ceria gadolinium-doped cerium oxide (CGO), Fe, and Co. The electrodes were further studied for their electrochemical performance using electrochemical impedance spectroscopy (EIS) at open circuit voltage (OCV) in different hydrogen to steam ratios and at various operating temperatures (850–650 °C). Infiltration of electrocatalysts significantly reduced the polarization resistance and among the studied infiltrates, at all operating temperatures, Ni-CGO showed excellent electrode performance. The polarization resistances in 3% and 50% H2O/H2 atmosphere were found to be 0.072 and 0.025 Ω cm2, respectively, at 850 °C, and 0.091 and 0.076 Ω cm2, respectively, at 750 °C, with Ni-CGO. These values are approximately three orders of magnitude smaller than the polarization resistance (25 Ω cm2) of back bone material measured at 750 °C.

Evaluation of Porous Ni-YSZ Cermets With Ni Content of 0–30 Vol. % as Insulating Substrates for Segmented-in-Series Tubular Solid Oxide Fuel Cells

2012 ◽  
Vol 9 (2) ◽  
Author(s):  
Zhenwei Wang ◽  
Masashi Mori ◽  
Takanori Itoh
Keyword(s):  
Thermal Properties ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Ni Content ◽  
Isothermal Expansion ◽  
In Series ◽  
Oxide Ions

Nickel was added to a substrate composed of porous Y2O3-stabilized ZrO2 (YSZ) in order to minimize anode damage during redox cycling in segmented-in-series tubular solid oxide fuel cells (SOFCs) with YSZ electrolytes. In this study, the electrical insulating and thermal properties of these materials were evaluated for their suitability as substrates in the tubular SOFCs. When the Ni content was ≤20 vol. %, the porous cermets showed an electrical resistance of ≤67 Ω cm at 900 °C, indicating that the theoretical open circuit voltage for the tubular SOFCs could be achieved. However, the cermet with 20 vol. % Ni was destroyed during the first heating cycle in air because of large isothermal expansion. However, no obvious cracks were observed for cermets with ≤10 vol. % Ni. From the viewpoint of thermogravimetric measurement, this suggests that there are two redox mechanisms for Ni particles in the substrate. They were reduced/oxidized by both the gases and the oxide-ions passing through the YSZ framework. Based on the insulating and thermal properties of the substrate, the optimal composition was found to be approximately 10 vol. % Ni.

Plasma-Sprayed Y2O3-Stabilized ZrO2 Electrolyte With Improved Interlamellar Bonding for Direct Application to Solid Oxide Fuel Cells

2014 ◽  
Vol 11 (3) ◽  
Author(s):  
Shan-Lin Zhang ◽  
Cheng-Xin Li ◽  
Chang-Jiu Li
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Deposition Temperature ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Plasma Sprayed ◽  
Ysz Electrolyte ◽  
Gas Tightness

Atmospheric plasma spraying was employed to prepare anode, cathode, and Y2O3-stabilized ZrO2 (YSZ) electrolyte to aim at reducing manufacturing cost. YSZ electrolytes were deposited on the anode at different deposition temperatures of 200 °C, 400 °C and 600 °C to optimize the gas tightness of plasma-sprayed YSZ electrolyte. The influences of the deposition temperature on the microstructure and gas-tightness of plasma-sprayed YSZ electrolyte were investigated. The effect of microstructure and the gas-tightness of YSZ electrolyte on the open circuit voltage and the output performance of solid oxide fuel cells (SOFCs) were examined. The results showed with the increase of deposition temperature, the porosity of YSZ electrolytes almost decreased by about 80% and the microstructure of YSZ electrolytes changed from the typical lamellar structure to the continuous columnar crystal structure. At a deposition temperature of 600 °C the gas permeability decreased to 1.5 × 10−7 cm4gf−1s−1, and the highest open circuit voltage can reach 1.026 V, indicating the applicability of the as-sprayed YSZ directly to the SOFC electrolyte.

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