scholarly journals Surface Segregation in Solid Oxide Cell Oxygen Electrodes: Phenomena, Mitigation Strategies and Electrochemical Properties

2020 ◽  
Vol 3 (4) ◽  
pp. 730-765 ◽  
Author(s):  
Kongfa Chen ◽  
San Ping Jiang
Keyword(s):  
Surface Segregation ◽  
Driving Forces ◽  
Critical Role ◽  
Electrical Power ◽  
Electrical Energy ◽  
Influential Factors ◽  
Solid Oxide ◽  
Mitigation Strategies ◽  
Electrolysis Cell ◽  
Oxygen Electrodes

Abstract Solid oxide cells (SOCs) are highly efficient and environmentally benign devices that can be used to store renewable electrical energy in the form of fuels such as hydrogen in the solid oxide electrolysis cell mode and regenerate electrical power using stored fuels in the solid oxide fuel cell mode. Despite this, insufficient long-term durability over 5–10 years in terms of lifespan remains a critical issue in the development of reliable SOC technologies in which the surface segregation of cations, particularly strontium (Sr) on oxygen electrodes, plays a critical role in the surface chemistry of oxygen electrodes and is integral to the overall performance and durability of SOCs. Due to this, this review will provide a critical overview of the surface segregation phenomenon, including influential factors, driving forces, reactivity with volatile impurities such as chromium, boron, sulphur and carbon dioxide, interactions at electrode/electrolyte interfaces and influences on the electrochemical performance and stability of SOCs with an emphasis on Sr segregation in widely investigated (La,Sr)MnO3 and (La,Sr)(Co,Fe)O3−δ. In addition, this review will present strategies for the mitigation of Sr surface segregation. Graphic Abstract

scholarly journals Chromium deposition and poisoning of La0.8Sr0.2MnO3 oxygen electrodes of solid oxide electrolysis cells

2015 ◽  
Vol 182 ◽  
pp. 457-476 ◽  
Author(s):  
Kongfa Chen ◽  
Junji Hyodo ◽  
Aaron Dodd ◽  
Na Ai ◽  
Tatsumi Ishihara ◽  
...  
Keyword(s):  
Surface Segregation ◽  
Oxygen Electrode ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Electrolysis Cell ◽  
Electrolyte Interface ◽  
Oxygen Electrodes ◽  
Inner Surface ◽  
Solid Oxide Electrolysis ◽  
Electrolyte Surface

The effect of the presence of an Fe–Cr alloy metallic interconnect on the performance and stability of La0.8Sr0.2MnO3 (LSM) oxygen electrodes is studied for the first time under solid oxide electrolysis cell (SOEC) operating conditions at 800 °C. The presence of the Fe–Cr interconnect accelerates the degradation and delamination processes of the LSM oxygen electrodes. The disintegration of LSM particles and the formation of nanoparticles at the electrode/electrolyte interface are much faster as compared to that in the absence of the interconnect. Cr deposition occurs in the bulk of the LSM oxygen electrode with a high intensity on the YSZ electrolyte surface and on the LSM electrode inner surface close to the electrode/electrolyte interface. SIMS, GI-XRD, EDS and XPS analyses clearly identify the deposition and formation of chromium oxides and strontium chromate on both the electrolyte surface and electrode inner surface. The anodic polarization promotes the surface segregation of SrO and depresses the generation of manganese species such as Mn2+. This is evidently supported by the observation of the deposition of SrCrO4, rather than (Cr,Mn)3O4 spinels as in the case under the operating conditions of solid oxide fuel cells. The present results demonstrate that the Cr deposition is essentially a chemical process, initiated by the nucleation and grain growth reaction between the gaseous Cr species and segregated SrO on LSM oxygen electrodes under SOEC operating conditions.

Intermediate-temperature solid oxide electrolysis cells with thin proton-conducting electrolyte and a robust air electrode

2017 ◽  
Vol 5 (44) ◽  
pp. 22945-22951 ◽  
Author(s):  
Libin Lei ◽  
Zetian Tao ◽  
Xiaoming Wang ◽  
John P. Lemmon ◽  
Fanglin Chen
Keyword(s):  
Electrical Energy ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Chemical Energy ◽  
Electrolysis Cell ◽  
Proton Conducting ◽  
Electrolysis Cells ◽  
Solid Oxide Electrolysis ◽  
Solid Oxide Electrolysis Cell ◽  
Solid Oxide Electrolysis Cells

A proton-conducting solid oxide electrolysis cell (H-SOEC) is a promising device that efficiently converts electrical energy to chemical energy.

scholarly journals Molten Salt Synthesis of High-Performance, Nanostructured La0.6Sr0.4FeO3−δ Oxygen Electrode of a Reversible Solid Oxide Cell

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2267
Author(s):  
Xiaodong Zuo ◽  
Zhiyi Chen ◽  
Chengzhi Guan ◽  
Kongfa Chen ◽  
Sanzhao Song ◽  
...  
Keyword(s):  
Molten Salt ◽  
High Performance ◽  
Reaction Medium ◽  
Solid Oxide ◽  
Molten Salt Synthesis ◽  
Electrolysis Cell ◽  
Molten Salt Method ◽  
Assembly Method ◽  
Oxygen Electrodes ◽  
Direct Assembly

Nanoscale perovskite oxides with enhanced electrocatalytic activities have been widely used as oxygen electrodes of reversible solid oxide cells (RSOC). Here, La0.6Sr0.4FeO3−δ (LSF) nanoscale powder is synthesized via a novel molten salt method using chlorides as the reaction medium and fired at 850 °C for 5 h after removing the additives. A direct assembly method is employed to fabricate the LSF electrode without a pre-sintering process at high temperature. The microstructure characterization ensures that the direct assembly process will not damage the porosity of LSF. When operating as a solid oxide fuel cell (SOFC), the LSF cell exhibits a peak power density of 1.36, 1.07 and 0.7 W/cm2 at 800, 750 and 700 °C, respectively, while in solid oxide electrolysis cell (SOEC) mode, the electrolysis current density reaches 1.52, 0.98 and 0.53 A/cm2 under an electrolysis voltage of 1.3 V, respectively. Thus, it indicates that the molten salt routine is a promising method for the synthesis of highly active perovskite LSF powders for directly assembled oxygen electrodes of RSOC.

An Electrochemical Study of a Solid Oxide Fuel Cell Stack Operating at Intermediate Temperature for Distributed Generation Applications

Green ◽  
2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Giovanni Brunaccini ◽  
Giorgio Dispenza ◽  
Marco Ferraro ◽  
Vincenzo Antonucci ◽  
Stefano Modena
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Distributed Generation ◽  
Conversion Efficiency ◽  
Electrical Power ◽  
Electrical Energy ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Electrical Performance ◽  
Oxide Fuel

AbstractA state-of-the-art Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) stack was investigated. The stack was a pre-commercial one, with a nominal power output of 600W. The study was focused on the electrical performance and the possible thermal energy recovery. Moreover, to evaluate the technology limitations for Distributed Generation (DG) applications, a 15 h test cycle with slow electrical power variation was performed. At the end of the tests, it was envisaged the capability of proper energy conversion efficiency. This technology appears promising for the high conversion efficiency of natural gas chemical energy into electrical energy, with proper perspectives for distributed generation.

scholarly journals Magnetic capsulate triboelectric nanogenerators

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Pengcheng Jiao ◽  
Ali Matin Nazar ◽  
King-James Idala Egbe ◽  
Kaveh Barri ◽  
Amir H. Alavi
Keyword(s):  
Energy Harvesting ◽  
Critical Role ◽  
Electrical Power ◽  
Low Frequency ◽  
Electrical Energy ◽  
Electrical Performance ◽  
Research Attention ◽  
Voltage Range ◽  
Significant Research ◽  
Triboelectric Nanogenerators

AbstractTriboelectric nanogenerators have received significant research attention in recent years. Structural design plays a critical role in improving the energy harvesting performance of triboelectric nanogenerators. Here, we develop the magnetic capsulate triboelectric nanogenerators (MC-TENG) for energy harvesting under undesirable mechanical excitations. The capsulate TENG are designed to be driven by an oscillation-triggered magnetic force in a holding frame to generate electrical power due to the principle of the freestanding triboelectrification. Experimental and numerical studies are conducted to investigate the electrical performance of MC-TENG under cyclic loading in three energy harvesting modes. The results indicate that the energy harvesting performance of the MC-TENG is significantly affected by the structure of the capsulate TENG. The copper MC-TENG systems are found to be the most effective design that generates the maximum mode of the voltage range is 4 V in the closed-circuit with the resistance of 10 GΩ. The proposed MC-TENG concept provides an effective method to harvest electrical energy from low-frequency and low-amplitude oscillations such as ocean wave.

scholarly journals A Theoretical Study on Reversible Solid Oxide Cells as Key Enablers of Cyclic Conversion between Electrical Energy and Fuel

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4517
Author(s):  
Saheli Biswas ◽  
Shambhu Singh Rathore ◽  
Aniruddha Pramod Kulkarni ◽  
Sarbjit Giddey ◽  
Sankar Bhattacharya
Keyword(s):  
Energy Demand ◽  
Electrode Materials ◽  
Scale Up ◽  
High Capacity ◽  
Electrical Energy ◽  
Solid Oxide ◽  
Lower Efficiency ◽  
Internal Reforming ◽  
Fuels And Chemicals ◽  
The Cost

Reversible solid oxide cells (rSOC) enable the efficient cyclic conversion between electrical and chemical energy in the form of fuels and chemicals, thereby providing a pathway for long-term and high-capacity energy storage. Amongst the different fuels under investigation, hydrogen, methane, and ammonia have gained immense attention as carbon-neutral energy vectors. Here we have compared the energy efficiency and the energy demand of rSOC based on these three fuels. In the fuel cell mode of operation (energy generation), two different routes have been considered for both methane and ammonia; Routes 1 and 2 involve internal reforming (in the case of methane) or cracking (in the case of ammonia) and external reforming or cracking, respectively. The use of hydrogen as fuel provides the highest round-trip efficiency (62.1%) followed by methane by Route 1 (43.4%), ammonia by Route 2 (41.1%), methane by Route 2 (40.4%), and ammonia by Route 1 (39.2%). The lower efficiency of internal ammonia cracking as opposed to its external counterpart can be attributed to the insufficient catalytic activity and stability of the state-of-the-art fuel electrode materials, which is a major hindrance to the scale-up of this technology. A preliminary cost estimate showed that the price of hydrogen, methane and ammonia produced in SOEC mode would be ~1.91, 3.63, and 0.48 $/kg, respectively. In SOFC mode, the cost of electricity generation using hydrogen, internally reformed methane, and internally cracked ammonia would be ~52.34, 46.30, and 47.11 $/MWh, respectively.

Analysis of Surface Waste Heat Recovery in IC Engine by Using TEG

2015 ◽  
Vol 787 ◽  
pp. 782-786 ◽  
Author(s):  
R. Prakash ◽  
D. Christopher ◽  
K. Kumarrathinam
Keyword(s):  
Waste Heat ◽  
Electrical Power ◽  
Electrical Energy ◽  
Surface Heat ◽  
Heat Energy ◽  
Ic Engine ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Heat Energy Recovery

The prime objective of this paper is to present the details of a thermoelectric waste heat energy recovery system for automobiles, more specifically, the surface heat available in the silencer. The key is to directly convert the surface heat energy from automotive waste heat to electrical energy using a thermoelectric generator, which is then regulated by a DC–DC Cuk converter to charge a battery using maximum power point tracking. Hence, the electrical power stored in the battery can be maximized. Also the other face of the TEG will remain cold. Hence the skin burn out accidents can be avoided. The experimental results demonstrate that the proposed system can work well under different working conditions, and is promising for automotive industry.

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