bluuebunny/crossref_metadata_2025 huggingface dataset:
Aptamer-Based Electric-Double -Layer (EDL) Extended-Gated FET Biosensor for Detection of Cadmium Ion
Authors: Kuo Tzu Han , Wang Yu-Lin Lin , Lin Chia Kai , Paulose Akhil K
Published: May 2023

In this study, we developed an electric double-layer (EDL) extended-gate field effect transistor sensor based on aptamers to detect cadmium ions (Cd2+). Since the aptamer has a specific binding ability to cadmium ions. The signal is amplified through the transconductance of the FET. The linear detection range of this sensor for cadmium ions is from 1 nM to 10 uM. The Cd2+ calibration curve is shown a high correlation coefficient (R2 = 0.981) and an excellent detection limit as low as 0.094 nM. Importantly, it responds to Cd2+ within 10 seconds. The sensor exhibits high selectivity in the presence of other heavy metals. It also can be reused without significant signal attenuation. The advantages of this method are convenient portability, short detection time, high sensitivity, and simple operation. It has a good prospect for detection in the daily life of cadmium environmental pollution.
Simple Fabrication Method for Solution-gated One-piece Transistors for Biosensing Applications
Authors: Katayama Ritsu , Sakata Toshiya
Published: May 2023

In this paper, we report on a novel and simple fabrication method for solution-gated thin-film indium tin oxide (ITO) channel field-effect transistors (FETs). These devices can be fabricated by etching a part of deposited conductive ITO film with about 100 nm thickness to 20 nm thickness as the channel, which exhibits semiconductor characteristics. The current measurement during etching enables the direct observation of the change in current at the channel, that is, the precise optimization of FET characteristics. The devices fabricated show a steep subthreshold slope (~80 mV/decade) and a large I
d/I
g ratio; thus, they have the potential to be applied in highly sensitive affordable biosensors.
(Invited) Air-Permeable MXene Electrode with Miura-ori Structure for Biosensing
Authors: Lin Tzu-En , Tsai Chih-Ning , Yang Pei-Wen , Huang Chih-Ching
Published: May 2023

In this work, we present an air-permeable MXene electrode capable of recording surface electromyographic (sEMG) signals on the skin surface based on the Miura-ori structure. MXene is a two-dimensional (2D) nanomaterial composed of transition metal carbides, nitrides, and carbonitrides developed in recent years. Taking advantage of the Miura-ori structure, MXene-based electrodes have high breathability as well as low and stable electrode-skin interfacial impedances, facilitating long-term reliable electrophysiological monitoring. The electrolytic gel on conventional wet Ag/AgCl gel electrodes increases the impedance between the electrode and the skin as it gradually dries, inhibits sweat evaporation and affects signal acquisition. Therefore, we provide a fascinating electrode design that can be used to obtain high-quality sEMG signals for assessing body movements such as swallowing.
Temperature Dependence of Water Crossover in Proton Exchange Membrane Water Electrolysis
Authors: Friedrichs-Schucht Maurice , Hasché Frédéric , Oezaslan Mehtap
Published: May 2023

In this work, we investigated the temperature dependence on the water transport coefficient for proton exchange membrane water electrolysis (PEMWE). The experimental parameters varied between 40 and 80 °C at a current density of 1 A cm-2
geo and ambient pressure. The water crossover to the cathode was measured by cooling the exhaust and weighing the liquid fraction over 4 hours under steady conditions. The remaining water vapor from the gaseous fraction was taken into account by the temperature-dependent vapor pressure curve. The resulting data of the water crossover [mg cm-2
geo min-1] depends on the temperature, time and current density applied. The main driving force of the water crossover is the proton flux through the membrane and can be established by fitting the data of the relative changes in water mass over time with a linear function. For now, the water diffusion which has a minor contribution is not considered. Our results reveal that the water transport coefficient derived from the proton flux increases from 2.4 at 40 °C to 3.1 at 80 °C (growth of +29%). In summary, we have developed a method to more accurately determine the water transport coefficient, which is very useful in modeling the water crossover in PEMWE.
Developing Reversal-Tolerant Anode for PEFCs by Introducing Iridium-Based Layered Structure
Authors: Manjunatha Likhith , Nagayama Mayumi , Hayashi Akari , Sasaki Kanzunari
Published: May 2023

The cell voltage reversal phenomena occurring at the anode was focused on for the purpose of extending the lifetime of PEFCs. In order to address both the carbon-based degradation and alloying-based degradation at the anode. Multifunctional layered anodes were proposed. Anodes were designed in order to separate the Pt/C and IrO2 layers. This approach successfully increased durability toward the carbon-based degradation. This is most likely because a water electrolysis reaction rather preferentially occurs at the IrO2 layer near the electrolyte membrane, leading to suppression of carbon corrosion reaction at the Pt/C layer. Regarding to the alloying-based degradation, contacting two layers of Pt/C and IrO2 lead to Pt-Ir alloying even though two layers were separately made. However, when two layers of Pt/C and IrO2 were completely separated by inserting the carbon layer, Pt-Ir alloying was totally avoided.
(Invited) Current Status of SOFC Deployment and Technology Developments in Korea
Authors: Song Rak-Hyun
Published: May 2023

The current deployment of stationary fuel cells in Korea is about 880 MW including the 220 MW SOFC systems, About 40 MW in 2021 and 50 MW in 2022 were installed respectively. In Korea, the fuel cell deployment is accelerated by the mandatory supply and the promotion regulations driven by government. Several Korean companies have developed the SOFC and SOEC technologies under the national program, and major projects are the development of a 200 kW SOFC and a 20 kW SOEC systems. The 2~8kW class SOFC products have been developed already and are in deployment. The Korean government enacted the Hydrogen Law in 2020, and under this law, development and deployment of hydrogen and fuel cell-related technologies are in progress. The achievements of the SOFC R&D and deployment, and national hydrogen roadmap in Korea are introduced in more detail.
Enhancement of Ni-YSZ Fuel Electrode Performance Via Pressurization and GDC Infiltration
Authors: Grimes Jerren , Zhang Yubo , Cox Dalton , Barnett Scott A
Published: May 2023

Ni–(Y2O3)0.08(ZrO2)0.92 (YSZ) and Ce0.8Gd0.2O2
-
δ (GDC) infiltratedNi-YSZ fuel electrodes are investigated using impedance spectroscopy as a function of total pressure P from 1 to 5 atm in 25%, 50%, and 75% humidified H2 mixtures at a temperature of 600˚C. The charge transfer resistance decreases significantly with infiltration for all conditions, and the total polarization resistance RP is reduced by ~20%. Fitting the P dependence to a power-law, RP ∝ P−n, yields an exponent of ~0.21 for both un-infiltrated and infiltrated tests. Increasing the total pressure from 1 to 5 atm results in an average 29% reduction in RP for both electrodes. Increasing the humidification from 25 to 75% generally results in a reduction in RP. The Ni-YSZ:GDC electrode at 5 atm had a RP value ~44% lower than that of the Ni-YSZ electrode at 1 atm, a substantial combined effect.
Solid Oxide Cell Technology for Power Generation, Hydrogen Production and Energy Storage
Authors: Ghezel-Ayagh Hossein
Published: May 2023

The progress in maturation of solid oxide cell technology has led to development of new applications that will flourish its presence in many areas far beyond the traditional power generation. The solid oxide cell technology has the potential to have a formidable presence in production of hydrogen and, eventually, long duration storage of electric power. Following the successful operation of a200 kW SOFC system under a project supported by Department Energy/NETL, FuelCell Energy (FCE) is pursing the development of solid oxide-based plant configurations from subMW power plant products to high temperature electrolysis for production of hydrogen, and further, to energy storage applications.
The Influence of Water Concentration on High-Temperature Reactive Evaporation and Condensation of Cr in 800°C Air
Authors: van Leeuwen Travis Kent , Dowdy Ryan , Guerrero Amberly , Gannon Paul
Published: May 2023

Reactive evaporation of Cr from stainless steels used in solid oxide electrochemical systems, such as solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) systems, is well-documented as the cause of Cr poisoning; however, the condensation and interactions of volatilized Cr species onto and with surrounding interfaces during complex and dynamic system exposures is less understood. Understanding these interactions during operation is critical for improving system performance and safeguarding environmental, health and safety, as some condensed Cr forms toxic hexavalent chromium (Cr(VI)) species. The objective of this study is to investigate and report on condensation pathways of Cr vapors within representative high-temperature system environments. To accomplish this objective, Cr vapors, produced by high-temperature (800°C) air exposures of trivalent chromium (Cr(III)) oxide (Cr2O3) powder with variable moisture content, were condensed onto various ceramic materials at lower temperatures (<400°C). Both the total amount of Cr and ratios of oxidation states were measured using ICP-MS and colorimetric analyses. An increase of Cr condensation was observed with increased water content, with similar Cr(VI) to Cr(III) ratios. Results and interpretations are discussed in context of improved understanding of Cr reactive evaporation and condensation in SOFC/SOEC and related high-temperature materials and systems.
Steam Reforming Catalytic Layer on Anode-Supported and Metal-Supported Solid Oxide Fuel Cells for Direct Ethanol Operation
Authors: Machado Marina , Tabuti Francisco , Piazzolla Fernando , Moraes Tamara , Abe Ricardo , Guimarães Rafael Mariz , Miura Yohei , Fukuyama Yosuke , Fonseca Fabio Coral
Published: May 2023

A catalyst based on lanthanum chromite with exsolved metallic ruthenium nanoparticles (LaCrO3-Ru) was applied as a catalytic layer for internal ethanol steam reforming of anode-supported and metal-supported solid oxide fuel cells. The metal support exhibits limited catalytic properties for the ethanol steam reforming reaction. Thus, the LaCrO3-Ru catalysts were optimized for operating temperatures in the 600-700 °C range to promote stable ethanol reforming. The catalytic layer had no significant impact on the electrochemical properties of the fuel cell, and samples with and without the catalytic layer exhibited similar performance in hydrogen. Initial durability tests with LaCrO3-Ru layer have shown that the catalytic layer plays a crucial role in the stability of the metal-supported fuel cell under ethanol.
Improved DRT Determination Through a Modified Sparse Spike Deconvolution
Authors: Bergmann Tobias , Schlüter Nicolas
Published: May 2023

Impedance spectroscopy is a powerful characterization method to evaluate the performance of electrochemical systems such as batteries and fuel cells. However, overlapping signals in the resulting impedance spectra oftentimes cause misinterpretation of the data. The distribution of relaxation times (DRT) method overcomes this problem by transferring the impedance data from the frequency domain into the time domain, which yields DRT spectra with an increased resolution. Unfortunately, the determination of the DRT is an ill-posed problem, and appropriate mathematical regularizations become inevitable to find suitable solutions. Different algorithms exist to find the best solution for this regularization. The following work tests and shows unconventional algorithms for the calculation of the DRTs. This manuscript is related to Poster SOFC-0064.
Electrochemical Study of La0.31Sr0.58Ti0.97Ni0.03O3-δ Thin Film and Pt-10Sc1CeSZ Electrodes
Authors: Ainsar Mait , Kooser Kuno , Kodu Margus , Romann Tavo , Nurk Gunnar
Published: May 2023

In this work thin film SOFC anode MIEC La0.31Sr0.58Ti0.97Ni0.03O3-δ (LSTN) electrodes with embedded 200 nm thick Pt current collectrors (CC-s) and electrodes without CC-s deposited on 10Sc1CeSZ electrolyte were studied in 650 °C in 98.5% H2 and 1.5 % H2O at ambient pressure. Additionally Pt-10Sc1CeSZ electrodes were characterized to determine CC-s own electrochemical activity. It was found that the embedded Pt was the most active part of an LSTN electrode with Pt CC despite the common presumption that covering Pt current collector with dense MIEC layer makes it inactive. Diffusion of H2 through both LSTN and Pt layers and reaction on the Pt-10Sc1CeSZ interface is proposed. Formation of bubbles under embedded Pt in hydrogen atmosphere was seen and is explained with formation of trapped H2O.
Design of High Specific Power Solid Oxide Fuel Cells
Authors: He Hongpeng , Suzuki Toshio , Rehaag Jessica , Junaedi Christian , Vilekar Saurabh , Roychoudhury Subir
Published: May 2023

Fuel-Cell Electric-Vehicle demonstrated by PCI was fueled with military-spec F-24/JP-8 and does not require on-board hydrogen storage. An onboard fuel reformer with integrated sulfur trap was used for processing these fuels. The 10-kW electric generator included a SOFC and balance of plant components. It was hybridized with a rechargeable battery for startup, peak loads, and load following. The power produced was sufficient for vehicle propulsion and export power. Both 28-32 VDC and 110 VAC for charging batteries and supporting external load demands were available onboard. Initial off-road demonstrations were successfully conducted at PCI and customer sites. This prototype unit showed the feasibility of utilizing hydrocarbon fuels with on-board reforming and SOFC stack to generate power suitable for mobile applications while the system weight and start-up time still need to be improved. To reduce the system weight and start-up time, we are separately investigating advanced SOFC’s that show potential to address the known limitations of the state-of-the-art technology. These advanced SOFC’s demonstrated potential for fast start-up and high-power density on the cell level at 750-800°C of operating temperatures. By optimizing the configuration and design, the system performance is expected to be further improved.
Investigation of the Abnormal I-V Curve Shape of Hybrid Direct Carbon Fuel Cell Using Lanthanum Strontium Calcium Titanate-Based Anode
Authors: Liu Xinyu , Irvine John T.S.
Published: May 2023

Solid oxide direct carbon fuel cells are being developed for use with waste derived materials. We have fabricated solid oxide fuel cells with La0.2Sr0.25Ca0.45MxTi1-xO3-δ (M=Ni, Fe, or Co) anodes, YSZ electrolyte, and LSM cathode. Electrochemical performance of these cells has been evaluated with solid carbon as the fuel and promising results have been recorded. For example, fuel cells with La0.2Sr0.25Ca0.45Ni0.05Ti0.95O3-δ anode tested in hybrid direct carbon fuel cell mode reached a maximum power density of 82.3 mW/cm2 measured in N2 purging gas at 850 °C. During hybrid direct carbon fuel cell testing with solid carbon fuel and nitrogen purging gas, I-V curves obtained showed an abnormal shape between 0.6V and 0.7 V. To investigate the origin of this line shape, we have used methods such as electrochemical impedance spectroscopy, potentiostatic study, and analysis of off gases from fuel cell using gas chromatography.
Electrochemical Activation and NAP-XPS As Well As EIS Characterization of La0.31Sr0.58Ti0.97Ni0.03O3-δ Thin Film Electrode
Authors: Nurk Gunnar , Ainsar Mait , Kodu Margus , Kelp Glen , Romann Tavo , Lust Enn , Gallet Jean-Jacques , Kukk Edwin , Kooser Kuno , Möller Priit
Published: May 2023

To improve catalytic activity of LaxSr0.9-xTiyM1-yO3-δ, La1-xSrxCryM1-yO3-δ based materials, doping of perovskite B-site with metals (M) like Ni, Co, Mo or Cu has been proposed. It has been demonstrated, that at elevated temperatures and in reducing atmosphere these dopants exsolve to perovskite surface and form nanometer scale catalyst particles. Exsolution process could be accelerated by using electrochemical polarization. In the present study thin film La0.31Sr0.58Ti0.97Ni0.03O3-δ electrodes was prepared using pulsed laser deposition (PLD) technique. Current collectors were made from Pt (using magnetron sputtering) and placed under the thin film electrode layer. Electrodes were characterized using XPS and EIS method at near ambient pressure conditions (1-5 mbar) at 650 °C, activated electrochemically and characterized again to see the effect of activation. Changes on the electrochemical performance as well as on XPS data caused by electrochemical activation were observed and analyzed.
Study on Exsolution Process of Sr2FeMo0.6Ni0.4O6 via in Situ Cathodic Polarization
Authors: Duranti Leonardo , Felli Andrea , Marelli Marcello , Dosa Melodj , Di Bartolomeo Elisabetta , Piumetti Marco , Boaro Marta
Published: May 2023

In this work, the behavior of the double perovskite Sr2FeMo0.6Ni0.4O6-δ (SFMN) under cathodic polarization was investigated. The structural changes due to the exsolution process caused by polarization or by chemical reduction were studied by X-ray diffractometry and by electron microscopies and electrochemical performances of a H2-SOFC electrode were analyzed to clarify the role of the different phenomena involved in the structural transformation of the double perovskite.
An Experimental Method to Measure Electrokinetics of Oxygen Electrodes in High Temperature Solid Oxide Electrolyzers through Symmetrical Cell Configuration
Authors: Wen Yeting , Zhang Yongliang , Huang Kevin
Published: May 2023

Using high temperature solid oxide electrolytic cells to produce
hydrogen from steam has thermodynamic advantages in efficiency
and yield over its low temperature counterparts. However, SOECs
generally exhibit faster performance degradation than solid oxide
fuel cells, thus presenting a major challenge to the technology scale
up for mass production of hydrogen. One leading cause for the
degradation is the delamination of oxygen electrode (OE),
particularly under high current densities or hydrogen production rate.
Establishing the relationship between delamination behaviors and
electrochemical properties of OE is critical to the understanding of
the root cause of the failure mechanisms. For this purpose, we here
in this paper report a new experimental methodology to extract key
electrokinetics of OE using three-electrode symmetrical cell
configuration.
Experimental Analysis of the Effect of Cathodic CO2 Supply to Industrial Solid Oxide Fuel Cells
Authors: Pagliari Michele , Montinaro Dario , Martelli Emanuele , Campanari Stefano , Donazzi Alessandro
Published: May 2023

In the SOS-CO2 cycle, a newly developed hybrid cycle for blue power production, the SOFC cathode is supplied with a CO2-rich oxidizing stream, while the anode is fed with a reformate mixture. The performance and the durability of 25 cm2 Ni-YSZ anode-supported SOFCs are experimentally evaluated under the SOS-CO2 cycle conditions for 150 h. By testing symmetric cells with LSCF-GDC and LSC-GDC electrodes, the effects of the CO2-rich atmosphere on the cathodic material are also investigated. The results show that the loss of performance caused by the cathodic supply of CO2 is stable in time, but also reversible when switching back to air. The cathodic supply of CO2 causes both an increase of the polarization resistance and of the ohmic resistance, suggesting a reduction of electronic conductivity compatible with formation of carbonates on the perovskite surface.
Experimental Evaluation of SOFC System Exposed to Marine Inclination Conditions
Authors: Veldhuizen Berend , Zera Emanuele , van Biert Lindert , Modena Stefano , Aravind P.V. , Visser Klaas , Hopman Hans
Published: May 2023

Marine actors are showing an increased interest in the application of Solid Oxide Fuel Cells (SOFCs) for deep sea shipping, because of their high conversion efficiency, low pollutant emissions, and fuel flexibility. However, it is unknown how the operation of SOFC systems is affected by large inclinations and motions, which can be present in ships for instance by seawaves. The goal of this research is to evaluate the influence of static and dynamic inclinations on the operation and safety of SOFC systems. Ship motions are emulated using a one-axial oscillation platform up to 30 degrees of inclination. The SOFC system was successfully operated on the platform and demonstrated stable power production under a variety of test conditions without any noticeable safety hazards. The results of the experiments are used to propose design improvements for marine SOFC systems, ultimately contributing to reduce the emissions of the shipping industry.
Computational Modeling for Cr and S Poisoning Pathways on La0.6Sr0.4Co0.2Fe0.8O3 Surfaces
Authors: Liu Bill , Yildiz Bilge
Published: May 2023

Solid oxide fuel cells (SOFCs) are highly efficient devices for energy conversion. However, their performance is hindered by the poisoning of their oxygen electrode materials by chromium and sulfur species. While previous studies have proposed a nucleation theory of Cr and S poisoning as a mechanism, little is known about the adsorption behaviors and compound formation steps during the poisoning process. This knowledge is critical for understanding the poisoning mechanisms and developing effective mitigation strategies. In this study, the state-of-the-art SOFC oxygen electrode material, La0.6Sr0.4Co0.2Fe0.8O3 (LSCF), is used as a modeling system. A realistic surface structure will be constructed by grand canonical Monte Carlo (GCMC) simulation. Then, the adsorption energies as a function of surface chemistry will be calculated using density functional theory (DFT). The results revealed the importance of surface chemistry in determining the energetics and kinetics of precursor adsorption and compound formation.
The Investigation of Current Collector Layers and Design Modification of SOFCRoll Cell with LCNT-Based Electrode
Authors: Nowicki Kamil Maciej , Irvine John Thomas Sirr
Published: May 2023

Solid Oxide Fuel Cells (SOFCs) with an alternative fuel electrode based on nickel-doped lanthanum calcium titanate (La0.43Ca0.37Ni0.06Ti0.94O3-γ, LCNT) were produced with SOFCRoll geometry. The SOFCRoll is a self-supporting cell based on a double spiral shape, where all the layers are tape cast, rolled and fired in a single step. The SOFCRoll has the advantage of the planar system, thick film manufacturing techniques, robustness of the tubular design and very high volumetric surface area. The paper presents further work on cell optimisation to improve the current collection and gas distribution within a cell structure. The design modification and co-sintering of the newly developed collector fuel electrode layers allowed the optimal use of a 12 cm2 surface area.
Modeling the Distribution of Oxygen Partial Pressure in the Electrolyte of Solid Oxide Cells and Its Implication on Microstructure Evolution in the Hydrogen Electrode
Authors: Lei Yinkai , Cheng Tianle , Yang Tao , Epting William K. , Abernathy Harry W. , Wen You-Hai
Published: May 2023

The distribution of oxygen partial pressure in the electrolyte has an important effect on the stability of solid oxide cells (SOCs). It is well known that the high oxygen partial pressure at the oxygen electrode and electrolyte interface causes delamination, while its effect in the hydrogen electrode (HE) has received comparatively little attention. The only existing model for the distribution of oxygen partial pressure in the electrolyte of SOC is proposed by Virkar et al., which is a one-dimensional model that does not consider the Butler-Volmer equation at triple phase boundary (TPB) nor the microstructure’s effect. In this work, the Virkar’s model was extended to three dimensions and the Butler-Volmer equation was added at TPB to investigate the distribution of oxygen partial pressure in the actual electrode microstructure. The oxygen partial pressure in the yttria-stabilized-zirconia (YSZ) phase of HE near the HE-electrolyte interface was found to be significantly greater than the oxygen partial pressure in the pore phase of HE, which may lead to Ni oxidation. Furthermore, a phase field model was employed to simulate the microstructural evolution of Ni particles on YSZ surfaces with the assumption that NiO forms at the Ni-YSZ interface. The NiO formation affects the microstructure evolution in HE by changing the shape of the Ni particles.
Scale Up and Coupling of the MOXIE Solid Oxide Electrolyzer for Both Terrestrial and Space Applications
Authors: Hollist Michele , Larsen Dennis , Gomez Abel , Hafen Tyler , Czernichowski Piotr , Valdez Skyler , Lingen Jeffrey , Izatt Becca , Pike Jenna , Hartvigsen Joseph , Elwell Jessica , Elangovan S
Published: May 2023

Since developing the Solid Oxide Electrolysis (SOXE) stacks for the Mars Oxygen ISRU Experiment (MOXIE) program in 2017, the OxEon team has made significant advancements in both the scale and capabilities of the technology with the support of a NASA NextSTEP ISRU, SMTD Tipping Point, and SBIR award. Newer variants of the SOXE stack have a five-fold increase in cell area and a 6.5-fold increase in cells per stack. The scaled-up stacks utilize an interconnect specially designed to allow for a sealed anode perimeter and internally manifolded collection of the 99.9% pure O2 produced during operation. Additionally, OxEon has investigated materials to improve redox tolerance of the nickel-based cathode. Demonstration system have been built and testing with the mission-scale stacks, under relevant test conditions, for Lunar, Martian, and terrestrial applications. Results from operating the mission-scale demonstration systems, both at ambient and relevant test conditions, will be presented.
Electrospun Nanofiber Electrodes with in situ Exsolved Nanocatalysts for Symmetrical SOCs
Authors: Lach Jakub , Zheng Kun , Gogacz Michał , Czaja Paweł , Luo Jie , Brzoza-Kos Agnieszka
Published: May 2023

In this work, A-site deficient Sm0.9Ba0.9Mn1.8−xFexCo0.1Ni0.1O6−δ (x = 0, 0.45 and 0.9) double perovskites with in situ exsolved nanoparticles were successfully obtained and evaluated as electrode materials for symmetrical Solid Oxide Cells (SOCs). All obtained oxides belong to the P4/nmm tetragonal system, and a phase transition from P4/nmm to P4/mmm was recorded by the HT-XRD in the air. The in situ exsolution of nanoparticles has been confirmed by the XRD and SEM analysis. The proposed materials present excellent redox stability and moderate thermal expansion coefficients. Electrospun nanofibers (with 150 nm diameter) were successfully fabricated, indicating an excellent potential application in the electrode. The results show the developed A-site deficient double perovskites with iron doping at Mn-site can be potentially applied as novel electrode materials for symmetrical SOCs.
Enhancing the Catalytic Activity of Ce(Mn, Fe)O2 on a Perovskite-Based Electrode via Spraying for High-Temperature CO2 Electrolysis
Authors: Lee Sang Won , KIm Minkyu , Lee Seok Hee , Shin Tae Ho
Published: May 2023

Solid oxide electrolysis cells (SOECs) have the potential to be highly efficient devices for high-temperature CO2electrolysis. However, commonly used Ni-based cathodes suffer from redox instability under CO/CO2 conditions. La(Sr)Cr(Mn)O3 (LSCM) is a promising alternative due to its coking resistance, but it has poor catalytic activity on CO2reduction. To address this, Ce(Mn, Fe)O2 (CMF) was added as a catalyst to accelerate CO2 adsorption. In this study, the non-touchable coating process by spraying was employed to fabricate the well-decorated embedded CMF on LSCM surface, without complicated pretreatment and infiltration. The performances of the highly decorated electrode surface with CMF nano catalyst were measured at 1123 K, exhibiting a maximum power density of 0.503 W cm-2 in fuel cell mode (H2) and electrolysis performance of 0.835 A cm-2 at 1.5 V in CO2 reduction. This approach shows potential for enhancing the catalytic activity of LSCM cathodes and advancing the development of SOECs for sustainable energy production.
Multiphysics Simulation for the Performance of Tubular Solid Oxide Fuel Cells Operated on Coal Syngas
Authors: Yang Tao , Abernathy Harry W. , Zhong Yu , Wang Rui , Lei Yinkai , Liu Zhien , Thakare Jivan , Kalapos Thomas
Published: May 2023

Solid oxide fuel cells (SOFCs) can be operated directly on coal syngas, but the various contaminants in coal syngas affect the performance and durability of the device. In the present study, three-dimensional multiphysics simulations were developed to investigate the performance degradation of tubular SOFCs operated on coal syngas. The numerical model includes charge conservation, species transport within the electrodes/channels, and heat transfer within the device. These physical processes are coupled by the chemical/electrochemical reactions, which are represented by a Butler-Volmer type formula. Based on the thermodynamic database of impurity interactions with the Ni-YSZ composite anode, the contaminants are assumed to be adsorbed on the anode surface and form secondary phases. These formed phases affect the microstructural properties, electrical conductivity, and the number of active sites for electrochemical reactions. During the operation, the contaminants diffuse from the channel/anode interface to the anode/electrolyte interface, causing further irreversible degradation. The in-house developed multiphysics simulation is robust for prediction of interaction between anode materials with different types of contaminants (e.g., PH3, H2S, AsH3, etc.). With the calibrated model parameters, the performance of the tubular SOFCs with different levels/types of contaminants is predicted. The tolerance limits of the cells are also predicted. Furthermore, the degradation resulted from Ni redistribution, are also implemented into the model to mimic the performance of realistic SOFCs operating on coal syngas. The performance degradation investigation in this study provides guidance for experimental testing with syngas exposure, which is eventually beneficial to the cost reduction of the coal syngas clean-up technology.
Numerical Analysis of Humidification Condition Effects on Protonic Ceramic Fuel Cell Performance Considering Concentration Overpotential
Authors: Li Kunpeng , Ryogo Takatera , Nagata Yohei , Murakami Takeru , Araki Takuto , Okuyama Yuji , Mori Masashi
Published: May 2023

Protonic ceramic fuel cells (PCFCs) operating at an intermediate temperature range (400–600 °C) show high performance due to high proton conductivity in the electrolyte. Especially, because the water steam is generated at the oxygen side, so there is less dilution effect on fuel. Therefore, one of the main merits of PCFCs is that it can operate with extremely high fuel utilization. Furthermore, a higher fuel humidification rate leads to higher proton conductivity. However, under relatively high steam partial pressure, the concentration overpotential effect on cell performance may become non-negligible. In the present study, the performance of PCFC under several fuel humidification conditions is investigated by considering the influence of concentration overpotential by numerical analysis.
Thermal Integration of Solid Oxide Electrolysis Cell Systems with External Heat Sources to Maximize Heat Recuperation and Exergetic Efficiency
Authors: Choi Saeyoung , Hong Jongsup
Published: May 2023

The purpose of this study is to explain the basis of thermal integration and to investigate the effects of internal and external thermal integration on the whole system performance. The basic concept of the thermal integration of SOEC system is presented while considering internal heat recuperation and coupling with external heat sources. By using temperature-heat transfer analysis, the procedure to design the optimal thermal integration of the SOEC system is described. Based on the proposed system, a parametric study with respect to stack operating conditions (i.e., stack inlet temperature, air utilization, steam conversion, hydrogen fractions) is conducted in order to elucidate their effect on the system level performance. Then, the effects of external heat sources such as steam injection, indirect heat transfer with hot fluids and heat supply by an electrical heater are examined, with pinch analysis and exergetic performance evaluation.
Investigation of the Reaction Mechanisms in La1-XSrxCo1-YFeyO3 Electrode by DFT Calculations
Authors: Hartmann Cintia , Geneste Grégory , Saravanabavan Karthikeyan , Laurencin Jérôme
Published: May 2023

La1-xSrxCoy-1FeyO3-δ (LSCF) is a widely used oxygen electrode in Solid Oxide Cells (SOCs). Despite its high electrochemical activity combined with a good mixed ionic and electronic conductivity, it is prone to a phase decomposition upon operation decreasing the global cell performance. However, the underlying mechanisms for the reaction mechanism and the degradation are still not precisely understood and require investigations at atomic scale. Therefore, Density Functional Theory (DFT) calculations are used to better unravel the mechanisms occurring in the electrode. In particular, the interaction of the dioxygen gas with the AO-terminated (100) surface is studied. In this context, the oxygen reduction reaction is decomposed in a series of elementary steps including oxygen vacancy formation, adsorption of the dioxygen molecule on the bare surface and into a surface vacancy accompanied with the formation of intermediate oxygen species, followed by the dissociation and incorporation into the bulk. The calculations have been carried out at two different Cobalt contents (y=0.125 and y=0.25).
Comparison of Carbon Deposition and Removal from Ni-YSZ and Ni-BCZY Composites Using Operando Optical Methods
Authors: Maza William A , Steinhurst Daniel , Pomeroy Elias D , Kee Robert J. , Ricote Sandrine , Walker Robert A. , Owrutsky Jeff
Published: May 2023

In this study, 50%-50% Ni-8YSZ and Ni-BCZY27 composites were exposed to CH4 in the absence and presence of H2O. Carbon deposition at 750 °C and carbon removal were estimated by exposure to steam using operando vibrational emission spectroscopy and thermal imaging. Carbon removal reveals more CO2 + CO formation from Ni-8YSZ compared to Ni-BCZY27, suggesting more carbon on the surface of the former. Carbon removal from composites exposed to CH4 alone indicates limited formation and fast depletion of CO over Ni-BCZY27. Over Ni-8YSZ, CO and CO2 depletion is gradual and sustained, suggesting carbon formation over Ni-BCZY27 is restricted and full oxidation readily occurs. Methane cracking over Ni-8YSZ is accompanied by more cooling compared to Ni-BCZY27. Wet reforming results in similar cooling over Ni-8YSZ and Ni-BCZY27. The results are discussed in the context of recent work using operando spectroscopies of fuel utilization over Ni-8YSZ SOFCs.
First-Principles Studies for Optimal Model of the Ni/YSZ Triple Phase Boundary in Solid Oxide Cells
Authors: Wakamatsu Katsuhiro , Yasuda Takaaki , Okada Yuji , Ogura Teppei
Published: May 2023

To resolve the existing issues of solid oxide cells such as degradation and efficiency improvement, it is essential to understand reaction mechanisms on the surface/interface such as triple phase boundary (TPB) as a highly active site that consists of catalysts, electrolytes, and gas phases. However, the reliable TPB model has not been still uniquely defined to discuss the property. In this study, we have focused on the TPB model comprising Ni catalysts, yttria-stabilized zirconia (YSZ) electrolytes, and gas phases and aimed to theoretically identify a reliable TPB model. In concrete, we identified firstly the stable structure of YSZ surface models by using density functional theory calculations considering different oxygen vacancy positions, yttrium atom arrangements, yttria concentration, and YSZ surfaces. Thereafter, we discussed a reliable Ni/YSZ interface model based on our proposed YSZ model by evaluating different Ni structure types, Ni interfaces in contact with the YSZ surface, and interface positions.
Effect of Water Vapor and Hydrogen Concentration on Power Generation Characteristics of Protonic Ceramic Fuel Cell
Authors: Nagata Yohei , Araki Takuto , Li Kunpeng , Ryogo Takatera , Murakami Takeru , Kuroha Tomohiro , Mikami Yuichi , Yamauchi Kosuke , Mori Masashi , Matsuda Ryuma , Kobayashi Shun
Published: May 2023

To investigate the effect of water vapor in the feed gas on the power generation characteristics of PCFCs, the water vapor concentration was changed to 3%, 15%, 30%, and 50%, while the hydrogen concentration in the gas fed to the anode was fixed at 50%. The impedance measurements showed that the ohmic resistance decreased with increasing water vapor concentration, which was attributed to the increase in the proton conductivity of the electrolyte. The measured current density-voltage characteristics showed that the power output increased with increasing water vapor concentration, which was attributed to the decrease in ohmic overvoltage caused by the increase in proton conductivity. In addition, as a more practical condition, the power generation characteristics were measured when the water vapor concentration was varied while the hydrogen concentration was varied in an anode gas consisting only of hydrogen and water vapor.
Recycling and Reuse Strategies for Ceramic Components of Solid Oxide Cells
Authors: Sarner Stephan , Menzler Norbert H. , Hilgers Andrea , Guillon Olivier
Published: May 2023

The integration of solid oxide cells (SOCs) into circular economy is crucial to enable efficient preservation of critical and high-cost resources such as rare earth elements, cobalt, and nickel used in conventional SOC applications. Based on the fuel electrode-supported cell (FESC) design, a semi-closed loop recycling approach was applied for cell material from CeramTec/Forschungszentrum Jülich. We show that more than 85 wt% of the ceramic components can be successfully reprocessed to new fuel electrode-based substrate that can be further used in cell production. Reprocessing of sintered bodies requires a multi-stage procedure. Increasing the amount of recyclate in the substrate leads to changes in substrate properties such as higher porosities and reduced shrinkage.
Effect of a-Site Cation Defect on Electrochemical Performance and Stability of La0.8Sr0.2Co0.2Fe0.8O3-
δ Cathode
Authors: Zhang Xuebai , Jin Yingmin , Dai Changsong , Su Delin , Xiong Yueping
Published: May 2023

The application of Solid oxide fuel cells (SOFCs) is restricted by the insufficient catalytic activity in oxygen reduction reaction and the impedance increase of cathode in long-term operation at medium and low temperature. In this work, we prepare La0.8Sr0.2Co0.2Fe0.8O3-δ (LSCF) nanofiber cathode material with different A-site defects by electrospinning technology, and systematically explore the influence of A-site cation defect on the electrochemical performance and long-term stability of LSCF cathode. La0.77Sr0.2Co0.2Fe0.8O3-δ, (La0.8Sr0.2)0.97Co0.2Fe0.8O3-δ and La0.8Sr0.17Co0.2Fe0.8O3-δ cathode materials are successfully prepared by controlling the proportion of nitrate input, among which La0.77Sr0.2Co0.2Fe0.8O3-δ obtains the best electrochemical performance, and the polarization impedance is 0.09 Ω·cm2 at 800 ℃.
Integration of Reversible Solid Oxide Electrolysis (rSOC) to Wastewater Treatment Plants for Sustainable Green Gas Production and Balancing of Green Power
Authors: Weiss Robert , Rautanen Markus , Saarinen Ville , Kiviaho Jari , Pennanen Jari , Himanen Olli
Published: May 2023

Biogas produced from anaerobic digestion (AD) of sewage sludge and organic wastes at wastewater treatment plants (WWTPs) can present an important energy contribution to a sustainable society. Raw AD biogas contains 50-65 molar% methane (CH4) and 50-35 molar% carbon dioxide (CO2) and can be upgraded to biomethane (with over 98 molar% CH4). During the CO2 separation step of biomethane upgrading, substantial amounts of CO2 are emitted to the atmosphere. A methanation unit can convert this CO2 into sustainable Synthetic Natural Gas (SNG) and replace the conventional CO2 separation unit for biomethane upgrading, but needs addition of hydrogen from water electrolysis. The water electrolysis can be built as a novel high-performance reversible Solid Oxide Electrolysis (rSOC), as demonstrated in the European H2020 project BALANCE. To highlight the zero-emission potential of the rSOC, this paper emphasizes author’s earlier results from the European H2020 project DEMOSOFC, demonstrating zero-local emission SOFC using raw biogas from WWTP sewage sludge and organic wastes. In this paper, profitability estimations for optimal rSOC and methanation investment and operation strategies at a modern city level WWTP in Finland, Europe, are presented. Power used in rSOC electrolysis mode (SOEC) origins from intermittent wind power, while power produced in rSOC fuel cell mode (SOFC) uses raw AD biogas. A dedicated Power-to-X optimization model is used, optimizing power market operations, dimensions of renewable power sources, plant dimensions and operational scheduling. High profitability is shown using European energy crisis market data 2021-2022, resulting in sustainable biomethane net production costs of 30-70 €/MWh.
Development of a Versatile and Reversible Multi-Stack Solid Oxide Cell System Towards Operation Strategies Optimization
Authors: Cubizolles Geraud , Alamome Simon , Bosio Félix , Gonzalez Brigitte , Tantolin Christian , Champelovier Lucas , Fantin Sebastien , Aicart Jerome
Published: May 2023

Solid oxide cell technology is currently experiencing a rapid industrialization phase. To investigate operational strategy, CEA/LITEN has designed and constructed its first multi-stack reversible solid oxide cell (rSOC) module. While it is able to host four of CEA’s standard 25-cell stacks, the present work reports on preliminary validation results obtained in a 2-stack configuration. Thermal losses have been quantified and identified. While the hotbox is showing high performances, the overall losses increased twofold when taking into account pass-through piping and current connections. Module fluid distribution was verified to be homogeneous, and does not affect nominal stack operation. A durability test of more than 2 kh is presented. Over the first 1.1 kh, the stacks behavior was compared to that of a stack previously operated on a test bench. The remarkable similarities indicate adequate control of the module. Finally, a detailed analysis of the recorded efficiency was conducted.
Durability and Interfacial Elemental Diffusion about BZYb based Protonic Ceramic Fuel Cell
Authors: Mikami Yuichi , Yamauchi Kosuke , Kuroha Tomohiro , Shimada Hiroyuki , Mizutani Yasunobu , Matsuda Ryuma , Mori Masashi , Okuyama Yuji
Published: May 2023

The durability of protonic ceramic fuel cells (PCFC) using Yb-doped BaZrO3 (BZYb) as electrolyte was investigated by 1000 h power generation tests and EPMA analysis of Co from cathode and Ni from anode. In addition, the effect of buffer layer of BaCeZrYYbO3-δ (BCZYYb) between the cathode and the electrolyte on durability and elemental diffusion was also investigated. In the cell with the buffer layer, the degradation of polarization resistance was suppressed in 1000 h power generation test. From EPMA analysis, Ni and Co segregation was observed in the electrolyte and the cathode after 1000 h power generation test in the cell without the buffer layer, which was suppressed in the cell with the buffer layer. These results suggested that the suppression of the segregation by use of BCZYYb buffer layer might have reduced the degradation of polarization resistance.
Reversible Solid Oxide Cells for Energy Storage in the Netherlands: Thermodynamics and Fuel Selection
Authors: Amladi Amogh Gautam , Resink Friso , el Tambouli Omar , Venkataraman Vikrant , Woudstra Theo , Aravind P.V.
Published: May 2023

We investigated a large-scale energy storage system based on reversible solid oxide cells, for a future Dutch electrical grid powered entirely by intermittent renewables. Three fuels — hydrogen, ammonia and methane — were investigated for such a system, to find the most suitable one in terms of minimizing the required fuel storage and renewable power generation capacity. The required sizes of fuel storage and power generation using each fuel were estimated using process models of rSOC systems, and a mathematical model of a storage-supported power grid. The results show that the use of hydrogen would lead to the smallest power generation requirement. It is found that the potential storage capacity in the Netherlands exceeds the requirement for storing any fuel, while the renewable power capacity planned for 2030 is insufficient to meet the demand. Under these conditions and assumptions, we find hydrogen to be the appropriate fuel for the Netherlands.
Load Regulation Strategies of Solid Oxide Electrolysis System Coupled with External Heat Sources
Authors: Cui Tonghui , Han Minfang , Ni Meng
Published: May 2023

Solid oxide electrolysis system requires electrical and thermal energy. Five scenarios are defined according to various cases of external heat sources coupling and electrical energy sources. Three methods are proposed to track variations in electrical or thermal load, including constant flow rate (F method), constant steam utilization (Us method) and constant cell operating voltage (V method). Through system process simulation, the applicability of three methods in different scenarios is explored to obtain load regulation strategies. In the scenario coupled with low-temperature heat and intermittent power and the scenario with no heat coupling, the F method is preferred at high loads and the V method is preferred at low loads, while it is the opposite in the scenario coupled with high-temperature heat and intermittent power. The V method is preferred at low loads in the scenario coupled with low-temperature heat and high loads in the scenario coupled with high-temperature heat.
Experimental Investigation of Naphthalene Induced Degradation of Reversible Solid Oxide Cells Operated on Bio-Syngas
Authors: Steinrücken Benjamin , Herrmann Stephan , Feigl Karsten , Schwiers Alexander , Lenser Christian , Menzler Norbert H. , Spliethoff Hartmut
Published: May 2023

The model tar Naphthalene is used to experimentally investigate the influence of polycyclic aromatic components on the performance of 10 x 10 cm² fuel-electrode supported solid oxide cells operated at artificial bio-syngas under internal reforming conditions. Two different fuel electrodes based on yttrium-stabilized zirconia (YSZ) and gadolinium-doped ceria (GDC) are investigated. A parameter study of the operational temperature and the operation mode is conducted with the YSZ based fuel electrode to quantify the effect on the degradation. The influence of the set-up is investigated by an experiment without the cell. The fuel off-gas composition as well as electrochemical impedance spectroscopy is used to characterize the cell prior to the experiment and to monitor its performance during the poisoning and regeneration process. The measurements are interpreted via the distribution of relaxation times.