bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Improvements in Thermal Budget and Film Properties Using Low Pressure Cure Technology for Advanced 3D Integration Packaging
Authors: Song Kay , Karim Zia , Tan Xinxuan , Bhat Abhishek , Sautter Kenneth , Mingardi A , Vangoidsenhoven D
Published: May 2023

This paper reviews the low-temperature and low-pressure thermal polymerization of dielectric polyimides that are used for redistribution layers (RDLs). Specifically, this presentation illustrates the significant impact of the low-pressure cure process in reducing cure temperature (by 20° to 50°C) and cure times (by as much as 25%) while providing better imidization ratio, film stress, mechanical (elongation %, tensile strength, Young’s modulus), thermal (Tg, Td5%, CTE), and electrical (Dk, Df) properties for different types of dielectric polyimides. Among the many low-temperature polyimides we have studied, we focus here on the Fujifilm LTC-9300 series (LTC-9310 and LTC-9320) and the Asahi BL-300 series. The excellent post-curing polymerization ratio (as measured by FT-IR) and film stress results are also described. Finally, a proposed mechanism for these dielectric polyimides’ polymerization under reduced pressure is discussed.
Aluminum Josephson Junction Formation on 200mm Wafers Using Different Oxidation Techniques
Authors: Lang Simon , Schewski Alexandra , Eisele Ignaz , Kutter Christoph , Lerch Wilfried
Published: May 2023

This work focuses on the manufacturing of Al/AlOx/Al Josephson junctions (JJs), which are essential components of many quantum circuits. Two processes were studied to understand the oxidation of the aluminum surface. Static oxidation was performed by removing native AlOx in a cluster system with Ar-ion beam milling and controlling the final tunneling oxide by applying a specific O2 pressure in the chamber. Controlled plasma oxidation was performed by removing native AlOx with a H2 plasma followed by a defined reoxidation with an oxygen plasma. The resulting oxides had thicknesses up to 10 nm and their electrical properties were analyzed on wafer level, providing insight into the structure and composition of the aluminum oxides and their applicability for Qubits. This work is crucial for reliable industrial manufacturing on full-scale 200 mm wafers with a very high uniformity level.
(Digital Presentation) Internal Friction, Mechanical Spectroscopy in SiO2/Si Wafers
Authors: Onanko Yurii Anatoliyovich , Charnyi Dmytro Volodymyrovych , Onanko Anatoliy Petrovich , Matseliuk Eugene Michaylovich , Dmytrenko Oksana Petrivna , Kulish Mukola Polikarpovich , Pinchuk-Rugal Tatiana Mukolaivna , Ilyin Petro Petrovich , Kuzmych Anna Andriivna
Published: May 2023

In this work, after X-ray and electron irradiation, the outcomes of the evaluation dynamic characteristics of interstitial atoms Sij
, vacancy V, and O-complexes were evaluated to account for the annealing conditions to derive specific structural defects in the SiO2/Si wafer. A non-destructive method, which allows the determination of the internal friction difference ΔQ-1/Q-1
0
of the elastic vibration structure defect density Nd
and the depth of the broken layer hb
, is offered for the SiO2/Si wafer. The method was developed, the installation was designed and manufactured for the excitation and registration of damped bending resonant oscillations in a SiO2/Si disc-shaped wafer with a thickness hSiO2
≈ 100 nm, his
= 300÷500×103 nm, and diameter D = 60÷100×10-3 m to measure the structurally sensitive internal friction Q-1
. Measurement of the internal friction background Q-1
0
at harmonic frequencies f0
and f2
allowed us to experimentally determine the nodal lines of the oscillating disks.
(Invited) The Future of Nanoelectronics Devices from a Theoretical Point of View: The Search for New Channel Materials
Authors: Fischetti Massimo , Gaddemane Gautam , Gopalan Sanjay , Van de Put Maarten Ludo , Vandenberghe William
Published: May 2023

The search for alternatives to Si in the VLSI technology is based on experimental and theoretical work. Here, we consider only the latter and, looking at a few two-dimensional materials of current interest, we use them as examples to emphasize the difficulties faced by theorists in assessing their potential: Silicene and germanene are examples of materials whose properties suffer from the strong scattering of electrons with flexural acoustic phonons; phosphorene highlights how small inaccuracies of ab initio methods prevent a reliable assessment of transport properties; finally, we consider transition metal dichalcogenides to show how surrounding dielectrics (the substrate and/or a top-gate insulator) depress significantly the carrier mobility and the performance of devices that use these materials as channels.
(Invited) Potential of Silicon Oxide Films for Low-Cost and High-Performance Resistive Switching Devices
Authors: Omura Yasuhisa
Published: May 2023

This paper reviews our experimental studies on the resistive switching behaviors of sputter-deposited Si oxide films. Theoretical simulations are also demonstrated to elucidate the physical mechanisms of resistive switching behaviors. These suggest the various potential applications for low-energy sensor network systems, neuromorphic computing systems and low-cost commercial electronic systems.
(Invited) Cryogenic Electronics for Quantum Computing ICs: What Can Bring FDSOI
Authors: Casse Mikael , Cardoso Paz Bruna , Bergamaschi Flavio , Ghibaudo Gérard , Balestra Francis , Vinet Maud
Published: May 2023

We present an overview of the performances of FDSOI CMOS transistors down to deep cryogenic temperature, highlighting in particular the benefits brought by the back bias. FDSOI transistors are operational from room temperature down to temperature as low as 100mK. The main DC electrical characteristics, as well as variability properties and reliability are measured and analyzed. We also point out specific behaviors appearing at cryogenic temperature, and discuss their physical origin and modeling.
(Invited) New Layout Styles to Boost the Electrical, Energy, and Frequency Response Performances of Analog MOSFETs, Considering a Wide Range of High Temperatures
Authors: Gimenez Salvador Pinillos , Galembeck Egon Henrique Salerno
Published: May 2023

The manuscript performs a review of the differentiated new layout styles for the Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) that can boost their electrical performance and ionizing radiation tolerance. Firstly, we present the elements of the first generation of layout styles, the effects intrinsic to their structures, and the first-order analytical models of their drain current. After, we study the first element of the second generation of layout styles, which presents a hybrid gate geometry, aiming mainly to further reduce its effective channel length in comparison to those reached by the first generation and consequently further boosting the electrical performance of the analog MOSFETs. The experimental results in room temperature and high temperature found to show that the first element of the second generation can be considered an alternative hardness-by-design to improve the electrical performance and ionizing radiation of the analog MOSFETs.
MoS2-Based MOS Capacitor for In-Memory Light Sensing
Authors: Kumar Dayanand , Rezk Ayman , Nayfeh Ammar , El-Atab Nazek
Published: May 2023

In this work, we investigate solution processable MoS2 based MOS (metal oxide semiconductor) capacitor device for data storage and in-memory light sensing. The MOS capacitor exhibits a good memory window of about 2.5 V with the operating voltage of +6/-6 V and good endurance of 1000 cycles without any degradation. The device shows a good memory window from 0.4 V to 5 V when the operating voltage was varied from 4/-4 to 8/-8. Importantly, the memory window of the device was increased from 2.5 V to more than 5 V when optical light with different wavelengths was induced onto the device. These promising features of the device make it suitable for data storage and in-memory light sensing.
(Invited) A Novel Computational Framework for Simulations of Bio-Field Effect Transistors
Authors: Kumar Naveen , Dhar Rakshita , Pascual Garcia Cesar , Georgiev Vihar Petkov
Published: May 2023

In this work, we presented a novel simulation tool called the Biomolecule-Oxide Simulator (BOxSim) and its application in simulating the behavior of BioFETs. The capabilities of BOxSim are shown by investigating the impact of various high-k dielectric materials on important Figures of Merits such as current in the channel of the device, surface potential, sensitivity, and intrinsic buffer capacitance. The capabilities of our BOxSim framework allow us to discover new features in the variation of differential capacitance with respect to the second gradient of drain current and surface potential. The profile of the surface potential is used to uniquely identify the signatures (fingerprints) of amphoteric molecules like acids or peptides. The proposed model prospects the possibility to develop an efficient method for protein sequencing. The reliability of the designed model is confirmed by calibrating the simulated results with experimental data for different physical conditions. The results presented in this paper demonstrate the potential of this framework for advancing the field of biosensors and bioelectronics for the biorecognition of different molecules.
(Invited) CMOS-Based Multimodal Sensing
Authors: Noda Toshihiko , Sawada Kazuaki
Published: May 2023

Our research group has proposed the measurement concept of multimodal sensing, in which sensors with broad detection characteristics are used to realize the sensing of multiple items, and has developed semiconductor CMOS-based sensors to realize this concept. In this talk, we introduce ion image sensors and odor sensors as examples of CMOS-based sensors suitable for multimodal sensing, and data analysis using machine learning, which is important for this measurement concept will be mentioned and introduce an example of machine learning-based sensing. The application of these sensors to smart agriculture and other fields will also be discussed, as well as the current status and issues for the practical application of sensor systems.
(Digital Presentation) Analysis of MIS-HEMT Kink Effect in Saturation Region
Authors: Perina Welder , Martino Joao , Agopian Paula
Published: May 2023

In this work, the Metal-Insulator-Semiconductor High Electron Mobility Transistor (MIS-HEMT) behavior in saturation region was analyzed and compared with a GaN MOSFET. The MIS-HEMT presents a current level about 30 times higher than GaN MOSFET, for the same bias conditions. The different saturation points (VDS sat) of the MOS and HEMT conductions is responsible for the appearance of a kink in the drain current (IDS) current as a function of drain voltage (VDS) curve. The output conductance (gD) of the MOSFET presented a strong dependence on VGT, while the MIS-HEMT only a slightly dependence was observed. The MIS-HEMT kink effect (MH kink) was defined by the drain voltage where the bump occurs. The MH kink only occurs for a high enough gate bias to enable the MOS conduction, and MH kink value increases with the gate voltage overdrive (VGT) and its variation tends to saturate for VGT higher than 3,5V.
(Invited) From Lab to Fab: The Journey of Waveguide-Enhanced Raman Spectroscopy
Authors: Michon Jerom , Kita Derek , Hu Juejun
Published: May 2023

WERS, or waveguide-enhanced Raman spectroscopy, is a promising method for sensitive and selective detection of chemical and biological compounds on a chip-scale platform. Here we discuss our ongoing efforts in transitioning WERS from a laboratory test into a technology that can be deployed for commercial applications such as process monitoring in pharmaceutical, petrochemical and agrochemical industries.
Electric-Double-Layer (EDL)-Gated FET Aptasensors for Highly Sensitive MMP7 Detection
Authors: Lin Chia Kai , Wu Chia-Che , Paulose Akhil Kavanal , Hou Yueh-Ju , Lee Chee-Seng , Chen Heuy-Ling , Wang Yu-Lin
Published: May 2023

Biliary Atresia (BA) is a severe liver disease that affects newborns. This disease may cause cholestasis and progressive hepatic failure or even death if not treated immediately. ELISA blood tests for metabolic screening are the current method of diagnosing BA. However, Newborns need rapid BA detection for treatment in the future. Level increase of intrahepatic matrix metalloproteinase-7 (MMP7) is a factor known to cause BA-related liver fibrosis. We brought out a platform to detect BA using an electric-double-layer (EDL)-gated field-effect transistor (FET). MMP7 concentration differences affect gate voltages then consequent in the sensitivity of this platform. EDL-gated FETs are planned to display in hospitals for medical personnel to accurately detect BA in infants.
Waste Tire Derived Carbon Support for Non-Platinum-Group Metal Catalyst Materials for Oxygen Reduction Reaction in Alkaline Medium
Authors: Laanemäe Joel , Jäger Rutha , Teppor Patrick , Volobujeva Olga , Lust Enn
Published: May 2023

A porous carbon material was synthesized using waste tire granules via pyrolysis. Six non-platinum-group metal catalyst materials were synthesized based on this carbon material, Fe(NO3)3 · 9H2O, and either dicyandiamide or guanidine carbonate as the nitrogen source. Synthesis parameters such as pyrolysis temperature, precursor mass ratios, and acid washing time were varied for each material. All catalysts were characterized physically using HR-SEM, SEM-EDX, and N2 sorption analyses as well as electrochemically using the rotating disk electrode method in 0.1 M KOH. The materials were rich in nanofibers, and exhibited moderate porosity and specific surface area (S
BET = 77-194 m2 g-1). By modifying the synthesis parameters of the materials, the electrochemical properties were successfully improved, achieving E
onset = 0.92 V vs RHE and E
1/2 = 0.82 V vs RHE (Fe-guan III 900). The number of transferred electrons in the ORR was n = 4 for the more active materials.
(Digital Presentation) Synthesis of Proton Exchange Membrane Fuel Cell Catalyst and Optimization of Membrane Electrode Assembly Preparation Parameters
Authors: Allikmäe Anna-Mai , Telpt Robert , Nerut Jaak , Teppor Patrick , Valk Peeter , Koppel Miriam , Aruväli Jaan , Lust Enn
Published: May 2023

The oxygen reduction catalyst was synthesized by depositing Pt nanoparticles on carbon black using ethylene glycol as a reducing agent. The synthesized catalyst material contained approximately 60 wt% of Pt, and the average Pt crystallite size was under 3 nm. The catalyst had a micro-mesoporous structure with a specific surface area of 320 m2 g−1. Electrochemical characterization was performed in H2/air fuel cell. The catalyst was deposited on the Nafion membrane or gas diffusion layer using an ultrasonic coating system. The thickness of Teflon gaskets as well as hot pressing conditions were optimized. Lowering catalyst loading on the anode did not show a decrease in electrochemical activity up to 0.05 mg cm−2. However, it was found that the cathode catalyst loading can be reduced only up to 0.60 mg cm−2.
(Invited) DOE EERE Activities in High Temperature Electrolysis and Reversible Fuel Cells
Authors: Gibbons William , Peterson David , Papageorgopoulos Dimitrios
Published: May 2023

The Hydrogen and Fuel Cell Technologies Office (HFTO) within the U.S. Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy (EERE) supports a range of solid oxide-based research, development, and demonstration efforts that fall under the areas of high temperature electrolysis (HTE) and reversible fuel cells (RFCs). These efforts range from earlier stage R&D on cell components to demonstrating early system technology. HTE technology, particularly when used in conjunction with high temperature process heat, shows promise for highly efficient, cost effective, sustainable hydrogen production at large volumes. This potential has led to its inclusion in multiple HFTO initiatives, including two national lab-led consortia separately focused on next generation materials and overcoming technical barriers to manufacturing durable, affordable, and efficient HTE systems. These consortia objectives, efforts, scopes, and developments are discussed in the context of HTE and recent DOE initiatives and announcements, including the Hydrogen Energy Earthshot and DOE’s H2@Scale® vision.
(Invited) The SOFC Program at the DOE’s Office of Fossil Energy and Carbon Management (FECM) and National Energy Technology Laboratory (NETL)
Authors: Vora Shailesh , Williams Mark
Published: May 2023

The Solid Oxide Fuel Cell (SOFC) Program, managed by the U.S. Department of Energy (DOE) Office of Fossil Energy and Carbon Management (FECM) and administered by the FECM’s National Energy Technology Laboratory (NETL) is currently developing low-cost SOFC’s and reversible SOFC systems (rSOCFs). SOFC power systems have the potential to achieve greater than 60 percent efficiency. The SOFC’s operating temperature is lower than combustion-based processes and precludes NOx formation. In addition, there are near-zero emissions of CO2, criteria pollutants, and particulates. Furthermore, SOFC power systems require approximately one-third the amount of water relative to conventional combustion-based power systems. The Program includes the testing of SOFC with natural gas in distributed applications, including data centers. In addition to SOFC, there are several projects on various aspects of high-temperature solid oxide electrolysis cell (SOEC) for electrolysis of water. Development of reversible SOFC systems, rSOCFs, is the new central focus of FECM. The development of efficient systems for hydrogen production is very interesting, especially when supplementary heat is provided from solar or other waste heat sources such as nuclear power plants.
(High-Temperature Energy, Materials, & Processes Division Subhash Singhal Award) From Electrochemical to Mechanical Modeling of SOFCs and Their Experimental Validation
Authors: Kawada Tatsuya , Watanabe Satoshi , Budiman Riyan Achmad , Yashiro Keiji , Sato Kazuhisa , Hashida Toshiyuki , Kimura Yuta , Nakamura Takashi , Amezawa Koji , Sato Masami , Nomura Reika , Muramatsu Mayu , Terada Kenjiro
Published: May 2023

Tohoku University has been conducting research on the mechanical reliability of SOFCs under the financial support by NEDO (New Energy and Industrial technology Development Organization, Japan). Both numerical and experimental approaches have been taken at various levels, from electrochemical to structural analyses. An in-house code, SIMUDEL, was developed to simulate oxygen potential distribution inside the constituent materials in order to account for the chemical strain in cell/stack analyses. Non-linear stress-strain behaviors and inelastic deformation of the materials were characterized to improve the accuracy of the simulation. Predicting actual cell behavior, however, is still difficult, as unexpected factors often remain for each specific case. It is thus important to have in-situ or operando tools to observe the behavior of cells, such as deformation and stress generation. For that purpose, laser profilometer and X-ray stress analyzer were employed with a specially designed cell holder. Methods for evaluating local current density was also proposed. Currently, we are developing a protocol for testing robustness of planar SOFCs. Severe condition tests will be performed, and the results will be analyzed with the above-mentioned simulation.
Enhancing Low-Temperature SOFC Performance and Durability via Surface Modification
Authors: Wachsman Eric , Robinson Ian , Huang Yilin , Horlick Samuel Aaron , Hussain A. Mohammed , Pesaran Alireza
Published: May 2023

The development of active cathodes is one of the most critical challenges to lowering the operating temperature for SOFCs. By modifying the cathode surface chemistry the activity and durability can be simultaneously enhanced on high-performing, low-temperature cathodes. This low-temperature modification using multi-valent cations activates the highly defected surface and maintains the nanoscale electrocatalysts by bypassing the high-temperature sintering procedure for SOFC fabrication. The modified cathode at 600 °C shows an order of magnitude reduction in impedance to only 0.05 Ωcm2 with a peak power density of 1.1 W/cm2 and increases stability over 2000 hours. The combination of in situcharacterization, distribution of relaxation time analysis on impedance spectroscopy, and surface chemistry analysis reveals the importance of surface chemistry control on the gas-solid reaction activity and durability and provides the design principle for future solid oxide cells.
High-Performance Solid Oxide Electrochemical Cells with Ultrathin and Dense Double-Doped Ceria Interlayers
Authors: Yu Hyeongmin , Im Ha-Ni , Lee Kang Taek
Published: May 2023

In this study, we utilized a La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF)-GDC composite oxygen electrode on a thin and dense doubly doped ceria interlayer for a high-performance solid oxide electrochemical cell (SOC). The ceria interlayers were generated via a non-vacuum solution deposition process with gelatin. The SOC achieved a high maximum power density (MPD) of 2.46 W/cm2 at 750oC along with stable operation for 30 hours in the fuel cell (FC) mode. Our results suggest that the integration of the LSCF-GDC composite and the dense ceria interlayer holds a significant promise for development of high-performance SOCs.
Results of Continuous 200kW SOFC Power Generation Using Biomethane Gas from a Brewery's Wastewater Treatment Process
Authors: Kawamura Kimito , Taniguchi Shunsuke , Nomura Tomohiko , Oshima Toshihiro , Kawabata Tsutomu , Sasaki Kazunari
Published: May 2023

Asahi Quality and Innovations, a research subsidiary of Asahi Group Holdings, is committed to innovative R&D for the future of our global liquor, soft drinks and food business. Therefore, with the aim of reducing CO2 emissions, we have developed a technology to utilize carbon-neutral biomethane gas, a byproduct of the wastewater treatment process at breweries, for SOFC power generation instead of conventional combustion. Although many attempts have been made to use biomethane gas for fuel cell power generation, there have been no reports of successful practical applications. We believed that this was due to the unstable purification of the poisoned substance. Therefore, we have succeeded in stabilizing the purification process by employing a gas-in-liquid dispersion method instead of a conventional scrubber for the purification operation. As a result, we have succeeded in long-term continuous power generation using a 200 kW SOFC. This paper reports on the technical details and results.
Commercialization of Ceres SteelCell® Technology for Power Generation and Electrolysis
Authors: Leah Robert , Bone Adam , Hjalmarsson Per , Selcuk Ahmet , Lankin Mike , Rahman Mahfujur , Felix Florence , De Vero Jeffrey , Macauley Chandra , Charbonneau Cecile , Rios Laura , Mukerjee Subhasish , Hargrove Caroline , Selby Mark
Published: May 2023

Ceres’ SteelCell® technology is establishing itself as the global standard for SOC. The technology is rapidly moving to volume production, with Robert Bosch GmbH in Germany and Doosan Fuel Cell in South Korea having licenses to manufacture Ceres SteelCell® cells and stacks at the hundreds of MW per year scale. Ceres SteelCell® technology has multiple power generation applications ranging from small scale <10kWe combined heat and power (CHP) systems to 100s of kW to MWs. An increasing area of interest for the application of Ceres SteelCell® technology is the marine sector operating efficiently on a range of low-carbon fuels including liquefied natural gas (LNG), methanol and liquid ammonia, as well as hydrogen. This is also driving development of systems in the MW range. An exciting new development is the application of Ceres SteelCell® technology to steam electrolysis. Ceres has recently signed an agreement with Shell to operate a 1MW-class electrolyzer in Bangalore, India, running for 3 years from 2023.
Solid Oxide Fuel Cells for Aviation
Authors: Nehter Pedro , Geisler Helge , Ahilan Vignesh , Friedl Stephan , Rohr Oliver , Walter Aurelie , Metzner Christian , Zimmermann Kristian
Published: May 2023

The Solid Oxide Fuel Cell (SOFC) offers major benefits, namely electrical efficiency and fuel versatility, for hybrid-electric aircraft propulsion. The combined development of novel SOFC concepts and corresponding manufacturing processes are regarded as key objectives for the SOFC activities at Airbus Central Research and Technology. Airbus is designing, manufacturing and testing SOFC concepts with the aim to achieve highest gravimetric power densities. Novel manufacturing technologies for metallic and ceramic materials have the potential to enable lighter functional layers for SOFCs with increased intrinsic mechanical stability and surface area. Different cell concepts with an optimized current collection are currently under development at Airbus. The micro-tubular and monolithic SOFC are seen as the most promising concepts, whereas around 2 kW/kg on a cell level has recently been achieved in a performance test at Airbus.
Analysis of Degradation Phenomena of SOC Stacks Operated in Reversible SOFC / SOEC Cycling Mode
Authors: Lang Michael , Lee Young-sang , Lee In-sung , Szabo Patric , Hong Jongsup , Cho Joonhoon , Costa Rémi
Published: May 2023

The present paper focusses on the detailed analysis and discussion of degradation phenomena of two SOC stacks during galvanostatic steady-state SOFC and reversible SOFC/SOEC cycling operation. The stacks with ASCs of Elcogen (Estonia) were fabricated by the industrial project partner E&KOA (Daejeon, Korea) within the Korean-German project “Solid Oxide Reversible Fuel Cell / Electrolysis Stack” (SORFES). The first 10-cell stack was tested at DLR during 1400 h and the results were used to improve the second 6-cell stack, which was operated during 2800 h at E&KOA. For electrochemical characterization jV-curves and electrochemical impedance spectroscopy were measured. The results between galvanostatic steady-state operation and reversible SOFC/SOEC cycling are presented and compared. The degradation of the OCV, the power and the different resistances of the individual repeat units are presented and discussed. Moreover, the improvement of the stack components and of the operating conditions between the two SOC stacks are outlined.
Co-Electrolysis of CO2 and H2O Using an Exsoluted Perovskite Layer
Authors: Lo Faro Massimiliano , Campagna Zignani Sabrina , Vecino-Mantilla Sebastian , Monforte Giuseppe , Arico Antonino
Published: May 2023

Solid oxide electrolysers (SOECs) are a key class of technology that offers an efficient solution to storing renewable energy. One of the key characteristics of this technology is its ability to reduce both H2O and CO2. Currently, commercial cells are adapted from those made for power generation (i.e. SOFCs) and are not suitable for generating gas of higher quality than syngas due to the limited behaviour of the cells. Electrochemical analyses and gas chromatography were used to examine the ability of SOEC cells to improve gas quality. With the addition of a functional layer to the cathode, we achieved a complementary effect between electrochemical mechanisms taking place at the cathode and catalytic mechanisms involving CO2 and CO methanation. In spite of the fact that the results could be significantly improved, this approach demonstrated the potential for CO2 and H2O co-electrolysis at intermediate temperatures.
Interfacial Interaction Between Ni and Oxide in SOFC Anodes
Authors: Matsui Toshiaki , Tsujimoto Hiroaki , Muroyama Hiroki , Eguchi Koichi
Published: May 2023

Solid oxide fuel cells (SOFCs) have attracted as a highly efficient energy conversion devices. The operating of SOFC system under high fuel utilization is preferable from the standpoint of efficiency. However, the anode degradation proceeds readily under high fuel utilization conditions, especially at the downstream part of the anode. This is because the anode is exposed to the severe conditions due to the depletion of fuel and high steam concentration. Thus, the agglomeration, coarsening and oxidation of nickel will lead to the performance deterioration during long-term operation when the nickel-based cermet is applied as an anode. Although the wettability analysis is one of the methods to clarify the agglomeration mechanism, there have been no sufficient studies on the application to solid metal/oxide interfaces. In this study, then, the interfacial properties of Ni/oxide were quantitatively evaluated by determining the contact angle of nickel particles on oxide substrates at the operating temperature of SOFCs.
Preparation of Ni/YSZ Catalysts for Application of Solid Oxide Electrolysis Cell Methanation
Authors: Horiguchi Genki , Yamaguchi Toshiaki , Tateno Hiroyuki , Bagarinao Katherine Develos , Kishimoto Haruo , Mochizuki Takehisa
Published: May 2023

Combination of co-electrolysis of CO2 and steam using solid oxide electrolysis cells (SOECs) and methane production (methanation) offers an attractive process for CO2 conversion to hydrocarbon fuels. Ni-based (Ni/YSZ is a typical example) SOECs could be used as catalytic reactor for CH4 production because Ni has been found to be an active catalyst for methanation. Therefore, Ni/YSZ SOECs could be used as catalytic reactor for methanation. Based on this concept, in this study we have prepared a Ni/YSZ material that can be used in the catalytic reactor. The performance of the prepared Ni/YSZ was evaluated as a catalyst for CO2 methanation. Ni/YSZ catalysts with a Ni loading of 55wt% calcined at 800-1100 ºC gave a high CO2 conversion of up to 86% and a high methane selectivity of >99% at 250-350 ºC of reaction temperature under ambient pressure.
Phase Stability of SrTi1-XFexO3- δ Under Solid Oxide Cell Fuel-Electrode Conditions: Implications for Related Exsolution Electrode Materials
Authors: Reinke Jakob Michael , Schmauss Travis Anthony , Zhang Yubo , Cox Dalton , Barnett Scott A
Published: May 2023

SrTi1-xFexO3-δ (STF) has shown promise as a fuel electrode, and as a basis for fuel electrodes with catalytically active nanoparticle exsolution. This study aims to determine trends in performance and stability of STF in highly reducing environments as Fe-content is varied from x = 0.5 to 0.8. Here we report that, while polarization resistance of STF fuel electrodes decreases with higher Fe-content, this is accompanied with lower stability in highly reducing conditions. For too-reducing conditions and too-high x, partial decomposition of the original perovskite phase is observed with the formation of metallic Fe and a Ruddlesden-Popper STF phase.
Influence of A-site Deficiency and Ni/Co Ratio in B-site on Electrochemical Performance of (La0.25Sr0,25Ca0.45)yTi0.95Ni0.05-xCoxO3-
d
Anode
Authors: Kivi Indrek , Moeller Priit , Aruväli Jaan , Nurk Gunnar
Published: May 2023

In this paper A-site deficient (La0.25Sr0.25Ca0.45)yTi0.95Ni0.05-xCoxO3-
d (LSCTNCA-) with different ratios of Ni and Co is presented. LSCTNC is a promising perovskite (ABO3) type mixed ionic-electronic conductive (MIEC) anode material for solid oxide fuel cells (SOFCs). LSCTNC has good electronic and ionic conductivity at low oxygen partial pressures, which allows efficient electron and ion transfer and is precondition of high MIEC anode activity. LSCTNC has good thermal stability and mechanical properties, which is important for the long-term durability of SOFCs. A significant amount of attention has been paid to clarify stability issues if the material is used as an anode in a solid oxide fuel cell. So far, there is a lack of information about the dependence between A-site stoichiometry and stability of chemical composition- and electrochemical performance of those type materials.
Design and Experimental Investigation of Temperature Control for a 10 kW SOFC System Based on an Artificial Neuronal Network
Authors: Kruse Nicolas , Tiedemann Wilfried , Hoven Ingo , Deja Rober , Peters Roland , Kunz Felix , Eichel Rudiger-A
Published: May 2023

In this work the authors designed and experimentally evaluated different controller topologies for fuel cell operation (SOFC) of a reversible solid oxide cell (rSOC) system. Aim of the controller is to operate the SOFC system autonomously at a constant maximum temperature for maximum efficiency. The controller design incorporates an artificial neuronal network (ANN) for real time state predictions. The training data for the ANN was generated by a Digital Twin of this system. The generated training data consists of about 16,000 different steady state operating conditions.
Approaches for Optimum Thermal Management of SOFC Cells: Fitting Operating Conditions & Smart Cell Design
Authors: Judez Xabier , Jimenez-Martín Gonzalo , Aguado Mónica , Garbayo Iñigo
Published: May 2023

In this work, the guidelines for the design of the thermal management of solid oxide fuel cells (SOFC) by means of computational fluid dynamics (CFD) and numerical optimization tools are proposed. These approaches combine acting both on operating conditions and cell geometry. Initially, the influence of inlet gas flows is evaluated, describing how to optimize the flows while maximizing the energetic outcome. Afterwards, a description of how numerical methods can allow fitting feeding gas temperatures to avoid overheating is provided. Finally, we go a step further by optimizing interconnect plate geometries in order to minimize internal temperature gradients. All in all, a demonstration of how CFD studies can accelerate SOFC design in order to maximize performance and extend lifespan is provided.
Model Based Comparative Analysis of GDC and YSZ Based Solid Oxide Fuel Cells
Authors: Ashar Akhil , Zhu Huayang , Kee Robert J. , Jackson Greg , Braun Rob J
Published: May 2023

Although solid oxide fuel cells (SOFC) offer high fuel-to-electric energy conversion efficiencies, their relatively low power-to-weight ratios make it difficult to integrate them with aircraft propulsion systems. This paper explores the feasibility of designing high throughput SOFCs for hybridization with gas turbines in aircraft powerplants. This paper explores and compares two SOFC technologies for achieving high specific power (kW/kg) with different membrane electrode assembly architectures, one with thin-film yttria-stabilized zirconia (YSZ) electrolytes and the second with high-power density gadolinia doped-ceria (GDC) electrolytes. The studies explore the operation of the respective SOFC stacks with synthetic CH4 as a carbon-neutral aviation fuel. Down-the-channel SOFC models are calibrated to experimental measurements of YSZ- and GDC-electrolyte cells at Elcogen and at the University of Maryland respectively. The model results provide a basis for determining the flow inlet conditions that enable each cell type to achieve high specific powers. The results also indicate the requirement of high airflows and upstream fuel preprocessing to sustain the high specific powers with sustainable cell operating conditions.
Multiscale Modelling of Solid Oxide Cells Validated on Electrochemical Impedance Spectra and Polarization Curves
Authors: Sassone Giuseppe , Da Rosa Silva Eduardo , Prioux Manon , Hubert Maxime , Morel Bertrand , Léon Aline , Laurencin Jérôme
Published: May 2023

Solid oxide cells (SOCs) are high temperature energy-conversion devices, which have attracted a growing interest in the recent years. Indeed, this technology presents a high efficiency and a good reversibility in fuel cell (SOFC) and electrolysis (SOEC) modes. Nevertheless, SOCs durability is still insufficient due to performance degradation during operation. In this context, a physics-based model has been proposed to investigate the impact of operating conditions on the electrodes reaction mechanisms and cell performance. This multiscale model has been developed considering a typical cell composed of a dense electrolyte in Y0.16Zr0.84O1.92 (8YSZ) sandwiched between an oxygen electrode in La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.8Gd0.2O2-δ (LSCF-GDC) and a hydrogen electrode made of Ni-YSZ. The model has been validated on global and local polarizations curves in SOFC and SOEC modes, and electrochemical impedance spectra at the open circuit voltage (OCV). The different contributions arising in the impedance spectra have been identified and discussed.
A New Strategy: Achieving High-Performed SOCs Using Sonic-Spraying as an Advanced Manufacturing
Authors: Lee Sang Won , Kim Suji , Jeong Baek Yun , Lee Seok Hee , Shin Tae Ho
Published: May 2023

Many studies have been reported for not only efficient production of hydrogen via SOECs but also high performed SOFCs, and La1-x
Sr
x
Ga1-y
Mg
y
O3-δ (LSGM), a substitute for yttria-stabilized zirconia (YSZ) has emerged as a rising candidate for the electrolyte due to its superior ionic conductivity even in intermediate temperature (≤1073K). LSGM has superior ionic conductivity even at intermediate temperatures, allowing for better durability and efficiency at lower operating temperatures. However, there are still challenges with LSGM, such as lower mechanical strength and higher reactivity with electrodes, which make it difficult to manufacture cost-effectively and find compatible materials. Strategies for advanced manufacturing have been developed at KICET, including lowering temperature processing, ultra-thinner self-standing electrolytes, non-touchable electrode coating processing, and optimal microstructure. The innovative activity on recent LSGM-based solid oxide electrochemical devices will be discussed, including achieving outstanding maximum power density and high electrolysis performance.
Fabrication of Low-Temperature Solid Oxide Fuel Cells via Development of Magnetron Sputtering Process
Authors: Ryu Sangbong , Yu Wonjong , Tran Quang Tuyen , Thieu Cam Anh , Lee Sanghoon , Sreenarayanan Bhagath , Feng Shijie , Meng Shirley , Fullerton Eric E. , Liu Ping , Minh Nguyen Q.
Published: May 2023

We herein report the development of the sputtering process for the fabrication of low-temperature thin film solid oxide fuel cells (TF-SOFCs) supported by anodized aluminum oxide (AAO). The process development has been conducted for each component, anode, electrolyte, electrolyte/cathode interlayer, and cathode to scale up the cell from 1cm x 1cm to 15 cm x 15 cm. In order to fabricate a uniform thin film regardless of the size of AAO, sputtering conditions such as power, pressure, angle, target-to-substrate distance (TSD), and time have been developed. The recipe for the anode and cathode has aimed at a porous structure with nano-grains for high reactivity. In contrast, the recipe for the electrolyte has been optimized for thickness uniformity and high density. With these sputtering recipes TF-SOFCs with the required microstructure and thickness uniformity have been successfully fabricated on 15 cm x 15 cm AAO substrates.
Kinetic Study of Carbon Deposition in Solid Oxide Fuel Cells (SOFCs)
Authors: Lin Chen , Kerscher Florian , Herrmann Stephan , Steinrücken Benjamin , Spliethoff Hartmut
Published: May 2023

Owing to many irreplaceable advances, solid oxide fuel cells (SOFCs) have a promising and competitive potential in the application of green power supply and greenhouse gas reduction. Especially the utilization of biomass-derived syngas shows a high efficiency potential for the overall system. However, carbon deposition at the anode is a major challenge for the practical application. Once carbon deposited at the anode, the degradation of SOFC performance is permanent and irreversible to a certain extent. The carbon deposition is closely associated with the inner temperature distribution and fuel gas composition within the SOFCs, which is determined by complex chemical and electrochemical reactions. In this study, competing kinetic rates for carbon deposition and regasification are analyzed based on CFD methods for typical biomass-derived syngas compositions. Based on this method, reasonable operating conditions and flow field configuration can be recommended, which reduce the kinetic rate of carbon deposition at the SOFC anode. It is also worth mentioning that the specific anode area where carbon deposition occurs firstly will be detected numerically under different fuel gas components, operating temperatures and flow filed configurations. In summary, an effective method is provided to reduce the carbon deposition at the anode and improve the life expectancy of SOFCs, which is meaningful for SOFC design and operation in practical applications.
Performances of Ni−SDC Hydrogen Electrodes in Reversible Operation Between SOEC and SOFC-Modes
Authors: Uchida Hiroyuki , Da'as Eman H. , Nishino Hanako , Ramachandran Rajakumaran , Takahashi Yosuke , Yamada Yuuki
Published: May 2023

It was found recently that the durability of Ni‒Co dispersed on a samaria-doped ceria (SDC) hydrogen electrode was improved remarkably via reversible cycling operation between steam electrolysis and fuel cell-modes. The microstructure was observed to be stabilized, with certainty, due to a strong interaction between Ni‒Co and SDC. Aiming to develop a durable, practical hydrogen electrode with such a stabilized microstructure, we prepared new Ni–SDC H2 electrodes by a convenient protocol by the use of Ni nanoparticles with uniform size. The initial performance of the Ni–SDC H2 electrode thus prepared was comparable or slightly higher than that of our Ni‒Co dispersed SDC electrode prepared by an impregnation method.
Modeling High-Power Density Ceria-Based Direct Ammonia Fueled SOFC Stacks for Mobile Applications
Authors: Wehrle Lukas , Ashar Akhil , Deutschmann Olaf , Braun Rob J
Published: May 2023

SOFCs can be directly run with ammonia (NH3), which is anticipated to play a major role in future renewable energy systems due to its superior conditioning and storage characteristics. Here, we numerically investigate the performance of NH3-fueled SOFC stacks based on a high-power density ceria-based cell design by means of detailed multi-scale simulations on 1D-button cell and 3D-stack level. The model is validated based on electrochemical performance data collected on a Ni-GDC/GDC/SSC-GDC button cell at 500-650 °C. While the decomposition of NH3 at the surface of the Ni-particles is modeled by employing an elementary kinetic framework, a physically-based distributed charge-transfer model is consulted to account for the leakage current across the GDC electrolyte as a function of operation conditions. In this way, the intricate coupling between the mass, heat and charge transport phenomena, as well as the electrochemistry and thermo-catalytic chemistry can be studied on the industrially relevant scale to assist integration into a hybridized power generation system. Model predictions indicate the 120-cell stack running on NH3 to reach a very promising performance in the intermediate-temperature range.
Energy Transition Scenarios in Off-grid Communities using SOFC-CHP/Battery Hybrid Systems
Authors: Nousch Laura , Tremblay Marie-Lise , Besner Simon , Jeanmonod Guillaume , Hartmann Mathias , Herold Daniela , Simoneau Martin , Michaelis Alexander
Published: May 2023

Today, off-grid communities rely mainly on diesel gensets with limited electrical efficiency and diesel furnaces for electricity and heat generation, respectively. The CO2 emissions associated with this electricity production can be reduced by improving the electrical efficiency of the system thus reducing the fuel consumption. Additionally, waste heat from the electricity production can be recovered for heating thus creating a combined heat and power system. In this work, a solid oxide fuel cell combined heat and power system hybridized to a battery was proposed for this purpose. Simulation of the annual electricity and heat production were performed using real temporal electrical demand data. Results showed that a reduction of up to 36 % in primary energy consumption can be reached compared with the current situation.
Advanced Nanoscale Characterizations of Solid Oxide Cell Electrodes
Authors: Sassone Giuseppe , Celikbilek Ozden , Hubert Maxime , Bagarinao Katherine Develos , David Thomas , Guetaz Laure , Martin Isabelle , Villanova Julie , Rorato Lea , Morel Bertrand , Léon Aline , Laurencin Jérôme
Published: May 2023

Solid oxide cells (SOCs) have attracted a growing attention thanks to their high efficiency and ability to operate in both electrolysis (SOEC) and fuel cell (SOFC) modes. Despite its great potential, the current SOC technology faces significant cell degradation during long-term operation. The degradation phenomena are still not well understood as they involve complex and intricate processes arising at different length scales. Additionally, it has been shown that the degradation rate under SOEC operation is generally higher than in SOFC mode. To address this issue, durability tests were performed in SOEC mode at 750, 800 and 850 °C for 2000 h at -1 A cm-2 in 10/90 vol.% H2/H2O and dry air. The electrochemical performance of the cells was assessed using electrochemical impedance spectroscopy. In addition, advanced characterization techniques with nanometer and atomic resolution have been used to study material degradation after long-term testing.
Benchmarking and Simulation of Solid-Oxide Steam Electrolysis for Propellant Production in a Vacuum Chamber-Simulated Lunar Environment
Authors: Dickson David , Emadi Nasim , Dreyer Christopher , Jackson Greg , Hollist Michele , Larsen Dennis , Czernichowski Piotr , Wilson Merrill , Yarosh Ainsley , Hartvigsen Joseph
Published: May 2023

Federal space agencies across the globe have prioritized development of in-situ resource utilization (ISRU) technology, such as propellants from lunar ice, to support space activities. High-temperature, solid oxide electrolysis cell (SOEC) systems integrated with an efficient balance-of-plant (BOP) have the potential to produce H2 and O2 at specific energy (kWhelec/kgH2) lower than conventional liquid-phase alkaline and PEM electrolysis systems, due to lower voltages for steam electrolysis (vs. liquid H2O). This NASA-sponsored collaboration explored the feasibility of achieving such low specific energy in a high-temperature SOEC system operating in a cryo-vacuum characteristic of permanently shadowed craters on the lunar surface where H2O ice can be found. A lab-scale »2.5-kWelec SOEC stack and BOP achieved a specific energy < 50 kWhelec/kgH2 at a production rate of > 0.075 kgH2/h operating in a cryo-vacuum chamber. System-level simulation models of the lab-scale SOEC stack were benchmarked with experimental tests and used to explore scaling of a system for lunar deployment. The lab-scale tests and scale-up modeling suggest a pathway to a MW-scale SOEC system that can achieve < 46 kWhelec/kgH2 with relatively low specific mass (kgsystem/(kgH2/h)).
Tracking Localized Degradation of Solid Oxide Cells Via Multi-Physics Modelling of Impedance Spectroscopy
Authors: Taubmann Julian , Sun Xiufu , Chatzichristodoulou Christodoulos , Frandsen Henrik Lund
Published: May 2023

Multi-physics models have proven valuable tools for describing and understanding degradation of solid oxide cells (SOC). One shortcoming of the approach is the restricted validation of degradation theories with only the transient voltage or current characteristics measured globally over SOCs. Such an approach disregards the additional insights via periodically measured impedance spectra that is common practice in experimental durability tests. This work overcomes these limitations by applying a combined transient-frequency domain approach permitting the description of temporal changes and the evolution of impedance spectra. It finally leads to a framework allowing trustworthy validation of degradation mechanism represented via multi-physics models. This approach is implemented for an electrode-supported SOC operated in electrolysis mode at -1 A/cm2 aiming at a separation between the different degradation modes of the Nickel/8mol% Yttria stabilized Zirconia electrode.