bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Sulfide-Based Solid Electrolytes (SSE) Sensitivity Towards Humidity
Authors: Leteyi Mfiban Ivan , Profatilova Irina , Tarnopolskiy Vasily , Reytier Magali
Published: September 2023

All-solid-state lithium-ion batteries (ASSBs) represent a new generation of energy storage tools containing only solid components. They are of great interest to researchers and manufacturers thanks to their high energy density, which makes them promising candidates for electric transport applications. Among different types of solid-state electrolytes for lithium-ion batteries (LIBs), sulfide-based electrolytes (SSEs) have several advantages, such as high ionic conductivity and malleability [1, 2]. However, one of their main drawbacks is a high sensitivity towards air humidity [3]. Fast reaction of the SSEs with water results in the degradation of their structure and release of toxic gas (H2S) when exposed to even low concentrations of humidity. This factor leads to significant process cost and safety issues associated with mass production of ASSBs with sulfide-based SEs.

The purpose of the present work is to study in details reactivity of SSEs towards humidity by following two main directions:

The development of a flow-through setup that allows a better identification and highly precise quantification of gases (H2S or others) generated during reaction between water (humidity) and commercial SSEs: this flow-through setup intends to solve problems usually encountered when using closed-type setups, which are the most used setups in the literature[3, 4]. These problems include over-concentration of detected gases and low reproducibility of measurements;

Physico-chemical and electrochemical characterizations of pristine and humidity exposed-SSEs in order to reveal the main factors affecting sensitivity towards humidity and to understand the degradation mechanisms.

First, the efficiency of the flow-through gas analysis setup developed had been validated: H2S detection curves obtained for commercial SSE powders (Li6PS5Cl, Li6PS5Br, Li7P3S11, Li3PS4, Li10GeP2S12) in contact with humid Argon (30 to 200 ppm H2O in Ar) are highly reproducible (see example in Fig. 1 and Table 1). Measurements conducted at different humidity levels allowed accessing kinetics of water-induced degradation reactions involved. SSE powders characterizations using XRD, Raman, XPS, SEM, EIS, granulometry before and after exposure to humidity provided an insight into degradation-related phenomena taking place: morphology deterioration, loss of structure and conductive structural groups, drastic increase of ionic resistance. A relationship between the structure of SSE and its reactivity towards water was found and described.

Refs

[1] Energy Storage Mater. 2018, 14, 58–74 ; [2] Nano Energy 2021, 83, 105858 ; [3] Solid State Ion. 2011, 182 (1), 116–119 ; [4] Chem. Mater. 2020, 32 (6), 2664–2672.

Figure 1
(Invited) Electrochemistry of Exceptionally Inert Systems: Determination and Speciation of Arsenic(III) and Arsenic(V)
Authors: Cox James A. , Rutkowska Iwona A. , Kulesza Pawel J.
Published: September 2023

There has been growing interest in development of new methods for the determination of arsenic oxo species due to their high toxity and increasing population in the environment. Electrochemical methods for the determination of arsenic can be considered as complimentary to spectroscopic and chromoatographic ones because they are fairly simple, and they are subject to different selectivity criteria. In this respect, various stripping voltammetric procedures are becoming popular. The actual stripping voltammetric measurement consists of two steps in which preconcentration of an analyte at the electrode surface is followed by the so called „stripping” step involving electrode reaction recorded in a form of the voltammetric peak. A representative approach involves reduction of the analyte anions upon application of the sufficiently negative potential to form As(0) on the electrode (e.g. gold) surface; this step is followed by voltammetric oxidation (anodic stripping) of the deposit (to As(III)). In a case of so called cathodic stripping voltammetry, the stationary Hanging Mercury Drop Electrode (HMDE) is often used. During the preconcentration step, an insoluble salt (e.g. Cu3As2) is produced on the electrode surface. There is also a need to differentiate between As(III) and As(V) oxo-species, which are relatively more and less toxic, respectively.

Because sensitivity and detection limit in electroanalytical determinations strongly depend on the current densities measured, there is a need to search for specific catalytic materials that would induce otherwise highly slow and irreversible redox processes of As(III) (oxidation) and, in particular, As(V) (reduction). Our research interests concern development of highly specific catalytic systems leading to the enhancement of the electrooxidation of arsenic (III). We explore here the capability of various noble metals nanoparticles (Pt, Rh, Pd) of inducing the arsenic(III) oxidation in acidic medium. The recorded currents have been compared to those observed previously at the electrodes modified with oxocyanoruthenates, the most potent system for the electrocatalytic oxidation of AsIII(OH)3. Reduction of arsenic (V) is even the more inert reaction. Network films of bimetallic (PtRu) nanoparticles (bare and derivatized) permit preconcentration of arsenic(V) species on their surfaces. The stripping step would allow determination of low concentrations of arsenic (10-6 mol/dm-3 or lower).
Promoting Hydrogen Evolution and Oxidation by Reconstructing Hydrogen-Bonding Network of Interfacial Water
Authors: Sun Qiang , Oliveira Nicholas J , Yan Yushan , Kwon Soonho , Goddard William , Li Jingkun , Tyukhtenko Sergiy , Guo Jason , Myrthil Nathalie , Lopez Steven , Kendrick Ian , Mukerjee Sanjeev , Ma Lu , Ehrlich Steven , Jia Qingying
Published: September 2023

The hydrogen evolution and oxidation reactions (HER/HOR) at the electrode-water control the performance of water electrolyzers and hydrogen fuel cells, two important devices for deep decarbonization of our economy (1). Platinum (Pt) catalyzes the HER/HOR with exceptional activity and stability across a wide pH range. However, its activity progressively decreases by about two orders of magnitude as the pH increases from 0 to 13 (2, 3). The lack of understanding of this pH dependence reflects our fundamental knowledge gaps in electrochemistry and has hindered the advancement of alkaline electrolyzers and fuel cells.

Herein, we promoted the HER/HOR of Pt in base by introducing N-methylimidazoles in the Pt-water interface. In situ spectroscopic characterization of the interface together with computations showed that the N-methylimidazoles form strong hydrogen-bonding with neighboring water molecules thereby reconstructing the H-bond network of interfacial water. We accordingly established a unified mechanism by which the HER/HOR in acid and base proceeds via diffusion of protons and hydroxides, respectively through the H-bond network of interfacial water by the Grotthuss mechanism. This mechanism accounts for the pH-dependent HER/HOR kinetics of platinum, a long-standing puzzle. Utilization of N-methylimidazoles as the HER/HOR probes and promoters not only leads to the elucidation of the HER/HOR mechanism but also holds great promise for applications. We have demonstrated 40% performance improvement of an anion exchange membrane water electrolyzer by adding 10-5 M 1,2-dimethylimidazole into the 0.1 M potassium hydroxide solution fed into its Pt cathode.

Acknowledgements

This work was supported by the Office of Naval Research (ONR) grant N000141712608 (Q.J.)

This research used beamline 7-BM (QAS) of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory Contract DE-SC0012704. Beamline operations were supported in part by the Synchrotron Catalysis Consortium Grant DE-SC0012335.

V. R. Stamenkovic, D. Strmcnik, P. P. Lopes and N. M. Markovic, Nat. Mater., 16, 57 (2017).

J. Durst, A. Siebel, C. Simon, F. Hasché, J. Herranz and H. A. Gasteiger, Energy Environ. Sci., 7, 2255 (2014).

W. Sheng, Z. Zhuang, M. Gao, J. Zheng, J. G. Chen and Y. Yan, Nat. Commun., 6 (2015).

Figure 1
Potential-Dependent Competitive Adsorption of Electrolytes Kinetically Inhibits High-Current Hydrogen Oxidation in Non-Aqueous Media
Authors: Fong Andy , Lun Toh Wei , Wang Hai-Xu , Surendranath Yogesh
Published: September 2023

Performing electrochemical transformations in non-aqueous media can unlock new reactivities and selectivities unattainable in aqueous media. For instance, non-aqueous media (e.g. acetonitrile (MeCN), dimethylformamide (DMF), dimethylsulfoxide (DMSO)) allow the dissolution of organic compounds and enable water-incompatible organic electrosynthesis reactions. On the other hand, the lithium-mediated nitrogen reduction reaction (NRR) carried out electrochemically in tetrahydrofuran (THF) is one of the most promising routes towards electrifying the Haber-Bosch reaction and thus eliminating the need for hundreds of atmospheres of pressure and high temperatures. However, many cathodic non-aqueous electrochemical reactions either do not operate with well-defined anodic reactions (e.g. unproductive solvent and/or electrolyte oxidation) or are often coupled with the sacrificial oxidation of a dissolving metal electrode (e.g. magnesium, zinc). Hence, the development of a non-sacrificial anodic reaction is essential for engineering practical, sustainable non-aqueous electrochemical transformations. In this study, we investigate the hydrogen oxidation reaction (HOR) in a variety of non-aqueous solvents (MeCN, DMF, DMSO, THF) and buffers (AcO-/AcOH, Cl-/HCl, etc.) whose base serves as the proton acceptor for HOR. The reason why HOR can be sustainable is because it produces protons, which can be paired with a number of proton-demanding electro-reductions such as NRR, carbon dioxide reduction (CDR) to form oxalic acid or carboxylic acids, and more. Hydrogen is also stoichiometrically cheaper and less greenhouse-emitting than sacrificial metals, making HOR both cheaper and greener. First, we demonstrate a fabricated gas diffusion electrode (GDE) architecture that supports high H2 transport-limited current densities in non-aqueous solvents at ambient pressure. We find that the maximum HOR current density obtained is not H2 transport-limited but instead depends on the kinetics influenced by the pKa and steric profile of the buffer electrolytes present. By also varying the buffer electrolyte concentration and H2 partial pressure and conducting voltametric studies in the absence of H2, we demonstrate that the HOR current density reaches a maximum due to a competitive adsorption mechanism of the buffer electrolytes, limiting the surface concentration of adsorbed hydrogen atoms from H2 dissociative adsorption and thus inhibiting HOR. Based on these findings, we outline strategies for mitigating HOR inhibition via this competitive adsorption mechanism to unlock higher HOR current densities.
The Unusual Striation Patterns in Hydrogen Plasma Near the Cathode Region: A Bifurcation Model Study
Authors: Lee Szetsen , Huang Bo-Xuan
Published: September 2023

RF or microwave-generated hydrogen plasma has been widely used in academic research and industrial manufacturing processes. The plasma region probed or used in processing is usually in the positive column, where the distribution of plasma species is relatively more uniform than in other regions. It is known that by changing some plasma conditions such as pressure and composition, stable standing striations can be generated. Starting from the cathode with a relatively large dark gap called Faraday dark space (FDS), a sequence of bright-dark alternating striation patterns gradually becomes blurred in the positive column towards the ground. Under our plasma conditions, a peculiar pattern of striation with bright doublet regions spaced by a narrow dark gap is formed. The dark gap between each pair of the bright doublet is wider than the one inside the bright doublet. It not only indicates that the electric field in these regions is not uniform, but also the degrees of excitation of species may be different in the bright and dark regions. The field-reversal theory has been used to explain the plasma inhomogeneities and instabilities in electric field strength and electron density and energy distribution. In this work, we have adopted a new approach from the point of view of plasma chaos. In the simulation of electron-molecule and ion-molecule reaction kinetics, by adjusting the electron temperature and the pressure of hydrogen gas, we can see the transition of the species distribution from chaos to bifurcation within the range of our experimental conditions. By modulating the electron density with various kinds of waveforms, the experimentally observed striation patterns can be simulated.
Synthesis of Self-Assembled Molecules Based on Tetraphenylethene-Core Inducing Emission
Authors: Tran Hoang Thi Thuy , Kim Donghwan , Rémond Maxime , Kim Eunkyoung
Published: September 2023

Aggregation-induced emission (AIE) organic materials have been extensively explored for a future sensible and interactive display to provide high luminescence in ordered states. However, it is challenging for reducing exciton quenching of aggregated materials to achieve high emission and increasing ordered structure to yield high crystallinity as well. To this end, the new structures based on tetraphenylene (TP) core were synthesized by attaching TP with clipping groups (C) consisting of a self-assembling group (SAG) to enhance emission intensity and spectra shift.

As the emissive materials for self-assembly, TPCns with different clip numbers (n=1,2,4) were synthesized through the Wittig-Hörner reaction, where clips consist of extended π-conjugated moiety and the alkyl chain as a segment. The clips could introduce van der Waals interaction to facilitate self-assembly among clips and clip-connected aromatic units. These structures were confirmed and analyzed by different tools including 1HNMR, 13CNMR, FTIR-ATR, element analysis, MALDI-TOF/TOF. The optical properties of TPCns were discussed in solution state and solid state. In terms of photoluminescent emission, the TPC4 showed a more yellowish-green emission (λem = 525nm in THF) and large aggregation-induced emission enhancement (EAIE) in aqueous (fw > 50%) THF solution. The greenish blue emission was realized for TPC1 at the maxima wavelength 481 nm and reached 100% quantum yield in the solid state. Furthermore, due to strong twisted intramolecular charge transfer, TPCn molecules had large Stokes shifts in ranges of 5800–6800 cm−1 for TPC1, TPC2, and 10700–12500 cm−1 for TPC4.
Electrochemical Detection of Sulfite Using Ni-Ru-Based Heterometallo-Supramolecular Polymer
Authors: Ahammad A. J. Saleh , Islam Santa , Naher Shamsun , Hossain Md. Delwar
Published: September 2023

We have fabricated a Ni (II)-Ru(II)-based heterometallo-supramolecular polymer (HMSMP)-modified glassy carbon electrode for the selective and sensitive electrochemical detection of sulfite (SO3
2-). The modified electrode (polyNiRu/GCE) was characterized by using scanning electron microscopy (SEM) and fourier transmission infrared (FT-IR) spectroscopy. Molecular weight of synthesized polymer (4.77 × 105 Da) was measured through intrinsic viscosity measurement following Mark-Houwink equation. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behavior of the modified electrode. The modified electrode showed high sensitivity of 0.06 µAµM-1cm-2 for SO3
2-. The detection limit (S/N = 3) for SO3
2- was 0.97 µM with a linear range of 10 to 1000 µM. The developed sensor was successfully examined for real sample analysis with tap water. Excellent recovery with lower relative standard deviation (RSD) and high stability for 4000s in analytic solution confirmed the reliability of using this polyNiRu/GCE in practical assessment.
A Nonenzymatic Sensor Platform Fabricated by a Consumable Inkjet Printer
Authors: Truong Nguyen , Prado Megan , Wanekaya Adam
Published: September 2023

Inkjet printing has been shown to be a cost-effective technique for sensor fabrications. In this work, a nonenzymatic sensor platform capable of tunable sensing applications was designed and fabricated by a consumable inkjet printing technique. To establish the platform’s capability, a well-known and studied analyte, glucose, was used to demonstrate the proof of concept. The limit of detection, linear range, sensitivity, reproducibility, and selectivity of the sensor in the presence of several interfering species was comparable to or better than existing ones. This sensor platform has the potential for modifications for the detection of other analytes.
(Digital Presentation) Design and Development of Leaf Disease Detection Using the ML and Open CV for Tomato Plants
Authors: Prasanna N Merrin , Lakshmi Prasanna K , . Govardhan G , Mahammad Shafi K , Yamuna P , Siva Kalpana R
Published: September 2023

This paper proposes a system for identification of the accurate disease of the plants through the captured images and provides the remedies to increase the crop yielding. Initially the images disease leaf images are taken from the internet and created a database of different plant species and the named according to their disease for the checking the accuracy and this data available in the data base is the training data. The classifier is trained with the data base to achieve the optimum accuracy of the predicted output. Convolution Neural Network (CNN) is used for the prediction of the disease that consists of different layers. To capture the leaf images in the agriculture fields with large area drones are used with high resolution cameras that gives the input to the system. 78% accuracy is obtained from the proposed system to detect the plant is health. The proposed systems use ML and Open CV to detect the plant disease. Keywords— Disease, Machine Learning, Open-CV, SVM, plant leaf disease
Ultrastretchable Self-Healing Paampsa/PANI/PA Polymer Complex as a Piezoresistive Sensor
Authors: Duprey Colton , Lu Yang , Wujcik Evan
Published: September 2023

Wearable sensors, stretchable electronics, and many soft robotics materials must have a sufficiently high balance of conductivity, stretchability, and robustness. Intrinsically conductive polymers offer a critical step toward improving wearable sensor materials due to their tunable conductivity, soft/compliant nature, and ability to complex with other synergistic molecules (i.e., polyacids, small molecule dopants). This work demonstrates a new regenerative polymer complex composed of poly(2-acrylamido-2-methyl-1-propanesulfonic acid), polyaniline, and phytic acid as a skin-like electronic material. It exhibits ultrahigh stretchability (1935%), repeatable autonomous self-healing ability (repeating healing efficiency >98%), quadratic response to strain (R2 > 0.9998), and linear response to flexion bending (R2 > 0.9994), outperforming current reported wearable strain sensors. While nanofillers typically increase conductivity at the expense of mechanical properties, here we show an increase in both conductivity and mechanical properties when silver nanowires are added, forming a polymer nanocomposite with high electronic sensitivity, unprecedented mechanical properties (a maximum strain of 4693% at ambient humidity; ~52 RH%), and repeatable, autonomous self-healing efficiencies of greater than 98%.
(Invited) Electrochemical Aptamer-Based Sensors for Real-Time Molecular Monitoring in the Body
Authors: Arroyo Netz
Published: September 2023

The ability to continuously monitor fluctuating concentrations of specific molecules in the body can drastically improve precision medicine by allowing the real-time correlation of dynamic molecular processes with health and disease. While this ability has been pursued from multiple directions, electrochemical strategies have been successful and commercializable platforms. For example, continuous glucose monitors have dramatically improved the therapeutic management and quality of life for Type 1 diabetics. Unfortunately, the enzymatic sensing used in glucose monitors is not applicable to a large number of clinically relevant biomarkers. This limitation significantly reduces the scope of dynamic biochemical processes we can probe to study healthy human physiology and disease. In response, my laboratory is developing in vivo electrochemical aptamer-based sensors, a platform that is generalizable to the highly specific sensing of arbitrary molecular targets and supports continuous molecular monitoring in the body. In this presentation I will discuss the current state-of-the-art of these sensors, and the challenges we are addressing to enable preclinical and clinical applications.

Figure 1
Engineering Surface-Enhanced Raman Scattering Probe for Enhanced Detection of Acute Diseases with Paper Microfluidics
Authors: Hang Yingjie , Tan Weirui , Wang Anyang , Wu Nianqiang
Published: September 2023

Effective and fast detection of acute diseases is still a main challenge for early diagnosis and monitoring treatment. In this work, surface-enhanced Raman scattering (SERS) probes are incorporated into a microfluidic paper strip for antigen biomarker detection. First, a new material is designed to tune plasmon band position and intensity. Second, geometry is optimized to maximize the SERS enhancement factor. The Finite-Difference Time-Domain simulation has confirmed that more hotspots are generated by the above optimization. As a results, the paper microfluidic strip has achieved the limit of detection at pg/mL level toward antigen detection in blood plasma. The paper microfluidic device shows a great potential in early detection of acute diseases at home, clinics, and remote areas with limited resources.
Microneedle Enabled Electrochemical Aptamer-Based Sensing: Real Time Measurements Using Stainless Steel Microneedles
Authors: Downs Alex , Miller Phil , Weaver Bryan , Polsky Ronen , Monteith Hailey , Wolff Nathan
Published: September 2023

Electrochemical aptamer-based (EAB) sensors are among the only generalizable sensing platforms that resist fouling enough to function directly in bodily fluids and in situ in the living body. Already, these sensors have enabled the real-time measurement of a range of small molecule targets in vivo, including pharmaceuticals and drugs of abuse. EAB sensors consist of an electrode-attached, redox reporter-labeled aptamer that binds to its target species. Target binding causes a shift in electron-transfer rate between the redox reporter and electrode surface, easily detected by a range of electrochemical techniques. Here, we explore the application of EAB sensors to minimally-invasive molecular monitoring. Specifically, we adapt the platform to a microneedle device format. Microneedles can provide direct access to the skin’s interstitial space – a bodily compartment that holds valuable information ranging from drug distribution and immune status. And because microneedles can penetrate into the top layers of the skin with minimal nerve endings, they can avoid eliciting notable pain responses.

In this work, we demonstrate the substantial miniaturization of the sensing platform into electrodes thinner than a human hair, and then integrate them with ultra-fine, hollow microneedles. To ensure needle sterilizability and sharpness while avoiding complex fabrication, we utilize commercial off the shelf stainless steel microneedles. Using an EAB sensor responding to the high-toxicity small molecule drug, vancomycin, as a model system, we achieve quantitative measurements directly in body temperature, undiluted whole blood. Building on this milestone, we explore the application of the sensors when inserted into porcine skin. In porcine skin (a common proxy for human skin), we observe facile microneedle penetration and stable electrochemical signaling. Because of the individual addressability of the sensing electrodes and the generalizability of the aptamer platform, this technology is capable of multiplexed, simultaneous detection of many different molecular targets. Thus, microneedle-enabled aptamer-based sensors offer a promising route forward for non-invasive physiological monitoring – applicable to therapeutic drug monitoring, pain-free biomarker detection, and disease management.
Techno-Economic Optimization of SOC Design and Operating Conditions in a Solid Oxide Fuel Cell-Gas Turbine Hybrid System
Authors: Rosner Fabian , Samuelsen Scott
Published: September 2023

In a circular economy, highly efficient energy conversion systems are paramount to maximize resource utilization and minimize waste production, including carbon dioxide emissions. Solid oxide fuel cell-gas turbine hybrid systems, which can reach efficiencies of greater than 75%-LHV, have demonstrated to be a promising technology on the way to cleaner power generation. During the energy transition period, solid oxide fuel cell-gas turbine hybrid systems are likely to be operated on natural gas, however, their scalability allows these systems to reach very high efficiencies even at small scales, enabling the use of distributed resources such as biogas. In this presentation the authors will discuss key performance and economic metrics of small-scale (10 MW) advanced solid oxide fuel cell-gas turbine hybrid systems and their relation to cell design and system design elements. Current challenges in solid oxide fuel cell development include thermal cell management and production cost. This presentation presents findings of how cell design parameters influence thermal gradients and specific solid oxide cell costs on a $/kW-basis under hybrid system operating conditions. Moreover, specific cell components are identified, and effects will be discussed that can synergistically reduce thermal stress and specific cell cost at the same time. Informed by this analysis, the optimized cell design is integrated into a solid oxide fuel cell-gas turbine hybrid system in order to provide a comprehensive analysis of system operating conditions under consideration of thermal cell gradients, and new insights into economics and levelized cost of electricity are provided. The presentation will discuss the impact of fuel utilization, operating voltage, and operating pressure upon the heat integration, system’s operating window, and power output. A discussion of economic parameters will highlight cost driving factors to inform research on the next generation of solid oxide cells.
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: September 2023

Many studies have been reported for not only efficient production of hydrogen via SOECs but also high performed SOFCs, and La1-xSrxGa1-yMgyO3-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). Since solid oxide electrochemical devices with LSGM can work in intermediate temperatures, it can have better durability and efficiency at lower temperature operating conditions. However, a few essential requirements must still be addresses for the widespread use of commercial LSGM based electrochemical device; their lower mechanical strengths and higher reactivity with electrode compared to the YSZ based electrolyte makes it difficult to find a cost-effective manufacturing process and compatible materials. In this regard, several strategies for advanced manufacturing have been carried for competitive commercialization of LSGM based SOCs at KICET: (a) lowering temperature processing, (b) ultra-thinner self-standing electrolyte, (c) non-touchable electrode coating processing, and (d) optimal buffer layer. Our innovative activity on the recent LSGM based SOCs will be discussed in detail.

Consequently, the fabricated cell exhibits outstanding maximum power density of 1.40 W cm-2 with the ohmic resistance of 0.131 Ω cm2 at 1073K through the effects of the thinner buffer layer and modified electrode surface via the simple-step sonic spraying technique. When the higher electrolysis performance was, subsequently, achieved on reverse SOC operation mode; a high current density of 1.01 A cm-2 at 1073 K, when applied 1.3 V.

Fig. (a) The cell performance using nano CMF decorated LSCM cathode on (a) fuel cell (H2 fuel)

Figure 1
Computational Modeling for Cr and S Poisoning Pathways on La0.6Sr0.4Co0.2Fe0.8O3 Surfaces
Authors: Liu Bill , Yildiz Bilge
Published: September 2023

Perovskite oxygen electrode degradation caused by cation segregation sets the limit of performance and lifetime of solid oxide fuel cells (SOFC) [1][2]. For the state-of-art perovskite oxygen electrode, (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ (LSCF), the commonly known degradation mechanism is through Sr segregation, which can be further poisoned by Cr and as well as by S impurities to form insulating layers, limiting the oxygen evolution reaction (ORR) [3][4]. In order to advance our understanding of Cr and S poisoning pathways on LSCF surfaces, we will combine ab initio density functional theory (DFT) reaction energetics, defect chemistry, and microkinetic modeling to establish a quantitative model to find the deposition reaction on different termination slabs. To predict the reaction mechanism and kinetics of Cr and S poisoning reactions, we will study CrO3 and SO2 molecules deposition pathways on pristine LSCF, and surface-modified (eg. Hf, Zr, Pr, Nd, Ce surface-doped) LSCF slabs. I will correlate adsorption energies with LSCF surface characteristics to explain the origin of the deposition, and use these characteristics to evaluate the effectiveness of the surface infiltration. Ab initio molecular dynamics (AIMD) will be applied at different ensembles to investigate further steps of the reaction, and show how the surface modification will inhibit poisoning reactions. These findings will help to guide the design of better performance and more durable oxygen electrodes for SOFCs.

[1] Neagu, D., Tsekouras, G., Miller, D. N., Ménard, H., & Irvine, J. T. (2013). In situ growth of nanoparticles through control of non-stoichiometry. Nature Chemistry, 5(11), 916–923.

[2] Lee, K. T., & Wachsman, E. D. (2014). Role of nanostructures on SOFC performance at reduced temperatures. MRS Bulletin, 39(9), 783–791.

[3] Jiang, S. P., & Chen, X. (2014). Chromium deposition and poisoning of cathodes of solid oxide fuel cells – a review. International Journal of Hydrogen Energy, 39(1), 505–531.

[4] Chen, K., & Jiang, S. P. (2020). Surface segregation in solid oxide cell oxygen electrodes: Phenomena, mitigation strategies and electrochemical properties. Electrochemical Energy Reviews, 3(4), 730–765.
Design and Fabrication of an Easily Assembled Anode Supported Microtubular SOFC Stack
Authors: Zhang Ruiyu , Wang Yuqing , Shi Jixin , Shi Yixiang
Published: September 2023

Microtubular solid oxide fuel cells have shown many advantages that make them suitable for mobile and portable applications. In this study, a microtubular SOFC stack consisting of 8 cells was designed and fabricated using a metallic current collector and interconnect, enabling a pluggable modular design pattern. To avoid the difficulty of high-temperature sealing, the cold sealing method was adopted, where the temperature at the sealing position was under 130°C when the stack was operated at 700°C. The open circuit voltage (OCV) reached over 4 V while the power output reached over 20 W with a 2 (in series)×4 (in parallel) array. The stack module can be further connected in series or in parallel to satisfy larger power requirements.
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: September 2023

The Solid Oxide Fuel Cells (SOFCs) with an alternative fuel electrode based on the nickel-doped lanthanum calcium titanate (La0.43Ca0.37Ni0.06Ti0.94O3-γ, LCNT) were produced with alternative 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. In the previous work, 27.75 cm2 of surface area was incorporated in a spiral structure with a volume of about 2.5 cm3.

For cell production, all tapes were cast on each other by sequential casting and co-sintered at 1350 °C. The cell assembly included one layer of La0.43Ca0.37Ni0.06Ti0.94O3-γ /Zr0.92Y0.08O2-γ composite fuel electrode with 50% of LCNT by volume (LCNT/YSZ50), two layers of Zr0.92Y0.08O2-γ (YSZ) electrolyte, one layer of (La0.8Sr0.2)0.95MnO3 /Zr0.92Y0.08O2-γ active oxygen electrode with 50% of LSM (LSM/YSZ50), and LSM/YSZ current collector layer with high 90% of LSM content (LSM/YSZ10). The described methodology allowed to co-sinter four different layers of ceramic material and produced a stable SOFCRoll cell with minimum internal defects. The shrinking profile during sintering was the most crucial factor and was controlled by the initial pre-sintering of the material and the size of the particles.

The current 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 current collector fuel electrode layer with high Ni content allowed for the optimal use of 12 cm2 surface area in the smaller cell version. The use of shorter tapes gave shorter diffusion and current collection distance; also, the LSM/YSZ10 layer was not needed, as the whole area of the oxygen electrode was exposed for current collection purposes. While for the fuel electrode side, new tapes for the current collector were developed, such as LCNT/Ni50 composite with 50% of Ni by volume and Ni/YSZ10 composite with 90% of Ni by volume. Moreover, the co-casting method for SOFCRoll preparation was modified and improved. Giving better control over co-cast tape parameters and letting to avoid structural defects created during a cell assembly.

The paper aims to deliver the complete procedures behind the manufacturing and testing of SOFCRoll with a new configuration and assembly. These include the guidelines for material preparation and processing, tapes development, analysis of shrinking profile, cell assembly, set up of electrochemical test, data interpretation and post-mortem analysis.
Sr3Fe1.5Zn0.5O7-δ as Cathode for Protonic-Conducting Solid Oxide Fuel Cells with Enhanced Oxygen Reduction Reaction Activity
Authors: Sun Yueyue , Liu Zhengrong , Zhou Zilin , Yang Jiaming , Zhao Hongfei , Yin Chaofan , Wu Kai , Zhou Jun
Published: September 2023

Common concerns about green energy have led to a wide focus on solid oxide fuel cells (SOFCs) for their environmental friendship and high efficiency. As the most popular electrode, perovskite materials feature the flexible structure and abundant oxygen sites, which correspondingly leads to diverse doping strategies and good electrochemical performance. However, the high operating temperature results in hot corrosion of both cells and encapsulating materials. Operating under various atmospheres, the generated impurities also cause a measure of irreversible degradation. Here, we first introduced Zn to Sr3Fe2O7-δ perovskite cathode in protonic ceramic fuel cells (PCFCs). Ruddlesden-Popper oxides Sr3Fe2-xZnxO7-δ (SFZx, x=0, 0.1, 0.5) were successfully synthesized and exhibited great performance under intermediate temperatures. The polarization resistance is 0.072 Ω·cm-2 which is 47% lower than that of the undoped Sr3Fe2O7-δ, and the maximum peak power density of the single-cell of NiO-BaZr0.1Ce0.7Y0.2O3-
δ(BZCY)|BZCY|SFZ05 reaches 523.56 mW·cm-2 at 750℃, increased by 22%. The improvement is attributed to the formation of oxygen vacancies and the larger triple-phase boundary areas. Furthermore, the electrochemical impedance spectra (EIS) and distribution of relaxation time (DRT) results manifest that the rate-limiting steps are accelerated charge transfer and ionic migration processes. Finally, SFZ05 also presented better CO2 tolerance under an atmosphere of 5% CO2/air. These results display that SFZ05 is a promising candidate for a highly active and stable cathode for PCFCs.
An Analysis of Capacitive Contributions of the Cell Impedance during High-Temperature CO2 and Co-Electrolysis
Authors: Dittrich Lucy , Vinke Izaak C. , Eichel Rudiger-A , de Haart L.G.J. (Bert)
Published: September 2023

High-temperature electrolysis is often studied by electrochemical impedance spectroscopy (EIS). The EIS spectra are analyzed using equivalent circuit models (ECM). In many cases, these models use basic elements such as resistor, capacitances or inductances. The discussion of the modelling results is often limited to resistances [e.g. 1-4]. Only some rare papers discuss capacitances as well [e.g. 5-7]. A detailed analysis of all capacitive contributions of the overall cell impedance in electrolysis mode in dependence on temperature, current and composition is missing in literature.

The present study provides this detailed analysis of the capacitive contributions, which in the models are usually represented by constant phase elements (CPEs). Impedance spectroscopy measurements of high-temperature CO2 and co-electrolysis on conventional fuel electrode supported cells were performed. The cells consisted of a Ni/YSZ fuel electrode, a YSZ electrolyte, a GDC barrier layer and a (La,Sr)CoO3 air electrode. The spectra were analyzed by an ECM consisting of an inductance, a serial resistance and four RQ elements (resistance and constant phase element in parallel). The dependences of the resistances on operating conditions were already reported elsewhere [1,8].

The variation of the parameters temperature, current and composition showed different trends for the single elements. For example, the capacitive contribution of processes 1 – 3 (high to middle frequency range) increases with temperature while it decreases for process 4 (low frequency range). The low frequency process had been assigned to a gas phase diffusion process according to the dependence of the corresponding resistance [1]. The CPE element of process 4 also shows a prominent dependence on the current density. This might correlate with the changing ratio of CO2 to CO in the gas phase and thus support the assignment. Further results of the dependencies of the elements will be presented and discussed.

[1] S. Foit, L. Dittrich, T. Duyster, I. Vinke, R.-A. Eichel, L.G.J. de Haart, Processes
2020, 8, 1390.

[2] S.E. Wolf, L. Dittrich, M. Nohl, T. Duyster, I.C. Vinke, R.-A. Eichel, L.G.J. de Haart, J. Electrochem.
Soc.
2022, 169, 034531.

[3] S.D. Ebbesen, X. Sun, M. B. Mogensen, Faraday Discuss.
2015, 182, 393–422.

[4] A. Leonide, V. Sonn, A. Weber, E. Ivers-Tiffée, J. Electrochem. Soc.
2008, 155, B36.

[5] S. Primdahl, M. Mogensen, J. Electrochem. Soc.
1997, 144, 3409.

[6] E.-C. Shin, J. Ma, P.-A. Ahn, H.-H. Seo, D. T. Nguyen, J. S. Lee, Electrochim. Acta
2016, 188, 240-253.

[7] X. Ge, C. Fu, S. H. Chan, Phys. Chem. Chem. Phys.
2011, 13, 15134-15142.

[8] L. Dittrich, Tailoring of the Synthesis Gas Composition during High-Temperature Co-Electrolysis (Aachen, Germany) (2021).
Understanding La2NiO4-La0.5Ce0.5O2 Oxygen Electrode Phase Evolution in a Solid Oxide Electrolysis Cell
Authors: Olszta Matthew , Liu Tian , Escobar Julian , Le Long , Marina Olga A
Published: September 2023

This work aims to understand the decomposition mechanism of a La2NiO4 phase in La2NiO4-La0.5Ce0.5O2 (LNO-LDC) oxygen electrodes after testing in a solid oxide electrolysis cell (SOEC) at 800oC. Scanning/transmission electron microscopy (S/TEM) examination of LNO-LDC electrode at atomic level before and after testing was undertaken. Pure LNO and LDC phases as well as a low density of lanthanum phosphate (LPO) grains were detected in the as prepared (untested) oxygen electrode. P enrichment, a potential constituent in some of the synthesis additives, was found as small, nanometer scale, deposits along all grain boundaries which is suggested to poison the LNO phase during SOEC operation. Mild to aggressive decomposition of La2NiO4-La0.5Ce0.5O2 (LNO-LDC) oxygen electrode was observed after SOEC operating at 800 °C at 1.3V for 920 hours. Detailed microstructural and microchemical characterization of the decomposed regions was performed using an aberration (CS) corrected JEM-ARM200CF transmission electron microscope operated at 200 kV. The evolution of the LNO phase decomposition was noted beginning with the expulsion of Ni into the surrounding LNO matrix and grain boundaries, forming La-rich and Ni-rich phases in the LNO correspondingly. An acicular La2O3 phase was always noted initiating at either the LNO/LDC or LNO/LNO interfaces, growing and eventually intersecting one another, especially in aggressively decomposed regions. Initial decomposition exhibited single layers of Ni atoms along (004) plane of LNO, followed by gradual formation of La3Ni2O7, LaNiO3, and fine NiO (several nanometer in size) phases during moderate to aggressive decomposition. In addition, NiO was noted at LDC/LDC grain boundaries ranging from a few to several tens of nanometers thick. This presentation will demonstrate how P contamination may affect the stability of SOEC cells.
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: September 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 and the 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 about impurities interaction 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 available for electrochemical reactions (i.e., hydrogen and carbon monoxide oxidation). During the cell operation, the contaminants diffuse from the fuel channel/anode interface to the anode/electrolyte interface, causing further irreversible degradation. The in-house developed multiphysics simulation is designed to be robust for prediction of interaction between anode materials with different types of contaminants (e.g., PH3, H2S, H2Se, AsH3, and user-defined). With the model parameters calibrated in the previous study, the performance of the tubular SOFCs with different levels/types of contaminants is predicted. The tolerance limits of the SOFC cell on single and multiple contaminants are also predicted with the simulations. Furthermore, the degradation resulted from Ni coarsening and 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.
Electrical Conductivity and Electrochemical Performance of Pr Doped Ceria
Authors: Dubey Pawan Kumar Kumar , Hong Junsung , Lee Kevin X , Belko Seraphim , Aphale Ashish , Rahman Muhammad Anisur , Reisert Michael , Singh Prabhakar
Published: September 2023

PCO (Praseodymium Cerium Oxide) solid solution (0-50% PrOx) has been prepared by the conventional solid-state ceramic processing of mixed CeO2 and PrOx powders in the desired stoichiometry at 1500°C in air. Synthesized powder has been characterized for phase chemistry and lattice structure. Electrochemical characteristics of the synthesized powder has been examined using electrochemical impedance spectroscopy. The observed increase in the electrical conductivity of PCO are associated with increased concentration of oxygen vacancies created by replacement of Ce4+ ions with Pr+3 ions. The addition of PrOx also lowered the polarization and ohmic losses.
Total Energy for the SOFC and SOEC
Authors: Williams Mark , Gemmen Randall
Published: September 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) is currently developing low-cost SOFC and SOEC systems. This paper develops the governing Total Energy (TE) (kilowatt-hours per kilogram hydrogen) equation for the SOEC. The eight-component TE equation includes heat input, exergetic flows, enthalpy of vaporization, pressurization, heat loss, area specific resistance, etc. The eight-component TE equation developed, as it would happen, correlates well with the Idaho National Laboratory (INL) proven SOEC performance of 45 kilowatt-hours per kilogram hydrogen at 20 bars and 725K. TE is the key performance equation necessary for designing, predicting, and planning for SOEC and SOFC performance and cost. Important ramifications of TE are discussed.
Performance and Electrochemical Behavior of LSM Based Fuel Electrode Materials Under High Temperature Electrolysis Conditions
Authors: Vibhu Vaibhav , Vinke Izaak , Eichel Rudiger-A , de Haart L.G.J. (Bert)
Published: September 2023

High-temperature solid oxide electrolysis cells (SOECs) have gained considerable attention due to more favourable thermodynamic and electrochemical kinetic conditions over low-temperature electrolysis. The SOECs can be used for the production of hydrogen from steam electrolysis, syngas (H2 + CO) from co-electrolysis, and carbon mono-oxide from pure CO2 electrolysis. Despite several advantages, the long-term durability of SOECs is still an issue. The long-term durability of SOEC depends on the stability of electrodes as well as on the operational conditions, for example current load, temperature, and fuel gas composition. The conventional cermet-based fuel electrode i.e. Ni-YSZ shows good initial performance, however, it experiences severe degradation during long-term due to Ni- agglomeration and migration away from the electrolyte. Therefore, searching for new electrode materials is crucial in order to enhance the overall performance and durability of SOECs.

In this work, we have considered Lanthanum strontium manganite-based perovskite oxides as fuel electrodes i.e. La0.6Sr0.4MnO3 (LSM). LSM is very stable chemically under oxidizing atmosphere, however, it undergoes phase transformation into a Ruddlesden-Popper (La0.6Sr0.4)2MnO4±δ phase under reducing atmosphere. We have first prepared the electrolyte-supported single cells using 8YSZ electrolyte and LSM+YSZ/LSM oxygen electrodes. The single cells were then electrochemically characterized using AC- and DC-techniques under steam electrolysis, co-electrolysis, and CO2-electrolysis conditions in 800-900 °C temperature range. Moreover, the electrochemical behaviour of LSM+GDC (50:50) and LSM+YSZ (50:50) composite electrodes containing single cells were also investigated. The LSM and LSM+GDC fuel electrode containing single cells show good electrochemical performance in all three electrolysis modes. However, lower performance is observed for LSM+YSZ fuel electrode containing single cell. For example, a current density of 997, 1025, and 511 mA.cm-2 at 1.5 V, are obtained for LSM, LSM+GDC, and LSM+YSZ fuel electrode containing single cells respectively, with 50% N2 and 50% H2O feed gas mixture at 900 °C. Furthermore, the impedance spectra were also recorded for all these cells under OCV and polarization conditions, and fitted with an equivalent circuit model using an inductor, a series resistance and 4 R//CPE elements. The impedance spectra vary significantly with the gas compositions. The detailed electrochemical results will be presented and discussed in detail.