bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Temperature Oxidation of Zircaloy-4 Under Conditions Simulating a Loss of Cooling Accident in Spent Fuel Pools Examined with Raman Imaging and 18o Tracer Techniques
Authors: Mermoux Michel , Duriez Christian 
Published: February 2024

Since the Fukushima accident, an increased attention is continuously paid to the vulnerability of the Spent Fuel Pools (SFPs). In SFPs, for different reasons, degradation of the fuel rods induced by oxidation in air-steam mixtures after dewatering is a major safety concern: (i) the cladding material is the only barrier left against fission product dissemination, (ii) the heat released by the oxidation reactions can overcome the residual decay heat of the fuel and may become the main driving force to the accident escalation, (iii) hydrogen production is a strong concern because of the presence of steam, (iv) presence of air in the atmosphere is known to be an aggravating factor because of the “catalytic” role of nitrogen on the oxidation mechanism.
In this study, high temperature oxidation tests in oxygen, air and air - steam atmospheres were performed with Zircaloy-4 cladding tubes and plates specimens. Because spent fuels are concerned, the presence of the corrosion oxide scale formed in reactor during in-service operation was also considered. The tests described in this study were restricted to the 700 – 950°C range, and mostly performed at 850°C. Raman imaging was used to examine the specimens after the oxidation tests, either directly at the oxide surface, or on metallographic preparations for cross-section examinations.
We first used new opportunities given by Raman imaging to analyze, at least qualitatively, the structural and mechanical phenomena involved in this particular corrosion phenomena. Indeed, this method can provide information on the nature of phases that are present in the scale and on the stress level with sub-micron spatial resolution. The different methods used to extract this information that is present in the Raman data will be described and discussed.
Moreover, isotopic substitution was also considered. Actually, Raman spectroscopy has also the ability to quantitatively extract the 18O distribution in a zirconia oxide scale after a two stage experiment with a fair accuracy. Raman imaging gave clear evidence for different characteristic distributions of 18O in the scales. Some of them have been correlated with the development of cracks and porosity in the oxide which allows the corroding medium to penetrate locally in the scales. Nitrogen appears to have no or limited influence on the oxygen diffusion, but is observed to reach the metal/oxide interface much faster than oxygen. Thus, we also emphasize the potential of this method to investigate the 18O distribution in such complex corrosion scales.
Anodization and Plasma Electrolytic Oxidation Treatments of AZ91D Mg Alloy in Alkaline Aqueous Solutions
Authors: Shao Zheng , Nishimoto Masashi , Muto Izumi , Sugawara Yu 
Published: February 2024

Mg alloys, such as AZ91 (Mg-9mass%Al-1mass%Zn), are lightweight materials with excellent mechanical properties. The applications of Mg alloys in automobiles could significantly contribute to reducing carbon dioxide emissions. Mg alloys are fully recyclable and abundantly available, which increases their desirability in light of rising environmental consciousness. However, the low corrosion resistance of Mg alloys is one of the major limitations to further applications.
In Mg alloys, corrosion behavior is known to be related to the microstructure. During the real-time in situ observation of the corrosion process under galvanostatic polarization, filiform corrosion proceeded along the outside of the β phase (in lamellar α + β microstructure and along the α-mother phase 1. Furthermore, the β phase exhibited a higher potential in the OCPs of each phase and a small area with the boundary in 0.1 M NaCl at pH 8.0 2. Thus, the surface films of β phases was thought to suppress the corrosion of Mg alloys. Mg alloys can be treated by anodic oxidation or plasma electrolytic oxidation to obtain excellent corrosion resistance. The latter is similar to anodic oxidation but applies a higher voltage, which causes a discharge on the electrode surface and the resulting plasma modifies the oxide film significantly.
In this study, anodic oxidation and plasma electrolytic oxidation were performed on AZ91D Mg alloy in alkaline solutions such as sodium phosphate. This study aims to compare the two methods in the same solution and to produce an Al-rich surface film with excellent corrosion resistance.
In anodic oxidation, the size of the electrode area was approximately 1 cm2. The surface of the specimen was coated with epoxy resin, followed by paraffin. The reference electrode was Ag / AgCl (3.33 M KCl). The experiments were performed at 25 ℃. The scan rate of potentiodynamic polarization was set at 23 mV min-1. The starting potential was set at 20 mV lower than the open-circuit potential. The anodic oxidation treatments were terminated at 0 V, 3 V, and 5 V. Plasma electrolytic oxidation was performed with a liquid volume of 500 mL. The sample was mounted on a resin holder. The electrode surface was approximately 50 mm2. A Pt plate was used as the counter electrode. The sample and the counter electrode were fixed at a distance of 0.5 cm. A plasma-generating power supply was used. The solution was cooled down to 20 ℃ while the voltage was applied. The frequency and the pulse interval were adjusted. The voltage and type of solution were changed to produce the film.

Z. Shao, M. Nishimoto, I. Muto, and Y. Sugawara, Corrosion Science, 192, 109834 (2021).

Z. Shao, M. Nishimoto, I. Muto, and Y. Sugawara, Journal of Magnesium and Alloys, 11, 137-153 (2023).
Visualization and Location Determination of Pit Initiation Sites in Martensitic Stainless Steel during Corrosion-Fatigue Cyclic Plastic Deformation
Authors: Lacasse Robert , Hitz Christophe , Deschênes Pierre-Antony , Montplaisir Isabelle , Damphousse Lydia , Lapointe Alexandre , Baillargeon Carlo , Grandy Lindsay , Mauzeroll Janine 
Published: February 2024

Low-carbon martensitic stainless steels, such as 13%Cr4%Ni, are widely used in manufacturing hydraulic turbine runners. High tensile strength steel, such as cast CA6NM or wrought S41500 martensitic stainless steel, has an acceptable resistance to corrosion and cavitation, and reduces the weight and cost while offering a more efficient design. During operation, the combined effect of cyclic loading (fatigue) and corrosion reduces the fatigue strength and can initiate cracks at localized corrosion surface defects.
In this study, we determined the bulk and localized corrosion behavior of wrought (S41500) and cast (CA6NM) 13%Cr4%Ni stainless steel before and after plastic deformation.
Susceptibility to pitting corrosion was studied using open circuit potential and potentiodynamic polarization measurements in 0.020 M NaCl. Localized corrosion behavior was studied using a scanning droplet cell (SDC) and oil immersed scanning electrochemical cell microscopy (OI-SECCM). The bulk and localized electrochemical measurements after different surface preparation methods (mechanical polishing, followed by etching or electro-etching in different media) were compared.
The surface defects including micro-voids and inclusions of different types were characterized. The location of pit initiation was then determined using scanning electron microscopy and profilometry imaging. A three-electrode microcell with a working electrode of 1 mm² was designed and hyphenated with optical microscope to allow in situ tracking of pit initiation and growth. Chronopotentiometry and chronoamperometry controlled pit initiation, while optical microscopy demonstrated dynamic release of corrosion products and measured oxide repassivation kinetics.
Finally, the in situ technique was developed further to include a microtensiometer fatigue apparatus to study the synergy effect between corrosion and fatigue. Location of pit initiation was compared with and without plastic deformation. Videos of pit initiation and growth will be presented.
Application of Impedance Spectroscopy in the Study of Aluminium Alloy 1100 in Cement Pastes
Authors: Li Xiang , Caes Sébastien , Pardoen Thomas , De Schutter Geert , Kursten Bruno 
Published: February 2024

In the context of an investigation of the corrosion inhibition effect of LiNO3 and Li2CO3 on Aluminium Alloy 1100 embedded in ordinary Portland cement pastes, Electrochemical Impedance Spectroscopy (EIS) technique was used to gain information on the corrosion rate and mechanism.
In parallel to the corrosion property analysis, information on the porosity of the cement paste matrix could be retrieved from EIS. This was realised by an innovative methodology combining the equivalent circuit model fitting the EIS curves with a two-phase model from the general effective media theory (GEM). The effective resistance of the cement paste used in the GEM is approximated by the resistance of connected capillary pores as provided by EIS analysis to determine the evolving porosity of cement pastes. The porosity of cement pastes is also experimentally measured by the mercury intrusion porosimetry (MIP) and is then compared with the results obtained from EIS. Meanwhile, two different curing methods were studied their influence on the porosity: (1) the cement pastes were cured in saturated Ca(OH)2 solution and (2) the cement pastes were cured in a humid argon atmosphere before to be transferred in saturated Ca(OH)2 solution.
Both MIP and EIS/GEM methods revealed similar porosity results, proving that this innovative methodology is suitable for the in situ determination of the porosity of cementitious matrices in parallel with the analysis of the corrosion reactions.
Optimization of Material Distribution in Electrodes of Power Generating Devices: A Mixed Approach
Authors: Alizadeh Mehrzad , Charoen-amornkitt Patcharawat , Suzuki Takahiro , Tsushima Shohji 
Published: February 2024

Electrochemical devices are becoming increasingly common, and advanced optimization techniques are utilized to enhance their performance. Topology optimization [1, 2] is one such technique, and it is gaining more attention as a means of improving the performance of electrochemical device. Moreover, as fabrication technologies advance, electrodes with more complex structures are becoming feasible. Previous studies [3-5] have attempted to optimize the composition of various electrochemical devices, such as fuel cells and redox flow batteries, to improve overall cell performance. Using topology optimization methods, those research works seek heterogenous distribution of materials within the electrode design domain to increase the cell efficiency. Although the methods and procedures reported in those studies are promising, their optimization approach does not provide globally optimized results. This is due to the fact that those studies only focus on optimization in a specific horizontal or vertical direction on the polarization surface. In other words, their outputs are dependent on the point at which the optimization is performed.
Power sources in electrochemical systems have an inherent optimal operating point that corresponds to the maximum output power. This presents an opportunity for a more comprehensive topology optimization strategy for power generating devices. This study introduces a novel approach called mixed topology optimization, which aims to enhance the efficiency of power sources by making simultaneous modifications to both the electrode structure and the operating conditions. The proposed strategy is self-directed and independent of the starting point. Given the highly nonlinear nature of electrochemical devices, such an approach is advantageous in identifying the globally optimized material distribution in a topologically optimized electrode. The proposed method is tested on a triple-phase electrode, and its superiority is compared with that of conventional approaches.

Acknowledgment

This work was partially supported by Grant-in-Aid for JSPS Fellows number 22J20603, JSPS KAKENHI Grant number 21H04540, and Research Strengthening Project of the Faculty of Engineering, King Mongkut's University of Technology Thonburi.

References

[1] Wu J., et al. Struct. Multidiscip. Optim.,63.3 (2021): 1455.
[2] Charoen-amornkitt P., et al. Int. J. Heat Mass Transfer, 202 (2023): 123725.
[3] Lamb J. and Andrei P. ECS Transactions, 98.9 (2020): 67.
[4] Beck V. A., et al. J. Power Sources, 512 (2021): 230453.
[5] Thomas R., et al. Struct. Multidiscip. Optim., 65.6 (2022): 171.
Accelerating Battery Electrolyte Design Process Via Closed-Loop Optimization of Simulations and Experiments
Authors: Chang Jin Hyun , Fisker-Bødker Nis , Vincent Smobin , Martinez Victor , Ta Thi Dinh , Vegge Tejs 
Published: February 2024

Designing and discovering new material combinations for battery applications has been and remains to be a slow and expensive process. It is a challenging task to develop battery electrolytes that are safe, high-performant, and cost-effective, as there are many design parameters to consider. There are many recent efforts to expedite such a process, ranging from the use of machine learning optimization techniques and lab automation to utilizing computer simulations.
We propose an automated, closed-loop optimization strategy to design electrolytes by integrating machine learning-based optimization algorithms, autonomous robotics, and molecular simulations. In particular, we demonstrate the application of our approach for designing room-temperature ionic liquids (RTILs) for Li-ion batteries, which consist of multiple salts, cations, and anions. The composition space is too vast to explore via a conventional approach. Thus, we use intelligent decision-making algorithms for selecting which composition to test next, which is carried out by the in-house robotic platform. The molecular simulations are also used to provide an in-depth understanding of the experimentally observed behavior, and the simulation results are also fed into the optimization algorithm. The presented approach is designed to be general, so it can be applied to other electrochemical applications with minimal modifications to the algorithms or the experimental setup.
Microplasma Nanoengineering of Hybrid Plasmonic Nanostructures for Rapid and Ultrasensitive Surface-Enhanced Raman Scattering-Based Sensing
Authors: Yeh Yi-Jui , Tung Kuo-Lun , Chiang Wei-Hung 
Published: February 2024

Surface-enhanced Raman scattering (SERS) is a useful analytical tool that allows ultrasensitive molecular-level detection through an enhanced electromagnetic field generated by plasmonic metal nanoparticles (MNPs), which is helpful for biomedical-based detection, environmental pollution monitoring and chemical industry. Recent study suggests that porous MNP with enhanced SERS active area and hybrid plasmonic nanostructures such as core-shell NPs and metal-semiconductor-based NPs with designed and controlled plasmonic properties can further improve the SERS responses.
Here we report a microplasma nanoengineering of plasmonic nanostrutures including Au-Ag core-shell NPs, Ag-GQD nanohydrids, and porous Au nanosturtures for ultrasensitive SERS-based applications. Microplasmas are low-emperature plasmas that feature microscale dimensions and a unique high-energy-density and a nonequilibrium reactive environment, which makes them promising for the fabrication of advanced nanomaterials and devices for diverse applications. Detailed characterization indicates the microplasma-enable controllable-designed growth of plasmonic nanomaterial with heterostructure effect, the providing enhanced charge transportation , adsorption ability or forster resonance energy transfer during Raman scattering. To understand the plasmonic effect, we use 3D confocal microRaman scattering study that shows that a large SERS volume was formed in the as-fabricated SERS-active substrates, leading to significant SERS properties of low limit of detection and high enhanced factor (EF) with the Rhodamine 6G (R6G) as the Raman probe. Furthermore, we also used the biomoleculars , medicines , and dyes as the target molecule. Our work not only provides environmentally friendly fabrication technique with strong potential for the design and growth of the nanostructure but also the fundamental insight of plasmonic nanostrutures for emerging applications including nanocataysis, sustainable energy, and biomedical imaging.
(Invited) Lithium Battery Interfacial Engineering with Thin Conformal Polymer Coatings
Authors: Tenhaeff Wyatt 
Published: February 2024

Coupled chemical and mechanical phenomena at electrode interfaces largely govern the reversibility and long term stability of lithium ion and lithium metal batteries. A well-known example in lithium ion batteries is the formation of the electrically insulating, ionically conductive, continuous solid electrolyte interface (SEI) on graphitic anodes, which passivates the electrode against further electrochemical reduction of the electrolyte. Unfortunately, this stable passivation does not occur in Si and Li metal anodes. High voltage cathodes are also prone to detrimental interfacial processes, resulting in electrolyte oxidation, gas formation, and transition metal dissolution. In response, a myriad of coating technologies has been developed to mitigate and control these interfacial phenomena and enable next-generation electrodes. These technologies must provide thin, conformal coatings over the entire electrochemically active surface area of the electrode; the coatings must also possess the requisite mechanical properties to accommodate volume dilation due to lithium insertion/extraction.
This presentation will describe the development of conformal, compliant polymer thin film coatings for lithium battery electrodes. The polymer thin films are prepared by initiated chemical vapor deposition (iCVD), which provides exquisite control over film composition and morphology by facilitating heterogeneous free-radical polymerization of vinyl monomers with thickness precision on the order of 1 nm. Poly(1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane) (pV4D4) was deposited onto silicon thin film electrodes using iCVD. 25 nm-thick pV4D4 films on Si electrodes improved initial coulombic efficiency by 12.9% and capacity retention over 100 cycles by 64.9% relative to untreated electrodes. PV4D4 coatings also improved rate capabilities, enabling higher lithiation capacity at all current densities. Post-cycling FTIR and XPS showed that pV4D4 inhibited electrolyte reduction and altered the SEI composition, with enrichment in LiF. In another example, thin conformal coatings of perfluorinated polymer were deposited onto battery-grade Cu current collectors to function as an artificial solid electrolyte interface. The effect of the film thickness on Li cycling reversibility was characterized. By galvanostatically cycling Li in an asymmetric Li||Cu cell using 1M LiFSI in a 1:1 (v/v) mixture of dioxolane:dimethoxyethane at 30°C, it was shown that the average coulombic efficiency averaged over 50 cycles increased from 98.36% for bare, untreated Cu to 99.08% for Cu coated with 25 nm of the fluoropolymer. Moreover, the 25 nm coating suppressed interfacial impedance growth on the current collector; the resistance of the coated Cu was 40% lower than the untreated Cu after 100 cycles. The mechanism by which the polymer coating enhances coulombic efficiency and suppresses side reactions will be discussed, along with discussion of the performance in practical anode-free lithium metal batteries.
Development of a NMR Device Adapted to Operando Analysis of Electrochemical Commercial Cells
Authors: Praud Raphaël , Sarou-Kanian Vincent , Sicsic David , Deschamps Michael , Salager Elodie 
Published: February 2024

NMR (Nuclear Magnetic Resonance) spectroscopy is a common analytical technique for analysing electrode materials. Most of these analyses are ex situ NMR measurements, a post mortem analysis of the cell. Yet, development of in situ and operando NMR considerably increased. Since the first in situ measurement reported by Gerald et al [1] in 2000, a large variety of operando NMR approaches have been developed and applied to batteries [2–5].Two levers of improvement remain for operando NMR: the battery-casing design, usually home-made, and the geometry of the NMR resonator used to detect the spectrum.
Battery-casing goes from flexible cells in a clear pouch to capsule, Swagelok or coin cells. Home-made casings are usually used to avoid distortion and sensitivity loss in the NMR measurement, attributed to the conductive casings. Another way of improvement is the type of NMR resonator to fit a larger variety of cell geometries. Solenoids, saddle coil, hairpin coil or parallel plates are currently used.
Electrochemistry is sensitive to cell fabrication, so home-made cells are intrinsically less reproducible than commercial cells. To increase the repeatability for a higher number of cycles and from one cell to another, we collaborate with a cell maker to get industrial pouch cells and we use commercial protocols. Nevertheless, studying such cells implies new challenges. First, strong and controlled pressure must be applied on the cell. An innovative pressure system was created to be compatible with the NMR requirements, mainly low available space and the absence of magnetic or strongly paramagnetic materials. It also involved adapting the resonator to the commercial cell geometry. The second challenge is the attenuation and distortion of the NMR signal by conductors (skin effect for radio-frequency fields).
Recently, Walder [6]. arose our interest with their report on operando NMR measurement for a stainless steel coin cell. We will present measurements that quantify the influence of the components of a commercial battery (casing material, electrodes, current collector and number of stacks).
This development and these measurements will lead in close future to performing operando NMR of commercial cells in fast charging conditions (for example on silicon Li-ion batteries).
[1] R. E. Gerald et al., J. Power Sources 89, 237 (2000).
[2] X. Liu et al., Adv Mater 33, 2005878 (2021).
[3] O. Pecher et al., Chem. Mater. 29, 213 (2017).
[4] K. Gotoh et al., J. Mater. Chem. A 8, 14472 (2020).
[5] K. J. Sanders et al., Carbon 189, 377 (2022).
[6] B. J. Walder et al., Sci. Adv. 7, eabg8298 (2021).