bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Study on Vanadium Oxide Nano-Spheres As an Efficient Electrodes for Supercapacitor
Authors: Kumar Arun kumar , Deepak Nav , Shukla Shobha , Saxena Sumit
Published: February 2024

Due to the intermittence nature of renewable sources of energy, the research community has paid close attention to energy storage devices for ensuring the continuous supply of energy. Among the other transition metal oxides, V2O5 nanostructures have some inherent properties such as their layered structure, numerous oxidation states, low cost, ease of availability, and low toxicity, seems to fit to work as an electrode material for supercapacitor application. In the current study, V2O5 nanospheres were created using a solvothermal technique. To determine the ideal calcination temperature for the synthesis of V2O5 nanospheres, a thorough experimental examination was conducted. The resulting V2O5 nanospheres were thoroughly evaluated for their temperature-dependent morphological, structural, and compositional characteristics using a variety of cutting-edge analytical techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron dispersive spectroscopy (EDS). The diameters of the nanospheres range from 1-2 micrometers, but their widths are only a few nm. The generated nanospheres electrochemical examination was performed using an aqueous LiCl electrolyte. The generated nanospheres exhibit a cyclic stability of 66% capacitance retention after 500 cycles and the maximum specific capacitance of about 360 F/g at 0.5 A/g. The exceptional reversibility and cyclic stability of the nanospheres were caused by the surface alteration brought on by calcination. The slower kinetics of electrode dissolving can be used to explain the improved cycle performance seen in this study as a result of the reduction in stress during the electrochemical reaction.

Keyword: Supercapacitor, Vanadium Pentoxide, Energy storage, Electrochemistry.
Effects of Mg2Si Addition on the Pitting Corrosion Resistance of AA7075 Prepared by Spark Plasma Sintering
Authors: Ebina Ko , Muto Izumi , Nishimoto Masashi , Sugawara Yu
Published: February 2024

AA7075 containing Mg2Si was fabricated by Spark plasma sintering (SPS). Gas-atomized AA7075 powders and Mg2Si powders were mixed and sintering was performed at 773 K for 15 min. After sintering, hot-forging was conducted at 773 K, and heat-treatment was conducted at 688 K for 2 h. The specimens were polished with a diamond paste down to 0.25 µm.

The surface of specimens was observed using an optical microscope and a field emission scanning electron microscope (FE-SEM) equipped with energy dispersive X-ray spectroscopy system (EDS). Electrochemical measurements were performed in 0.1 M NaCl at pH 6.0 adjusted with NaOH. With the exception of the electrode area, the surfaces of specimens were coated with an epoxy resin. The size of the exposed electrode area was ca. 5 mm × 5 mm. Dip and dry tests were conducted to evaluate the corrosion resistance of the specimens. The specimens were dipped in 0.1 M NaCl (pH 6.0) for 20 min and dried at 298 K and 50%RH for 60 min. In addition, the effect of Mg2Si on pH of 0.1 M NaCl was investigated. The variation of pH due to addition of Mg2Si to 1 L of 0.1 M NaCl at pH 6.0 was measured.

The open circuit potential of Mg2Si-containing AA7075 decreased significantly after immersion compared to AA7075. In 20 cycles of dip and dry, mass loss was reduced by Mg2Si addition. Oxide films containing Al were formed on the Mg2Si-containing AA7075; however, Mg was not detected from the films. When Mg2Si was added to 1 L of 0.1 M NaCl, the pH increased significantly. The increase in pH on the specimen surface is thought to contribute to improvement of the pitting corrosion resistance.
Electrochemical Frequency Modulation: Investigation of Double Layer Capacitance and Solution Resistance
Authors: Lalvani Shashi , Jaslow Ian
Published: February 2024

Electrochemical frequency modulation (EFM) is increasingly finding acceptance for the estimation of corrosion current and the Tafel parameters due to the fact that it does not cause damage to the specimen under examination. In addition, EFM assumes the open-circuit potential corresponds to the corrosion potential of the specimen. However, the current methods do not consider the influence of the double layer capacitance and solution resistance in determining the corrosion parameters. In this study we have thoroughly investigated the effect of these variables in determination of the corrosion characteristics. Two approaches involving determination of the current vs time and harmonics using a semi-analytical and numerical approach were investigated. The data show a high degree of agreement between the two approaches. In addition, our method also allows for the determination of the corrosion potential.
1-(Tert-Butoxy)Propan-2-Amine and It's Efficacy Towards Corrosion Inhibition of Mild Steel in Marine Environment – Experimental Study
Authors: Subash Smrithy , Moharana Sumedha
Published: February 2024

The alloy of iron has wide applications in industries ranging from health to construction sector. The mild steel is the most sought alloy of iron in industries and is preferred due to its low cost and better mechanical properties. Even though mild steel possesses high mechanical strength it may readily undergo corrosion during its usage in adverse environments. Therefore, in the present research an effort was made to improve the inhibition of mild steel corrosion in the presence of chloride ions using 1-(tert-butoxy)propan-2-amine. The mild steel samples were initially investigated for weight loss measurements to assess the state of mild steel in different concentrations of 1-(tert-butoxy)propan-2-amine and later subjected to electrochemical studies using Tafel polarisation and Electrochemical Impedance Spectroscopy (EIS) to know the corrosion state when exposed to inhibited and uninhibited solutions of 3.5% NaCl. The microstructural characterisation using Scanning Electron Microscopy (SEM) analysis gives the surface micrographs of the mild steel subjected to corrosion and inhibition. The inhibitor is found to perform better with high inhibition efficiency from above tests when compared to the uninhibited solution and is a clear indication of the corrosion inhibiting property of the employed inhibitor. The presence of π-electrons on heteroatoms in the employed organic inhibitor is the main reason for the inhibition efficiency and effective adsorption on the mild steel surface.
Semantic Technologies to Model Battery Data and Knowledge
Authors: Flores Eibar , Hansen Hannah , Clark Simon
Published: February 2024

Data-intensive battery research is here to stay. With open data incentives on the rise and simpler software interfaces granting access to powerful machine learning algorithms, researchers are uncovering a wealth of insights from battery data. However, data without context are just unusable digital bits. Battery data must be appropriately described to render it interoperable and reusable for traditional and data-intensive research. This requires overcoming numerous challenges associated to data heterogeneity, inconsistency, standardization, and meaning. Semantic technologies address these challenges by providing a unified and flexible framework for integrating and reasoning about data from heterogeneous sources.

In this contribution, we will introduce Semantic Technologies and how they enable both human and software agents to understand and reuse battery data. We will present the tools we are developing to i) encourage the adoption of a common standard vocabulary to describe the battery domain[1], ii) connect research resources (datasets, experts, reports, publications, projects) within an accessible platform[2], and iii) reduce the effort required to upgrade data with semantic context. Overall, these tools take concrete steps towards guaranteeing compliance with FAIR data principles. We will further outline plans for future development, including strategies for reaching out to the global battery landscape, facilitate the curation of battery data for data-driven research, and enable knowledge exploration via natural language models.

[1] S. Clark et al., "Toward a Unified Description of Battery Data," Adv. Energy Mater., vol. 2102702, 2021.

[2] https://github.com/BIG-MAP/Demo-BatteryDataSemanticSearch
Redox Additive Electrolyte Study of Metal-Organic Framework Derived Nickel Phosphide/Carbon Composite for Supercapacitors
Authors: Sundriyal Shashank , Dubey Prashant , Shrivastav Vishal , Nogala Wojciech , Bakandritsos Aristeidis
Published: February 2024

The performance and operation of an energy storage device are significantly influenced by the electrolyte and electrode materials. Therefore, it is crucial to create an electrode material with a rational design and ensure that it is compatible with the electrolyte. In this study, we prepare nickel phosphides/carbon (NP@C) nanostructure from Nickel metal-organic framework (Ni-MOF) using one-step phosphidation technique for supercapacitor applications. This method aims to produce a distinctive structure with more redox-active sites as well as improved conductivity and a high-polarized surface that will speed up ion migration between the electrolyte and the surface. In order to further enhance the redox additive sites and thus the charge transport, we have employed redox additive electrolyte (0.2M K3[Fe(CN)6] in 1M Na2SO4). Using three electrode electrochemical system, NP@C electrode obtained a phenomenal specific capacitance of 2136.3 F/g at 3A/g with a specific capacitance retention rate of 90.6% after 5000 cycles. Furthermore, a symmetric supercapacitor device is assembled using two NP@C electrodes and redox additive electrolyte that renders a high energy density of 52.5 Wh/kg at a power density of 750 W/kg along with a long cycle life of ~93% after 10000 cycles. Hence, this study demonstrates how NP@C and redox additive electrolyte work in perfect harmony to generate a high-performance supercapacitor.
Evaluating the Corrosivity of Relevant Environments That Can Form on the Surface of Spent Nuclear Fuel Canisters
Authors: Katona Ryan Michael , Knight Andrew , Bryan Charles , Schaller Rebecca Filardo
Published: February 2024

Austenitic stainless steels (SS), utilized extensively in coastal environments due to their enhanced corrosion resistance, are susceptible to localized corrosion and stress corrosion cracking (SCC) when exposed to chloride environments and sufficient stresses. One potential scenario under which SCC may pose a concern is the storage and eventual transport of spent nuclear fuel (SNF) in SS canisters. The SS canisters are stored in many locations across the United States and may be subjected to corrosion from brines formed by deliquescence of salt aerosols of varying compositions. Recently, the compositions of salts collected from the surface of SNF interim storage canisters at four different storage sites have been evaluated; these represent both coastal and inland sites, and widely differing compositions. The observed salt chemistries vary from laboratory salts commonly used in corrosion testing (i.e., NaCl, MgCl2, and artificial seawater). Herein, we evaluate the relative corrosivity of the brines through polarization scans, exposure tests, and modeling efforts. The results of this study are discussed in terms of potential canister degradation and improved methods to determine the corrosivity of field-relevant environments.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. This document is SAND2023-02443C.
In Situ Measurement of Hydrogen Absorption into Copper-Coated Titanium Using Neutron Reflectometry and Electrochemical Impedance Spectroscopy
Authors: Situm Arthur , Bahadormanesh Behrouz , Bannenberg Lars , Ooms Frans , Feltham Hunter , Popov Guerman , Behazin Mehran , Goncharova Lyudmila V. , Noël James J.
Published: February 2024

We set out to investigate the possibility that a small amount of hydrogen, generated by sulfide-driven corrosion or radiolytic processes, might be absorbed into the copper coating proposed for use as corrosion protection for the used nuclear fuel containers (UFCs) to be stored in a deep geological repository (DGR) in Canada. Hydrogen absorption may have the potential to alter the mechanical properties of the copper coating. This contribution discusses our initial study, using in situ neutron reflectometry (NR) and electrochemical impedance spectroscopy (EIS), of hydrogen absorption into a 50-nm layer of copper coated onto 4 nm of Ti on a Si single-crystal substrate. In situ NR-EIS experiments detected no increase in the hydrogen content within the copper layer of the copper-titanium thin film following 55 h of polarization in deoxygenated 0.1 M NaCl solution at pH 9, at potentials ranging from −444 mV/SCE to −1300 mV/SCE (detection limit ~2 at.%). However, these NR results showed that hydrogen can be absorbed into copper when the latter is cathodically polarized below about ─900 mV/SCE, which is the experimentally measured potential threshold for the hydrogen evolution reaction (HER) under these conditions. Although hydrogen did not accumulate in the outer Cu layer, our experiments revealed that the absorbed hydrogen quickly traversed the Cu layer to concentrate in the underlying titanium layer, which favours absorbed hydrogen. This observation is consistent with hydrogen uptake measured using inert gas fusion analysis on oxygen-free, phosphorus-doped (OFP) copper, which showed that in the absence of hydrogen recombination inhibitors (e.g., As(III)), only a small increase of 22 wt. ppm hydrogen was absorbed into the copper after 24 h at E = −1300 mV/SCE, and no increase in absorbed hydrogen occurred at potentials of −1100 mV/SCE or more positive. The initial absorption efficiency for electrolytically produced hydrogen atoms at the copper surface was determined to be 3.2%, suggesting that there may be an upper limit for hydrogen uptake by the copper coating of the UFC, although studies on 3 mm copper-coated steel samples representative of UFC materials will be required to confirm that. This result supports the prediction that hydrogen absorption is unlikely to lead to any failure of the copper barrier within a proposed DGR, in which it will not be possible to achieve such negative electrochemical potentials. Intended future research using in situ NR-EIS to study hydrogen absorption during the corrosion of copper thin films by HS⁻ ions and further studies on hydrogen absorption into 3-mm-thick copper-coated steel samples will help to validate these conclusions.
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.
Biomass Derived Flexible Free-Standing Electrodes for a High Performance Supercapacitor
Authors: Vashishth Ekta
Published: February 2024

Global energy demand, the depletion of fossil fuels, and environmental deterioration have spurred a search for significant improvements in energy conversion and storage. The need for efficient methods of electrical energy storage for on-demand use is critical. Batteries and supercapacitors (SCs) are two of the main energy-storing technologies. SCs and batteries are frequently used in everyday items like smartphones, wearable electronics, electric cars, and portable electronic devices. Supercapacitors (SCs) continue to generate a lot of attention due to their higher energy storage capacity than conventional capacitors and faster rate performance than rechargeable batteries. Supercapacitors, on the other hand, have a high-power density (>10 kWkg-1), extended cycle stability, and an increased capacity for charging and discharging quickly. Supercapacitors are divided into two major categories: EDLC and pseudo-capacitors, depending on the charge storage mechanism. At the electrode-electrolyte contact in EDLC, a double layer of charge is created. Charge transfer reactions between the electrode and electrolyte cause pseudo-capacitance to arise. Compared to EDLCs, pseudocapacitive materials have a greater capacitance. Materials that are pseudo-capacitative include transition metal oxides (TMOs) like, Fe2O3, CoO, NiO, ZnO2, TiO2, and V2O5. which are good candidates for high-performance supercapacitors. Herein, we have proposed a pseudocapacitive material functionalized carbon fabrics produced from cellulosic-based biomass material as a free-standing electrode for supercapacitor application. The fibrous electrode not only provides good mechanical flexibility but also a large surface area for electron transportation in the charging-discharging process. An excellent specific capacitance of ~ 1024 Fg-1 was exhibited in the three-electrode system. An electrochemical study for a full-cell asymmetric supercapacitor was also carried out which showed that the electrodes have an appreciable energy density of ~ 32 Wh kg-1 at a power density of ~ 120 W kg-1. In addition, a flexible asymmetric supercapacitor was also fabricated. A specific capacitance of ~ 40 Fg-1 was achieved in the device. Also, after bending at different angles there was no change in the cyclic voltammetric curve, suggesting that functionalized carbon fabric has good flexibility.

Keywords

: Supercapacitor, Cellulosic material, Free-standing, Carbon fibre
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.
Plasma and Etch Process Modulation of Subgap Trap State Density in a-Ingaznox Thin-Film Transistors
Authors: Mattson George , Vogt Kyle , Wager John F , Graham Matt Werden
Published: February 2024

Amorphous oxide semiconductors such as amorphous InGaZnOx (a-IGZO) possess a high concentration of subgap electronic trap states that control the performance of thin-film transistors (TFTs). Using an ultrabroadband spectroscopic method capable of directly resolving the subgap density of states, we report the effects of different etch processing and plasma treatments on the subgap. Back channel etch a-IGZO TFTs are shown to possess an acceptor-like zinc vacancy state centered at ~2.2 eV below the conduction band mobility edge, which is not present in top gate a-IGZO TFTs. We also explore how different active channel compositions and thermal annealing-activated hydrogen incorporation impact the subgap density of states of amorphous oxide semiconductors. Hydrogen is found to behave as a donor in both a-IGZO and a-ITGZO, forming a complex with valence band oxygen states after donating its electron due to its negative-U character in amorphous oxide semiconductors.

Figure 1
Influence of Dielectric Material Thickness on the Formation of Atmospheric Plasma
Authors: Polanšek Juš , Cvelbar Uros
Published: February 2024

This research examines the effects of dielectric material thickness and geometry on the formation of surface dielectric barrier discharge (DBD) in air. To initiate the discharge process, electrodes are connected to a high voltage source, ionizing the surrounding air and forming a thin layer of plasma near the dielectric material. The electrohydrodynamic (EHD) forces generated during this process are measured and analyzed to determine the influence of dielectric thickness and geometry on plasma formation. This study provides a more comprehensive understanding of the roles that dielectric material properties play in atmospheric plasma generation, contributing to potential optimization in the application of plasma-based technologies.
(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.
(Invited) A Flexible Anti-Biofilm Hygiene Coating for Water Devices
Authors: Niu Junjie
Published: February 2024

Biofilm is a microbiome complex comprising different bacterial colonies that typically adhere to device surfaces in water, which causes serious medical issues such as indwelling infections and outbreaks. Here we introduce a non-nanoparticle, flexible anti-biofilm hygiene coating consisting of lithocholic acid (LCA), zinc pyrithione (Zn) and cinnamaldehyde (Cn) (named as LCA-Zn-Cn) that largely prevents the bacteria adhesion to various water device surfaces such as stainless steel and glass through a synergistic mechanism (ACS Applied Bio Materials, 5 (2022) 3991). The existing chelated groups on LCA and Cn attract plenty of bacteria via hydrophobic interaction. Both bactericidal reaction by grafting biocidal groups from both LCA and Cn and bacteriostatic reaction by inhibiting cell division via zinc ions (Zn) lead to a largely improved bacteria/biofilm prevention. The antibacterial performance was assessed by using JIS Z 2801/ISO 22196 method. The designed LCA-Zn-Cn coating displayed log10 reduction of 4.23 (99.9% reduction) of E. coli and log10reduction of 3.51 (99.8% reduction) of E. faecalis on stainless steel, which are much higher than the control samples, demonstrating a promising colonization inhibition. Due to the strong crosslinked configuration, the coating still showed >90.9% bacterial reduction after 3000 abrasion cycles and over 99.9% bacteria reduction after a high flow velocity of 1.99 m/s test, which confirmed the enhanced mechanical durability. By applying either spray or dip-coating, the designed polymer composite can be coated on a variety of irregular water devices with mass production using auto-controlled robot arm. The desired hybrid coating provides an effective solution to prevent bacterium and biofilm formation on flexible water devices.

Keywords: Anti-biofilm; Anti-bacteria; Coating; Water devices; Flexibility
Effect of Annealing Temperature on the Electrochemical Behavior of Hydrothermal Assisted Bismuth Phosphate Nanostructures
Authors: Joshi Aman , Saini Sunaina , Bansal Sonia , Sharma Bharat , Chand Prakash
Published: February 2024

Abstract:

In the present scenario, society requires various energy sources due to the depletion of fossil fuels. In the current work, Bismuth Phosphate nanostructures are synthesized via the hydrothermal method at different aging periods and were further annealed at 300 These samples are abbreviated as BP6300, BP12300, BP18300, and BP24300. Further, we analyzed the synthesized samples' structural, morphological, and electrochemical behavior. X-ray Diffraction Technique is used to analyze the phase and crystal structure of all the synthesized samples. A field emission scanning electron microscope (FESEM) is used to analyze the morphology. Raman and FTIR spectra also approved the structure of materials and functional groups of all the synthesized samples. EDX spectra analysis confirmed the results quantitatively by detecting all the elements present in the synthesized material. High–resolution X-ray photoelectron spectroscopy (XPS) spectra confirmed the oxidation states of the synthesized samples. Various aging period treatments with annealing temperatures play a significant role in tuning the electrochemical behavior of working electrodes for battery or hybrid energy storage applications. The drop casting method was adopted for the fabrication of working electrodes, and all the electrochemical analysis of these electrodes was done in the 2 M KOH electrolyte solution. Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS) of all the samples were analyzed in the 3-electrode setup and exhibited a high potential window of 1.4 V. The specific capacity is found to be maximum for BP12300 samples. The investigation revealed that synthesized material could be used as an electrode for various energy storage device applications.

Keywords: Bismuth Phosphate, Cyclic Voltammetry, Galvanostatic charge-discharge, and hydrothermal method.
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).