bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Cost Printed Point-of-Care Electrochemical Sensors for Detecting Cortisol
Authors: Mariappan Siva Ananth , Velayutham Jayasudha , Karuppaiah Gopi , Murugesan Sindhu Monica , Sekhar Praveen Kumar , Manickam Pandiaraj
Published: November 2022

Screen printing system has been used as one of the important technologies for developing ready to use portable biosensor devices. Screen printing allows the batch production of sensors on flexible substrates, textile materials and other wearable accessories. Owing to an exceptional performance such as flexibility, low cost, simple fabrication, and ability to translated into industrial scale production, screen printing technique advances the marketing potential of the electrochemical sensors. Unlike the advanced printing techniques, the screen-printing technique is less dependent on surface charge, particle size and the viscosity of the printing ink. In this work, we have attempted to develop a flexible electrochemical sensor for detecting cortisol levels using screen printing technique. Batches of three electrode sensor systems were designed and printed in uniform dimensions (2 cm x 2 cm). The mask for sensor design is fabricated using a transparent polyester sheet with an aid of XY cutter/plotter. Graphene ink was used to create working and counter electrodes, while the Ag/AgCl ink was used to create the reference electrode. A homemade silver ink stabilized with hydrogel network was used to create conductive tracks. A reagent-free detection of cortisol was demonstrated using a redox probe (methylene blue) tagged cortisol specific aptamer immobilized onto the working electrode. The variability between the sensor batches is also investigated. The functionality of the printed sensor was demonstrated for monitoring cortisol levels in human saliva samples. The printed sensing platform can also be integrated with wearable textile platform for monitoring cortisol levels in sweat.
Fabrication of Aptamer-Modified Microelectrodes for Npy Detection in Artificial Cerebrospinal Fluid Using Methylene Blue As Electrochemical Signal Amplifier
Authors: Melendez-Rodriguez Dorian Enid , Cunci Lisandro , Vazquez Yolimar , Fernandez-Vega Lauren
Published: November 2022

In recent years microelectrodes (ME) have been a great tool in the study of neuroscience. Microelectrodes are often used in neurotransmission research due to characteristics such as their small diameter, electrochemical capabilities, and compatibility with quick electrochemical procedures. Using methylene blue (MB) as an electrochemical signal amplifier allows us to assess adsorption of Neuropeptide Y (NPY) on the electrode surface in artificial cerebrospinal fluid (aCSF) with a pH of 7.4. Electrochemistry has a number of significant benefits over other methods of detection. One of these benefits is the ability to monitor a variety of molecules rather than only those that oxidize or decrease by changing the electrodes' material and altering their surfaces to provide selectivity toward the biomolecule of interest. In order to measure NPY using aptamer-modified microelectrodes with MB we first must prepare the microelectrodes by aspirating a platinum fiber into a quartz material and creating a connection. These are then cleaned electrochemically and characterized bare before being left in an aptamer solution to be modified. Then they are characterized again and left in a MB solution to complete the modifications. We were able to see the difference between the bare and modified electrodes during the characterizations as well as a constant peak of MB through the use of Square Wave Voltammetry (SWV) when characterized in aCSF which leads us to conclude that our method is successful in measuring and detecting different concentrations of NPY. We were able to measure NPY at varying concentrations ranging from 1 to 1000 pg/ml. This was observed as a reduction of the signal of the MB peak as the concentration of NPY is increased.
Npy Selectivity on Methylene Blue Aptamer-Modified Microelectrodes
Authors: Ospina-Alejandro Monica , Fernandez-Vega Lauren , Vazquez Yolimar , Melendez-Rodriguez Dorian Enid , Cunci Lisandro
Published: November 2022

Over the past 50 years, there has been a significant improvement in our understanding of neurotransmitters, especially in relation to depression, schizophrenia, Parkinson's disease, and Alzheimer's disease. However, little is known about how neuropeptides are released and work, and much of their activity is inferred through indirect observations. Since neuropeptides are non-electroactive molecules and are therefore challenging to detect, it is essential to develop an analytical approach for measuring them. The most prevalent neuropeptide in the brain is called neuropeptide Y (NPY), and it has been linked to a wide range of biological functions and diseases, including post-traumatic stress disorder (PTSD), depression, anxiety, obesity, alcoholism, mood swings, and eating disorders. There is currently no technology for measuring NPY in the brain with great temporal and spatial resolution. In order to comprehend the process in which NPY is engaged, we thus proposed the building of a biological sensor. This study focuses on affinity-mediated electrochemical techniques for NPY detection and measurement. In order to take advantage of the affinity between Pt and a thiol group in the aptamer structure, an aptamer—a short single-stranded DNA with high affinity by NPY—was connected to a Pt surface of a microelectrode. The aptamer was then conjugated to a redox molecule, such as methylene blue (MB), to boost the electrochemical signal and enable quick monitoring of NPY levels in real time. To find NPY in synthetic Cerebrospinal Fluid (aCSF), real-time methods including square wave voltammetry (SWV) and cyclic voltammetry were investigated. We were able to determine the concentration of NPY in aCSF (pH = 7.4) since MB produced a distinctive signal in both procedures. As the NPY molecules interacted with the aptamer, the MB electrochemical signal was altered, resulting in a "signal-off" sensor. With the aid of these findings, we were able to create a calibration curve that will serve as the foundation for further Fast Scan Cyclic Voltammetry (FSCV) experiments that will improve the temporal and spatial resolution of our studies. Recent studies have been directed towards the testing of the selectivity by measuring different neuropeptides and their selectivity towards the aptamer-modified microelectrodes.
Multichannel Bioelectronic Sensing Using Engineered Escherichia coli
Authors: Zhang Xu
Published: November 2022

Whole cell bioelectronic sensors enable the conversion of chemical signals into electrical signals using extracellular electron transfer pathways. However, these sensors use a single extracellular electron pathway as a single electrochemical channel, severely limiting the capacity of the information exchange. To expand the information content, we report a multichannel bioelectronic sensor in which different chemical modules modulate distinct extracellular electron transfer pathways in Escherichia coli. We have introduced two reporting channels into a single Escherichia coli: 1) Mtr pathway from Shewanella oneidensis; 2) riboflavin synthesis pathway from Bacillus subtilis. By upregulating the exogenous riboflavin pathway, we doubled the extracellular flavin concentration. The presence of flavins yielded a distinct electrochemical signal at more negative potentials than the Mtr pathway. To demonstrate multichannel bioelectronic sensing of heavy metals, expression of the Mtr and RF pathways were placed under control of As and Cd responsive promoters. Using a redox-potential-dependent algorithm, multichannel bioelectronic sensors could distinguish As, Cd, and a combination of As and Cd in situ in environmental samples. These accomplishments provide a new platform for multichannel bioelectronic sensors that simultaneously detect different chemicals and expand the information content from biosensors to help safeguard human and environmental health.
Synthesis, Structural and Electrochemical Properties of Sodium Transition Metal Fluorosulfate Cathodes for Na-Ion Batteries
Authors: Ahuja Vinita , Senthilkumar Baskar , Senguttuvan Premkumar
Published: November 2022

The development of low-cost and sustainable rechargeable batteries is attractive for storing energy from renewable sources. At present, the expansion of Na-ion batteries (NIBs) serves as an appealing solution from the perspective of both raw material abundance as well as the cost in comparison with the existing Li-ion batteries.1 However, the energy densities of NIBs are lower compared to their Li-ion counterparts due to thermodynamic reasons. To address this issue, researchers have turned their attention towards the development of high energy density cathodes, such as Na3V2(PO4)2F3 and Na3V2(PO4)3-type materials,2 in which the operation of multi-redox couples render high storage capacities. Moving forward, the replacement of PO4
3- by SO4
2- provides higher intercalation voltages (due to inductive effect), thereby further improving the overall energy density of cathode. 3 The inclusion of fluoride into the sulphate based polyanionic frameworks will help to increase the operating voltage through inductive effects.4 This will enhance cationic mobility by reducing electrostatic interactions along conduction channels, thereby, lead to increase in cell capacity.

Herein, we report synthesis, structural and electrochemical properties of two classes of sodium transition metal fluorosulfates, namely Na3MF2(SO4)2 and jarosites NaM3(SO4)2(OH/F)6 (M= V and Mn etc.,). The Na2VF3(SO4)2 framework consists of chains of trans-VO2F4 octahedra linked to each other via vertex sharing of F atoms and bridged by SO4 tetrahedron as adjacent pairs. 5 Jarosite is a natural mineral to be found in acidic and sulfate-rich environments with a general formula of AM3(SO4)2(OH)6, where A = K+, Na+, and NH4
+ and M = Fe3+, Cr3+, V3+, Ga3+, Al3+, and In3+. Jarosite crystals stabilize in a trigonal system with space group R3m. The structure is composed of 2D uneven layers formed by linkage of transition metal octahedra [MO2(OH)4] and sulfate tetrahedra (SO4), that are stacked along the c direction. 6 We unveil the details of growth mechanism of these materials in hydro- and solvo-thermal conditions using X-ray diffraction and microscopy techniques. Further, the mechanism of electrochemical (de)sodiation reactions in these materials will be presented using galvanostatic cycling and in-operando XRD measurements.

References:

Hwang, J. Y.; Myung, S. T.; Sun, Y. K. Sodium-Ion Batteries: Present and Future. Soc. Rev.
2017, 46 (12), 3529–3614.

Lalère, F.; Seznec, V.; Courty, M.; David, R.; Chotard, J. N.;Masquelier, C. Mater. Chem. A. 2015, 3, 16198-16205

Lander, L.; Tarascon, J. M.; Yamada, A. Chem. Rec.
2018, 18, 1394–1408

Senthilkumar, B.; Murugesan, C.; Sharma, L.; Lochab, S.; Barpanda, P. Small methods
2019, 3, 1800253

Wang, Q.; Madsen, A.; Owen, J. R.; Weller, M. T. Commun.
2013, 49 (21), 2121–2123.

Gnanavel, M.;Pralong, V.; Lebedev, I.; Caignaert, V.; Bazin, P.; Raveau, B.Chem. Mater.
2014, 26, 15, 4521–4527
Alloy Anodes for Nonaqueous Calcium-Ion Batteries
Authors: Briselli Vincent , Yang Zicheng , Cora Saida , Sa Niya
Published: November 2022

In the search to find new battery technologies that will extend current Li-ion technology towards the high-energy density and stability required for extended-range electric vehicles and efficient grid energy storage, earth-abundant working metal ions are increasingly being investigated. Calcium ion batteries are of interest due to calcium’s wide accessibility and abundance in the earth’s crust, but present novel challenges, such as sluggish diffusion kinetics and lack of known suitable intercalation hosts. The replacing of Ca metal anodes with new alloy materials that can work reversibly in current electrolyte systems is one practical route towards realizing the high voltage and capacity of a calcium battery. This complements current research in conventional Li-ion batteries to replace the conventional graphite anode by Group IIIA and IV elements. In this work, research into new alloy designs in novel electrochemical systems for Ca batteries will be explored and evaluated alongside key issues and challenges towards commercial applications.
Influence of the Molar Ratio of Co and V in Bimetallic Oxides on Their Pseudocapacitive Properties
Authors: Quispe Garrido Lady , Monje Ivonne , López Elvis O. , Gonçalves Josué M. , Ruiz Montoya José G. , Planes Gabriel , Baena Moncada Angélica
Published: November 2022

Abstract

Bimetallic oxides have attracted significant attention as supercapacitor electrode materials due to their highly reversible redox processes, which are commonly associated with their surface chemistry and morphological features. In this work, bimetallic oxides with different molar compositions of Co and V, denoted Co0.6V0.4, Co0.65V0.35, and Co0.7V0.3, were synthesized by a modified solvothermal method using glycerol as stabilizing agent. The electrochemical characterizations were measured in a three-electrode cell. The role of the composition of CoV oxides on the pseudocapacitive properties was studied through the analysis of the energy storage mechanism following the power - law and Dunn's methodology (Wang et al., 2007), to obtain the b values. The synthesized CoV oxides were observed to be small conglomerate particles with undefined morphology and crystal structure corresponding to Co3V2O8 with small shifts due to crystal lattice distortion as was evidenced by TEM and XRD characterizations (Fig.1). These results indicated that the bimetallic oxides with a molar composition of Co0.6V0.4, Co0.65V0.35 and Co0.7V0.3 showed values of b of 0.91, 0.73, and 0.82 and a capacitive current contribution of 68, 63, and 66% analyzed at a scan rate of 1 mVs-1, respectively. In addition, the Co0.7V0.3 oxide showed a specific capacitance of 299 F g-1 at a current density of 0.5 A g-1 using 1 mol L-1 of KOH, and a high-rate capability of 81% at current densities of 0.5 - 6 A g-1. The better electrochemical performance of this sample is attributed to the synergistic effect of the Co and V atoms, since a minimal amount of V atoms may distort the crystal lattice and improve the electrolyte diffusion.

Keywords:

Co-V oxides; capacitance;
pseudocapacitive; supercapacitors; rate capability.

References

Wang, J., Polleux, J., Lim, J. & Dunn, B. (2007). Pseudocapacitive contributions to electrochemical energy storage in TiO2 (anatase) nanoparticles. The Journal of Physical Chemistry C, 111(40), 14925–14931.

Figure 1
Energy-Efficient Synthesis of Surface-Modified LiCoO2 for Better Performance at Higher Voltage, Higher Rate through Suppression of Transition Metal Dissolution, and Li-Vacancy Ordering in the Monoclinic Phase
Authors: Mishra Govind Kumar , Gautam Manoj , Sau Supriya , Mitra Sagar
Published: November 2022

The necessity for a 300-mile driving range with 60–70 kWh of energy at the battery pack level has steered LIB research toward high-energy-density-based cathode materials. Because of its larger theoretical capacity (274 mAh g-1) compared to lithium iron phosphate and lithium manganese oxide-based cathodes, layered oxide cathodes have the potential to attain higher energy density LIBs. Despite its greater cost, LCO still has a higher demand (>21%) than any other cathode material. The current research on LiCoO2 (LCO) as a cathode is centered on its surface protection which allows for the extraction of more than half of the Li. Several techniques have been investigated to protect the LCO surface from direct contact with the liquid electrolyte while retaining structural integrity at higher cut-off voltages (≥4.5 V). The LiCo0.5Mn1.5O4 (LCMO) coating material is utilized here, which has a spinel structure and allows for three-dimensional (3D) lithium diffusion. Microwave-assisted heating was used for the synthesis of surface-modified LCO material. During synthesis, some Mn3+ diffused into the bulk of LCO, increasing its lattice parameter and allowing Li-ion kinetics in LCO to function at a faster cycling rate for longer cycle life. The modified LCO is subjected to a higher rate (3C) for longer cycle life with ~57.3 % capacity retention after 500 cycles. Here, a novel understanding of higher rate capability (at 3C, 5C, and 10C current rates) and stability at the higher cut-off voltage for modified LCO has been proposed. Entropy measurements were used to evaluate the arrangement of Li-ion and vacancy in the LCO lattice at different states of charge to investigate the stability of coated LCO at the higher voltage. The full cell and 15 mAh pouch-type cell were also fabricated with Si as an anode for its commercial scalability.
Critical Barriers to Successful Implementation of Mn-Rich Cathodes: A Study of Low SOC Impedance
Authors: Chen Jiajun , Gutierrez Arturo , Saray Mahmoud Tomadoni , Shahbazian-Yassar Reza , Balasubramanian Mahalingam , Wang Yan , Croy Jason R.
Published: November 2022

The development of sustainable materials for lithium-ion batteries is of paramount significance with the ever-growing demand of energy storage for the transportation sector. Lithium- and manganese-rich oxides are of great interests because of inherently high capacities/energies and the potential economic benefits associated with earth-abundant manganese-based compositions. With several challenges hindering the commercialization of these cathodes, there have been many studies on understanding the mechanisms of voltage fade, hysteresis, and oxygen activity. However, relatively little attention has been given to understanding the impedance of these materials. In particular, the drastic rise in area specific impedance at lower states of charge, and the overall impedance rise on extended cycling due to surface issues, are critical barriers that need to be understood and addressed to accelerate deeper market penetration.

This poster will present a detailed study of the impedance behavior in cobalt-free, lithium- and manganese-rich cathodes. A combined surface-treatment/electrolyte-additive has been used to probe the behavior over long-term cycling in the absence of (i.) surface issues, (ii.) the impedance rise due to electrolyte interactions, and (iii.) capacity loss. The results presented in the poster support the hypothesis that the anomalous rise in impedance at lower states of charge is directly associated with the bulk processes of voltage fade and voltage hysteresis. Furthermore, a preliminary conceptual model is presented for understanding the impedance behavior of these activated materials, which can be described as layered-type, ordered-domain network with facile Li diffusion, where interspersed, disordered, low-voltage sites within this network hinder the Li insertion.
(Digital Presentation) Synthesis of Fluorescent Carbon Nanoparticles (CNPs) By Microwave-Assisted Polymerization of Sp-Carbon Rich Precursors
Authors: Jayswal Vijay Kumar , Ritcey Anna M. , Morin Jean-François
Published: November 2022

Carbon nanoparticles (CNPs) have emerged as one of the most promising nanomaterials due to their distinct optoelectronic properties for a diverse range of applications. These unique properties arise from the network of hybridized sp2
carbon atoms as it allows delocalization of the electrons over the entire surface of the molecule. These surface groups help CNPs emit strong fluorescence in visible region. The significant fluorescence of CNPs combined with low toxicity, and photostability makes them suitable for various applications in biosensing, bio-imaging, and OLEDs. Despite several advantages and unique properties, the transformation from laboratory to industrial products has been slow for carbon nanoparticles. The synthetic methods reported until now chemically inert nanoparticles, increasing the difficulty to modulate their morphological, optical, and electronic properties. The organic synthesis methods for synthesizing CNPs often involve several synthesis steps, long reaction time, low yield, non-scalable and inefficient purification methods. Most of these synthesis methods involve several catalysts and removal of catalysts is always a challenge. Resulting nanoparticles also need functionalization using another synthesis step to give them properties such as fluorescence and making them soluble. Therefore, a synthesis method with minimum steps, minimum catalysts which could result in soluble and fluorescence nanoparticles is desired.

This work investigates the use of highly reactive sp-carbon rich precursors for polymerization with microwave heating with minimum use of catalysts resulting in fluorescent CNPs. The sp-carbon rich precursors such as TMS-Benzene, butadiyne and acetylene were used as starting material. These alkynes are highly reactive and reacts to other alkynes present in the system in the presence of heat and form polyyne intermediates which are thermodynamically unstable in the form of long chains and decompose to provide us with CNPs. The plan is to use the high reactivity with microwave heating for polymerization without catalysts and further investigate the use of oxidants or minimum catalysts to increase the rate of polymerization and conversion into CNPs. The resulting nanoparticles required minimum purification in centrifuge and were isolated easily as there were no catalysts involved. The resulting nanoparticles were characterized with various techniques to study the morphology, structure, composition, and optical properties of CNPs. The resulting nanoparticles had blue fluorescence under the UV lamp. The single step synthesis of blue fluorescence CNPs was performed with microwave assisted polymerization of sp-carbon rich precursors without any catalysts. Further investigation of this method will provide a single step synthesis method for fluorescent CNPs which would be suitable for application in sensing and OLEDs.
Low Shear Force Defect Removal from SiC Using Megasonic Enhanced Cleaning
Authors: Miliauskas Mantas M. , Keleher Jason J. , Caridi Adam T.
Published: November 2022

Wide band gap (WBG) materials (i.e., Silicon Carbide (SiC)) have attracted much attention in the semiconductor arena because of their intrinsic properties (i.e. high capacitance, thermal stability, and wear resistance). In order to achieve the desired removal rate and surface planarity during the Chemical Mechanical Planarization (CMP) process of SiC substrates high shear force and chemically aggressive conditions are employed. Although effective this process can result in significant surface contamination/defectivity (i.e., organic residue, abrasive particles, etc.) post-polish. Current methods of post-CMP cleaning for SiC substrates implement a Polyvinyl Alcohol (PVA) brush scrubbing to aid in surface contaminate removal. A balance of controlled shear force and interfacial adsorption/redox reactions are necessary to effectively remove rouge contaminates without any generation of secondary defects. This research focuses on development of a “soft” (low-shear force) post-CMP cleaning process for SiC which uses transient cavitation effects via megasonic energy coupled with catalytic complexes to enhance reactive oxygen species (ROS) generation. More specifically, hydroxyl radical (*OH) generating organometallic complexes were incorporated into the cleaning fluid to increase ROS and provide additional surface-active chemistries to disrupt the defects non-covalent surface binding energy. Initial results show increased ROS generation (which is complex structure dependent) improved defect removal efficiency under static megasonic conditions with no changes to the surface energy of the final polished SiC substrate.
Magnetron Sputtering Deposition of Lead-Free (SAC) Thin-Film Alloys and Mechanical Characterization Using Nanoindentation
Authors: Ojha Manish , Mohamed Yousuf S , Baumgart Helmut , Elmustafa Abdelmageed
Published: November 2022

Electronic packaging industries are in an ongoing transition to lead free soldering due to the adverse effect on environment and human health [1]. Sn-Ag-Cu (SAC) have been recognized as promising alternatives due to its low eutectic temperature, higher wettability and strength, superior resistance to creep and thermal fatigue. Surface roughness has a significant influence on mechanical parameters determined nanoindentation tests. Although research has been conducted to analyze the mechanical properties of bulk SAC material, there have been limited prior studies on SAC thin films and their mechanical properties since fabricating a smooth SAC thin film is a fundamental challenge. SAC thin films with four different Sn–Ag–Cu ternary eutectic composition: 96.5Sn-3.0Ag-0.5Cu, 95.5Sn-3.8Ag–0.7Cu, 95.5Sn-3.9Ag–0.6Cu & Sn-4.0Ag–0.5Cu will be deposited using RF magnetron sputtering with different deposition rates and annealed at various temperature to fabricate a smooth continuous film. Figures 1 and 2 depict SAC05 deposited using RF magnetron sputtering at Figure 1: SEM image of SAC-05 surface at 10,000X. 20W, 2.4 mTorr pressure, and argon flow flow rate of 20.5 sccm. Surface morphology will be examined using Field emission Scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). Crystallinity of the deposited film will be examined using X-ray diffraction (XRD). Mechanical properties will be studied using nanoindentation [2]. Properties of the thin film will be compared with the bulk material with similar eutectic composition.

References

M. Abtew G. Selvaduray. (2000). Lead-free Solders in Microelectronics. Materials Science & Engineering. a Review Journal., 27(5-6), 95.

Long, X., Wang, S., Feng, Y., Yao, Y., & Keer, L. M. (2017). Annealing Effect on Residual Stress of Sn-3.0Ag-0.5Cu Solder Measured by Nanoindentation and Constitutive Experiments. Materials Science and Engineering: A, 696, 90-95.

Figure 1
Rapid Joule Heating Method Applied to Solid State Electrolyte Materials
Authors: Berz Lily L , Westover Andrew S , Liu Nian , Sacci Robert L
Published: November 2022

Designing a solid-state battery is a balancing act. Fast charging rates and high capacity are preferable, but safety and long battery lifetimes must also be preserved. When making a solid-state electrolyte, amorphous materials with greater lithium content are ideal—they have greater conductivity than their lower-lithium-content counterparts. In addition to high lithium content, recent studies have focused on eliminating grain boundaries in solid state electrolytes. Eliminating grain boundaries allows for safer charging and discharging by reducing the chances of dendrite formation and subsequent shorting. Through experiments, we tried to reconcile amorphous character and relatively higher lithium content to produce a mechanically robust, conductive electrolyte material that lasts over many cycles. We first coarsened Li3BO3 powder in a tube furnace, then pelletized the powder at 253,411 bar via hydraulic press. The rapid joule heating method involves two carbon papers connected in parallel with a DC power supply. Using this configuration, we had access to rapid quenching rates that typically require expensive technology. Resistance from the carbon paper resulted in a rapid temperature increase proportional to the applied current so the carbon paper acted as a heating element. The Li3BO3 pellet was inserted between the two papers where it heated to its melting temperature (760-880°C) within 20 sec. We hypothesized that shorter ramping and cooling times introduced by rapid joule heating would promote amorphous character in Li3BO3, compared to samples prepared in a tube furnace with longer heating and cooling times. Full width at half maximum values calculated from X-ray diffraction results for each sample suggest the samples prepared using rapid joule heating formed smaller crystalline domains than those manufactured in the tube furnace. Scanning electron microscopy images taken at 5.0k magnification confirm this calculation. Large grains can be seen in the traditionally heated sample whereas no grains are observable in the rapid joule heated sample. Smaller crystalline domains emphasize the effects of rapid cooling and encourage future studies in escalating heating and cooling rates to produce amorphous or partially amorphous electrolytes.
Electrodeposition of Rhenium Sandwich Structures and the Superconducting Transition Behavior
Authors: Ahammed Kamal , Huang Qiang
Published: November 2022

Superconductors with enhanced superconducting critical temperatures (Tc) above the boiling point of liquid helium (4.2 K) are of interest for interconnections in superconducting quantum computing systems to avoid ohmic heating[1]. Crystalline Re in bulk is a type-I superconductor with a Tc of about 1.7K[2]. An elevated Tc up to about 6K in electrodeposited amorphous Re has been reported[3]. In addition, various elevation in Tc has also been reported for Re film under shear strain[4] or doped with foreign elements such as Tungsten (W), Osmium (Os), and Carbon (C)[5, 6].

This work aims to test a hypothesis that the Tc of electrodeposited Re films can be tuned using compressive and tensile strains on the Re films generated with thermal expansions difference. Figure 1 shows a diagram of the strains on Re film sandwiched between metals with different coefficients of thermal expansions (CTEs) when the temperature is lowered. For example, Cu has a higher CTE than Re and Cr has a slightly lower CTE than Re. Such sandwich structures are prepared at room temperature using electrochemical deposition. The DC resistance measurements at cryogenic temperatures confirmed that the superconducting transition for the Re films sandwiched between Cu occurs at a lower temperature than the Re film alone. On the other hand, when Cr is used, the sandwiched Re structure shows a slightly enhanced superconducting critical temperature. The effect of thermal annealing i.e., the recrystallization of electrodeposited Re films at an elevated temperature, and electrochemical behavior of Re, Cr, and Cu electrodeposition will be discussed in the talk.

References

Radenbaugh, R., Refrigeration for superconductors. Proceedings of the IEEE, 2004. 92(10): p. 1719-1734.

Hulm, J.K., Superconductivity of Pure Metallic Rhenium. Physical Review, 1954. 94(5): p. 1390-1391.

Pappas, D.P., et al., Enhanced superconducting transition temperature in electroplated rhenium. Applied Physics Letters, 2018. 112(18): p. 182601.

Mito, M., et al., Large enhancement of superconducting transition temperature in single-element superconducting rhenium by shear strain. Scientific Reports, 2016. 6(1): p. 36337.

Chu, C.W., W.L. McMillan, and H.L. Luo, Superconductivity of Re-Os, Re-Ru, Ru-Os, and Re-W hcp Alloy Systems and Slightly Doped Re. Physical Review B, 1971. 3(11): p. 3757-3762.

Zhu, Q., et al., Anisotropic lattice expansion and enhancement of superconductivity induced by interstitial carbon doping in Rhenium. Journal of Alloys and Compounds, 2021. 878: p. 160290.

Figure 1
Mixed Metal Oxides for Oxygen Reduction Reaction: Strategies for Suppressing H2O2 Formation
Authors: Biswal Sekhar Kumar , Ranjan Chinmoy
Published: November 2022

Widespread implementation of fuel cell technology has been hampered by challenges originating from the oxygen reduction reaction (ORR). Even the most advanced ORR catalysts present high overpotentials and poor selectivity for the reduction of O2 to H2O. A substantial amount of H2O2 is generated as a product of incomplete reduction.

We developed a series of cost-effective cobalt-doped copper oxide (Cu[Co]Ox) catalysts supported on Au. These catalysts not only show lower overpotentials but also very high selectivity for the complete reduction of O2 to H2O.

Specifically, Cu-rich compositions, such as Cu0.8Co0.2Ox/Au, demonstrated remarkable activity and > 97% selectivity for H2O over a sizeable potential range (1.0 – 0.6 V) relevant to ORR. These catalysts were found to even outperform Pt in both activity, selectivity, and performance stability.

These catalysts have been investigated using in situ Raman Spectroscopy and X-Ray Photoelectron Spectroscopy. Our studies indicate that the doped materials have a Co-active site embedded within the CuOx framework. The resulting sites lower the free energy of the potential determining step and enhance yield for the complete reduction to H2O. Specifically, these catalysts preferentially cleave the O-O bonds result in high selectivity for the 4e pathway.

Figure 1
A Mechanistic Approach to Enhance and Better Understand the Carbon Dioxide Reduction Reaction
Authors: Weiss John , He Yanghua , Zelenay Piotr
Published: November 2022

While the carbon dioxide reduction reaction (CO2RR) is a promising approach to the synthesis of value-added chemical conversion, much is left unknown regarding the kinetic and mass transport mechanisms which govern product selectivity and overall reaction rate. This study investigated Ni- and Cu-based catalysts largely derived from ZIF-8 precursors with the aim of generating products with high partial current densities and faradaic efficiencies. A particular focus was put on tandem electrocatalysis, where Cu-based active sites were synthesized in the presence of Ni-N-C to achieve multi-carbon products in increased quantities. Both H-cell and rotating disk electrode (RDE) voltammetry experiments were employed to determine the mechanistic tendencies and limitations for several catalysts showing high selectivity for individual CO2RR products. Results have indicated the tunability of several catalysts towards the production of syngas with varying ratios of CO and H2. The kinetic characteristics and tendencies of tandem electrocatalysts are also inferred through the variation of active site loading and proximity, as well as the use of electrode rotation during electrochemical measurements.
Controlled Nanoporous Structures of Ultrathin π-Conjugated Polymer Films for Highly Sensitive Gas Sensors
Authors: Wi Eunsol , Tran Vinh Van , Chang Mincheol
Published: November 2022

Conventional OFET-based chemical sensors have severe limitations in terms of sensitivity owing to poor analyte diffusion and poor interaction between the analyte and charge carriers in the CP film. To overcome this drawback, it is imperative to fabricate CP films that can facilitate analyte diffusion and provide large adsorption sites for interactions between the analytes and charge carriers concentrated in the conducting channel of OFETs. This study is to develop a facile strategy to fabricate ultrathin nanoporous Conducting polymer(CP) films for high-performance OFET gas sensors based on shearing-assisted phase separation (SAPS) of polymer blends, followed by selective solvent etching. In this method, the morphological features of nanoporous CP films, such as pore size and film thickness, can be tuned in the nanoscale regime by simply varying the shear rate. This indicates that the nanoporous P3HT films were ultrathin. Owing to these morphological features, the resulting OFET sensors exhibited excellent sensing performance when exposed to NH3 gas. We demonstrated that our approach for modulating the morphological features of CP thin films is also applicable to other CP/insulating-polymer-blend systems, including P3HT/PMMA and DPP-DTT/PS. The proposed strategy is simple and universal and can be used to fabricate ultrathin nanoporous CP films, which in turn can enable the development of high-performance, low-cost, portable OFET sensors for various commercial applications.
Sacrificial Template Method to Fabricate Highly Sensitive Porous Capacitive Pressure Sensor for Full Pulse Waveform Detection
Authors: Chowdhury Azmal , Jafarizadeh Borzooye , Pala Nezih , Wang Chunlei
Published: November 2022

Due to the recent advancements in sensing technology, skin mountable wearable devices have gained much attention due to their non-invasive usage and wearer comfort for health care monitoring. For instance, monitoring pulse waveform from the wrist arterial sites bears tremendous information about cardiovascular health and can show abnormalities such as hypertension or arterial fibrosis. Acquiring a high-quality pulse waveform from the wrist artery requires high-pressure sensitivity and fast response time. However, the need for building highly sensitive and low-cost fabrication of the sensors for subtle physiological monitoring is still challenging. Targeting these issues, this study presents a facile and cost-effective approach to realizing a flexible capacitive pressure sensor by sandwiching porous polydimethylsiloxane (PDMS) polymer functionalized by multi-walled carbon nanotubes (MWCNTs) fabricated by sacrificial template method for physiological monitoring. The fabrication steps for the dielectric layer involve mixing sucrose as the porogens and MWCNTs as the functionalizing material with PDMS followed by casting the mixture in a mold and curing of the PDMS. Subsequently, the sucrose particles are dissolved in water. The sucrose particles are easily dissolved in water leaving a highly uniform and porous structure behind. The dielectric layer is then sandwiched between two conductive textile based electrodes for physiological monitoring. The electromechanical tests were performed for different concentration of MWCNTs content in porous PDMS to obtain the best sensing performance. The champion sensor exhibits ultrahigh-pressure sensitivity of 2.41kPa-1 and a minimum detection limit of 1.4Pa in contrast to the sensor exhibiting only 0.31kPa-1 without addition of any MWCNTs. In addition, the pressure sensor shows a fast response time of 0.18s and excellent cyclic stability over 6000 cycles. The ultrahigh-pressure sensitivity comes from the addition of conductive MWCNTs filler that increases the dielectric permittivity. The highly porous structure of the polymer reduces the typical viscoelastic effects of polymer resulting in fast response time. The pressure sensor could detect arterial pulse waveform from the wrist artery with all the key characteristic points showing its promises for low-cost physiological monitoring. The detailed results will be discussed during the presentation.
Milligrams to Kilograms - Scaling Production of Cobalt Free Lithium Excess Cathode Materials through Rotary Calcination
Authors: Burke Sven Anders , Whitacre Jay
Published: November 2022

Both Tesla and the Government of the United States have listed the elimination of cobalt and the resilience of the battery cathode supply chain as critical issues in need of advancement 1,2. This investigation answered this call to action through scaling the production of a high-performance cobalt free lithium excess cathode material using rotary calcination. The cathode in this investigation is of the chemical series Li[NixLi(1/3-2x/3)Mn(2/3-x/3)]O2 (where x = 0.25), and to our knowledge this marks the first time an investigation has demonstrated the scaling of this class of materials. In order to achieve the several orders of magnitude increase in production scale the precursor feedstock for rotary calcination required comparison of sol-gel, Pechini, and solid-state precursors routes. Viability of each precursor synthesis route required comparison of synthesis time, synthesis complexity, Thermogravimetric Analysis, Dynamic Scanning Calorimetry, X-Ray Diffraction of intermediate and final materials, as well as Galvanostatic cycling of final cathode materials. Modification and controlled decomposition of sol-gel processing was ultimately used for the scaled production of precursor powders. Once the precursor feedstocks were fed through the rotary kiln we used X-Ray Diffraction, X-Ray Fluorescence, Galvanostatic Testing, and Scanning Electron Microscopy of resultant materials to optimize rotary calcination conditions to find the pareto optimal conditions that allowed for maximized material quality, and output, with minimized energy and time costs. These materials were also compared to our baseline material, which was made in a box furnace in ambient conditions over the course of 24 hours. Synthesis conditions were also modified to allow for the inclusion rapid water quenching of final scaled material to ensure material quality.

Sources:

F. C. for A. Batteries, National blueprint for lithium batteries 2021–2030, (2021).

E. Musk and R. Denholm, UPDATES TO 2020 ANNUAL MEETING OF STOCKHOLDERS AND BATTERY DAY EVENT, (2020).
Strain and Temperature Behavior of Lithium-Ion 18650 Cylindrical Batteries
Authors: Bezsonov Igor Igorevich , Nadimpalli Siva , Waller Gordon Henry , Hendricks Christopher
Published: November 2022

Modern technology, from portable electronics to electric vehicles, is increasingly reliant on lithium-ion batteries for energy storage, but their use poses safety concerns, namely due to the risk of thermal runaway [1]. This process results in toxic off-gassing, smoke, fire, and explosions, causing damage to property and endangering people. Therefore, early detection of thermal runaway is critical. Voltage, current, and temperature sensors are used to monitor batteries and identify the onset of thermal runaway, but these have limitations. For example, the heat generated inside the battery will take time to be detected due to the low thermal conductivity of polymers and other battery components. Past studies have measured the stress generated in each electrode during cycling [2] and investigated the volumetric expansion of batteries during cycling [3,4]. Therefore, strain measurement of cells could provide insight into the reversible and irreversible phenomenon inside of a battery in real time. To this end, strain and temperature response of a commercially available high capacity (3.4 Ah) 18650 lithium-ion battery were investigated in this study. Strain measurements were conducted while cycling in a temperature-controlled environment. During battery cycling the maximum strain was recorded at 100% state-of-charge (4.2V) in the hoop direction at the center of the battery. Strain was returned to a baseline value upon discharge. In all the cycling scenarios, the electrochemical reaction peaks coincided with change in strain response. Repeated measurements across multiple cycles and multiple identical cells have produced similar strain behavior. The results from this study indicate that strain measurements on a battery’s surface are directly correlated to the reversible electrochemical behavior of a battery, and therefore be used as a diagnostics tool for battery operation to detect irreversible phenomenon. This presentation will describe the methods of strain measurement as well as potential applications of this technique as a diagnostic or early fault detection tool.

Figure 1: Middle hoop strain and battery potential during a full cycle.

Figure 1
Structured Cathodes Enabled By Freeze Tape Casting for High Energy Density/High Power Li Ion Batteries
Authors: Polyzos Georgios , Tao Rumming , Li Jianlin
Published: November 2022

The development of new cathode architectures that will enable low-tortuosity and speed up the Li ion dynamics is imperative to achieve high energy density and high-power Li ion batteries. To address this barrier, bi-layer cathode configurations were developed and tested. The bottom layer was densified through calendering. Freeze tape casting (FTC) of aqueous based slurries was applied on top of the densified cathode layer. The structure and porosity of the ice-templated layer were optimized to maximize the overall loading of the active material. The electrochemical performance at several C-rates and the interfacial resistance of the cathode were evaluated and modeled. The results were compared against non-structured cathodes. The developed FTC application techniques can be scaled using a high throughput FTC configuration. This research was sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office (VTO) (Program Manager: Peter Faguy).
(Invited) Artistic: An AI and Modeling-Supported Digital Infrastructure for Battery Manufacturing Optimization
Authors: Franco Alejandro A.
Published: November 2022

Energy, power, lifetime and safety of Lithium ion batteries (LIBs) are determined in part by the internal microstructure of the electrodes. That microstructure is characterized by the spatial location and the resulting interfaces between the active material particles, the conductive additive, the binder and the pores. The microstructure is determined by the manufacturing process of the electrodes, which encompasses, in its traditional wet form, multiple steps and numerous parameters. Therefore, its optimization is difficult and can be time consuming and costly if carried out only on the basis of a trial and error approach.

In this lecture I discuss a digital infrastructure for accelerated optimization of the manufacturing process of LIBs that we are developing since few years: ARTISTIC.1 Such digital infrastructure is supported on a hybrid approach encompassing a physics-based multiscale modeling workflow, Artificial Intelligence (AI)/machine learning models and high throughput experimental characterizations.2 ARTISTIC simulates different steps along the battery cells manufacturing process, such as the electrode slurry preparation, the coating, the drying, the calendering and the electrolyte infiltration. For that purpose, it uses a combination of sequentially-coupled 3D-resolved physical models based on experimentally-validated Coarse Grained Molecular Dynamics, Discrete Element Method and Lattice Boltzmann Method. This allows predicting the impact of the manufacturing process parameters on the final electrode microstructure in three dimensions. The predicted electrode microstructures are then injected in a continuum performance simulator capturing the influence of the electrode microstructure on the solid electrolyte interphase formation (for anodes) and the electrochemical response (of anodes vs. lithium, cathodes vs. lithium and the full cells). Machine learning models are used to unravel manufacturing parameters interdependencies from the physical models’ predictions and experimental data, and to suggest manufacturing process optimizations. The predictive capabilities and chemistry-neutrality of the ARTISTIC digital infrastructure are illustrated with results for different LIB electrode formulations and chemistries (NMC, LFP, graphite, silicon/graphite blends) and also for organic active materials for sodium ion batteries. Finally, I discuss the free online battery manufacturing simulation services (online caculator and associated databases) offered by our project and that you can use interactively from your Internet Browser.3

References:

[1] ERC Consolidator Project ARTISTIC, grant agreement #772873 (
https://www.erc-artistic.eu/
).

[2] See our ARTISTIC-related publications here: https://www.erc-artistic.eu/scientific-production/publications .

[3] T. Lombardo, F. Caro, A. C. Ngandjong, J.B. Hoock, M. Duquesnoy, J.C. Delepine, A. Ponchelet, S. Doison, A.A. Franco, Batteries & Supercaps, 5(3) (2022) e202100324.

Figure 1
Single Step Electrochemical Recovery and Regeneration of Cathode Materials
Authors: Sederholm Jarom Glen , Patra Arghya , Braun Paul V.
Published: November 2022

Sustainable battery production is a major challenge for the future of electrification. The rise in battery usage, particularly in portable electronics and electric vehicles, has led to a massive increase in the demand for critical battery materials. However, global supply has already begun to strain under the increased demand and projections predict that the global demand could easily surpass global supply in a matter of decades.

Current battery recycling and recovery techniques for battery components involve multistep regenerative processes through either pyrometallurgical, hydrometallurgical, or direct recycling methods route. Our work demonstrates for the first time, the dissolution and electrochemical deposition of transition metal oxides in the same solvent for sustainable battery material usage and recovery for slurry cast and electroplated Li-ion battery cathodes. Ultra-dense, high-performing, binder and additive free cathodes are formed at the end of the recycling process.

This discovery generates high quality energy dense battery cathodes from “end-of-life” batteries and paves the way towards a simplified recycling conditions for more sustainable battery production.