bluuebunny/crossref_metadata_2025_split huggingface dataset:
In-Situ Raman Spectroscopy of Li+ and Na+ Storage in Anodic Nanotubes
Authors: Kowalski Damian , Vincent Mewin 
Published: August 2024

Anodizing is a high-voltage electrochemical conversion process that forms barrier-type oxide layers or self-organized nanoporous/nanotubular structures. So far, the Al2O3-like nanopores and TiO2-like nanotubes could be successfully synthesized on many valve metals and alloys.
Recently, it become possible to form nanotubular structures on iron and consequently control the ratio of hematite (Fe2O3) to magnetite (Fe3O4) by subsequent thermal treatment.1 Electrochemically active nanotubes, such as self-organized TiO2 are of high interest in the battery field due to a unique one-dimensional (1D) geometry offering high volume expansion tolerance and applications without binders and conductive additives. Herein, we report an in
-
situ Raman spectroscopy study under current control for a better fundamental understanding of Li+/Na+ storage in nanotubes and correlate the structural fingerprints with the electrochemical data on differential capacity plots of d(Q–Q
0) dE
–1.2 Real-time measurements revealed that the nanotubes had undergone two major phase transformations with increasing lithium content, disclosing the sequential steps of a lithium intercalation type of storage. In contrast, sodium-ion insertion induced no significant crystal structure modification but instead a slight crystallinity rupture, signifying a dominant nondiffusion-limited capacitive type of storage. The insight into the charge storage in a 1D material in relation to other nanostructures such as nanoparticles3 will be discussed.
1. L. Fadillah, D. Kowalski, M. Vincent, C. Zhu, S. Kitano, Y. Aoki and H. Habazaki,
ACS Applied Materials & Interfaces
, 2023, 15, 52563-52570.
2. M. Vincent and D. Kowalski,
ACS Applied Nano Materials
, 2023, 6, 6528-6537.
3. M. Vincent, S. S. Kumar and D. Kowalski,
Electrochimica Acta
, 2023, 469, 143161.

Figure 1
Benefits and Limitations of Encapsulating Platinum Electrocatalysts with Niobium Oxide
Authors: Hadley Annabelle M. K. , Gautam Sakshi , Gates Byron D. 
Published: August 2024

The development of energy infrastructure based on renewable sources is vital to reduce our reliance on fossil fuels. Technologies such as hydrogen fuel cells and water electrolyzers are able to bridge the gap between the intermittency issues associated with green energy sources such as wind and solar, and the demand for reliable electricity by being able to convert between electrical and chemical energy. Nanostructured and mesoporous platinum (Pt) prepared by electrodeposition or sputter coating have been shown to have increased performance in hydrogen fuel cells compared to the industry standard of Pt nanoparticles supported on carbon.1,2 Over the lifetime of a fuel cell Pt nanostructures and nanoparticles are, however, known to restructure and lose their surface area by mechanisms such as Ostwald ripening, dissolution, and coalescence. Previously, thin film Pt catalysts have been shown to be stabilized by a nanoscale film of niobium oxide.3 Herein, nanoscale thin films of niobium oxide are investigated as a stabilizing material through use by encapsulating nanostructured Pt catalysts.
Nanostructured Pt catalysts were electrodeposited onto Pt-coated Si wafer substrates. Subsequently, niobium oxide films with thicknesses of 0.5 nm, 3 nm, and 4.5 nm were deposited onto the Pt catalyst using atomic layer deposition. X-ray fluorescence and conductive atomic force microscopy techniques were used to confirm the presence and coverage of the niobium oxide layer on the Pt catalyst. The performance of the encapsulated and un-encapsulated Pt catalysts as oxygen reduction reaction catalysts over the course of up to a thousand degradation cycles were evaluated using electrochemical techniques. The morphology of the catalyst before and after the degradation testing was also assessed using scanning electron microscopy techniques. Electrochemical impedance spectroscopy indicated that increasing the thickness of the niobium oxide layer increased the resistance of the catalyst towards the oxygen reduction reaction. The combined results of the analyses performed by electrochemical techniques and electron microscopy measurements revealed a range of film thicknesses for the niobium oxide that successfully stabilized the electrochemically active surface area and surface morphology of the Pt catalyst.

Paul, M. T. Y.; Gates, B. D. Mesoporous Platinum Prepared by Electrodeposition for Ultralow Loading Proton Exchange Membrane Fuel Cells. Sci Rep
2019, 9, 4161.

Debe, M. K. Tutorial on the Fundamental Characteristics and Practical Properties of Nanostructured Thin Film (NSTF) Catalysts. Electrochem. Soc.
2013, 160, F522.

Eastcott, J.; Gates, B. D. Nanoscale Thin Films of Niobium Oxide on Platinum Surfaces: Creating a Platform for Optimizing Material Composition and Electrochemical Stability. Can. J. Chem.
2017, 96, 260–266.
Direct Comparisons of Oxygen Electro-Reduction across Molecular and Extended Oxides
Authors: Thakkar Shreya , McKone James 
Published: August 2024

Our work is focused on understanding hydrogen transfer in redox-active metal oxides as candidates for next-generation catalytic architectures, using oxygen electro-reduction as a model reaction. We are specifically studying the interrelationships between hydrogen transfer electrocatalysis across what we term the “molecules-to-materials design continuum” by directly comparing electrochemical properties of molecular tungsten-based polyoxometalates (polyoxotungstates) and extended tungsten oxides.
The goal of this study was to critically compare trends of activity and selectivity towards the two-electron oxygen reduction reaction using a series of three catalyst composites derived from molecular polyoxotungstates: (1) the intact molecule adsorbed on a conductive carbon support; (2) the same composite after thermal decomposition of the molecule to bulk WO3; and (3) an intermediate state comprising the partially decomposed molecule.
Catalyst composites were synthesized by wet impregnation of the polyoxotungstate (TBA)4W10O32 (TBA = tetrabutylammonium) from acetonitrile on Vulcan carbon, targeting catalyst loadings that yield well-dispersed molecular units. We then used thermal treatments over a range of temperatures associated with progressive thermal decomposition to the intermediate and fully decomposed states. Thermal decomposition reactions and products were further characterized using thermogravimetric analysis and in-situ powder X-ray diffraction. Electrocatalytic measurements were made using standard analytical protocols comprising rotating-disk electrode voltammetry of carbon-supported catalysts deposited as thin films on glassy carbon substrates.
On thermal treatment, we observed that the polyoxotungstate loses stabilizing counterions with progressive rearrangement into disordered clusters and ultimately crystalline nanoparticles of orthorhombic WO3. Each of these various forms exhibit broadly similar reactivity towards the oxygen reduction reaction. Electroanalytical results suggest all three tungsten-based composites are poor oxygen reduction catalysts with activities comparable to that of the carbon support. Nonetheless, Levich analysis suggests high selectivity for 2-electron conversion to H2O2 and catalytic onsets that correlate well with distinct voltametric features corresponding to H-activation and, in the case of extended oxides, bulk proton insertion. Ongoing work is focused on extending these studies toward more tractable hydrogen transfer reactions and identifying alternative catalysts with more thermodynamically accessible mechanisms for H activation.
More broadly, we hypothesize that these types of apples-to-apples comparisons between molecular and extended catalysts will reveal vital information about the impact of active site composition and electronic structure on H-transfer catalysis.
Magnetically-Enhanced Electrochemical ELISA for the Detection of Sars-Cov-2 Nucleoprotein
Authors: Anderson Morgan J , Cordeiro Milton , Koehne Jessica E. 
Published: August 2024

Here we report on the development of a novel, magnetically-enhanced electrochemical (MagEC) bioassay targeting SARS-CoV-2 nucleoprotein. The sensing strategy is similar to microbead-based enzyme linked immunosorbent assays (ELISA) with optical detection. The target analyte is captured using a magnetic microbead functionalized with an antibody specific to SARS-CoV-2 nucleoprotein. Once SARS-CoV-2 nucleoprotein has been captured a detection construct, consisting of polystyrene microbeads functionalized with horseradish peroxidase (HRP) and antibodies specific to SARS-CoV-2 nucleoprotein are attached to form the full microbead construct.
Once the full microbead constructs are assembled, they are injected into an electrochemical cell containing an assay solution where they are magnetically enriched at the electrode surface. This magnetic localization brings all of the reactants close to their point of detection at the electrode surface and also creates a positive feedback loop, drastically enhancing signal. The electrochemical assay was optimized using model constructs to emulate the fully assembled bead constructs and identify the optimal electrode configuration. Using the model constructs, we found a 60-fold decrease in limit of detection using the MagEC ELISA compared to optical detection with model bead constructs. We compared performance of a bare gold electrode to several geometries of gold microelectrode arrays. We obtained preliminary results for the detection of SARS-CoV-2 nucleoprotein. Additionally, the assay was expanded to incorporate a fluidic manifold to enhance signal, enhance throughput and enable operation in microgravity environments.
Stable Operation and Enhanced Sensitivity via Composite Structure Design for Efficient Photoplethysmography and Motion Sensors
Authors: Yang Zhao , Kim Byung Gi , Cho Jae Sang , Jang Woongsik , Park Keum Hwan , Park Jong Hyeok , WANG DONG Hwan 
Published: August 2024

Healthcare sensors have attracted lots of interests owing to saving a patient's life by continuously monitoring the patient's health via early diagnosis of the symptoms by using healthcare sensors. Many health-care sensors are available in wearable application that can monitor continuously patient health. There are some common parameters such as a heart rate and human motion that are used to monitor human activity.
In order to realize stable operation of health-care sensors, material designs are required considering human-body compatibility. In this research, light-sensors fabricated from low-toxicity organic materials by introducing neutral poly(3,4-ethylenedioxythiophene)-(polystyrene sulfonate) (PEDOT-(PSS)) to improve human-body compatibility as well as to strengthen photoplethysmography (PPG) signal. [1] Neutral PEDOT-(PSS) with heterocyclic 1,3-diazole (HDZ) enhances the polymerization degree, carrier mobility, and other physicochemical properties. Consequently, the presented OPD-based PPG sensor has the ability to diagnose blood circulation status and cardiovascular diseases.
Second, we fabricate motion sensors by utilizing metallic glass, i.e., amorphous metallic alloy, which is an alloy composition without grain boundaries and long-range ordering. The unique structure of metallic glass results in excellent tensile strength and strain-resistivity as well as chemical stability to those of conventional metals. The Al-Sm MG-based sensors results in enhanced sensitivity and considerable device stability, because of its amorphous phase. [2]
[1] Adv. Funct. Mater. 2023, 10.1002/adfm.202309271
[2] Electrochimica Acta, 2023, 446, 142053
Pure 3D Conducting Polymer Network for an Ultra-Sensitive and Flexible Hydrogen Gas Sensor at Room Temperature
Authors: Zhigerbayeva Guldana , Nuraje Nurxat , Turlybekuly Amanzhol , Adilov Salimgerey 
Published: August 2024

Hydrogen (H2) is considered a next-generation energy source with diverse applications across valuable social, economic, and industrial sectors, including transportation, biomedical, power generation, and space exploration. Due to its low ignition energy and wide flammable range, there is an urgent global demand for ultrasensitive, lightweight, portable, wearable, and flexible hydrogen sensors to identify early gas leaks and prevent environmental and economic implications.
In this study, we present a flexible hydrogen gas sensor based on conducting polymers, namely polypyrrole (PPY) with graphene nanoparticles, synthesized by the bi-continuous microemulsion polymerization method. The one-step scalable synthetic procedure enables the design of 1D, 2D, and 3D conducting polymers and their nanocomposites with tunable morphological and electrical properties. The unique multilayered oil-to-water nature of the bi-continuous microemulsion allows the fabrication of pure mesoporous 3D conducting polymers and their composites without the addition of any cross-linkers with excellent electrical properties. The 3D pure porous polymer network acts as a monolithic conducting framework that facilitates electron and ion transport and promotes the diffusion of molecules and ions more efficiently than 1D or 2D structures. The soft and porous nature of the polymer improves the interaction and adsorption of the target gas molecules and sensing material by increasing the number of active sites.
This 3D PPY_graphene flexible network synthesized by the bi-continuous microemulsion method is successfully utilized to fabricate an ultra-sensitive flexible gas sensor. The performance of the sensor can be modified based on the reactor design. The sensor exhibits a notable response to 1 ppm of H2 gas. At room temperature, the fabricated sensor displayed 14 and 20 seconds of response and recovery time, respectively. To the best of our knowledge, no study has explored the application of 3D pure conducting polymers and their nanocomposites for hydrogen gas sensors using the bi-continuous microemulsion polymerization method, yielding such exceptional sensing results.

Figure 1
High-Performance Humidity Sensor Capable for Monitoring Low-Moisture Levels in Energy Industries
Authors: Chen Zhi David David , Ali Ronak 
Published: August 2024

Humidity sensors are extensively used in industrial processing and environmental control. There are two categories of humidity sensors: High-humidity (relative humidity) measurement and Low-humidity (moisture) measurement. The proper units for low-humidity measurement are dew point and parts per million in volume (ppmv) or parts per billion in volume (ppbv). It is very important to monitor moisture levels in natural gas during processing and transportation in pipelines. It is of critical importance to monitor moisture levels in lithium-ion battery manufacturing. In these cases, the moisture levels are limited to be less than -50°C dew point or 40 ppmv. The conventional relative humidity sensors cannot be used because of their low sensitivity. The dew point sensors on the market are polymer-based and gamma-phase-alumina based. The polymer-based sensors have low sensitivity, which can only accurately detect moisture levels of -60°C dew point and higher. The gamma-phase alumina sensors suffer from long-term drift due to phase change.
We present novel high-performance humidity sensors based on porous alpha-phase alumina and silicon dioxide nanostructures, which are capable of detecting moisture levels as low as -100°C dew point or 13 ppbv with excellent long-term stability. The porous alpha-phase alumina films were produced by anodic-spark-deposition on aluminum substrates in which electric sparks were produced due to high-voltage anodization (>120V). Local high-temperature (about 2200°C) at the points of sparks converted the amorphous alumina into alpha-phase alumina (Sapphire). It provides an extremely stable structure for humidity sensors. Hydrophilic silicon dioxide films deposited by atomic layer deposition was used as sensing materials. The sensors’ sensitivity, temperature coefficient, response speed, and long-term stability were studied in details. The sensors have great promise for monitoring moisture levels in natural gas industry and lithium-ion battery manufacturing.
Innovative Nanoscale Ceramic Separators to Boost Cycle Life and Cycle Efficiency of Lithium Metal Batteries
Authors: Kim Je Yeon , Ryoo San Deul , Lim Ji Yang , Jung Yongju 
Published: August 2024

In the pursuit of advancing energy storage, the extraordinary theoretical specific capacity of lithium metal at 3,860 mAh/g significantly outperforms traditional graphite anodes, which offer a capacity of around 372 mAh/g. This disparity underscores the potential of lithium metal batteries to facilitate a leap in energy density, heralding a new age of high-performance batteries.
Yet, the evolution of lithium metal batteries is hindered by the formation of dendritic structures during repetitive cycling, posing serious risks, including the likelihood of short circuits that underscore severe safety concerns. To mitigate these risks and enhance the longevity of lithium metal anodes, extensive research has been dedicated to various strategies, including surface modifications of lithium metal and the application of innovative coatings on separators. These strategies, however, often compromise energy density and ionic conductivity due to the addition of ceramic materials and binders.
Our study introduces a groundbreaking approach that utilizes nanoscale ceramic-coated separators, created via electron beam deposition. This method achieves a consistent nanoscale spread of metal oxide particles on conventional polyethylene (PE) separators. Crucially, this technique ensures even lithium-ion flow and greatly reduces dendrite growth. The effectiveness of this innovative approach was confirmed in comprehensive LiFePO4-Li cell tests, where cells with these ceramic-coated separators showed notable improvements in both cycle life and Coulombic efficiency, representing a significant advancement over traditional methods.
Using Micrometer Scale X-Ray CT and Pore Network Modeling to Assess High-Energy Bi-Layer Li-Ion Battery Cathode Structures
Authors: Pan Bonian 
Published: August 2024

The optimization of cathode pore space is pivotal for enhancing the rate capability of lithium-ion battery electrodes. Previous studies on simulated cathodes have highlighted the importance of achieving an optimal porosity gradient, with a gradual increase from the current collector side to the separator side to accommodate the growing demand for ion transport in that direction [1]–[3]. In this research, we address this requirement by introducing and investigating bi-layer NCM 811 cathodes. These cathodes consist of a slurry-coated dense bottom layer and a spray-coated highly porous top layer with varying relative thickness to approximate the desired porosity gradient. Employing Micrometer-scale X-ray CT characterization and pore network modeling, we evaluate the structural features, demonstrating the effectiveness of the design, and quantify essential parameters such as porosity and tortuosity. Furthermore, the cathodes are integrated into lithium anode half-cells and subjected to electrochemical cycling at different rates to assess ion transport and rate capability. Our findings reveal that to achieve the highest discharge spatial energy density above 1C for cathodes approximately 100μm thick, the compressed bottom layer with 30% porosity should have a thickness of 60μm, while the highly porous top layer with around 47% porosity should be 40μm thick.
Reference:
[1] A. Shodiev et al., “Deconvoluting the benefits of porosity distribution in layered electrodes on the electrochemical performance of Li-ion batteries,” Energy Storage Mater., vol. 47, pp. 462–471, May 2022, doi: 10.1016/j.ensm.2022.01.058.
[2] X. Lu et al., “3D microstructure design of lithium-ion battery electrodes assisted by X-ray nano-computed tomography and modelling,” Nat. Commun., vol. 11, no. 1, p. 2079, Apr. 2020, doi: 10.1038/s41467-020-15811-x.
[3] K. Song, C. Zhang, N. Hu, X. Wu, and L. Zhang, “High performance thick cathodes enabled by gradient porosity,” Electrochimica Acta, vol. 377, p. 138105, May 2021, doi: 10.1016/j.electacta.2021.138105.
In-Situ X-Ray Absorption Spectroscopy Investigations on the Transition Metal Cations Intercalation in Ti3C2Tx MXene for Electrochemical Applications
Authors: Wee Shianlin , Vazquez Dario Gomez , Lian Xiliang , Tayal Akhil , Salanne Mathieu , Lukatskaya Maria 
Published: August 2024

Synchrotron X-ray absorption spectroscopy (XAS) serves as a robust and powerful technique for probing the oxidation state and coordination surrounding of specific elements. In particular, operando XAS has been employed to elucidate charge storage mechanisms by monitoring changes in the oxidation state through the absorption edge energy of metals in electrodes such as MnO2 and RuO2 during charging/discharging[1]
[2]. Herein, we utilized in-situ XAS technique to uncover the charge storge mechanisms of transition metal (TM)-intercalated MXenes (Ti3C2Tx). We specifically probed the K-edges of intercalated TM and Ti MXene to reveal their oxidation states changes, shedding light on their respective contributions to capacitance. Aiming to gain further insights into the confined environment between MXene layers, we also employed ab-initio molecular dynamics (AIMD) to further interpret and validate the coordination environment obtained through in-situ extended X-ray absorption fine structure (EXAFS). This investigation lays the groundwork for tailoring the electronic and electrochemical properties of MXenes by the intercalation of various transition metal cations across diverse electrochemical systems.
[1] J.-K. Chang, M.-T. Lee, W.-T. Tsai, Journal of Power Sources
2007, 166, 590-594.
[2] Y. Mo, M. R. Antonio, D. A. Scherson, The Journal of Physical Chemistry B
2000, 104, 9777-9779.
Development of Coal-Derived Graphite for Lithium-Ion Batteries
Authors: Paul Abigail , Baca Isabel , Magee Regan , Wilczewski Warren , Wichert Nathan , Olson Rudolph , Al-Majali Yahya , Trembly Jason , Wolfe Kody D , Staser John A. , Garrick Taylor R. 
Published: August 2024

Graphite is one of many critical minerals that are utilized in lithium-ion batteries. The requirements for domestic sourcing of critical minerals used in Li-ion batteries as outlined in the Inflation Reduction Act have generated interest in exploring alternative production methods and feedstocks for critical minerals. An alternative feedstock for the production of graphite that is being evaluated is coal. Coal is an excellent candidate as a feedstock due to its abundance in the United States and its chemical structure.
In this poster, the characterization and electrochemical performance of multiple coal-derived graphites will be presented. A focus will be put on linking electrochemical performance to the microstructure of each material. Electrochemical performance data such as initial capacity loss, gravimetric capacity and columbic efficiency will be presented for both coin and pouch cells. The application of the Multi-Species, Multi-Reaction model on coal-derived graphite will also be presented.