bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Volume Change in Lithium Oxygen Battery Electrodes
Authors: Oldham Eric , Alvaré Javier , Wheeler Dean 
Published: December 2024

Lithium oxygen batteries have an exceptionally high theoretical specific capacity, but a variety of obstacles stand in the way of reaching that high capacity over many cycles. Recent research into catalysts and redox shuttles has improved the reversibility of the reaction between lithium ions and oxygen to form lithium peroxide, creating renewed interest in lithium oxygen technologies.
A significant obstacle is that achieving high capacity necessarily implies that a large volume fraction of lithium peroxide must be stored in the cathode during discharge, to be released upon charge. Likewise, a large volume fraction of lithium metal must be stored as part of the anode during charge, to be released upon discharge. Such large volume changes create severe materials and reversibility issues. For instance, lithium peroxide particles displace electrolyte and cause the cathode to expand many times its original volume. The cathode material must be carefully selected to provide a good conductive lattice with high porosity and the ability to handle massive volume changes while also allowing the movement of electrolyte in and out of the cathode.
To address this issue our research group has adopted the use of a binderless carbon nanotube (CNT) paper as our cathode. The CNT paper consists of layers of interconnected CNTs and displays high tensile strength, conductivity, porosity, and reaction sites. In typical slurry-coated electrodes a large volume expansion can cause fractures and cracks, electrically isolating sections of the carbon matrix and decreasing capacity with increased cycling. The durability and layer structure of the CNT paper permits high volumetric expansion with reduced damage to the carbon matrix.
The CNT paper cathodes showed a discharge capacity of 10.000 mAh/g C, which is equivalent to 12 mAh/cm2. Figure 1 shows the substantial volume changes during the charge process. During lithiation of the cathode from (a) to (b) we can observe the cathode increased from approximately 28 microns to 160 microns thickness, or about six times the starting volume. Discharged cathodes were then rinsed in DI water to dissolve the lithium peroxide and observe the response of the carbon matrix (panel c). It can be seen that the removal of lithium peroxide left large gaps in the carbon matrix, which must be subsequently remedied in a charge cycle. We will present these and other results from our experiments on this system.

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Multifunctional Mxene-Infused Textile Toward Energy Harvesting, EMI Shielding, Flame Resistance, and Joule Heating with Thermo-Chemo-Mechanical Robustness
Authors: Kim Jiheon , Choi Yong , Seo Byungseok , Choi Wonjoon 
Published: December 2024

The increasing demand for wearable devices and mobility platforms has garnered the importance of multifunctional components that integrate various features. To achieve this multifunctionality, the carbon-based two-dimensional nanomaterial Mxene (Ti₃C₂Tx) has been explored in various studies including smart textiles, owing to its high electrical conductivity, hydrophilicity, and abundance of functional groups. But the limitations of MXene applications are its low mechanical durability and flexibility, as well as its vulnerability to moisture and washing, which restrict its use in wearable smart textiles. In this study, we developed a novel type of multifunctional smart textile that incorporates energy harvesting, electromagnetic interference (EMI) shielding, flame resistance, and Joule heating. By integrating these functions, the synergy between them could maximize the benefits of the smart textile. MXene, polyvinyl alcohol (PVA), and polyacrylic acid (PAA) were cross-linked through sonication and a vortex generator, and this mixture was vacuum-filtered onto Hanji, a traditional Korean paper, to create a fiber with an asymmetric structure via a simple yet efficient process. Various analytical techniques confirmed the successful cross-linking of MXene/PVA/PAA (MPP), ensuring the fabrication of MXene/PVA/PAA-Hanji (MPP-H) textiles. Structural integrity and stable interfaces were confirmed through a series of experiments, and the performance of the multifunctional capabilities was evaluated.
In terms of the functionalities, The MPP-H fiber demonstrated the capability to generate power for over 1 h with the application of a small amount of electrolyte solution, producing a power density of approximately 100 µW/cm³. Additionally, it exhibited a high shielding effectiveness per unit thickness (SE/t) of up to 437 dB/mm within the X-band frequency range (8.2–12.4 GHz), indicating excellent shielding performance relative to its thickness. With an absorption shielding rate exceeding 90%, the developed textile was proven to be an absorption-based shielding material. Furthermore, the MPP-H displayed superior thermal and mechanical properties, including excellent flame retardancy, rapid Joule heating, durability through wash tests, and sonication resistance, making it practical for real-world applications.
The MPP-H textile efficiently integrates multiple functionalities into a single material, making it a promising candidate for next-generation wearable devices and mobile technologies.
The Potential for High Temperature Corrosion in the Naval Operating Environment
Authors: Shifler David 
Published: December 2024

In the marine environment, it is especially crucial to have reliable, high-temperature, propulsion materials that will enable increased capabilities, improved engine efficiency, reduced fuel costs, and decreased maintenance/total life cycle costs. Propulsion materials need to resist oxidation, various forms of corrosion, or alternating cycles of oxidation and corrosion.
Exploring the creation and development of propulsion materials involves, in part, the understanding of kinetics and thermodynamics of materials interactions and materials stability under marine operating environments and temperatures. In the naval environment, one needs to establish the mechanisms of simple and complex thermochemical and thermomechanical interactions of materials, such as hot corrosion and CMAS (calcium-magnesium-alumino-silicate) attack; and to advance life prediction of both existing and new materials under these scenarios.
Most papers in the literature since the 1970s consider sodium sulfate salt as the single specie contributing to hot corrosion. Recent Navy standards for Navy F-76 and similar fuels have dropped the sulfur content down to 15 parts per million (ppm) which many believe will end hot corrosion. However, the deposit chemistry influencing hot corrosion is known to be much more complex consisting of multiple sulfates and silicates. Sulfur species may still enter the combustion via ship’s air intake, which may include seawater entrained in the air. In addition to sodium sulfate, seawater contains magnesium, calcium and potassium salts, and atmospheric contaminants that may contribute to hot corrosion. This paper will cover some of the revised understanding of various forms of various forms of corrosion than may be encountered in Naval gas turbine engines.
Respirometric Studies on Transpassive Dissolution
Authors: Virtanen Sannakaisa 
Published: December 2024

Recently, we introduced respirometric methods for real-time monitoring of corrosion, both for atmospheric corrosion [1] and immersion conditions [2]. The approach is based on monitoring the rate of the cathodic reactions with help of different types of sensors; this enables to track the O2 reduction reaction and the H2 evolution reaction simultaneously. The set-ups have been used to study different corrosion scenarios under free corrosion conditions.
Even more recently, the respirometric setups were coupled with electrochemistry [3, 4], enabling the corrosion cases to be studied not only at open-circuit conditions but also for potential-controlled systems. With this, it is possible for instance to de-convolute the sum current measured by potentiodynamic polarization curves into different cathodic and anodic partial reaction rates. For passive metal and alloys, transpassive dissolution is being explored, by quantification of the amount of oxygen evolving during transpassive dissolution that typically occurs at potentials above the water stability region (i.e., the net anodic electrical current/charge is a sum of partial currents for oxygen evolution reaction, OER, and for metal oxidation/dissolution). Therefore, a true metal oxidation rate can be determined that is not directly assessable from the electrochemical measurement. Examples will be presented, to illustrate the potential of these techniques to reveal insights into corrosion mechanisms of active and passive metals and alloys.
References

M. Strebl, M. Bruns, S. Virtanen, Editors’ Choice—Respirometric in Situ Methods for Real-Time Monitoring of Corrosion Rates: Part I. Atmospheric Corrosion, J. Electrochem. Soc. 167 (2020) 21510

M.G. Strebl, M.P. Bruns, G. Schulze, S. Virtanen, Respirometric In Situ Methods for Real-Time Monitoring of Corrosion Rates: Part II. Immersion, J. Electrochem. Soc. 168 (2021) 11502

M.G. Strebl, M.P. Bruns, S. Virtanen, Coupling Respirometric HER and ORR Monitoring with Electrochemical Measurements, Electrochimica Acta 412 (2022) 140152

M.G. Strebl, M. Bruns, S. Virtanen, Respirometric In Situ Methods for Real-Time Monitoring of Corrosion Rates: Part III. Deconvolution of Electrochemical Polarization Curves, J. Electrochem. Soc. 170 (2023) 061503
(Digital Presentation) Investigation of Electrochemical Cu Deposition on Nanoscale Sculptured Al Surfaces by FFT-Impedance Spectroscopy
Authors: Gerngross Mark Daniel , Baytekin Gerngross Melike , Carstensen Juergen , Adelung Rainer 
Published: December 2024

Fast Fourier transform impedance spectroscopy (FFT-IS) is a well established technique to study in-situ e.g. the involved electrochemical dissolution and deposition phenomena at the electrolyte / substrate interface [1,2]. In contrast to conventional electrochemical impedance spectroscopy (EIS), FFT-IS allows for the simultaneous application of all probing frequencies at the same and thus highly time-resolved investigations of the ongoing electrochemical phenomena.
FFT-IS has been employed to study the electrochemical deposition process of Cu on nano-scale-sculptured Al during the entire deposition process, since such a nanoscale-sculptured Al surface exhibits a high multitude of different-sized cubic undercut structures that must be enclosed and overgrown by Cu to generate a good mechanically interconnection between Al and Cu.
The analysis of the IS data reveals that the deposition process can be modeled by an equivalent circuit consisting of a series resistance Rs and three Voigt-Kelvin elements, all connected in series to each other. The first one is a capacitor Cp1 and a resistor Rp1, followed by a Warburg element Zw and a resistor Rp2, and finally by another capacitor Cp3 and resistor Rp3 as last Voigt-Kelvin element, see Fig. 1.
The time resolved analysis of the above described parameters reveals that three major processes are involved in the Cu deposition process that occur locally in series on the surface, but parallel in time. Based on the time evolution of these fit parameters the Cu deposition process can be sub-divided into three stages that were identified by investigating the nanoscale sculptured Al surface during Cu deposition at characteristic points of each stage by scanning electron microscopy. The knowledge and understanding of these processes allows tailoring and fine-tuning the Cu electrolyte and the deposition process itself.
Fig. 1 Nyquist plot of recorded impedance data (boxes) and corresponding fit data (solid line) of the used equivalent circuit model
[1] M. Leisner, J. Carstensen, and H. Föll, J. Electroanal. Chem. 615(2), 124 (2008).

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Nanoscopic Observation of Perovskite Solar Cell with TEM
Authors: Uchida Satoshi , Segawa Hiroshi 
Published: December 2024

Recently, there has been a surge of interest in organometal halide perovskite solar cells (PSCs). These cells have exhibited a remarkable increase in power conversion efficiency (PCE), with certified PCEs reaching over 26% by employing mixed organic cations and halide anions. The PCE is significantly influenced by the photovoltaic properties of each component within the PSC.
Despite the crucial role of crystallographic information, micro-structural analysis of the perovskite layer has not been extensively pursued. The micro-structural observation analysis of the perovskite layer with high resolution TEM is the most promising approach to understand the crystal structure. It has been widely accepted that the organometal halide perovskite exists in distinct phases: orthorhombic phase < 165K < tetragonal phase < 327K < cubic phase. However, our recent observations have revealed the coexistence of tetragonal and cubic phases at room temperature in conventional MAPbI3 thin film devices. Moreover, we have made the surprising discovery of superlattices comprising a mixture of tetragonal and cubic planes without any compositional alterations. The formation of these superlattices occurs through intrinsic structural transitions, without the need for artificial modifications. Consequently, many phenomena related to structural superlattices are anticipated to occur spontaneously and automatically within relevant contexts. Organometal halide perovskites demonstrate a remarkable ability to self-adjust their micro-structural configurations and self-organize buffer layers inside crystals or at hetero-interfaces by introducing self-assembled superlattices. We believe that this report represents a pivotal advancement, bringing PCEs of organometal halide perovskite solar cells closer to their theoretical maximum and redefining the potential of these materials for a wide range of applications beyond solar cells.

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(Invited) Interface and Surface Control for High Performance Heterojunction Solar Cells
Authors: Usami Noritaka 
Published: December 2024

The transition towards a decarbonized society requires the broader use of photovoltaic power generation, which in turn necessitates the development of more efficient and high-value photovoltaic modules. To achieve this goal, we are carrying out various fundamental research projects aimed at improving crystalline silicon solar cells, which are the mainstream of photovoltaic power generation, as well as tandem solar cells for the future. Our focus is on improving the performance of heterojunction solar cells based on interface and surface control by developing new technologies for creating NATURE contact structures that provide high surface passivation performance and electrical conductivity [1], metal oxide thin films that can significantly reduce the cost of carrier selective passivating contacts [2], nanopyramid structures suitable for thin silicon solar cells and conformal spin coating of perovskite thin films [3], and nanoimprinting technology that enables long-wavelength optical confinement structures for the backside of multijunction solar cells. This presentation will review these fundamental technologies.
[1] R. Tsubata, K. Gotoh, M. Matsumi, M. Wilde, T. Inoue, Y. Kurokawa, K. Fukutani, N. Usami, Silicon Nanocrystals Embedded in Nanolayered Silicon Oxide for Crystalline Silicon Solar Cells, ACS Appl Nano Mater 5 (2022) 1820–1827. https://doi.org/10.1021/acsanm.1c03355.
[2] S. Miyagawa, K. Gotoh, K. Kutsukake, Y. Kurokawa, N. Usami, Application of Bayesian optimization for high-performance TiO
x
/SiO
y
/c-Si passivating contact, Solar Energy Materials and Solar Cells 230 (2021) 111251. https://doi.org/10.1016/j.solmat.2021.111251.
[3] Y. Li, H. Sai, T. Matsui, Z. Xu, V.H. Nguyen, Y. Kurokawa, N. Usami, Nanopyramid Texture Formation by One-Step Ag-Assisted Solution Process for High-Efficiency Monocrystalline Si Solar Cells, Solar RRL 6 (2022) 1–7. https://doi.org/10.1002/solr.202200707.
(Invited) Application of Impedance Spectroscopy to Analysis of Plasma-Surface Interaction
Authors: Urabe Keiichiro 
Published: December 2024

The impedance spectroscopy method is a way to investigate the electrical properties of the target system by applying an AC voltage and measuring the amplitude and phase of the current. From measured impedance spectra and a physics- and/or chemistry-based electrical circuit model, we obtain physical and/or chemical information about the target systems. This methodology has been widely used in electrochemical research fields, such as batteries. It can monitor the degradation of elements in the target system independently by continuously scanning the AC voltage frequency.
In this study, we applied impedance spectroscopy to the investigation of electrical properties and degradation features of dielectric materials during plasma exposure. Considering the plasma generation system, which has some critical differences from conventional DUT of impedance spectroscopy, we developed an in-situ impedance spectroscopy system to measure the impedance of materials under plasma exposure.
We applied the in-situ impedance spectroscopy system to measure the degradation features of SiO2/Si structures (SiO2 film on Si substrate) exposed to a low-temperature Ar plasma. By analyzing the measured data based on an equivalent circuit model considering the plasma and SiO2/Si structures, we obtained the resistance (R) and capacitance (C) values for the SiO2 film and SiO2/Si interface independently. One example is the sputtering of SiO2 film by high-energy ion irradiation. In addition to the decrease in thickness, we found dielectric-property degradation by ion irradiation based on the variations in the R and C values of the SiO2 film. Another example is the temporal variation of film and interface properties during continuous plasma exposure. The thickness-dependent degradation in the SiO2 film and SiO2/Si interface was analyzed and compared with the results of previous ex-situ measurement studies.
Further studies on the in-situ impedance spectroscopy are ongoing. We recently found a way to diagnose not only material properties but also plasma properties by measuring currents at harmonic frequencies of AC voltage. This harmonic spectroscopy method was demonstrated to capture surface oxidation of metal probe and plasma parameters (electron temperature and ion density) simultaneously. These studies have revealed the potential of impedance spectroscopy to contribute to fundamental and application research on plasma-material interaction.
(Invited) Heterostructure Engineering in Electrode Materials for Sodium-Ion Batteries
Authors: Xiong Claire 
Published: December 2024

Sodium-ion batteries (SIBs) have stepped into the spotlight as a promising alternative to lithium-ion batteries for large-scale energy storage systems. However, SIB electrode materials, in general, have inferior performance than their lithium counterparts because Na+ is larger and heavier than Li+. Heterostructure engineering is a promising strategy to overcome this intrinsic limitation and achieve practical SIBs. In this talk, I will discuss recent progress in heterostructure engineering of electrode materials and research on how the phase interface influences Na+ storage and transport properties.1,2 Combinations of phases can complement each other’s strengths and mitigate their weaknesses if their interfaces are carefully controlled. Efficient strategies for the design and fabrication of heterostructures (in situ methods) will be discussed, with a focus on the heterostructure formation mechanism. The heterostructure’s influence on Na+ storage and transport properties arises primarily from local distortions of the structure and chemomechanical coupling at the phase interface, which may accelerate ion/electron diffusion, create additional active sites, and bolster structural stability. Finally, our perspectives on the existing challenges, knowledge gaps, and opportunities for the advancement of heterostructure engineering as a means to develop practical, high-performance sodium-ion batteries will be discussed.
References

E. Gabriel et al., eScience, 3, 100139 (2023) https://www.sciencedirect.com/science/article/pii/S2667141723000642.

E. Gabriel, D. Hou, E. Lee, and H. Xiong, Energy Science & Engineering, 10, 1672–1705 (2022) https://onlinelibrary.wiley.com/doi/abs/10.1002/ese3.1128.
Li+ Ionic Mass Transfer Accompanied with Electrodeposition of Li Metal in High Concentration Electrolyte
Authors: Nishikawa Kei , Kamesui Go , Shinoda Keisuke , Matsushima Hisayoshi , Ueda Mikito , Kanamura Kiyoshi 
Published: December 2024

Li metal is a promising material for the negative electrode of next-generation secondary batteries because of very large capacity density. However, it is very difficult to keep uniformity of electrode morphology during repeating cycles. The charging reaction is corresponding to the electrodeposition of Li metal. Li metal forms dendrites very easily in the electrodeposition process. Dendrite is very typical non-uniform shape and causes the further current distribution to the electrode surface. The distribution accelerates the non-uniform electrodeposition, and then induces the short circuit phenomenon in the worst case. It is indispensable to understand the morphological variation and control the electrode surface shape during the charging and discharging of Li metal negative electrode for the realization of very high energy density batteries.
In general, the electrodeposition of metals is strongly influenced by the ionic mass transfer in the vicinity of the electrode surface. The ionic mass transfer rate is related with the concentration overpotential and decrease of the surface concentration induces the increase the overpotential of the electrode reaction, and the depletion of metal ions become trigger of the dendrite formation. Our previous studies found the Li metal dendrite is induced without the depletion of Li+ ion at the electrode surface. Further, it is noteworthy that the morphology of Li metal dendrite has many kinds of shape. This specialty of Li metal is due to the surface layer called by “Solid Electrolyte Interphase (SEI)”. This layer is formed by the reaction between the Li metal and chemical species in the electrolyte solution. Therefore, it is dependent on the composition of the electrolytes. It is necessary to understand not only the ionic mass transfer but also the nature of SEI layer. In this study, Li+ ionic mass transfer rate was in-situ measured by holographic interferometry microscope and the characterization of SEI was conducted by cryo-STEM-EELS technique. High concentration electrolytes were utilized and current density dependence of surface concentrations, morphological variation, and the characteristics of SEI on the electrodeposited Li metal were discussed. We would like to report these details in the presentation on the day.