bluuebunny/crossref_metadata_2025 huggingface dataset:
Repair and Reuse of Spent Lithium Battery Electrode Materials
Authors: Zhou Guangmin
Published: December 2024

With the popularity of new energy vehicles and various electronic devices, the use of lithium-ion batteries (LIBs) has shown explosive growth, which has resulted in a large number of spent LIBs. Spent LIBs contain a large amount of metal resources, and improper disposal will not only cause waste of resources, but also have potential environmental risks. The existing commercial recycling methods are mainly pyrometallurgy and hydrometallurgy recycling methods, both of which require re-extraction from the electrode material after destroying them to the atomic level for the preparation of new electrode materials, which is a long process with high cost, and involves the application of extreme conditions such as high temperature and strong acid, with inferior economic and environmental benefits. It is a major challenge in the field of battery recycling to develop innovative and clean recycling methods, to simplify the recycling process and to develop ways to reuse the recovered products. In view of the challenge of existing recycling methods, the reporters proposed the idea of direct recycling of electrode materials at the molecular scale, and designed innovative recycling methods such as direct repair of degraded lithium cobalt oxides with deep eutectic solvent (DES), repair of Ni-Mn-Co ternary (NCM) cathode with high failure degree by low temperature molten salt, and thermal regeneration of degraded lithium iron phosphate (LFP) with multifunctional solvent; and closed-loop design of the direct recycling process. In addition, we propose a high-value utilization path for the conversion of degraded electrode materials to high-performance electrode materials and nano-catalysts. It greatly simplifies the recycling process, avoids the use of extreme conditions, and provides a new technical system and theoretical guidance for battery recycling research and industry.
The Effects of Bismuth Addition on the Characteristics of Aluminum Alloys for Electric Vehicle Battery Housings
Authors: Kim Da Jeong , Yoon Sang Il , Choi Jee Seok , Lee HAN Chan
Published: December 2024

As the Electric Vehicle(EV) market has recently grown, the application of high-performance aluminum alloy, a representative lightweight material for lightening car bodies, is increasing. Among them, die casting is receiving the most attention due to its rapid productivity and excellent formability, and research on improving the properties of the mainly used Al-Si alloy is being actively conducted. In this study, the influence of additions of bismuth(Bi) on microstructure, thermal, and machinability of Al-10%Si alloy has been reported. Bismuth depressed the aluminum-silicon eutectic growth temperature and altered the silicon morphology. When the bismuth contents of the specimens were 0, 0.22, 0.5 and 1.8 wt%, results show that bismuth has a refining effect on the eutectic silicon and its refinement behavior is improved with increasing bismuth. Also bismuth is added to improve the mechanical and thermal properties of aluminium alloys for EV battery housing. Finally, we analyzed the heat emission characteristics and oxidation resistance of the battery housing using the developed aluminum alloy to study whether it could contribute to the stable operation of the battery.
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.
Coupled Point Defect Theory and Artificial Neural Network Studying Dynamic Behaviors of Rebar Corrosion
Authors: Zhu Yakun , Macdonald Digby D. , Engelhardt George
Published: December 2024

The degradation of reinforced concrete structures remains a serious issue in infrastructural systems, such as buildings, highways, and bridges. The problem is caused by the presence of chloride, either from being present in the concrete mix (e.g., from the use of brackish water or the addition of CaCl2 as a “setting agent”) or by ingress from the external environment (e.g., road salt or marine environments). A metric known as the chloride threshold (CT) has been developed to describe the susceptibility of the steel to chloride-induced passivity breakdown. Despite the widespread use of CT as a metric for describing the impact of chloride on the corrosion of rebar, a theoretical basis for this metric does not appear to have been established. In addition, the CT is a highly distributed parameter, reflecting the practical difficulty in controlling or measuring various environmental parameters in concrete and in reliably detecting passivity breakdown. Therefore, we have conducted several tasks to theoretically and practically understand how rebar corrosion is dependent on CT. We have established a rich database of CT and its associated primary and secondary influencing factors, in which each vector of CT includes about 20 variables. Statistical analyses reveal that CT is lognormally distributed whereas potential parameters are normally distributed. We developed a suitable theoretical basis, so that CT can be effectively related to the properties of the steel in the passive state and to its susceptibility to chloride-induced passivity breakdown. We also demonstrated that it is possible to calculate CT in pure, empirical manner using Artificial Intelligence (AI) techniques, in in accordance with theoretical prediction, through trained artificial neural network which was trained based on the CT database. However, a significant amount of work remains to be completed in the future in developing an understanding of steel corrosion in concrete. Our knowledge of underlying factors that control the CT is still very poor due to the paucity of accurate data in the literature, and it is ultimately insufficient to provide a more accurate estimate of CT than that obtained by either the ANN prediction or point defect theory analysis at this stage.
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
Co-Rolling Dry-Process Enables Thin and Robust Solid-State Electrolyte Layer for All-Solid-State Batteries
Authors: Lee Dong Ju , Jeon Yuju , Lee Jung-Pil , Zhang Lanshuang , Koh Ki Hwan , Vicencio Marta , Wu Junlin , Chen Yu-Ting , Chen Zheng
Published: December 2024

Dry-process is a sustainable and favorable fabrication approach for all-solid-state batteries by eliminating solvents. The feasibility of dry-process has previously been demonstrated, but a pragmatic fabrication design, especially for thin solid-state electrolyte separator layer, has not been established. Here we report a new approach to dry-processing thin SSE layer with minimal risk of mechanical failure. By roll-pressing SSE and cathode layers together (i.e., co-rolling), a uniform and thin SSE (50 µm) and high loading and active material ratio cathode (5 mAh cm−
2, 80wt%) layers are simultaneously achieved. The co-rolled film exhibited superior physical properties and cyclability at low stack pressure (2 MPa) owing to the unique fibrillation structure at SSE-cathode interface and intimate interfacial contact during co-rolling process, outperforming the freestanding counterparts prepared with the conventional approach. An all-solid-state pouch cell with high energy density and specific energy (933 Wh L−1 and 403 Wh kg−1) is also demonstrated.
(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).

Figure 1
Perovskite Film Passivation and Precursor Engineering for High Performance Devices
Authors: Dai Qilin
Published: December 2024

Perovskite films are attracting much attention due to their excellent optoelectronic properties. The corresponding photovoltaic devices have shown a record efficiency of 26.7% since 2009, which is very promising to surpass silicon solar cells. The defects of the perovskite films are the major negative factors in achieving high efficiency. The defects of the perovskite films are related to the polycrystal nature of the perovskite films, which is unavoided and caused by the solution-based method. Therefore, high-quality perovskite films with fewer defects are very critical to obtain high-efficiency devices. One strategy is to passivate defects of the films after the film fabrication. We passivate perovskite films with organic materials including polymers, organic small molecules as well as dye molecules. The organic molecules with the special organic functional groups interact with perovskite films to modify the defects of the films to improve the charge transport and reduce charge recombination, leading to improved device performance. The surface defects and the grain boundary defects of the perovskite films are passivated by the organic materials, which is confirmed by the electron/hole-only devices, electronic impedance spectroscopy (EIS) studies, photoluminescence, and time-resolved photoluminescence. The device efficiency increases significantly which is manifested by the J-V measurements. The passivation mechanism of the devices by organic materials is investigated and demonstrated. In addition, The other strategy is to incorporate some additives into the perovskite solutions to adjust the perovskite film growth toward fewer defects. We control the perovskite film growth process by precursor engineering via solvent and solute control. High-quality perovskite films can be obtained by our method for high-performance devices.
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.

Figure 1
(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.
Enhanced Efficiency and Stability of Inverted Solar Cells Utilizing Pure δ-FAPbI3 Single Crystal Perovskite
Authors: Heo Jin Hyuck , Park Jin Kyoung , Kim Woo-Sik , Im Sang Hyuk
Published: December 2024

A novel methodology has been devised to fabricate pristine δ-formamidinium lead triiodide (δ-FAPbI3) single crystals, crucial for highly efficient and stable perovskite solar cells (PSCs). This approach involves a liquid-phase reaction between FAI and PbI2 in N,N-dimethylformamide, succeeded by antisolvent crystallization with acetonitrile, ensuring the crystal's purity through precise molecular recognition during growth. Leveraging these pure crystals, inverted PSCs employing α-FAPbI3 were engineered, demonstrating an impressive power conversion efficiency (PCE) of 23.48% under standard sunlight, attributed to diminished trap-states. Additionally, surface treatment with 3-(aminomethyl)pyridine elevated the PCE to 25.07%. Notably, an unencapsulated device retained 97.22% of its initial efficiency after 1,000 hours of continuous exposure to sunlight at 85°C in a nitrogen atmosphere, underscoring superior durability. In comparison, a control device maintained only 89.93% of its efficiency under identical conditions.
(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.
Enhanced Thermal Stability in Dielectric Properties of (K0.8Na0.2)NbO3–Based Ceramics for X9R-Mlcc Applications
Authors: Nahm Sahn , Lee Geun-Soo , Kwak San , Min Byeong-Jae , Kim Seung-Hyun , Kim Jung-Soo , Kim In-Su
Published: December 2024

(1−x)(K0.8Na0.2)NbO3–xBaTiO3 [(1−x)(K0.8N0.2)N–xBT] ceramics are well densified at 1080 °C for 2 h. The Curie temperature (TC
) and orthorhombic–tetragonal phase transition temperature (TO-T
) of the ceramics considerably decrease and broaden with increasing x. Moreover, the ceramics (x≥0.08) have large relaxor properties. The (1−x)(K0.8N0.2)N–xBT ceramics (0.09≤x≤0.11) exhibit excellent thermal stability of dielectric properties, satisfying the X9R multilayer ceramic capacitor (MLCC) specification requirements. However, the (1−x)(K1-yNy)N–xBT ceramics (0.0≤x≤0.3 and y = 0.5 and 0.8), which contain a large amount of Na+ ions, cannot satisfy the X9R MLCC specification requirements owing to the weakened relaxor properties and reduced decreasing rate of TC
and TO-T
. An MLCC is fabricated using the 0.9(K0.8N0.2)N–0.1BT ceramic. The MLCC complies with the X9R MLCC regulation requirements and has excellent stability of the applied electric field. Therefore, the 0.9(K0.8N0.2)N–0.1BT ceramic serves as a promising candidate for X9R MLCC devices.
(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.
Room Temperature Synthesis of Hydrogen Permeation Barrier for Storage and Transportation Application
Authors: Amiri Nafiseh , Rabbi Ishtiaq , Brankovic Stanko
Published: December 2024

Distribution of hydrogen in future hydrogen-based economy requires a dense pipeline network for its safe delivery. Natural take is to consider the existing networks of natural gas (NG) infrastructure. However, the main issue is that hydrogen-embrittlement on NG pipes’ steels significantly reduces their fracture toughness and threatens their structural integrity1. Besides developing a new grade of steels less susceptible to the embrittlement, effective hydrogen permeation barriers (HPBs) remain important solution for re-purposing of the existing NG infrastructure for hydrogen transport. Besides a few specific metals, candidates are some oxides,carbides, and nitrides. These coatings require extreme conditions for their synthesis, which renders their application impractical.

We employed strategy for HPB synthesis based on electroless Cu-deposition process2. We have employ solution chemistries exploring a wide range of reducing agents. These include formaldehyde, glyoxylic acid, Na2HPO2 ... and others. Variety of complexing agents were considered as well; EDTA, sodium citrate, sodium potassium tartarate and others. Our optimum solution design favored a large driving force for Cu reduction providing high nucleation rates and films with fewer defects and dense grain boundaries. The comparative analysis between hydrogen permeation rates through bare steel samples and steel samples coated with Cu HPB films is performed using Devanathan - Stachurski permeation technique3. The Cu-HPB thickness varied from experiment to experiment. More than 30 samples have been evaluated. An integral example of these measurements is shown in Figure 1. Permeation reduction factor (PRF) for Cu-HPB as a function of the ratio between steel and Cu-HPB thickness is shown against theoretical calculations. Our results exceed theoretical predictions by factor of 2-5.

Figure
1: Calculations for PRF of Cu/(AISI 4340 steel) as a function of ds/df ratio. Square, circular, and triangular dots represent PRF measurements for Cu-HPB/(ASTM A36 steel) samples produced from tartaric acid (TA) and EDTA solutions. Insets show optical images of steel and Cu/steel samples (left) and SEM of Cu surface morphology (right).

References:

Nemanic, Hydrogen permeation barriers: Basic requirements, materials selection, deposition methods, and quality evaluation, Nuclear Materials and Energy, 19 (2019) 451-457.

Paunovic, Chapter 17: Electroless Deposition of Copper, in Modern Electroplating, fifth Edition, Eds, M. Schelsinger and M. Paunovic, Willey, NY (2005), p. 433.

Iyer, R.N., Pickering, H.V., 1990. Mechanism and kinetics of electrochemical hydrogen entry and degradation of metallic systems. Annu. Mater. Sci. 20, 299-338.

Figure 1
Electromagnetic Coils for a 3000 Psi Hydraulic MEMS Valve Assembly
Authors: Arrington Christian L. , St John Christopher , Finnegan Patrick Sean , Galambos PAUL C , LOVE Lonnie JOE
Published: December 2024

Electromagnetic coils serve many roles in MEMS technologies such as actuators, microfluidics, sensors, energy harvesting, wireless communication, inductive heating, and biomedical applications. Coils can be made using traditional semiconductor manufacturing techniques requiring near UV lithography to define photoresist molds, electroforming metal into the molds, chemical mechanical planarization, assembly, and packaging. Non-traditional techniques such as LIGA using x-rays and soft LIGA using near UV exposures can create higher aspect ratio structures therefor maximizing coil performance and minimizing coil size.

Our work explores micro-fabrication techniques using soft LIGA lithography to create single sided and double-sided copper electroformed MEMS coils. The target coil feature sizes are 100+ micron in thickness of copper, 50 micron feature size, 50 micron gaps, and millimeters in total form factor. The microfabrication process including lithography, copper electrodeposition, and through wafer vias will be discussed along with lessons learned to meet the design criteria. Our goal is the demonstration of a single sided coil and double-sided coil device that could be assembled and arrayed across a 6 inch silicon wafer microfabrication process to create a hydraulic valve assembly. This would enable a digital flow control high-pressure hydraulic valve system capable of reaching 3000 psi. Ultimately this goal minimizes size and weight while increasing efficiency and maximizing power. The figure below depicts a cross sectional view of a single sided coil design assembled with a device layer having a through-wafer etch flow path.

Figure 1: Cross sectional view showing a single hydraulic MEMs valve assembly. A single sided MEMs coil on top, a suspended spring able to open and close the valve, and a thru-wafer fluid flow path.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Figure 1
Effect of Ionic Liquids on Lithium Recovery in Lithium Deficient LiNi0.5Co0.2Mn0.3O2 Crystals
Authors: Ishikawa Shutaro , Yamada Tetsuya , Shishino Kazuyuki , Yanagisawa Kazumichi , Tipplook Mongkol , Hayashi Fumitaka , Teshima Katsuya
Published: December 2024

Cathode active materials for Lithium-ion battery (LIB) contains rare metals such as lithium, cobalt or nickel, thus recycling is important for its reuse. Currently, hydrometallurgy is the mainstream method, in which the active material is dissolved and separated through pH adjustment. However, this method is complicated, expensive and destructs the crystal structure, which reduces the value of recycled products. In recent years, a recycling method that can retain the crystal structure has been studied as an alternative to hydrometallurgy. As the end-of-life active materials are deficient in Li ions by battery charge and discharge, restoration of Li ion is the core issue of the recycling process. To restore the Li ion uniformly in the active material, thermal treatment in a solvent may be effective. However, inorganic molten salts as solvent has problems of high heating temperature and side reactions. In this study, we focused on ionic liquids (ILs) with low melting points and good solubility in oxides, and aimed to understand the role of ILs on Li regeneration and crystal growth of active material. LiNi0.5Co0.2Mn0.3O2 (NCM523) was selected as a model cathode active material.

Pristine Li1.0NCM523 (P-NCM) and deficient Li0.7NCM523 (D-NCM) were prepared by heating NCM precursors and lithium carbonate with arbitral molar ratios. NCM523 (R-NCM) were prepared by heating D-NCM with ILs and lithium sources. Chemical composition was identified using X-ray diffraction (XRD) and inductively coupled plasma (ICP) analysis. Crystal morphologies was observed by scanning electron microscopy (SEM). Battery performance was examined for half-cell batteries consist of various NCMs as cathode active materials and Li metal as anode.

The XRD pattern of D-NCM was consistent with that of NCM523, and ICP analysis show that the composition of D-NCM is Li/Ni = 0.70/0.50. The discharge capacity of D-NCM is 120 mAh/g, which is significantly lower than that of P-NCM (160 mAh/g). These results indicate the prepared D-NCM successfully reproduce the degraded battery performance. Next, the R-NCM was investigated. Elemental analysis shows the composition is Li/Ni = 0.58/0.50, suggesting the leakage of Li during the regeneration process. SEM images exhibit that grain growth with development of crystal face at higher regeneration temperatures, while no significant change occurred below the ILs pyrolysis temperature. This result indicates Li recovery by ILs is possible without any morphologic and phase changes. Further improvement of the regeneration, its mechanism, and battery properties of R-NCM will be discussed in the presentation.

Acknowledgement

This work was partly supported by the Strategic Innovation Program (SIP) of the Cabinet Office, joint research with a company.
(Invited) Application of Electroless Plating to 3D Interconnection Technology of LSIs
Authors: Shingubara Shoso
Published: December 2024

In the interconnection of LSIs and 3D integration technologies, high aspect ratio structures (HRS) such as via holes and trenches with very small dimensions were used. In these HRSs, deposition of metals has been studied using CVD or ALD which are based on a surface reaction dominated deposition process. On the other hand, electroless plating is also based on the surface reaction mechanism, therefore a conformal deposition profile is possible. Furthermore, with use of additives, control of deposition profile such as bottom-up fill is enabled by the electroless plating. Production cost would be significantly reduced by the use of electroless plating as compared to CVDs which use high vacuum chambers. Cu electroless bottom-up fill (superfill) is possible for sub-micrometer diameter holes with addition of inhibitors. Conformal deposition profile of electroless Co-alloy barrier metals is achieved for a high aspect ratio TSVs. In the high aspect TSV structures, a combination of electroless barrier metal and Cu electroplated bottom-up fill would be the most important technology. Furthermore, I would like to introduce electroplating of Ru using hydrazine as a reducing agent. This technology enables to deposit a Ru film which shows significant reduction of resistivity after annealing in the forming gas ambient.
(Invited) Assessing Mechanical Properties of Multilayer Copper Foils for Secondary Batteries
Authors: Shin Han-Kyun , Park Hyun , KIM Jung HAN , Lee Hyo-Jong
Published: December 2024

As the mobile phone and electric vehicle industries grow, demand for mechanically reliable copper foils used as a current collector in secondary batteries is also increasing. In this study, the mechanical properties of copper foils were investigated using a microstructure control electroplating technique which controls the grain sizes of the foils by adjusting the concentration of JGB (Janus Green B) added into the electroplating solution. The JGB addition played a role in suppressing recrystallization, which was confirmed through changes of the sheet resistance and microstructure measured using an EBSD (Electron Backscatter Diffraction) technique. These phenomena are related to the amount of JGB-originated impurities in foil that are co-deposited on the copper surface during electroplating. Using the JGB-based process, the multilayered thin foils were fabricated by alternately stacking a thin layer with a high impurity concentration and a thick layer with a low impurity concentration. The σ0 and KY constants of the Hall-Petch equation were obtained from the stress-strain curves through the tensile testing. Through comparing the σ0 and KY of the multilayered foils and the bulk copper, we secured more reasonable σ0 and KY constants in the Hall-Petch relationship.
Surface Roughness Control of Powder Bed Fused AlSi10Mg Alloy with Various Building Angles
Authors: Park Serim , Jo Hyunbin , Kim Jisu , Han Jungmin , Moon Hyoungseok , Lee Junghoon
Published: December 2024

Powder Bed Fusion (PBF) is advantageous for manufacturing complex shapes of metal products, so that its demand is increasing in various industrial fields. PBFed metal parts have a rough surface due to metal powders being partially melted and attached to the surface during the process. The surface roughness of the PBFed parts varies considerably according to the building angle. The rough surfaces with partially melted metal powder reduce dimensional accuracy limiting the performance of parts, so that some post-treatments are necessary to satisfy the designed part dimension of metal parts. Various surface post-treatment processes including sandblasting, shot peening, laser polishing, and chemical polishing are applied to PBFed parts to reduce surface roughness. However, these processes have limitations for complex shapes and to precisely control dimensional changes. On the other hand, electropolishing (EP) which is an electrochemical surface post-treatment process is not restricted by the shape of the workpiece. In addition, it is possible to control dimensional changes by controlling process parameters such as applied voltage and treatment time. Thus, the electropolishing can be a promising candidate for the post-treatment of PBFed metal parts. Even though various conventional EP solutions and processes have been introduced to control the surface roughness, effects on dimensional changes, which is essential for PBFed metal parts, were not widely explored. Therefore, it is necessary to explore EP processes to reduce the surface roughness of PBFed parts, while achieving a high dimensional accuracy. In this study, we studied various EP solutions for PBFed AlSi10Mg alloy, widely used in light metal parts, considering both surface roughness and dimensional change. The aim of this work is to find the optimum electropolishing condition to reduce roughness effectively while minimizing the dimensional change. Several electrolytes that are conventional used in EP of aluminum and its alloy were selected and applied to PBFed AlSi10Mg. Based on these electrolytes, a new electrolyte was also devised. The thickness and surface roughness change before and after EP according to the applied voltage and treatment time was analyzed to derive the optimum conditions. The optimum EP conditions were applied to the PBFed AlSi10Mg alloy manufactured with building angles of 45, 60, and 90˚ and investigated the reduction rate in surface roughness according to the building angle.
Radicals on Tap for Green Hydrometallurgical Ore Extraction and Li-Ion Battery Recycling
Authors: Tuya Nathalie , Dye Brandon , May Richard , Steingart Dan
Published: December 2024

The widespread use of lithium-ion batteries has resulted in an increased demand for critical minerals, accentuating the need for efficient and green processes for both ore extraction and LIB recycling. Conventional hydrometallurgical leaching to extract and isolate elements from mineral ores or LIB waste leverages strong acids (e.g., sulfuric or hydrochloric) in tandem with a reducing agent (e.g., peroxide or sulfide). A composition of sulfuric acid and hydrogen peroxide, colloquially known as piranha, is utilized at elevated temperature and pressure conditions to achieve fast leaching kinetics. However, the production, transportation, and integration of concentrated hydrogen peroxide streams are carbon intensive processes and pose significant health and environmental risks. In this work, hydrogen peroxide is generated electrochemically in situ during leaching through an electro-Fenton-like process. Pb/PbO symmetric electrodes uniquely electrolyze water, producing hydrogen peroxide and OH· radicals., therefore accelerate the leaching of the input material. Mechanical shedding of the electrodes is also prevented from the redox couples commonly found in battery/ore materials (Ni3+/Ni4+. Fe2+/Fe3+) even in the presence of high solid concentrations >50 g/L. Ultimately, in situ generation of peroxide enables radically lower reactor capex and safer, simpler leaching operations.