bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.

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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.
Theoretical Model and Control-Parameter Classification for Solid Oxide Fuel Cell System with Cooling Air Bypass into Burner
Authors: Ma Long , Lin Zijing 
Published: December 2024

When using solid oxide fuel cells (SOFCs) as the auxiliary power unit (APU) of automobiles, a stringent thermal control to limit the temperature and thermal stress of all components of the SOFC system is required. Various thermal management methods have been proposed, mostly involving the use of cooling air (CA). To avoid the thermal shock associated with directly adding CA into the SOFC stack air inlet stream, directing CA into the burner is a desirable alternative. Using CA bypass into the burner is a simple and effective way to control the excessive burner temperature, which in turn limits the temperatures of other system components.
In this study, a 5 kW SOFC system fueled by diesel and with CA into the burner is examined. The system consists of an SOFC stack and a balance of plant (BOP) that includes a steam generator, an air heat exchanger, a fuel heat exchanger, a pre-reformer and a burner, a water pump and an air blower. The burner burns the unused fuel and provides heat to the pre-reformer and heat exchangers. A thermocouple is installed near the outlet of the burner, which is connected to a CA pipe. When the burner temperature exceeds its set maximum temperature, TBM, the CA valve opens to allow fresh air to enter directly to the burner through the bypass pipe to maintain the burner temperature at the set value. A comprehensive theoretical model, including detailed sub-models for all system components, is developed and verified with multiple experimental data.
The theoretical model is used in a comprehensive control-parameter classification analysis, revealing the impacts of the fuel utilization, Uf, air flow rate, Vair, and TBM = (900 ℃, 1000 ℃) on the system performance. In particular, the effects of (Uf, Vair, TBM) on the system electrical efficiency, Esys, and the characteristic temperatures of the stack and BOP components are determined quantitatively. The main findings are: 1) It is confirmed that the CA bypass into the burner can limit the operating temperatures of all system components. 2) Changing TBM from 900℃ to 1000℃ can notably increase Esys only for low Uf, but may increase the maximum stack temperature, TM. It appears that TBM = 900℃ is more favorable than TBM = 1000℃. 3) Increasing Uf increases Esys, but may also increase TM and the maximum stack temperature difference, Tdiff. 4) TM and Tdiff as well as Esys decrease with the increase of Vair. Overall, the constrains of (TM ≤ 900℃,
Tdiff

≤ 200℃) can be satisfied together with Esys > 55%, if Vair is chosen properly.
It is concluded that the examined system design is suitable as an APU. Moreover, the system model presented here can be used for the design and operation optimization of similar systems, taking factors such as the stack size and performance, the thermal constrains the stack can withstand into considerations.
Zr-Based Thin Film Metallic Glasses As High-Efficiency Materials for Electrocatalysis of the Hydrogen Evolution Reaction
Authors: Howard Jerry , Carlson Krista , Chidambaram Dev 
Published: December 2024

The production of hydrogen through water electrolysis is a major limiting step in the implementation of hydrogen-based energy storage. Currently used materials for catalyzing the hydrogen evolution reaction require large overpotentials, reducing the efficiency of hydrogen production. Metallic glasses are of interest for use in electrocatalysis due to their high activity and diversity of catalytic sites. However, only a small selection of metallic glass compositions can be manufactured into bulk parts, necessitating the use of metallic glass coatings. In this research, a Zr-based metallic glass was produced as a thin film using sputtering deposition. Combinatorial co-sputtering was used to produce a library of quaternary Zr-based metallic glasses to enable high-throughput characterization of the anode material and electrochemical testing. Metallic glass surfaces were characterized prior to and after electrochemical testing using a range of techniques to explore the physiochemical properties of the catalytic surface. Nano-structured metallic glass coatings are a promising material for catalysis of the hydrogen evolution reaction.
This work is funded by ARPA-e under DE-AR0001697. JRH is funded as a fellow under the NSF GRFP.
Scalable Cross-Flow Multi-Tubular Electrochemical Cell for Electrochemically Mediated CO2 Capture
Authors: Lee Younghun , Massen-Hane Michael Edward , Hatton T. Alan 
Published: December 2024

The global concentration of carbon dioxide (CO2) in the atmosphere has increased by approximately 23 percent over the past 50 years, reaching an all-time record of 425 parts per million in March 2024. In efforts to achieve negative carbon emissions, electrochemically mediated CO2 separations have recently garnered increasing attention as a promising pathway due to their low energy requirements, modular scalability, and straightforward integration with renewable energies. Conventionally, flow systems requiring a membrane to prevent mixing of the anolyte and catholyte in the cell have been utilized in CO2 capture systems employing electrochemical reactions. However, the pumping costs and membrane have adverse impacts on energetics and CO2 transport in electrochemical systems.
In this study, a cross-flow multi-tubular electrochemical cell based on supported liquid membranes (without a solid membrane) between two gas diffusion electrodes with porous and tubular structures is proposed. The conductive and tubular electrodes are manufactured through a facile two-step dip coating method employing Teflon AF 2400 and silver, which maximizes the stability and electrical conductivity of the electrodes. This novel cell architecture enables continuous operation through diffusion without pulsed flow or mixing, as well as a two-stage system combining activation/absorption and deactivation/release, thereby minimizing thermodynamic and operating energy consumption. Furthermore, the cylindrical diffusion profile and high surface area of the hollow fiber electrodes ensure superior CO2 fluxes compared to conventional flat plate electrodes. In particular, this proposed cross-flow system, where anodic and cathodic fiber electrodes are orthogonally arranged within the cell, can realize a compact design and ease of scaling up. Ultimately, this system not only serves as a "process-ready" separation device but also offers a cutting-edge perspective on the fabrication of electrochemical cell structures.

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Carbon Fixation for Food Production
Authors: Almeida Simoes Andressa Juliana , Sit Chun Yat , Hong Sukhwa , Wachtveitl Josie , Moon Yewon , Kenis Paul J.A 
Published: December 2024

Demand for food is ubiquitous around the globe. Different regions of the world meet their food needs in different ways, but at times the normal production and supply mechanisms are interrupted. Reasons include drought and natural disasters such as hurricanes, tornados, floods, or situations arising from conflicts. The work here pursues the vision to develop a system able to produce food from minimal resources, e.g., water, as well as N2, O2, CO2 from air, using renewable energy (wind, solar, hydro). Realization of this vision will require CO2 capture, carbon and nitrogen fixation, as well as conversion of the carbon and nitrogen substrates into biomass for subsequent processing into food formats such as shakes or puddings.
This presentation will focus on developing the carbon fixation capability to help enable the vision of generating food from minimal resources. The specific approach involves the electroreduction of CO2 to CO in a membrane electrode assembly (MEA) cell, followed by the electroreduction in bipolar cells with a porous solid electrolyte of CO to acetate. This two-step approach is expected to achieve a higher selectivity for acetate than direction reduction of CO2 to acetate. An additional advantage is that the product stream of the second step is comprised of pure water with water-soluble products (acetate, traces of ethanol, etc.) without the presence of electrolyte salts, avoiding separation steps. This presentation will focus on catalyst, electrode, and cell optimization for both CO2 to CO and CO to Acetate conversion, with a focus on scaling of single cells and enhancing durability over multi-hour runs.
Manufacturing Scale-up of ALD Onto Synthetic Graphite Powder in a Continuous Vibrating Reactor for Battery Applications
Authors: Castro Brandon , Broerman Andrew , Gump Christopher , Dameron Arrelaine A 
Published: December 2024

As the demand for improved performance in battery material increases, development of large-scale, high-throughput ALD processes and equipment is necessary to meet production demands. Forge Nano has previously demonstrated ALD deposition onto natural and synthetic graphite over a range of scales (50 g – 50 kg) in both rotary bed and fluidized bed reactors. This process has now been successfully scaled-up to the highest throughput system (ton scale) with a continuous vibrating reactor (CVR). The CVR (and associated product Circe) is a spatial ALD system where the substrate powder travels down a porous deck, driven by vibration. Process gases flow at atmospheric pressure perpendicularly to the powder flow, up through the porous deck, and fluidize the moving powder bed and mixing the particles with the gases top to bottom in the process. The substrate travels through zones of the precursors and purge gases of an ALD cycle (Figure 1).
Reproducibility per batch and relative to successful graphite deposition criteria from smaller ALD batch systems was explored in a CVR system configured to perform 4 TMA/H2O ALD cycles. Commercial synthetic graphite was coated at a rate of 33 kg/h, in 45-50 kg batches, at 180°C. Precursor flow was controlled based on the calculated stoichiometry required to achieve 100% titration of available surface sites, as determined in experiments performed in small scale fluidized bed reactors. Samples of coated product were taken from the reactor effluent every 10 minutes. Effluent samples of replicate runs were analyzed using ICP to determine the Al loading, and to characterize the reproducibility of the coating process. An average of 84 ± 13 ppm Al was deposited for all replicate runs (each totaling 4 ALD cycles). The 1-2 initial samples for a given run comprised lower Al mass loadings, likely due to the system approaching steady state in terms of substrate and precursor flow. Additional tests with 150% of the calculated stoichiometric TMA flow rate showed the deposition to be self-limiting. Finally, the coated material was homogenized and then recycled through the CVR to demonstrate reproducibility at higher deposition levels. This material was recycled multiple times to achieve 20 TMA/H2O ALD cycles and establish an average and linear growth rate per ALD cycle. Additionally, bed height and speed conditions were explored to achieve higher material processing rates. Coated materials were tested in coin cells as anode powders for lithium-ion batteries, with performance being compared to coated graphite prepared via more traditional deposition in fluidized bed reactors under vacuum conditions. Coated materials demonstrated that increasing coating levels increased first cycle coulombic efficiency (FCE), reversible capacity, and cycle life.
Figure 1. Schematic and photo of the spatial CVR ALD system

Figure 1
Addition of Iodine Compounds in H3PO4 Solution for the Increase in Si3N4 Etching Rate
Authors: Han Jongwon , Lim Sangwoo 
Published: December 2024

Highly selective etching of silicon nitride (Si3N4) layers in the Si3N4/SiO2 multi-stack structure is crucial for the fabrication of 3D NAND flash memory devices. A high-temperature 85 wt% phosphoric acid (H3PO4) solution is commonly used for this process. With the increasing demand for higher-density memory devices, the number of stacked Si3N4-SiO2 pair-layers in 3D NAND devices continues to increase. This increase in the number of stacks produces various challenges in the selective Si3N4 etching process. For example, the Si3N4 etch byproduct cannot be effectively diffused out of the 3D NAND structure due to the high viscosity of the 85 wt% phosphoric acid solution. Additionally, the accumulated Si3N4 etch byproduct suppresses the etching reaction of Si3N4 by Le Chatelier’s principle. Moreover, in the high temperature 85 wt% phosphoric acid solution, the SiO2 layers in Si3N4/SiO2 multi-stack structures can be etched and become thin. The thinning of SiO2 layers can hinder post etching process such as metal deposition. Although some additives were introduced to suppress SiO2 thinning, they also disrupted the Si3N4 etching reaction, leading to lower throughput in the selective Si3N4 etching process. However, given the economic importance in the industry, increasing the etching rate of Si3N4 is crucial for improving throughput in the selective Si3N4 etching process.
In this study, iodine compounds which were expected to increase the Si3N4 etching rate by participating in the Si3N4 etching reaction, were introduced to the 85 wt% phosphoric acid solution. The effects of each additive on the etching rate were examined in Si3N4 and SiO2 films and Si3N4/SiO2 multi-stack structures which were prepared by depositing Si3N4 or SiO2 films using plasma-enhanced chemical vapor deposition. These films and Si3N4/SiO2 multi-stack structures were etched using an 85 wt% phosphoric acid solution with iodine compounds at 160 ºC for 15 min. It was observed the addition of iodine compounds to the phosphoric acid solution increased the etching rate of Si3N4 up to 21% on film and 17% on multi-stack structure compared to the condition of bare 85 wt% phosphoric acid solution. It is thought that iodine compounds can provide lone pair electrons to the Si atom in the Si3N4 layer, which has been conducted by water molecule of bare phosphoric acid solution. When this nucleophilic substitution occurs on the Si atom, the broken of Si-N bond which is the rate determining step of Si3N4 etching reaction will be followed. Since the addition of iodine compounds in addition to H2O in 85 wt% H3PO4 solution increases total concentration of species participating rate determining step, the etching rate of Si3N4 is accelerated. These results suggest that addition of iodine compounds can enhance throughput in selective Si3N4 etching processes. This is attributed to the participation of iodine compounds in the nucleophilic substitution of the Si3N4 etching process.