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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Status and prospects of lithium iron phosphate manufacturing in the lithium battery industry

Abstract Lithium iron phosphate (LiFePO 4 , LFP) has long been a key player in the lithium battery industry for its exceptional stability, safety, and cost-effectiveness as a cathode material. Major car makers (e.g., Tesla, Volkswagen, Ford, Toyota) have either incorporated or are considering the use of LFP-based batteries in their latest electric vehicle (EV) models. Despite LFP’s well-researched status as a cathode material, it is expected to fulfill additional demands in electric vehicle applications, such as fast-charging capabilities, wide temperature range adaptability, and higher energy density. This perspective examines the LFP supply chain, synthetic approaches, manufacturing processes, market trends, recent advancements, and evolving demands to better understand its future role in the EV market. Graphical abstract

Lu, Yanying↗
DOE OSTI2024

Red–green–blue Boolean image analysis of particulate debris laced with luminescent tracers

Abstract Particulate mass estimation from 3-pixel images is desirable in many fields. Red–green–blue (RGB) analysis and Boolean logic were shown to estimate the mass of luminescent tracers in microscopic images. With a controlled background intensity, an estimation error of 1.8 to 3.5% was achieved; in uncontrolled backgrounds, an error of about 18% was achieved. RGB analysis is a valuable tool for spatial location of particulates. This work shows it is possible to estimate the particulate mass in an image and gives RGB an extension into mass quantification that has far-reaching impacts in fields involving the fate and transport of particulate matter. Graphical abstract

36 MATERIALS SCIENCE↗
DOE OSTI2021

Unveiling oxidation mechanism of bulk ZrS2

Abstract Transition metal dichalcogenides have shown great potential for next-generation electronic and optoelectronic devices. However, native oxidation remains a major issue in achieving their long-term stability, especially for Zr-containing materials such as ZrS 2 . Here, we develop a first principles-informed reactive forcefield for Zr/O/S to study oxidation dynamics of ZrS 2 . Simulation results reveal anisotropic oxidation rates between (210) and (001) surfaces. The oxidation rate is highly dependent on the initial adsorption of oxygen molecules on the surface. Simulation results also provide reaction mechanism for native oxide formation with atomistic details. Graphic Abstract

Yang, Liqiu↗
DOE OSTI2021

A snapshot review—Fluctuations in quantum materials: from skyrmions to superconductivity

Abstract By measuring a linear response function directly, such as the dynamic susceptibility, one can understand fundamental material properties. However, a fresh perspective can be offered by studying fluctuations. This can be related back to the dynamic susceptibility through the fluctuation–dissipation theorem, which relates the fluctuations in a system to its response, an alternate route to access the physics of a material. Here, we describe a new X-ray tool for material characterization that will offer an opportunity to uncover new physics in quantum materials using this theorem. We provide details of the method and discuss the requisite analysis techniques in order to capitalize on the potential to explore an uncharted region of phase space. This is followed by recent results on a topological chiral magnet, together with a discussion of current work in progress. We provide a perspective on future measurements planned for work in unconventional superconductivity. Graphical abstract We describe a new X-ray tool for material characterization that will offer an opportunity to uncover new physics in quantum materials using coherent, short-pulsed X-rays. We provide details of the method and discuss the requisite analysis techniques in order to capitalize on the potential to explore an uncharted region of phase space. This is followed by recent results on a topological chiral magnet, together with a discussion of current work in progress. We provide a perspective on future measurements planned for work in unconventional superconductivity.

36 MATERIALS SCIENCE↗
DOE OSTI2021

The mechanical response of micron-sized molecular crystals

Abstract Microstructures and corresponding properties of compacted powders ultimately depend on the mechanical response of individual particles. In principle, computational simulations can predict the results of powder compaction processes, but the selection of appropriate models for both particle–particle interactions and particle deformations across all relevant length scales remain nontrivial tasks, especially in material systems lacking detailed mechanical property information. The work presented here addresses these issues by conducting uniaxial compressions in situ inside of a scanning electron microscope to characterize the mechanical response of individual micron-sized particles of a molecular crystal, hexanitrohexaazaisowurtzitane (CL-20). This experimental approach enabled the collection of quantitative force and displacement data alongside simultaneous imaging to capture morphology changes. The results reveal information about elastic deformation, yield, plastic deformation, creep, and fracture phenomena. Accordingly, this work demonstrates a generalizable approach for assessing the mechanical response of individual micron-sized molecular crystal particles and utilizing those responses in particle-level models. Graphic abstract

36 MATERIALS SCIENCE↗
DOE OSTI2021

Proton irradiation-induced blistering in UO2

Abstract Proton (H + ) irradiation effects in polycrystalline UO 2 have been studied. The irradiation was carried out using three ion energies and two different ion fluxes at 600 °C. Scanning electron microscopy (SEM) investigations showed that significant surface flaking took place. Focused ion beam (FIB) milling in SEM was successfully applied for extracting lamellas from uneven blistered surfaces for transmission electron microscopy (TEM) investigations allowing detailed investigations for the degradation mechanisms. High-resolution TEM for the flaked UO 2 surfaces revealed that the implanted H + formed sharp two-dimensional cavities at the peak ion-stopping region instead of diffusing to the matrix. The resulting lateral stress likely caused UO 2 surface deterioration in good agreement with previous blistering and flaking studies on crystalline materials. Graphical abstract

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

X-ray fluorescence mapping: Insights into mesoscale structure impact on battery functional electrochemistry

Abstract Electron transfer and ion transport occurs over multiple-length scales ranging from the atomic to mesoscale within battery materials and electrodes. Micro-X-ray fluorescence (µ-XRF) is an important characterization tool as it can resolve structural, compositional, and redox information while providing insight into the spatial distribution of an electroactive material. In this work, µ-XRF mapping is used to probe the distribution of iron within thin planar slurry-based and thick porous carbon nanotube (CNT)-based magnetite (Fe 3 O 4 ) electrodes. Notably, the porous CNT-based electrode showed homogenous distribution of Fe within the electrode whereas the planar electrode demonstrated distinct Fe aggregates. This information was used to rationalize the electrochemistry observed by cyclic voltammetry and galvanostatic cycling. The thick porous electrode delivered 215% more capacity per gram of magnetite during the first discharge, consistent with increased electrode homogeneity enabling effective ion access and electron transfer. Graphical Abstract

Sadique, Nahian↗
DOE OSTI2022

Material aspects of giga-Hertz ZnO TFTs for wireless systems

Abstract Having enabled high-value application capabilities through mass production of flat-panel displays, X-ray imagers, and solar panels, Large-Area Electronics (LAE) holds potential to open new frontiers in wireless applications for the Internet of Things and 5G/6G, by enabling unprecedented spatial control and power efficiency through large size and flexible form factor of radiative apertures. However, this requires boosting operation frequencies from the traditional limits in the range of 10–100’s of mega-Hertz to multi giga-Hertz. In this paper, we discuss critical device metrics, to characterize zinc-oxide (ZnO) thin-film transistor (TFT) operation frequency for both active (for signal amplification) and passive components in LAE-based circuits and systems. We then describe the key structural and material approaches towards recently demonstrated LAE-based giga-Hertz wireless systems employing ZnO TFTs. Bringing LAE to the giga-Hertz regime provides a path towards flexible and meter-scale monolithic integrated wireless systems. Graphical abstract

Ma, Yue (ORCID:0000000186724090)↗
DOE OSTI2022

Bioinspired synthesis of thermally stable and mechanically strong nanocomposite coatings

Abstract An innovative biomimetic method has been developed to synthesize layered nanocomposite coatings using silica and sugar-derived carbon to mimic the formation of a natural seashell structure. The layered nanocomposites are fabricated through alternate coatings of condensed silica and sugar. Sugar-derived carbon is a cost-effective material as well as environmentally friendly. Pyrolysis of sugar will form polycyclic aromatic carbon sheets, i.e., carbon black. The resulting final nanocomposite coatings can survive temperatures of more than 1150 °C and potentially up to 1650 °C. These coatings have strong mechanical properties, with hardness of more than 11 GPa and elastic modulus of 120 GPa, which are 80% greater than those of pure silica. The layered coatings have many applications, such as shielding in the form of mechanical barriers, body armor, and space debris shields. Graphical abstract

36 MATERIALS SCIENCE↗
DOE OSTI2023

Optimizing chemistry for designing oxidation resistant FeCrAl alloys

Abstract Traditionally, FeCrAl alloys played an important role in high-temperature applications due to their ability to form a passive Al oxide film at temperatures above ~ 800 °C. Recently, FeCrAl alloys became of interest for the application of accident tolerant nuclear fuel cladding. This study covers work done at GE Research for better understanding the role of Al, Cr, and Mo in oxidation kinetics and thermodynamics. Several models and commercial prototype alloys have been tested in hydrothermal corrosion autoclave loops, at low temperature steam exposure (~ 400 °C), high temperature steam exposure (~ 1000 °C or higher), and high temperature air exposures. The results provide insights on how chromium and aluminum play a significant role in both high temperature and low temperature oxidation of FeCrAl. Additionally, machine learning tools are used to gain further insights on both predicting future optimized chemistries for balancing the properties of hydrothermal corrosion, low and high temperature steam oxidation, and thermal aging (which is exacerbated due to radiation in a nuclear reactor environment). GE plans to use this framework to further optimize the FeCrAl alloy system for use in nuclear reactor environments. Graphical abstract

Roy, Indranil (ORCID:0000000336124323)↗
DOE OSTI2023

Predicting and understanding corrosion in molten chloride salts

Abstract Molten chloride salts are stable at higher temperatures than many other salts, including nitrate salts, and are thus promising for heat transfer and/or thermal energy storage in concentrating solar power, nuclear power, and other thermal energy storage applications. However, corrosion in molten chloride salts remains a significant problem. While many studies have been devoted to evaluation of corrosion, we find that a comprehensive method for predicting corrosion in molten chloride salts is lacking. Here, we present an evaluation of corrosion in molten chloride salts using Ellingham diagrams and chloride-oxide stability diagrams, which enable prediction of alloy performance in molten chloride salts and allow corrosion results to be interpreted at a fundamental level. Graphical abstract

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

A-site occupancy effects on structure, ionic conductivity, and thermodynamic stability of KxMgx/2Ti8−x/2O16

Abstract K x Mg x /2 Ti 8− x /2 O 16 (1.54 ≤ x ≤ 2) hollandite samples synthesized using a conventional solid-state route were used to investigate the effect of structure, ionic conductivity, and thermodynamic stability as a function of A-site (K) occupancy. The ionic conductivity, as measured using AC impedance spectroscopy, decreased as the A-site occupancy (and K content) increased. Titanate hollandite, of the form K x Mg x /2 Ti 8− x /2 O 16 , was measured using high-temperature oxide melt solution calorimetry in sodium molybdate (3Na 2 O $$\bullet$$ ∙ 4MoO 3 ) solvent at 804 $$^\circ{\rm C}$$ ∘ C . The enthalpies of formation are strongly exothermic indicating that they are thermodynamically stable relative to their constituent oxides. Previous studies have demonstrated increased stability with an increase in Cs content at fixed A-site occupancy. This work demonstrated an increase in the stability for the K-bearing hollandite samples with an increase in K content and tunnel occupancy. The measured enthalpies of formation (∆ H f,ox ) were in good agreement with density functional theory (DFT) predictions. Graphical abstract

Cassell, Nakeshma S.↗
DOE OSTI2024

Applying energy justice metrics to photovoltaic materials research

Abstract Achieving the energy transition sustainably requires addressing how new technologies may impact justice in the energy system. The Justice Underpinning Science and Technology Research (JUST-R) metrics framework was recently proposed to aid researchers in considering justice in early-stage research on energy technologies; however, case study evaluations of the framework revealed a desire from researchers to see metrics specialized to particular fields of study. Here, we refine metrics from the JUST-R framework to enhance its applicability to photovoltaic (PV) materials research. Metrics are reorganized to align with aspects of the research process (e.g., research team or source materials). For most metrics, baseline values are suggested to enable researchers to compare their project to competing technologies or standards at their institutions. These refinements are integrated into a tool to facilitate easier understanding and evaluation of justice considerations in early-stage PV research, which can serve as a template for evaluating other energy technologies. Graphical abstract

14 SOLAR ENERGY↗
DOE OSTI2024

Towards a study protocol: A data-driven workflow to identify error sources in direct ink write mechatronics

Abstract Using Direct Ink Write (DIW) technology in a rapid and large-scale production requires reliable quality control for printed parts. Data streams generated during printing, such as print mechatronics, are massive and diverse which impedes extracting insights. In our study protocol approach, we developed a data-driven workflow to understand the behavior of sensor-measured X- and Y- axes positional errors with process parameters, such as print velocity and velocity control. We uncovered patterns showing that instantaneous changes in the velocity, when the build platform accelerates and decelerates, largely influence the positional errors, especially in the X- axis due to the hardware architecture. Since DIW systems share similar mechatronic inputs and outputs, our study protocol approach is broadly applicable and scalable across multiple systems. Graphical abstract

36 MATERIALS SCIENCE↗
DOE OSTI2024

Modulating ion-binding at macromolecular interfaces during (bio)mineralization: A snapshot review for calcium carbonate and calcium phosphate systems

Abstract Local environments have strict influence over (bio)mineralization in calcifying systems. This snapshot review discusses recent insights into the roles of Ca 2+ -macromolecule interactions on the nucleation of calcium carbonate and calcium phosphate minerals. Experimental findings combined with simulations/modeling are providing breakthrough information and raising important questions for future studies. The emerging picture is that both nucleation and growth are driven by local ordering of ions and water about the macromolecule interface, rather than broader properties or molecular class. Tuning macromolecular properties at the atomic scale thus provides opportunities for highly specific controls on mineralization; however, many limitations and challenges remain. We highlight studies employing in-situ atomic force microscopy (AFM) and transmission electron microscopy (TEM) to observe crystallization processes on or near macromolecular substrates. As the distribution and ability of these techniques increases, fundamental studies integrating experimental and computational methods will be crucial to inform a broad range of applications. Graphical abstract

Knight, Brenna M. (ORCID:0000000244000067)↗
DOE OSTI2024

Exploring 2D X-ray diffraction phase fraction analysis with convolutional neural networks: Insights from kinematic-diffraction simulations

Abstract Deep-learning models are effective for analyzing the complex information in 2D X-ray diffraction (XRD) patterns. Accurately collecting parameters of the material sample is crucial during model training, significantly impacting model performance. In this study, we employ a kinematic-diffraction simulator to generate simulated 2D XRD patterns for Ti–6Al–4V alloy, allowing precise control of sample parameters. These simulated patterns are used to train convolutional neural networks, predicting $$\upbeta$$ β -phase volume fractions. The training data set consists exclusively of 2D XRD patterns with pure $$\upalpha$$ α - or pure $$\upbeta$$ β -phase, while the testing set incorporates patterns with intermediate phase volume fraction. In particular, we investigate how the architectures of the model influence prediction reliability and computational performance. Experimental results reveal that, with appropriate training, the convolutional neural network accurately detects intermediate phase volume fractions even trained with only pure-phase patterns, achieving a mean square error accuracy of $$9.4 \times 10^{-4}$$ 9.4 × 10 - 4 . Graphical abstract

Yue, Weiqi↗
DOE OSTI2024

A data integration framework of additive manufacturing based on FAIR principles

Abstract Laser-powder bed fusion (L-PBF) is a popular additive manufacturing (AM) process with rich data sets coming from both in situ and ex situ sources. Data derived from multiple measurement modalities in an AM process capture unique features but often have different encoding methods; the challenge of data registration is not directly intuitive. In this work, we address the challenge of data registration between multiple modalities. Large data spaces must be organized in a machine-compatible method to maximize scientific output. FAIR (findable, accessible, interoperable, and reusable) principles are required to overcome challenges associated with data at various scales. FAIRified data enables a standardized format allowing for opportunities to generate automated extraction methods and scalability. We establish a framework that captures and integrates data from a L-PBF study such as radiography and high-speed camera video, linking these data sets cohesively allowing for future exploration. Graphical abstract

36 MATERIALS SCIENCE↗
DOE OSTI2025

The importance of electron scattering in the analysis of actinide X-ray spectroscopy

Abstract Manifestations of electron scattering in X-ray spectroscopy have been evident for decades. Here, it will be shown that the proper interpretation of variants of X-ray Absorption Spectroscopy (XAS) of actinide materials must include an accurate treatment of features caused by electron scattering, i.e., EXAFS or Extended X-ray Absorption Fine Structure. These EXAFS features can be of such low energy that they are within ten to twenty electron volts of the Unoccupied Density of States (UDOS), immediately above the Fermi Energy or Band Gap. The adaption of simple models using the FEFF simulation program will be presented, including the demonstration of the robust nature of the results from different models. Graphical abstract

Tobin, J. G. (ORCID:0000000322943301)↗