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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

System and method for rapid, high throughput, high pressure synthesis of materials from a liquid precursor

The present disclosure relates to a system and method for synthesis of condensed, nano-carbon materials to create nanoparticles. In one embodiment the system may have a source of liquid precursor, a flow control element and a shock wave generating subsystem. The flow control element is in communication with the source of the liquid precursor and creates a jet of liquid precursor. The shock wave generating subsystem drives a shock wave through at least a substantial portion of a thickness of the jet of liquid precursor to sufficiently compress the jet of liquid precursor, and to increase a pressure and a temperature of the jet of liquid precursor, to create solid state nanoparticles.

Armstrong, Mike↗
DOE OSTI2024

Development of Novel Sintered Carbon-Ore Building Materials

The main objective for this project was to develop value-added products from carbon-ore leading to commercialization of a carbon-based product. These carbon-based products (LIG2 products) are produced using the sintered carbon-ore building materials (SCBM) technology and have carbon contents greater than 70 wt.% carbon with greater than 51wt.% of the carbon coming from carbon-ore. The project team produced LIG2 bricks at a rate of five bricks per day and characterized the material properties of the bricks. These products can then be used in fabrication of a carbon-based building. A technical and economic analysis (TEA), cradle-to-grave life cycle analysis (LCA), technology gap analysis, and conceptual design were also completed for the LIG2 carbon-ore brick manufacturing process.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2020

The polymeric conformational effect on capacitive deionization performance of graphene oxide/polypyrrole composite electrode

Exploitation of novel faradic materials is an alternative implementation for solving the problem of poor specific electrosorption capacity that conventional carbon materials are encountered in capacitive deionization. Particularly, composite electrode is just a suitable choice because of its potentially high ion-storage ability. Herein, a cyclic voltammetric treatment method with different low limit of potential window was used to manipulate the polymeric conformation and doping level of graphene oxide/polypyrrole (GO/PPy) composite electrode. Based on it, the effect of polymeric structure on the electrosorption performance was systematically studied. When the low limit of potential window is shifted negatively enough, the irreversible polymeric conformational shrinks of GO/PPy are promoted, which not only hinders the insertion process of ions, but also decreases the doping level of polymer due to the intensive interchain-action produced by more entangled polymeric chain. Thus, the number of intercalated ions should decrease, which is expressed by electrochemical impedance spectroscopy (EIS) results and is proportional to the electrosorption capacity of GO/PPy composite electrode in membrane capacitive deionization (MCDI) process. Finally, our work suggests that the less packing density, higher doping level and more charge delocalization on PPy backbone in electrode are beneficial to enhance its capacitive deionization performance.

42 ENGINEERING↗
DOE OSTI2022

Carbon nanotube (CNT) reinforced 316L stainless steel composites made by laser powder bed fusion: Microstructure and wear response

Carbon nanotube (CNT) reinforced 316L stainless steel (SS) composites were fabricated by laser powder bed fusion (LPBF) additive manufacturing (AM). This study focuses on microstructure evolution, hardness, and wear behavior. The wear behavior for AM 316L SS and 1 wt% CNT/316L SS was studied by a dry sliding test under normal loads of 10, 15, and 25 N. The addition of CNT to 316L SS led to the change of solidification mode from cellular/columnar to dendritic growth, producing grain refinement. Nanoscale dendrites were observed. Although TEM characterization confirmed the existence of CNT in cell interior, most CNT were damaged, resulting in carbon material segregation along cellular/dendritic boundaries. The wear rate was found dramatically decreased due to the improved hardness. Compared to the adhesive and abrasive wear in AM 316L SS, the wear mechanism of CNT/316L composite was adhesion and oxidative wear. Furthermore, enhanced cellular/dendritic boundary strengthening by carbon segregation was the main strengthening mechanism of CNT/316L composite.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Synthesis of high-entropy alloy nanoparticles on supports by the fast moving bed pyrolysis

High-entropy alloy nanoparticles (HEA-NPs) are important class of materials with significant technological potential. However, the strategies for synthesizing uniformly dispersed HEA-NPs on granular supports such as carbon materials, γ-Al 2 O 3 , and zeolite, which is vital to their practical applications, are largely unexplored. Herein, we present a fast moving bed pyrolysis strategy to immobilize HEA-NPs on granular supports with a narrow size distribution of 2 nm up to denary (MnCoNiCuRhPdSnIrPtAu) HEA-NPs at 923 K. Fast moving bed pyrolysis strategy ensures the mixed metal precursors rapidly and simultaneously pyrolyzed at high temperatures, resulting in nuclei with a small size. The representative quinary (FeCoPdIrPt) HEA-NPs exhibit high stability (150 h) toward hydrogen evolution reaction with high mass activity, which is 26 times higher than the commercial Pt/C at an overpotential of 100 mV. Our strategy provides an improved methodology for synthesizing HEA-NPs on various supports.

36 MATERIALS SCIENCE↗
DOE OSTI2022

MoS 2 -Decorated Graphene@porous Carbon Nanofiber Anodes via Centrifugal Spinning

Sodium-ion batteries (SIBs) are promising alternatives to lithium-ion batteries as green energy storage devices because of their similar working principles and the abundance of low-cost sodium resources. Nanostructured carbon materials are attracting great interest as high-performance anodes for SIBs. Herein, a simple and fast technique to prepare carbon nanofibers (CNFs) is presented, and the effects of carbonization conditions on the morphology and electrochemical properties of CNF anodes in Li- and Na-ion batteries are investigated. Porous CNFs containing graphene were fabricated via centrifugal spinning, and MoS 2 were decorated on graphene-included porous CNFs via hydrothermal synthesis. The effect of MoS 2 on the morphology and the electrode performance was examined in detail. The results showed that the combination of centrifugal spinning, hydrothermal synthesis, and heat treatment is an efficient way to fabricate high-performance electrodes for rechargeable batteries. Furthermore, CNFs fabricated at a carbonization temperature of 800 °C delivered the highest capacity, and the addition of MoS 2 improved the reversible capacity up to 860 mAh/g and 455 mAh/g for Li- and Na-ion batteries, respectively. A specific capacity of over 380 mAh/g was observed even at a high current density of 1 A/g. Centrifugal spinning and hydrothermal synthesis allowed for the fabrication of high-performance electrodes for sodium ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

High Selectivity Reactive Carbon Dioxide Capture over Zeolite Dual-Functional Materials

Reactive carbon dioxide capture (RCC) is a process where carbon dioxide (CO 2 ) is captured from a mixed gas stream (such as air) and converted to products without first performing a separation step to concentrate the CO 2 . Here, in this work, zeolite dual-functional materials (ZFMs) are introduced and evaluated for simulated RCC. The studied ZFMs feature high surface area, crystalline, microporous zeolite faujasite (FAU) as the support. Sodium oxide (“Na 2 O”) is impregnated as an effective capture agent capable of scavenging low concentration CO 2 (1,000 ppm). Exchanged and impregnated sodium on FAU chemisorbs CO 2 as carbonates and bicarbonates but does not promote the conversion of sorbed CO 2 to products when heated in hydrogen. The addition of Ru promotes the formation of formates, while the addition of Pt generates carbonyl surface species when heated in hydrogen. The active metal then promotes extremely high selectivity for CO 2 hydrogenation to either methane on Ru catalyst (~150 °C) or carbon monoxide on Pt catalyst (~200 °C) when heated in reducing atmospheres.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Systematic Evaluation of Carbon Hosts for High-Energy Rechargeable Lithium-Metal Batteries

Rechargeable lithium batteries (RLBs) have attracted wide attention for achieving high energy and low cost, but the poor stability of the Li anode has remained as a large challenge. In the last several years, great efforts have been made to develop carbon anode structures for RLB applications. A wide range of carbon structures as well as many chemical modification strategies have been investigated to improve the Coulombic efficiency and extend the cycle life of the anodes or the cells. However, currently there is no clear conclusion on key factors that determine the performance of such the types of carbon structures due to the wide range of experimental conditions used in such studies. In this study, we systematically evaluated and compared the electrochemical properties of representative carbon anode materials as well as chemically functionalized carbon materials in different electrolytes. We have found that chemical functionalization, metallic loading, and the types of micro or nano-structures all have an effect on Li deposition/stripping process, but by far the most critical factor is the nature of the electrolytes. All carbon materials produced poor Coulombic efficiency and cycle life in conventional carbonate or ether-based electrolytes. However, when a Li metal compatible is used, the average Coulombic efficiency of Li metal deposition on all carbon structures is increased to 99% or higher. This study provides critical lessons on the directions for carbon anodes for RLBs. Based on these findings, we constructed Li metal coin cells using prelithiated hard carbon, LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode, and compatible electrolyte and tested the cells under conditions of lean electrolyte, lean Li metal and high cathode loading required for more than 300 Wh kg-1 specific energy. More than 200 stable cycles were demonstrated with over 80% capacity retention. Furthermore, the existing challenges and potential approaches have been discussed to further extend the cyclability of lithium-metal batteries under practical conditions.

Liu, Yao↗
DOE OSTI2022

Evaluating the Physisorption and Chemisorption of Iodine on Bismuth-Functionalized Carbon Foams

Bismuth-containing carbon materials have been shown to be highly promising sorbents for the capture of radioiodine. However, there is still a need to understand the effects of carbon and bismuth on the iodine sorption mechanism. In this study, we show the relationship between the physical and chemical sorption of iodine under different bismuth loading conditions. Here, highly porous and non-friable conductive carbon foams were prepared and bismuth was electrodeposited to provide strong iodine binding sites. For pure carbon foams, equal ratios of physisorbed and chemisorbed iodine-carbon phases were detected before desorption. As the concentration of bismuth increased, the chemisorption between bismuth and iodine dominated the total capture mechanism and physisorption was almost completely eliminated. Additionally, chemisorption of iodine depended upon the size and specific surface area of the bismuth particles present within the framework of the foam.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Thermo-Catalytic Decomposition Comparisons: Carbon Catalyst Structure, Hydrocarbon Feed and Regeneration

Thermo-catalytic decomposition (TCD) activity and stability depend upon the initial carbon catalyst structure. However, further transitions in the carbon structure depend on the carbon material (structure and composition) originating from the TCD process. In this article, reaction data are presented that illustrates the time-dependent TCD activity as TCD-formed carbon contributes and then dominates conversion. A variety of initial carbon catalysts are compared, including sugar char, a conductive carbon black (AkzoNobel Ketjenblack), a rubber-grade carbon black (Cabot R250), and its graphitized analogue as formed and partially oxidized. Regeneration of carbon catalysts by partial oxidation is evaluated using nascent carbon black as a model, coupled with subsequent comparative TCD performance relative to the nascent, non-oxidized carbon black. Activation energies for TCD with nascent and oxidized carbons are evaluated by a leading-edge analysis method applied to TCD. Given the correlation between nanostructure and active sites, two additional carbons, engine soots, are evaluated for regeneration and dependence upon nanostructure. Active sites are quantified by oxygen chemisorption, followed by X-ray photoelectron spectroscopy (XPS). The structure of carbon catalysts is assessed pre- and post-TCD by high-resolution transmission electron microscopy (HRTEM). Last, energy dispersive X-ray analysis mapping (EDS) is carried out for its potential to visualize oxygen chemisorption.

03 NATURAL GAS↗
DOE OSTI2020

Surface Charge and Electrostatic Spin Crossover Effects in CoN 4 Electrocatalysts

Carbon materials doped with nitrogen and 3d transition metals have attracted a great deal of interest for catalyzing electrochemical reactions such as water splitting, oxygen reduction, and carbon dioxide reduction. Here, we employed density functional theory to study Co–N-doped carbon as electrocatalysts for the oxygen reduction and oxygen evolution reactions. Specifically, we investigated the interplay among adsorption energies, the spin state of the CoN 4 active center, and the applied potential. We found that adsorption energies strongly depend on both the applied potential and the spin state of the Co center. Furthermore, spin state transitions induced by the applied potential also play an important role in determining the adsorption energies. Here, this effect originates from a different potential of zero charge and capacitance of each spin state.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Insights into the Li Diffusion Mechanism in Si/C Composite Anodes for Lithium-Ion Batteries

Recently, Si/C composite materials have attracted enormous research interest as the most promising candidates for the anodes of next-generation lithium-ion batteries, owing to their high energy density and mechanical buffering property. However, the fundamental mechanism of Li diffusion behavior in various Si/C composite materials remains unclear, with our understanding limited by experimental techniques and continuum modeling methodologies. Herein, the atomic behavior of Li diffusion in the Si/C composite material is studied within the framework of density functional theory. Two representative structural mixing formats, that is, simple mixture mode and core-shell mode, are modeled and compared. We discover that the carbon material increases Li diffusion in silicon from 7.75 x 10 -5 to 2.097 x 10 -4 cm 2 /s. The boost is about 50% more obvious in the mixture mode, while the core-shell structure shows more dependence on the atomic structures of the carbon layer. These results offer new insights into Li diffusion behavior in Si/C composites and unlock the enhancing mechanism for Li diffusion in Si/C. Furthermore, this understanding facilitates the modeling of batteries with composite anodes and will guide the corresponding structure designs for robust and high-energy-density batteries.

25 ENERGY STORAGE↗
DOE OSTI2025

Polyanion-type iron-based sulfate cathode materials: From fundamental research to industrialization

Sodium-ion batteries (SIBs) with the merits of abundant sodium resources and low cost are considered significant supplements to lithium-ion batteries in large-scale energy storage systems. Among the discovered cathode materials for SIBs, iron-based sulfate materials have attracted widespread attention due to their high operating voltage, superior structural stability, and high safety. Here, in this review, we summarize the research achievements of iron-based sulfate cathode materials in fundamental research, as well as provide a comprehensive overview of its industrialization progress for the first time. Meanwhile, effective modification strategies (including morphology design, hybridization with carbon materials, and construction of heterostructure) and further research directions to boost the sodium storage performance of iron-based sulfate cathode materials are also proposed. This review can provide valuable guidance for developing high-performance iron-based sulfate cathode materials for practical application.

cathode materials↗
DOE OSTI2020

Capacitive deionization using carbon derived from an array of zeolitic-imidazolate frameworks

Capacitive deionization (CDI) represents one of the most thermodynamically efficient technologies for brackish water desalination. Its performance is highly reliant on the surface properties of carbon-based electrodes. Zeolitic-imidazolate framework (ZIF)-derived carbon materials have emerged among the most promising candidates owing to their high structural and compositional tuneability. However, the impacts of the precursory ZIF structure on the properties of the final carbon, and therefore, CDI capacity and efficiency remain to be further explored. In this work, four Zn-based ZIFs with different side-chain substitutions on the imidazolates were synthesized on a gram scale with high yields to produce N-doped carbons by pyrolysis. Next, the resulting carbons along with four commercial carbon blacks were characterized physically and electrochemically to explore the structure-performance relationship. We demonstrated that the imidazole side-chain substitution alters the ZIF's decomposition during pyrolysis, influencing the elemental compositions, surface properties, wettability and graphitization levels. The diverse carbon properties result in variable double layer capacitance and charge-transfer resistance, ultimately impacting the CDI performance. Among these carbons, Zn (4abIm)2-C afforded the greatest salt adsorption capacity of 14.19 mg NaCl $·g_C^{–1}$, while Zn (mIm) 2 -C showed the highest overall salt adsorption capacity and rate; both exceeded the performance of the commercial carbon blacks.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Molecular redox-active organic materials for electrochemical carbon capture

Abstract This prospective is a forward-looking outlook for researchers investigating electrochemical carbon capture utilizing molecular redox-active organic materials, with the following objectives: (1) identifying the essential components of an electrochemical carbon capture system, (2) introducing design principles for the system utilizing redox-active organic materials, encompassing their physicochemical properties and other critical factors, (3) presenting representative examples, and (4) promoting further experimental and theoretical studies on the application of redox-active organic materials for electrochemical carbon capture. Graphical abstract

Seo, Hyowon (ORCID:0000000295691902)↗
DOE OSTI2026

Cation-Diffusive Carbon Interlayers Stabilize Na Metal and Double the Current in Na-S Redox-Flow Batteries for Grid-Scale Energy Storage

The sodium-sulfur nonaqueous redox-flow batteries (Na-S NARFBs) using earth-abundant elements are highly attractive due to the low material cost and improved energy density for grid-scale energy storage. However, the low current performance, poor Na0/Na+ redox kinetics, and Na dendrite growth pose severe challenges. We introduce cation-diffusive layers (CDLs): thin and Na+ affinitive interlayers at the Na anode that direct Na+ transport and stabilize Na deposition. Benchmarking three archetypal materials—carbon paper (CP), glass microfiber paper (GF), and foam—across Na-Na and Na-Cu, and Na-S cells identifies CP as the optimum. CP reduces symmetric cell overpotential by more than 70%, achieves 98% Na plating-stripping efficiency, and doubles the Na-S cell current density from 0.5 to 1.0 mA cm−2 without sacrificing capacity or efficiency. Ex situ electrochemical and SEM/XPS analysis, combined with molecular dynamics (MD) studies, reveal that electron-rich carbon fibers disperse supporting salt aggregates, enrich near-surface Na+ density, and create ion transport pathways for fast Na0/Na+ exchange while mitigating membrane degradation. Because of the ion-centric mechanism, CDLs can be generalized to other metal-anode designs. Further, this work establishes CDL design rules—cationic affinity and appropriate micro/nanostructure—as a simple, scalable route to high-current, durable metal-anode flow batteries.

Wu, Wenda [ORNL] (ORCID:000900033307687X)↗