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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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15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Insights into Spontaneous Solid Electrolyte Interphase Formation at Magnesium Metal Anode Surface from Ab Initio Molecular Dynamics Simulations

Spontaneous chemical reactivity at multivalent (Mg, Ca, Zn, Al) electrode surfaces is critical to solid electrolyte interphase (SEI) formation, and hence, directly affects the longevity of batteries. Here, we report an investigation of the reactivity of 0.5 M Mg(TFSI)2 in 1,2-dimethoxyethane (DME) solvent at a Mg(0001) surface using ab initio molecular dynamics (AIMD) simulations and detailed Bader charge analysis. Based on the simulations, the initial degradation reactions of the electrolyte strongly depend on the structure of the Mg(TFSI)2 species near the anode surface. At the surface, the dissociation of Mg(TFSI)2 species occurs via cleavage of the N-S bond for the solvent separated ion pair (SSIP) and via cleavage of the C-S bond for the contact ion pair (CIP) configuration. In the case of the CIP, both TFSI anions undergo spontaneous bond dissociation reactions to form atomic O, C, S, F, and N species adsorbed on the surface of the Mg anode. These products indicate that the initial SEI layer formed on the surface of the pristine Mg anode consists of a complex mixture of multiple components such as oxides, carbides, sulfides, fluorides, and nitrides. We believe that the atomic level insights gained from these simulations will lay the groundwork for the rational design of tailored and functional interphases that are critical for the success of multivalent battery technology.

Agarwal, Garvit↗
DOE OSTI2023

Dating fractures using luminescence

Rock fracturing (cracking) is a universal process that drives and limits chemical degradation, sediment production and erosion, and deterioration of infrastructure. Despite extensive research gains in rock mechanics on one hand and geochronology on the other, there remains a glaring gap in our ability to understand the long term evolution of natural, in situ fractures. Here we develop a novel fracture exposure dating technique, grounded in modern advances in luminescence geochronology. We apply our new dating method to a granitic boulder from a glacial outwash terrace in California, US. We conclude that the longest, clast-splitting E-W fracture appeared shortly after the boulder's deposit, whereas the secondary N-S fracture appeared 5 ka after the deposition, approximately correlating with the Last Glacial Maximum and Younger Dryas periods of the region, respectively. However, dating of the third fracture (<< 50 µm width) which does not fully split the rock, is ambiguous due to negligible daylight penetration and poor determination of fracture width. The fracture dating method presented herein brings with it the potential to decipher relationships that are crucial for the interpretation and modeling of, for example, long-term landscape and atmospheric evolution relating rock weathering to climate change and erosion.

58 GEOSCIENCES↗
DOE OSTI2025

Probing Cretaceous-Paleogene crustal thickness in southern Tibet using quartz-zircon chronobarometry

Knowledge of the crustal thickness history of southern Tibet during the India-Asia collision is key to understanding what deformation mechanisms accommodated northward propagating crustal shortening. Thermoisotopic models suggest that a relatively thin margin of southern Asia persisted from ca. 200 to 45 Ma whereas trace element paleodepth proxies are interpreted to indicate a thinning phase from ca. 100 to 65 Ma when the crust reached ∼30 km-thickness. As neither of these methods directly measures crustal thickness, resolution of this conflict awaits development of a method that can. Here, in this study, we place bounds on the thickening history of southern Tibet using coupled quartz-zircon thermobarometry and U-Pb geochronology of granitoid plutons in the Gangdese batholith. We find that crustal thicknesses were as high (or higher) as 60–75 km at 65 Ma, or 10–15 Ma prior to the onset of hard continental collision. Magmatic inflation in the lower crust likely contributed to crustal thickening and thermal weakening of the lower crust, suggesting that pure shear in the lower crust was likely the primary accommodation mechanism for N-S shortening during collision. These data are in partial agreement with results of thermoisotopic models of crustal thickness but contradict thickness histories derived from empirical trace element proxies.

Chronobarometry↗
DOE OSTI2021

Episodic Earthquake Swarms in the Mineral Mountains, Utah Driven by the Roosevelt Hydrothermal System

Over 1,000 earthquakes (-2.0 < M < 2.0), identified using a matched-filter method, occurred in the Mineral Mountains, Utah between 2016 and 2019. The enhanced catalog is complete down to M -0.9 and contains roughly 15 times more events than originally cataloged. Earthquake relocation of ~800 earthquakes shows that activity is concentrated in a <2 km long E-W striking narrow zone, ~4 km east of the Roosevelt hydrothermal system. Two fault orientations, both N-S and E-W parallel to the Opal Mound and Mag Lee faults, respectively, are observed after computing composite focal mechanisms of highly similar earthquakes. Looking solely at the temporal distribution of the seismicity, we identify 15 periods of swarm-like activity, with two major clusters occurring in December 2016, recorded by three stations, and in October 2019 recorded by eight stations. The October 2019 swarm, the best recorded sequence in the area, provides evidence for the underlying triggering mechanism. We show that a complex mechanism of fluid diffusion and aseismic slip is responsible for the swarm evolution with migration velocities reaching 10 km/day. We hypothesize that these episodic swarms in the Mineral Mountains are primarily driven by migrating fluids that originate within the Roosevelt hydrothermal system.

58 GEOSCIENCES↗
DOE OSTI2023

Spatial controls of methane uptake in upland soils across climatic and geological regions in Greenland

Abstract In the Arctic, the spatiotemporal variation of net methane uptake in upland soils depends on unresolved interactive controls between edaphic and microbial factors not yet included in current models, underpinning the uncertainty of upscaling the Arctic methane budget. Here we show that upland soils in Greenland are consistent methane sinks (−1.83 ± 0.19 nmol methane g −1 dw d −1 ) across a N-S (64–83 °N) pedoclimatic transect. We demonstrate that methane oxidizers abundance, soil pH, and available soil copper are important controls on the spatial variation in methane oxidation. We revised a soil biogeochemical model with a high-resolution land classification and meteorological data for Greenland and tested it against our methane uptake measurements. The model simulated well the magnitudes of observed methane uptake but not the spatial variation across all sites. This work provides novel insights into the controls of methane uptake, which are critical for the accuracy of methane budgets.

Environmental Sciences & Ecology↗
DOE OSTI2023

$S$ Hmax orientation in the Alpine region from observations of stress-induced anisotropy of nonlinear elasticity

The orientation of $S$ Hmax is commonly estimated from in situ borehole breakouts and earthquake focal mechanisms. Borehole measurements are expensive, and therefore sparse, and earthquake measurements can only be made in regions with many well-characterized earthquakes. Here, we derive the stress-field orientation using stress-induced anisotropy in nonlinear elasticity. In this method, we measure the strain derivative of velocity as a function of azimuth. We use a natural pump-probe (NPP) approach which consists of measuring elastic wave speed using empirical Green’s functions (probe) at different points of the earth tidal strain cycle (pump). The approach is validated using a larger data set in the Northern Alpine Foreland region where the orientation of maximum horizontal compressive stress is known from borehole breakouts and drilling-induced fractures. The technique resolves NNW-SSW to N-S directed $S$ Hmax which is in good agreement with conventional methods and the recent crustal stress model. We confirm that the NPP method can be applied to dense large-scale seismic arrays. The technique is then applied to the Southern Alps to understand the contemporary stress pattern associated with the ongoing deformation due to counterclockwise rotation of the Adriatic plate with respect to the European plate. Our results explain why the two major faults in Northeastern Italy, the Giudicarie Fault and the Periadriatic Line (Pustertal–Gailtal Fault) are currently inactive, while the currently acting stress field allows faults in Slovenia to deform actively. We have demonstrated that the pump-probe method has the potential to fill in the measurement gap left by conventional approaches, both in terms of regional coverage and in depth.

58 GEOSCIENCES↗
DOE OSTI2020

Characterizing natural fractures and sub-seismic faults for well completion of Marcellus shale in the MSEEL Consortium project, West Virginia, USA

The Middle Devonian Marcellus shale play has emerged as a major world-class hydrocarbon accumulation and represents one of the largest and most prolific shale plays in the world. According to many outcrop studies in the region, natural fractures are well developed in the Marcellus Shale. However, evaluating fractures in the subsurface is often a significant challenge due to a lack of sufficient data. Therefore, in the Marcellus Shale Energy and Environment Laboratory (MSEEL) consortium project, significant efforts have been made to acquire high-quality image logs in the Marcellus laterals. The project provided tremendous opportunities to characterize the natural fractures and sub-seismic faults and to evaluate their impact on well stimulation. In this study, about 70,000 ft of acquired high-resolution logging while drilling (LWD) acoustic images from five long laterals located in Monongalia County, West Virginia, were processed and interpreted. In addition, the study used high-quality micro-resistivity images from a pilot well, allowing the evaluation of natural fractures in the entire Marcellus vertical sequence. Based on the available acoustic images, the natural fractures were classified into three basic categories: high-amplitude fractures, low-amplitude fractures, and faults. Further, larger open fractures can also be determined when a low-amplitude fracture is evident on caliper images. The fractures in the Marcellus usually have a medium to high angle dip; however, multiple fracture sets in terms of strike orientation were clearly observed in all the laterals. The fracture set with a strike at NE-SW (or 60-240 deg) seems to be the predominant one in all the wells. A few other sets, including those with N-S, NWW-SEE, and E-W strikes, were also observed. Several sub-seismic faults, with mostly a low dip angle and a NE-SW strike, have also been seen in two of the laterals. The fracture density is variable across all the laterals, ranging from very low (or none) to very high (up to 5 fractures per ft). The average fracture density for all the laterals is about 1 fracture per 10 ft. In the vertical sequence, the natural fracture development showed a clear preference for shale or shaly facies over carbonate-rich or thin limestone layers. The interpreted fracture and fault data were used as input data for the stimulation design with the purpose of better understanding the fractures’ impact on well stimulation. Production data from the laterals were also used to evaluate the natural fractures’ influence on well performance. The quality image database and the consistent interpretation results for the entire project enabled a systematic approach to characterizing fractures and, more importantly, to evaluating the impact of fractures on well stimulation and production.

03 NATURAL GAS↗
DOE OSTI2020

Hydraulic fracturing experiments at 1500 m depth in a deep mine: Highlights from the kISMET project

In support of the U.S. DOE SubTER Crosscut initiative, we established a field test facility in a deep mine and designed and carried out in situ hydraulic fracturing experiments relevant to enhanced geothermal systems (EGS) in crystalline rock to characterize the stress field, understand the effects of rock fabric on fracturing, and gain experience in monitoring using geophysical methods. The project also included pre- and post-fracturing simulation and analysis, and laboratory measurements and experiments. The kISMET (permeability (k) and Induced Seismicity Management for Energy Technologies) site was established in the West Access Drift of the Sanford Underground Research Facility (SURF) 4757 ft (1450 m) below ground (on the 4850 ft level (4850L)) in phyllite of the Precambrian Poorman Formation. We drilled and continuously cored five near-vertical boreholes in a line on 3 m (10 ft) spacing, deviating the two outermost boreholes slightly to create a five-spot pattern around the test borehole centered in the test volume 40 m below the drift invert (floor) at a total depth of ~1490 m (4890 ft). Laboratory measurements of core from the center test borehole showed P-wave velocity heterogeneity along each core indicating strong, fine-scale (~1 cm or smaller) changes in the mechanical properties of the rock. Field measurements of the stress field by hydraulic fracturing showed that the minimum horizontal stress at the kISMET site averages 21.7 MPa (3146 psi) trending approximately N-S (356 degrees azimuth) and plunging slightly NNW at 12°. The vertical and horizontal maximum stresses are similar in magnitude at 42-44 MPa (6090-6380 psi) for the depths of testing, which averaged approximately 1530 m (5030 ft). Hydraulic fractures were remarkably uniform suggesting core-scale and larger rock fabric did not play a role in controlling fracture orientation. Analytical solutions suggest that the fracture radius of the large fracture (stimulation test) was more than 6 m (20 ft), depending on the unknown amount of leak-off.

Oldenburg, C↗
DOE OSTI2020

Materials Data on S5N6 by Materials Project

N6S5 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four N6S5 clusters. there are three inequivalent N+1.67+ sites. In the first N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.62 Å) and one longer (1.63 Å) N–S bond length. In the second N+1.67+ site, N+1.67+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.62 Å) and one longer (1.63 Å) N–S bond length. In the third N+1.67+ site, N+1.67+ is bonded in a bent 150 degrees geometry to two S2- atoms. There is one shorter (1.55 Å) and one longer (1.73 Å) N–S bond length. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a bent 120 degrees geometry to two N+1.67+ atoms. In the second S2- site, S2- is bonded in a trigonal non-coplanar geometry to three N+1.67+ atoms. In the third S2- site, S2- is bonded in a bent 120 degrees geometry to two equivalent N+1.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SN by Materials Project

NS crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of two NS ribbons oriented in the (0, 1, 0) direction. N1+ is bonded in a bent 120 degrees geometry to two equivalent S1- atoms. There is one shorter (1.60 Å) and one longer (1.62 Å) N–S bond length. S1- is bonded in a water-like geometry to two equivalent N1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SN by Materials Project

NS crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two 1,3,2,4-dithiadiazetidine molecules. N1+ is bonded in an L-shaped geometry to two equivalent S1- atoms. There is one shorter (1.65 Å) and one longer (1.66 Å) N–S bond length. S1- is bonded in an L-shaped geometry to two equivalent N1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on S2N by Materials Project

NS2 crystallizes in the tetragonal P4_2nm space group. The structure is zero-dimensional and consists of four 1,2,3,5,4,6-tetrathiadiazinane molecules. N3+ is bonded in a bent 120 degrees geometry to two S+1.50- atoms. There is one shorter (1.58 Å) and one longer (1.66 Å) N–S bond length. There are three inequivalent S+1.50- sites. In the first S+1.50- site, S+1.50- is bonded in a distorted single-bond geometry to one N3+ and one S+1.50- atom. The S–S bond length is 2.08 Å. In the second S+1.50- site, S+1.50- is bonded in a water-like geometry to two equivalent S+1.50- atoms. In the third S+1.50- site, S+1.50- is bonded in a bent 120 degrees geometry to two equivalent N3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SN by Materials Project

NS is red selenium-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 1,3,5,7,2,4,6,8-tetrathiatetrazocane molecules. there are four inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a bent 120 degrees geometry to two S1- atoms. Both N–S bond lengths are 1.63 Å. In the second N1+ site, N1+ is bonded in a bent 120 degrees geometry to two S1- atoms. Both N–S bond lengths are 1.63 Å. In the third N1+ site, N1+ is bonded in a bent 120 degrees geometry to two S1- atoms. Both N–S bond lengths are 1.63 Å. In the fourth N1+ site, N1+ is bonded in a bent 120 degrees geometry to two S1- atoms. Both N–S bond lengths are 1.63 Å. There are four inequivalent S1- sites. In the first S1- site, S1- is bonded in a water-like geometry to two N1+ atoms. In the second S1- site, S1- is bonded in a water-like geometry to two N1+ atoms. In the third S1- site, S1- is bonded in a water-like geometry to two N1+ atoms. In the fourth S1- site, S1- is bonded in a water-like geometry to two N1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SN by Materials Project

NS is red selenium-derived structured and crystallizes in the orthorhombic Pbcn space group. The structure is zero-dimensional and consists of four 1,3,5,7,2,4,6,8-tetrathiatetrazocane molecules. there are three inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a bent 120 degrees geometry to two equivalent S1- atoms. Both N–S bond lengths are 1.63 Å. In the second N1+ site, N1+ is bonded in a bent 120 degrees geometry to two equivalent S1- atoms. Both N–S bond lengths are 1.63 Å. In the third N1+ site, N1+ is bonded in a bent 120 degrees geometry to two S1- atoms. Both N–S bond lengths are 1.63 Å. There are two inequivalent S1- sites. In the first S1- site, S1- is bonded in a water-like geometry to two N1+ atoms. In the second S1- site, S1- is bonded in a water-like geometry to two N1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on S3N2 by Materials Project

N2S3 crystallizes in the orthorhombic Pmn2_1 space group. The structure is two-dimensional and consists of one N2S3 sheet oriented in the (0, 1, 0) direction. N3+ is bonded in a trigonal planar geometry to three S2- atoms. There are a spread of N–S bond distances ranging from 1.67–1.79 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a water-like geometry to two equivalent N3+ atoms. In the second S2- site, S2- is bonded in a water-like geometry to two equivalent N3+ atoms.

36 MATERIALS SCIENCE↗