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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Foliar isotopic and elemental biochemistry and leaf mass per area (LMA), Parque Natural Metropolitano, Panama, 2022

Foliar N and C isotope composition, bulk elemental N and C composition, and leaf mass per area (LMA) for leaves sampled from the Parque Natural Metropolitano (PNM), Panama, from January to April 2022 are presented. Measurements were made on leaves from 17 different tree, shrub and liana species, from sunlit canopy and understory locations on 8 vertical profiles. Full sample details and leaf area index (LAI) from the vertical profiles at PNM are also included in the data package. The aim of this measurement campaign was two-fold: to improve our understanding of the vertical variation in leaf-level water use efficiency, and to improve models which can predict leaf traits from leaf contact spectral measurements. Biochemistry data and sample metadata are presented in .csv files. The original isotopic data report, which includes details about standards and data accuracy, is provided in .xlsx format. Data and metadata meet the ESS-DIVE reporting format requirements for file level metadata (FLMD) and comma separated values (csv). The protocol details are provided as pdf documents. In addition to foliar biochemistry data reported here these samples were also used for measurement of leaf gas exchange, and leaf optical properties. These data can be linked using the unique sample ID and are provided in separate data packages (NGT0192 and NGT0193).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

The Pantex Lightning Mapping Array (LMA) [Slides]

The LMA can pick up the smallest static discharge ongoing inside developing thunderstorms that could be the precursor to a future cloud-to-cloud or cloud-to-ground lightning strike. Research done at Pantex in 2020 of 20 different storms from February through November showed an average lead time of around 20 minutes from when “source densities” were detected inside developing thunderstorms over the Texas Panhandle to when the first cloud-to-cloud or cloud-to-ground lightning strike occurred.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

The Pantex Lightning Mapping Array (LMA) [Slides]

Research done at Pantex in 2020 of 20 different storms from February through November showed an average lead time of around 20 minutes from when “source densities” were detected inside developing thunderstorms over the Texas Panhandle to when the first cloud-to-cloud or cloud-to-ground lightning strike occurred.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Timing Calibration and Windowing Technique Comparison for Lightning Mapping Arrays

Abstract Since their introduction 22 years ago, lightning mapping arrays (LMA) have played a central role in the investigation of lightning physics. Even in recent years with the proliferation of digital interferometers and the introduction of the LOw Frequency ARray (LOFAR) radio telescope, LMAs still play an important role in lightning science. LMA networks use a simple windowing technique that records the highest pulse in either 80 μs or 10 μs fixed windows in order to apply a time‐of‐arrival location technique. In this work, we develop an LMA‐emulator that uses lightning data recorded by LOFAR to simulate an LMA, and we use it to test three new styles of pulse windowing. We show that they produce very similar results as the more traditional LMA windowing, implying that LMA lightning mapping results are relatively independent of windowing technique. In addition, each LMA station has its GPS‐conditioned clock. While the timing accuracy of GPS receivers has improved significantly over the years, they still significantly limit the timing measurements of the LMA. Recently, new time‐of‐arrival techniques have been introduced that can be used to self‐calibrate systematic offsets between different receiving stations. Applying this calibration technique to a set of data with 32 ns uncertainty, observed by the Colorado LMA, improves the timing uncertainty to 19 ns. This technique is not limited to LMAs and could be used to help calibrate future multi‐station lightning interferometers.

Hare, Brian M.↗
DOE OSTI2020

Lithium Metal Anodes with Nonaqueous Electrolytes

High-energy rechargeable lithium (Li) metal batteries (LMBs) with Li metal anode (LMA) were first developed in the 1970s, but their practical applications have been hindered by the safety and low-efficiency concerns related to LMA. Recently, a worldwide effort on LMA-based rechargeable LMBs has been revived to replace graphite-based, Li-ion batteries because of the much higher energy density that can be achieved with LMBs. Herein, this review focuses on the recent progress on the stabilization of LMA with nonaqueous electrolytes and reveals the fundamental mechanisms behind this improved stability. Various strategies that can enhance the stability of LMA in practical conditions and perspectives on the future development of LMA are also discussed. These strategies include the use of novel electrolytes such as superconcentrated electrolytes, localized high-concentration electrolytes, and highly fluorinated electrolytes, surface coatings that can form a solid electrolyte interphase with a high interfacial energy and self-healing capabilities, development of “anode-free” Li batteries to minimize the interaction between LMA and electrolyte, approaches to enable operation of LMA in practical conditions, etc. Combination of these strategies ultimately will lead us closer to the large-scale application of LMBs which often is called the “Holy Grail” of energy storage systems.

25 ENERGY STORAGE↗
DOE OSTI2022

Overcoming Anode Instability in Solid‐State Batteries through Control of the Lithium Metal Microstructure

Abstract Enabling the lithium metal anode (LMA) in solid‐state batteries (SSBs) is the key to developing high energy density battery technologies. However, maintaining a stable electrode–electrolyte interface presents a critical challenge to high cycling rate and prolonged cycle life. One such issue is the interfacial pore formation in LMA during stripping. To overcome this, either higher stack pressure or binary lithium alloy anodes are used. Herein, it is shown that fine‐grained ( d = 20 µm) polycrystalline LMA can avoid pore formation by exploiting the microstructural dependence of the creep rates. In a symmetric cell set‐up, i.e., LiǀLi 6.25 Al 0.25 La 3 Zr 2 O 12 (LLZO)ǀLi, fine‐grained LMA achieves > 11.0 mAh cm −2 compared to ≈ 3.6 mAh cm −2 for coarse‐grained LMA ( d = 295 µm) at 0.1 mA cm −2 and at moderate stress of 2.0 MPa. Smaller diffusion lengths (≈ 20 µm) and higher diffusivity pathway along dislocations ( D d ≈ 10 −7 cm 2 s −1 ), generated during cell fabrication, result in enhanced viscoplastic deformation in fine‐grained polycrystalline LMA. The electrochemical performances corroborate well with estimated creep rates. Thus, microstructural control of LMA can significantly reduce the required stack pressure during stripping. These results are particularly relevant for “anode‐free” SSBs wherein both the microstructure and the mechanical state of the lithium are critical parameters.

25 ENERGY STORAGE↗
DOE OSTI2022

Testing unified theories for ozone response in C 4 species

Abstract There is tremendous interspecific variability in O 3 sensitivity among C 3 species, but variation among C 4 species has been less clearly documented. It is also unclear whether stomatal conductance and leaf structure such as leaf mass per area (LMA) determine the variation in sensitivity to O 3 across species. In this study, we investigated leaf morphological, chemical, and photosynthetic responses of 22 genotypes of four C 4 bioenergy species (switchgrass, sorghum, maize, and miscanthus) to elevated O 3 in side‐by‐side field experiments using free‐air O 3 concentration enrichment (FACE). The C 4 species varied largely in leaf morphology, physiology, and nutrient composition. Elevated O 3 did not alter leaf morphology, nutrient content, stomatal conductance, chlorophyll fluorescence, and respiration in most genotypes but reduced net CO 2 assimilation in maize and photosynthetic capacity in sorghum and maize. Species with lower LMA and higher stomatal conductance tended to show greater losses in photosynthetic rate and capacity in elevated O 3 compared with species with higher LMA and lower stomatal conductance. Stomatal conductance was the strongest determinant of leaf photosynthetic rate and capacity. The response of both area‐ and mass‐based leaf photosynthetic rate and capacity to elevated O 3 were not affected by LMA directly but negatively influenced by LMA indirectly through stomatal conductance. These results demonstrate that there is significant variation in O 3 sensitivity among C 4 species with maize and sorghum showing greater sensitivity of photosynthesis to O 3 than switchgrass and miscanthus. Interspecific variation in O 3 sensitivity was determined by direct effects of stomatal conductance and indirect effects of LMA. This is the first study to provide a test of unifying theories explaining variation in O 3 sensitivity in C 4 bioenergy grasses. These findings advance understanding of O 3 tolerance in C 4 grasses and could aid in optimal placement of diverse C 4 bioenergy feedstock across a polluted landscape.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Crossover Effects in Batteries with High–Nickel Cathodes and Lithium–Metal Anodes

It is well understood that cathode-to-anode crossover, especially of transition-metal ions, can significantly impact the long-term cycling of lithium-ion batteries. The dissolved transition-metal ions in lithium-ion cells deposit on the graphite anode, disrupt the solid-electrolyte interphase (SEI), and catalyze further side reactions. Meanwhile, crossover effects in lithium-metal batteries have rarely been studied. This study is the first to investigate crossover effects in lithium-metal batteries with high-nickel layered-oxide cathodes. It is shown that the crossover of transition-metal ions from LiNi 0.9 Mn 0.05 Co 0.05 O 2 has minimal effect on the lithium-metal anode (LMA) due to the following reasons. The catalytic transition metals 1) have less effect on an inherently reactive LMA, 2) are diluted in a thicker SEI, and 3) are produced in overall lower quantity due to the limited cycle life of the LMA. Conversely, the LMA generates soluble decomposition products that cross over to the cathode even during early cycling. This crossover accelerates impedance growth and capacity fade at the cathode and is partially responsible for the mismatch between the performance of half and full-cells with layered-oxide cathodes. Finally, this study highlights the need for better battery design with LMA, potentially including electrolyte or cell modifications.

25 ENERGY STORAGE↗
DOE OSTI2023

Crystal Engineering of Two Light and Pressure Responsive Physisorbents

Abstract An emerging strategy in the design of efficient gas storage technologies is the development of stimuli‐responsive physisorbents which undergo transformations in response to a particular stimulus, such as pressure, heat or light. Herein, we report two isostructural light modulated adsorbents (LMAs) containing bis‐3‐thienylcyclopentene (BTCP), LMA‐1 [Cd(BTCP)(DPT) 2 ] (DPT=2,5‐diphenylbenzene‐1,4‐dicarboxylate) and LMA‐2 [Cd(BTCP)(FDPT) 2 ] (FDPT=5‐fluoro‐2,diphenylbenzene‐1,4‐dicarboxylate). Both LMAs undergo pressure induced switching transformations from non‐porous to porous via adsorption of N 2 , CO 2 and C 2 H 2 . LMA‐1 exhibited multi‐step adsorption while LMA‐2 showed a single‐step adsorption isotherm. The light responsive nature of the BTPC ligand in both frameworks was exploited with irradiation of LMA‐1 resulting in a 55 % maximum reduction of CO 2 uptake at 298 K. This study reports the first example of a switching sorbent (closed to open) that can be further modulated by light.

Castell, Dominic C.↗
DOE OSTI2023

Crystal Engineering of Two Light and Pressure Responsive Physisorbents

Abstract An emerging strategy in the design of efficient gas storage technologies is the development of stimuli‐responsive physisorbents which undergo transformations in response to a particular stimulus, such as pressure, heat or light. Herein, we report two isostructural light modulated adsorbents (LMAs) containing bis‐3‐thienylcyclopentene (BTCP), LMA‐1 [Cd(BTCP)(DPT) 2 ] (DPT=2,5‐diphenylbenzene‐1,4‐dicarboxylate) and LMA‐2 [Cd(BTCP)(FDPT) 2 ] (FDPT=5‐fluoro‐2,diphenylbenzene‐1,4‐dicarboxylate). Both LMAs undergo pressure induced switching transformations from non‐porous to porous via adsorption of N 2 , CO 2 and C 2 H 2 . LMA‐1 exhibited multi‐step adsorption while LMA‐2 showed a single‐step adsorption isotherm. The light responsive nature of the BTPC ligand in both frameworks was exploited with irradiation of LMA‐1 resulting in a 55 % maximum reduction of CO 2 uptake at 298 K. This study reports the first example of a switching sorbent (closed to open) that can be further modulated by light.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

High Current-Density-Charging Lithium Metal Batteries Enabled by Double-Layer Protected Lithium Metal Anode

The practical application of lithium (Li) metal anode (LMA) is still hindered by non-uniformity of solid electrolyte interphase (SEI), formation of "dead" Li, and continuous consumption of electrolyte although LMA has an ultrahigh theoretical specific capacity and a very low electrochemical redox potential. Herein, we report a facile protection strategy for LMA using a double layer (DL) coating that consists of a polyethylene oxide (PEO)-based bottom layer which is highly stable with LMA and promotes uniform ion flux, and a cross-linked polymer-based top layer which prevents solvation of PEO layer in electrolytes. Li deposited on DL-coated Li (DL@Li) exhibits a smoother surface and much larger size than that deposited on bare Li. The LiF/Li 2 O enriched SEI layer generated by the salt decomposition on top of DL@Li further suppresses the side reactions between Li and electrolyte. Driven by the abovementioned advantageous features, the DL@Li||LiNi 0.6 Mn 0.2 Co 0.2 O 2 cells demonstrate capacity retention of 92.4% after 220 cycles at a current density of 2.1 mA cm -2 (C/2 rate) and stability at a high charging current density of 6.9 mA cm -2 (1.5C rate). These results indicate that the DL protection is promising to overcome the rate limitation of LMAs and high energy-density Li metal batteries.

25 ENERGY STORAGE↗
DOE OSTI2025

A Universal Design of Lithium Anode via Dynamic Stability Strategy for Practical All‐Solid‐State Batteries

Abstract All‐solid‐state Li‐metal battery (ASSLB) chemistry with thin solid‐state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li‐metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra‐thin LMA (20 μm) is in situ constructed with uniform highly Li‐ion conductive solid‐electrolyte interphase and composite‐polymer interphase (CPI) via electroplating process. As a result, the passivation layer with poor Li‐ion conduction on Li anode can be dissolved and small surface resistance can be achieved due to the good compatibility of CPI to SSEs. The cycling of Li symmetric cell with Li 6 PS 5 Cl thin film electrolyte (<100 μm) shows a high critical current density of >2.0 mA cm −2 with excellent cycling stability at 1.0 mA cm −2 . The ASSLBs paring with Ni‐rich LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode demonstrated the feasibility of engineered LMA design by presenting good rate capability from 0.1 C to 1.0 C at room temperature, as well as long‐term cycling stability (81 % retention after 100 cycles). This work represents a general pathway to make thin dendrite‐free LMA available for high‐energy‐density ASSLBs.

Deng, Tao [Department of Chemical and Biomolecular↗
DOE OSTI2025

A Universal Design of Lithium Anode via Dynamic Stability Strategy for Practical All‐Solid‐State Batteries

Abstract All‐solid‐state Li‐metal battery (ASSLB) chemistry with thin solid‐state electrolyte (SSE) membranes features high energy density and intrinsic safety but suffers from severe dendrite formation and poor interface contact during cycling, which hampers the practical application of rechargeable ASSLB. Here, we propose a universal design of thin Li‐metal anode (LMA) via a dynamic stability strategy to address these issues. The ultra‐thin LMA (20 μm) is in situ constructed with uniform highly Li‐ion conductive solid‐electrolyte interphase and composite‐polymer interphase (CPI) via electroplating process. As a result, the passivation layer with poor Li‐ion conduction on Li anode can be dissolved and small surface resistance can be achieved due to the good compatibility of CPI to SSEs. The cycling of Li symmetric cell with Li 6 PS 5 Cl thin film electrolyte (<100 μm) shows a high critical current density of >2.0 mA cm −2 with excellent cycling stability at 1.0 mA cm −2 . The ASSLBs paring with Ni‐rich LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathode demonstrated the feasibility of engineered LMA design by presenting good rate capability from 0.1 C to 1.0 C at room temperature, as well as long‐term cycling stability (81 % retention after 100 cycles). This work represents a general pathway to make thin dendrite‐free LMA available for high‐energy‐density ASSLBs.

Deng, Tao [Department of Chemical and Biomolecular↗
DOE OSTI2023

The apparent reversal of the Law of Mass Action in concentrated multicomponent aqueous solutions

Although it is well known that aqueous electrolyte solutions behave non-ideally, few are so non-ideal that adding an electrolyte to a saturated solution with a common ion enhances rather than depresses solubility. Nonetheless, this apparent reversal of the Law of Mass Action (LMA) has been observed in simple nitrate solutions at high concentrations. A leading hypothesis is that ion clusters are formed and stabilized by ions having different charge densities. We report the present study examines this concept, in part by reviewing relevant data from multicomponent aqueous solutions containing sodium nitrate (NaNO 3 ), sodium nitrite (NaNO 2 ), sodium hydroxide (NaOH), and sodium aluminate (NaAl(OH) 4 ) - the major constituents in alkaline nuclear waste. Here, NaOH and NaAl(OH) 4 did not enhance the solubility of NaNO 3 or NaNO 2 , whereas NaNO 2 and NaNO 3 enhanced rather than depressed the solubility of each other despite each having the sodium cation (Na + ) in common. Solutions evaluated in this study have more than 20 molal total Na + concentration, and most have less than one mole of water per mole of ion. Thus, this reversal of the LMA occurs in solutions where there is not enough water to fully hydrate the ions, pointing to the importance of ion cluster formation. Within the composition range of the solutions analyzed here, this reversal of the LMA occurs regardless of NaAl(OH) 4 and NaOH concentrations. Elevated temperatures also result in the reversal of the LMA in the subsystems NaNO 2 -NaNO 3 -H 2 O and NaOH-NaNO 3 -H 2 O, consistent with spectroscopic and computational studies showing enhanced interactions at higher temperatures. Although speciation in these highly concentrated electrolyte solutions is not well understood, the stabilization of ion clusters by: (i) optimizing charge density around the ions through different combinations of mixed cations and anions in solution; and (ii) high temperatures where ions experience prolonged contact, offers important clues for future research into how these species control solubility.

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

Stable Solid Electrolyte Interphase Layer Formed by Electrochemical Pretreatment of Gel Polymer Coating on Li Metal Anode for Lithium–Oxygen Batteries

Lithium (Li)-oxygen (O2) batteries (LOBs) exhibit the highest theoretical specific energy density among candidates of the next-generation energy storage systems, but the instability of Li metal anode (LMA), air electrode, and electrolyte largely limit the practical energy density of these batteries. Herein, we report an effective method to protect LMA against side reactions between LMA and crossover contaminants such as highly reactive oxygen moieties. A solid electrolyte interphase (SEI) layer rich in inorganic components was formed on a LMA coated with polyethylene oxide thin-film through an in-situ electrochemical pre-charging step under oxygen atmosphere. This uniformly distributed stiff SEI layer interacted with flexible polymer matrix and formed a submicron-sized gel-like polymer layer. This polymer supported SEI layer leads to much longer cycle life (130 vs. 65 cycles) as compared to those of pristine cell under the same testing conditions (1.0 mAh cm-2 at 0.2 mA cm-2 in the voltage range of 2 to 5 V without any catalysts). It is also very effective during low voltage (2 to 4.5 V) cycling with a redox mediator (0.1 and 0.15M (2,2,6,6-tetramethylpiperidin-1-yl) oxidanyl). Therefore, this approach can be used to stabilize LMA/electrolytes interphase and improve the cycle life of rechargeable LOBs.

lithium-oxygen batteries, lithium metal anodes, ar↗
DOE OSTI2022

Intra-canopy leaf trait variation facilitates high leaf area index and compensatory growth in a clonal woody encroaching shrub

Leaf trait variation enables plants to utilize large gradients of light availability that exist across canopies of high leaf area index (LAI), allowing for greater net carbon gain while reducing light availability for understory competitors. While these canopy dynamics are well understood in forest ecosystems, studies of canopy structure of woody shrubs in grasslands are lacking. To evaluate the investment strategy used by these shrubs, we investigated the vertical distribution of leaf traits and physiology across canopies of Cornus drummondii, the predominant woody encroaching shrub in the Kansas tallgrass prairie. We also examined the impact of disturbance by browsing and grazing on these factors. Our results reveal that leaf mass per area (LMA) and leaf nitrogen per area (Na) varied approximately threefold across canopies of C. drummondii, resulting in major differences in the physiological functioning of leaves. High LMA leaves had high photosynthetic capacity, while low LMA leaves had a novel strategy for maintaining light compensation points below ambient light levels. The vertical allocation of leaf traits in C. drummondii canopies was also modified in response to browsing, which increased light availability at deeper canopy depths. As a result, LMA and Na increased at lower canopy depths, leading to a greater photosynthetic capacity deeper in browsed canopies compared to control canopies. This response, along with increased light availability, facilitated greater photosynthesis and resource-use efficiency deeper in browsed canopies compared to control canopies. Furthermore, our results illustrate how C. drummondii facilitates high LAI canopies and a compensatory growth response to browsing—both of which are key factors contributing to the success of C. drummondii and other species responsible for grassland woody encroachment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Using leaf and stomatal traits to predict biomass production and water use efficiency in Populus

Climate change is reshaping ecosystems, driving plants to adapt through leaf-trait plasticity that reflects strategies for growth and water use. Predicting biomass production and intrinsic water use efficiency (iWUE) remains challenging because of genetic, taxonomic, and environmental variability. Here, we used eastern cottonwood and Populus hybrids as a model system to test whether easily measurable leaf traits can serve as reliable predictors of performance, and whether adding stomatal and biochemical traits improves predictive power. Across two field sites in Mississippi, leaf mass per area (LMA), biomass production, iWUE, leaf area, and foliar nitrogen ( N %) differed significantly among taxa and sites, while other traits were conserved. Factorial analysis of mixed data (FAMD) revealed distinct clustering of taxa and sites, indicating coordinated variation among leaf and stomatal traits. Pairwise correlations highlighted fundamental trade-offs, with biomass positively related to LMA and petiole length but negatively associated with iWUE, N %, and carbon isotopic ratios (δ 13 C). Leaf temperature and leaf angle varied among taxa and were significantly correlated with LMA and petiole length, suggesting mechanisms of heat dissipation and leaf movability that link simple traits to gas exchange and productivity. Weighted multiple linear regression models explained 80%–91% of variation in biomass production and iWUE. Models using only LMA, petiole length, and stomatal metrics performed nearly as well as those incorporating N %, and δ 13 C, with complex traits adding approximately 10% explanatory power. These results demonstrate that simple morphological traits capture integrated functional trade-offs, while complex traits refine predictions. This tiered approach provides an efficient framework for selecting high-yielding, water-efficient genotypes of Populus and other hardwood species, offering practical pathways to enhance carbon uptake and iWUE under climate change.

biomass production↗