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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 1,369 records · Page 76
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Development of a DC Distribution Testbed for High-Power EV Charging

This paper explores the design and implementation of a power hardware-in-the-loop (P-HIL) setup for DC distribution infrastructure integrated with high-power charging (HPC) of electric vehicles (EVs), DC loads, and sources. The utilization of DC distribution holds significant potential for enhancing the operation of a HPC station architecture. However, there are challenges establishing a DC charging hub including interoperability, commoditization, distributed energy resource integration, stability, DC protection, and lack of common system level controllers. To address these challenges, a testing setup is required that accommodates commercial off-the-shelf (COTS) products to evaluate different use cases at rated power and voltage levels. The developed P-HIL setup features a dedicated DC charging hub, DC-coupled chargers, DC loads/sources, DC protection, and a communication architecture. The integrated P-HIL system provides a versatile testing environment to address technology and interoperability gaps and implements a smart energy management system (SEMS). This platform enables comprehensive and robust testing of COTS devices, charger prototypes, SEMS controllers and protection schemes, which together will accelerate transition to EVs at scale. The setup is tested for various use-cases at full-scale, integrating 950 V DC bus voltage, 660 kW grid-tied inverter, 150 kW COTS charger, and 100 kW energy storage system within an open-source SEMS platform.

ADVANCED PROPULSION SYSTEMS,POWER TRANSMISSION AND↗
DOE OSTI2025

Porous and Amorphous Mn x Mo 3 S 13 Chalcogel Electrode for High-Capacity Conversion-Based Lithium-Ion Batteries

While Li-ion batteries (LIBs) are a leading energy storage technology, their energy densities are limited by the low capacity of conventional intercalation cathodes, driving interest in high energy-density Li–S batteries that make use of conversion chemistry. Achieving high capacity, reversibility, and cycle stability, and controlling volume changes in conversion batteries during the charge–discharge process, however, remains challenging. Here, in this study, we present a porous, amorphous, sulfide-based Mn x Mo 3 S 13 chalcogel, which concurrently offers high capacity and cycle stability. The solution-processable room temperature synthesized Mn x Mo 3 S 13 (x = 0.25) chalcogel exhibits a local structure that resembles the Mo 3 S 13 cluster with Mn 2+ distributed across the Mo 3 S 13 matrix, as determined by synchrotron X-ray pair distribution function (PDF) and extended X-ray absorption fine structure (EXAFS). Ab initio molecular dynamics (AIMD) simulations reveal that Mn 2+ incorporation shortens the polysulfide chain in the gel matrix compared to the Mo 3 S 13 chalcogel, while forming a coordination environment with disulfide groups, analogous to the experimental findings. A Li/Mn 0.25 Mo 3 S 13 half-cell delivers 897 mAh g –1 capacity during the first discharge and retains 571 mAh g –1 capacity after 100 cycles at a C/3 rate. Distribution of relaxation time (DRT) unveils a stable solid–electrolyte interphase (SEI) formation upon cycling that enables charge–discharge reversibility. Here, the enhanced capacity retention and cycle stability compared to those of the Li/Mo 3 S 13 cell are attributed to the reduced dissolution of active mass into the electrolyte, facilitated by the formation of shorter polysulfide chains within the Mn 0.25 Mo 3 S 13 structure and the strong affinity of Lewis-acidic Mn 2+ for polysulfide anions generated during the charge–discharge process of the Li/Mn 0.25 Mo 3 S 13 cell. Thus, this work illustrates a design principle of material for high-capacity and cycle-stable Li-metal sulfide batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Understanding the heat generation mechanisms and the interplay between joule heat and entropy effects as a function of state of charge in lithium-ion batteries

The thermal performance of lithium-ion battery cells is critical for ensuring their safe and reliable operation across various applications. In this study, we employed an isothermal calorimetry method to investigate the heat generation of commercial 18650 lithium-ion battery fresh cells during charge and discharge at different current rates, ranging from 0.05C to 0.5C, and across various temperatures: 20 °C, 30 °C, 40 °C, and 50 °C. Our findings revealed a direct correlation between heat generation and current rates, indicating that higher current rates lead to increased heat generation within the cells. Conversely, we observed that heat generation remained relatively stable as the temperature rose, suggesting that temperature changes within this range may not significantly impact the heat generation of fresh cells during typical operations. Furthermore, our study explored irreversible heat generation, which depends on the applied current and overpotential, using the galvanostatic intermittent titration technique at 0.05C–0.5C and 30 °C. Additionally, electrochemical impedance spectroscopy was performed on the same cells during charge and discharge at 20 °C, 30 °C, and 40 °C to analyze cell impedance. Finally, our results indicated a consistent dependence of impedance on the state of charge and depth of discharge, with a significant increase in impedance observed at the end of the discharge process.

25 ENERGY STORAGE↗
DOE OSTI2020

Fast Charge-Driven Li Plating on Anode and Structural Degradation of Cathode

Enabling fast charging in lithium ion batteries (LIBs) is a key factor to make electric vehicles drive just like gasoline-powered vehicles when the time comes to refuel. However, fast charging to current LIBs (LiNi x Mn y Co 1–z O 2 /graphite) is limited by lithium plating, which is barely reversible and causes LIBs to lose capacity over time. Thus, research to quantify the lithium plating in LIB cells is extremely important in improving our fundamental understanding of lithium plating behavior and enabling fast charging for LIBs. Here, we precisely quantified the amount of fast-charge-driven lithium plating in a coin-cell composed of LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532)/graphite. We found that the amount of lithium plating gradually increases with the cycle count and reaches 25.59 μmole (26.80 mAh g –1 cathode ) by the 100th cycle. The study also reveals that the NMC532 has lost 19% of its original lithium content after 100 fast-charging cycles; this, correspondingly, causes a lattice volumetric strain of 0.59%.

25 ENERGY STORAGE↗
DOE OSTI2021

Fast Charging of Li-Ion Cells: Part V. Design and Demonstration of Protocols to Avoid Li-Plating

Fast charging of Li-ion batteries would make “fueling” of electric vehicles comparable in time to fueling of gasoline-powered cars, increasing consumer appeal of the new technology. Taking the US Department of Energy goal of safe 6 C charging to 80% capacity as a guide, we describe approaches that can mitigate Li plating on the graphite anode. To make this possible, a variable-rate anode potential charging protocol has been implemented by using a microprobe reference electrode to continuously monitor and adjust the current, in this way avoiding low anode potentials that favor Li deposition. Various implementations of the anode potential control are considered using electrochemical modeling and compared with the experimental data. For charge to 80% capacity at 30 °C, an average C-rate of 4.97 C was obtained for an NCM523/graphite cell with 70 μ m thick graphite electrode and 7.40 C for a cell with 47 μ m thick graphite electrode. Our electrochemical model accounts for these observations and provides a means to extrapolate the approach to other cell designs and operation regimes, drawing the maximum average fast charging rates that can still avoid Li plating.

25 ENERGY STORAGE↗
NASA NTRS1975

Analytical and experimental evaluation of techniques for the fabrication of thermoplastic hologram storage devices

The results of an experimental investigation on recording information on thermoplastic are given. A description was given of a typical fabrication configuration, the recording sequence, and the samples which were examined. There are basically three configurations which can be used for the recording of information on thermoplastic. The most popular technique uses corona which furnishes free charge. The necessary energy for deformation is derived from a charge layer atop the thermoplastic. The other two techniques simply use a dc potential in place of the corona for deformation energy.

Rogers, J. W.↗
DOE OSTI2022

Defect-driven anomalous transport in fast-ion conducting solid electrolytes

We report solid-state ionic conduction is a key enabler of electrochemical energy storage and conversion. The mechanistic connections between material processing, defect chemistry, transport dynamics, and practical performance are of considerable importance, but remain incomplete. Here, inspired by studies of fluids and biophysical systems, we re-examine anomalous diffusion in the iconic two-dimensional fast-ion conductors, the β- and β"-aluminas. Using large-scale simulations, we reproduce the frequency dependence of alternating-current ionic conductivity data. We show how the distribution of charge-compensating defects, modulated by processing, drives static and dynamic disorder, which lead to persistent sub-diffusive ion transport at macroscopic timescales. We deconvolute the effects of repulsions between mobile ions, the attraction between the mobile ions and charge-compensating defects, and geometric crowding on ionic conductivity. Our quantitative framework based on these model solid electrolytes connects their atomistic defect chemistry to macroscopic performance with minimal assumptions and enables mechanism-driven 'atoms-to-device' optimization of fast-ion conductors.

25 ENERGY STORAGE↗
DOE OSTI2023

Dynamic fracture processes in hydrogen embrittled iron

Mechanistic understanding of hydrogen embrittlement is critical to the transport and storage of hydrogen as a sustainable fuel. Experimental observation of dynamic fracture processes in hydrogen environments has been challenging. Here, in-situ transmission X-ray microscopy is used to image polycrystalline iron foils that are concurrently strained and electrochemically charged with hydrogen. Using this technique, voids and microcracks down to ∼30 nm in size are identified at or near the crack tip and tracked as strain is increased. We observe both hydrogen-induced transgranular failure and hydrogen-induced intergranular failure with distinct fracture processes. We find that transgranular fracture occurs through the formation of sharp branched structures at the main crack tip that are reminiscent of slip band formation. This is followed by void growth and coalescence, and interaction with secondary cracks that lead to propagation of the main crack. Intergranular fracture is found to occur through void coalescence along grain boundaries, along with significant secondary cracking near the crack tip. The crack growth rate is greater for void-mediated intergranular failure than for slip-mediated transgranular failure. Additionally, the removal of hydrogen results in recovered ductility for a crack initially propagated under hydrogen charging.

36 MATERIALS SCIENCE↗
NASA NTRS1976

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 12.0 ampere-hour nickel-cadmium spacecraft cells for the international ultraviolet explorer

An evaluation test program was conducted to insure that all cells put into the life cycle program are of high quality by the screening of cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open-circuit voltage above 1.150 volts during the internal short test. The 20 cells were manufactured for the National Aeronautics and Space Administration, Goddard Space Flight Center (GSFC). The cells are from a lot of 175 cells procured for the International Ultraviolet Explorer project. Due to a change in requirements, the project selected to use 6.0 ampere-hour cells. Therefore, the remaining cells of this lot have been placed in storage at GSFC for use on a future GSFC project. All the cells are rated at 12.0 ampere-hours and contain double ceramic seals. Test limits specify those values in which a cell is to be terminated from a particular charge or discharge. Requirements are referred to as normally expected values based on past performance of aerospace nickel cadmium cells with demonstrated life characteristics.

Harkness, J. D.↗
NASA NTRS2012

Control Algorithms Charge Batteries Faster

On March 29, 2011, NASA s Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) spacecraft beamed a milestone image to Earth: the first photo of Mercury taken from orbit around the solar system s innermost planet. (MESSENGER is also the first spacecraft to orbit Mercury.) Like most of NASA s deep space probes, MESSENGER is enabled by a complex power system that allows its science instruments and communications to function continuously as it travels millions of miles from Earth. "Typically, there isn't one particular power source that can support the entire mission," says Linda Taylor, electrical engineer in Glenn Research Center s Power Systems Analysis Branch. "If you have solar arrays and you are in orbit, at some point you re going to be in eclipse." Because of this, Taylor explains, spacecraft like MESSENGER feature hybrid power systems. MESSENGER is powered by a two-panel solar array coupled with a nickel hydrogen battery. The solar arrays provide energy to the probe and charge the battery; when the spacecraft s orbit carries it behind Mercury and out of the Sun s light, the spacecraft switches to battery power to continue operations. Typically, hybrid systems with multiple power inputs and a battery acting alternately as storage and a power source require multiple converters to handle the power flow between the devices, Taylor says. (Power converters change the qualities of electrical energy, such as from alternating current to direct current, or between different levels of voltage or frequency.) This contributes to a pair of major concerns for spacecraft design. "Weight and size are big drivers for any space application," Taylor says, noting that every pound added to a space vehicle incurs significant costs. For an innovative solution to managing power flows in a lightweight, cost-effective manner, NASA turned to a private industry partner.

Source record↗
DOE OSTI2021

On Secured Spinning Reserve Deployment of Energy-Limited Resources Against Contingencies

Featured with fast response abilities and high ramp rates, energy storage systems (ESS), such as pumped-storage hydropower (PSH) plants and battery storage systems (BSS), are considered as key first-responders to provide spinning reserve in response to system contingencies. However, ESSs are energy-limited resources, and their sustained spinning reserve deployment is restricted by the stored energy and available capacity. Indeed, the spinning reserve deployment against contingencies may deviate actual state-of-charge (SOC) from the scheduled value, inducing potential SOC boundary violations and non-dispatchability in later hours. This paper proposes the post-contingency operation model and the spinning reserve secure constraints to address these issues. The post-contingency operation model describes that spinning reserve from ESSs is promptly deployed when contingency occurs, and then gradually substituted by quick-start units when they are switched online. By leveraging this operation strategy, spinning reserve secure constraints in terms of SOC headrooms are adopted to guarantee its deplorability. Furthermore, a modified IEEE 118-bus system with multiple PSHs and BSSs is used to verify the proposed approach.

13 HYDRO ENERGY↗
DOE OSTI2020

Virtual storage capability of residential buildings for sustainable smart city via model-based predictive control

This paper evaluates the virtual storage capability of a residential air-conditioning (AC) system by utilizing the building mass as a thermal storage to enable sustainable cities through model-based predictive control (MPC). The control-oriented building model was developed with a grey-box model structure based on the experimental data to predict the indoor air temperature. Based on the model, the operation cost-saving potential of the MPC was investigated in a single house with different comfort levels, electricity prices, and prediction horizons. The cost-saving of the MPC was approximately 10.6 % compared to the conventional control. The MPC was expanded to a residential building cluster considering the peak demand charge. In an hourly shedding and load-up scenario, the performances of the MPC and the heuristic prior-based control (PBC) are promising. When shedding was enforced all day, the peak demand saving of the MPC was 36~38 %, whereas that of the PBC was 25.7 % compared to the baseline. In addition, the monthly electricity bill, including the operation and peak demand cost, was investigated with different demand charge rates and weather conditions. The total saving decreased with a low demand charge rate and hot conditions, and the operation cost saving was compromised with more aggressive demand shedding.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Ionothermally Synthesized Nanoporous Ti 0.95 W 0.05 Nb 2 O 7 : a Novel Anode Material for High-Performance Lithium-Ion Batteries

Although TiNb 2 O 7 is regarded as a fast-rechargeable lithium-ion battery (LIB) anode material, the intrinsic poor electrochemical kinetics of TiNb 2 O 7 still dramatically impedes its development. Herein, an ionothermal synthesis-assisted doping strategy is proposed for the preparation of a new W 6+ -doped TiNb 2 O 7 material (Ti 0.95 W 0.05 Nb 2 O 7 ) with nanoporous structure (denoted as NPTWNO). The improved Li + diffusion coefficient of NPTWNO suggests that the ionic-liquid-templated nanoporous architecture improves the Li+ diffusion kinetics. The density functional theory computational study reveals that the doped W 6+ successfully boosts the electronic conductivity due to the narrowed conduction-valance bandgap resulted from charge redistribution, which is reflected by the electrochemical impedance spectroscopy data. With the simultaneously enhanced Li+ diffusivity and electronic conductivity, NPTWNO achieves fast-rechargeability in LIBs. So this work indicates the potential of ionothermal synthesis-assisted doping strategy on energy storage materials and offers NPTWNO material with promising electrochemical performance.

25 ENERGY STORAGE↗
DOE OSTI2023

Enhancing Crystallization in Hybrid Perovskite Solar Cells Using Thermally Conductive 2D Boron Nitride Nanosheet Additive

Controlling crystallization and grain growth is crucial for realizing highly efficient hybrid perovskite solar cells (PSCs). In this work, enhanced PSC photovoltaic performance and stability by accelerating perovskite crystallization and grain growth via 2D hexagonal boron nitride (hBN) nanosheet additives incorporated into the active perovskite layer are demonstrated. Specifically, in situ X-ray scattering and infrared thermal imaging during the perovskite annealing process revealed the highly thermally conductive hBN nanosheets promoted the phase conversion and grain growth in the perovskite layer by facilitating a more rapid and spatially uniform temperature rise within the perovskite film. Complementary structural, physicochemical, and electrical characterizations further showed that the hBN nanosheets formed a physical barrier at the perovskite grain boundaries and the interfaces with charge transport layers, passivating defects, and retarding ion migration. As a result, the power conversion efficiency of the PSC is improved from 17.4% to 19.8%, along with enhanced device stability, retaining ≈90% of the initial efficiency even after 500 h ambient air storage. Here, the results not only highlight 2D hBN as an effective additive for PSCs but also suggest enhanced thermal transport as one of the pathways for improved PSC performance by 2D material additives in general.

2D materials↗
DOE OSTI2020

Copper Electrodeposition from Deep Eutectic Solvents—Voltammetric Studies Providing Insights into the Role of Substrate: Platinum vs Glassy Carbon

We report on the effect of the substrate on electrochemical deposition of Cu from deep eutectic solvent ethaline. We investigated the polarization behavior during electrodeposition of Cu on Pt and glassy carbon (GC) from both Cu 2+ and Cu + containing ethaline using cyclic voltammetry (CV). Formation of bulk Cu deposits on both substrates underwent nucleation and growth processes; however, the nucleation was considerably sluggish on GC compared to Pt. While experiments in Cu+ solutions indicated that coalescence of Cu islands on Pt is a slow process and that its surface may not be fully covered by Cu, such determination of Cu coverage could not be made on GC. Cu dissolution is also slower from GC than from Pt. It was observed that CV of Cu deposition on GC is influenced by the surface preparation method. Since ethaline has high chloride concentration, a parallel study in aqueous 3 M NaCl solution was conducted in order to examine the influence of the chloride medium on the electrodeposition process. Lastly, this revealed that electrodeposition in both media occurred in the same manner but with different charge and mass transfer rates caused by the differences in viscosity and chloride concentrations of the two solutions.

25 ENERGY STORAGE↗
DOE OSTI2023

Design Criteria of Dilute Ether Electrolytes toward Reversible and Fast Intercalation Chemistry of Graphite Anode in Li-Ion Batteries

To date, dilute ether electrolytes have been believed to be incompatible with graphite in Li-ion batteries due to the detrimental solvent cointercalation and graphite exfoliation. Here, in this paper, we provide design criteria of dilute ether electrolytes for a reversible graphite anode based on tailoring the solvation structures and thermodynamic properties. We clarify that ether solvents can support graphite reversibly by modulating the anion. Our redesigned electrolyte consisting of a single-solvent 1,3-dioxolane (DOL) and 1 M single-salt lithium bis(fluorosulfonyl)imide (LiFSI) shows weakened Li-solvent interaction and results in an inorganic-rich solid-electrolyte interphase. Consequently, we achieved ~99.9% Coulombic efficiency with >96% capacity retention (~350 mAh/g) after 300 cycles at C/5 using natural graphite. The weakly solvated electrolyte maintains desirable transport properties, enabling better rate capability than carbonate electrolytes with an areal capacity of 2–4 mAh/cm 2 . We have demonstrated the potential of dilute ether electrolytes for facile desolvation-based intercalation chemistry in graphite, creating a viable path toward fast-charge Li batteries.

25 ENERGY STORAGE↗
DOE OSTI2025

Emergent Dimer-Model Topological Order and Quasiparticle Excitations in Liquid Crystals: Combinatorial Vortex Lattices

Liquid crystals have proven to provide a versatile experimental and theoretical platform for studying topological objects such as vortices, skyrmions, and hopfions. In parallel, in hard condensed matter physics, the concept of topological phases and topological order has been introduced in the context of spin liquids to investigate emergent phenomena like quantum Hall effects and high-temperature superconductivity. Here, we bridge these two seemingly disparate perspectives on topology in physics. Combining experiments and simulations, we show how topological defects in liquid crystals can be used as versatile building blocks to create complex, highly degenerate topological phases, which we refer to as “combinatorial vortex lattices” (CVLs). CVLs exhibit extensive residual entropy and support locally stable quasiparticle excitations in the form of charge-conserving topological monopoles, which can act as mobile information carriers and be linked via Dirac strings. CVLs can be rewritten and reconfigured on demand, endowed with various symmetries, and modified through laser-induced topological surgery—an essential capability for information storage and retrieval. We demonstrate experimentally the realization, stability, and precise optical manipulation of CVLs, thus opening new avenues for understanding and technologically exploiting higher-hierarchy topology in liquid crystals and other ordered media.

36 MATERIALS SCIENCE↗