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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Impact of Testing Method on Safety Assessment of Aged Li-Ion Cells: Part II – Aged Cells Without Li Plating

Understanding the safety profile of aged Li-ion batteries is essential for developing effective battery management and hazard mitigation strategies. However, most safety assessments have focused on fresh batteries, with just a few calorimetry studies on aged batteries with metal oxide positive electrodes. This study provides a broad assessment of commercial 18650-type Li-ion batteries with NCA, NMC, and LFP positive electrodes, both uncycled and aged under conditions that promoted solid electrolyte interphase (SEI) growth as the dominant degradation mechanism. The cells underwent mechanical (nail penetration, crush), electrical (overcharge, overdischarge), and thermal (accelerating rate calorimetry) abuse tests. Safety was rated on general characteristics such as mass loss, maximum temperature, and EUCAR (European Council for Automotive R&D) hazard level, as well as characteristics specific to individual abuse tests. Generally, aged cells with SEI growth exhibited similar or improved safety compared to uncycled cells, contrasting with our previous findings on NCA cells with Li plating as the dominant aging mechanism (Part I of this series). Yet, some tests and characteristics indicated reduced aged cell safety, such as earlier triggering of mechanical failure. These results emphasize the need to examine aged battery safety across diverse empirical techniques, degradation modes, and chemistries.

Lithium-ion cells↗
DOE OSTI2025

Impact of the LiPF6 Concentration on the Interfacial Charge Transfer and Fast-charging Capabilities of Lithium-Ion Batteries

Fast-charging lithium-ion batteries (LIB) demand optimized electrolyte formulations to balance ionic conductivity, viscosity, and interfacial charge transfer kinetics. This study examines how LiPF 6 concentration shapes solvation structure, desolvation energy, charge transfer activation energy, and solid electrolyte interphase (SEI) properties, which are critical for fast-charging performance. Using Raman spectroscopy, electrochemical cycling, X-ray photoelectron spectroscopy, and atomistic modeling, we analyze how varying LiPF 6 concentrations impact interfacial and bulk transport properties. Our findings show that increasing LiPF 6 concentration alters lithium solvation structures, reduces desolvation energy, and accelerates charge transfer at the electrode interface. Higher concentrations lower the activation energy for charge transfer and suppress excessive SEI growth, improving interfacial kinetics. However, concentrations above a certain threshold increase viscosity and reduce ionic conductivity, limiting transport efficiency. These results offer insights into electrolyte solvation and interfacial charge transfer mechanisms, providing guidelines for designing next-generation fast-charging LIB electrolytes with enhanced efficiency, stability, and longevity.

Son, Seoung-Bum [Argonne National Laboratory (ANL)↗
DOE OSTI2025

The role of chromatin state in intron retention: A case study in leveraging large scale deep learning models

Complex deep learning models trained on very large datasets have become key enabling tools for current research in natural language processing and computer vision. By providing pre-trained models that can be fine-tuned for specific applications, they enable researchers to create accurate models with minimal effort and computational resources. Large scale genomics deep learning models come in two flavors: the first are large language models of DNA sequences trained in a self-supervised fashion, similar to the corresponding natural language models; the second are supervised learning models that leverage large scale genomics datasets from ENCODE and other sources. We argue that these models are the equivalent of foundation models in natural language processing in their utility, as they encode within them chromatin state in its different aspects, providing useful representations that allow quick deployment of accurate models of gene regulation. We demonstrate this premise by leveraging the recently created Sei model to develop simple, interpretable models of intron retention, and demonstrate their advantage over models based on the DNA language model DNABERT-2. Our work also demonstrates the impact of chromatin state on the regulation of intron retention. Using representations learned by Sei, our model is able to discover the involvement of transcription factors and chromatin marks in regulating intron retention, providing better accuracy than a recently published custom model developed for this purpose.

Biochemistry & Molecular Biology↗
DOE OSTI2021

Fundamental Investigations of Mechanical and Chemical Degradation Mechanisms in Lithium Ion Battery Materials (Final Technical Report)

The objective of our effort under the DOE EPSCoR Implementation grant is to establish a comprehensive and internationally recognized research program at Brown University and University of Rhode Island in understanding degradation mechanisms and to improve the cycle and calendar life of lithium ion battery (LIB) materials. A series of basic investigations are undertaken to characterize the mechanical and chemical degradation mechanisms, which can help enable new higher capacity and longer lasting electrode designs. Controlling mechanical and chemical degradation is the primary challenge in developing the next generation of higher energy density batteries. The development of failure resistant battery microstructures will require a fundamental understanding of the evolution of stress, deformation, damage, and electrochemistry in battery materials during cyclic charging and discharging. In addition, controlling the reactions at the electrode/electrolyte interface is critical for the formation of a stable SEI layer. We address these issues through a combination of controlled experiments on model battery materials and practical composite electrodes, together with multi-scale computations. Our effort is organized into three focus areas that encompass many critical challenges in Lithium Ion Battery Technologies: (i) Mechanical properties, fracture and damage in electrode materials; (ii) Chemistry and Mechanics of Solid Electrolyte Interphase (SEI); (iii) Mechanical and Chemical Integrity of Solid-Solid Interfaces in Practical Electrodes.

25 ENERGY STORAGE↗
DOE OSTI2023

Resumen del Informe de Progreso del PR100: Resultados Preliminares del Modelo y Conjuntos de Datos Solares y Eólica de Alta Resolución

El estudio de Resiliencia y Transiciones a 100% Energia Renovable de Puerto Rico (PR100) es un estudio de 2 anos de la Oficina de Movilizacion de la Red del Departamento de Energia y seis laboratorios nacionales para analizar exhaustivamente las rutas dirigidas por las personas interesadas hacia un futuro de energia limpia en Puerto Rico. En el Ano 1 del estudio, el equipo PR100, creo y analizo los modelos que alcanzan las metas de energia renovable para Puerto Rico y los objetivos de resiliencia energetica a corto y largo plazo. Este informe, que resume el progreso en el Ano 1, proporciona las consideraciones que pueden informar posibles decisiones de fondos e implementacion potenciales por parte de las agencias federales y locales clave y partes interesadas. El resumen de este informe sigue a la publicacion en julio 2022 de un Informe de Seis Meses de Progreso de PR100. (en ingles y espanol), asi como webinarios publicos en febrero 2022 para lanzar el estudio y julio 2022 para presentar la actualizacion a 6 meses. Un informe final por escrito y visuales por la web seran publicados a finales del 2023. Todas las publicaciones y eventos publicos asociados con el estudio estaran disponibles en ingles y espanol. This report is also available in English https://www.nrel.gov/docs/fy23osti/85018.pdf.

14 SOLAR ENERGY↗
DOE OSTI2024

Using the Principals of Electrochemistry to Understand and Overcome the Complicated Degradation Mechanisms of Silicon Anodes in Lithium-Ion Batteries [Slides]

Battery technology is the most significant problem facing widespread market adoption of battery electric vehicles (BEVs). The low energy density of state-of-the-art lithium-ion electrode materials leaves BEV owners and prospective buyers with lower ranges than a comparable internal combustion engine (ICE) vehicle, and vulnerable to a nascent fast charging network. Silicon has the potential to increase the anode energy density by nearly ten times compared to the incumbent material (graphite) and make BEVs a more competitive transportation option. However, lithiated silicon is extremely reactive towards components of the electrolyte and forms a heterogeneous, complicated, and dynamic solid at its surface known as the solid electrolyte interphase (SEI). Ideally, the SEI would passivate the silicon surface, but continuous chemical degradation persists even when the battery is not operating. This reactivity reduces silicon anode lifetimes well below the necessary standards for BEVs. The NREL-led Silicon Consortium Project is dedicated to understanding and solving these mechanisms of degradation. Here, I will discuss an electrochemical method that provides deep insights into the silicon interface during battery operation. I will link these observations to fundamental electrochemical principals and how they translate into actionable strategies that extend the lifetime of silicon anodes.

25 ENERGY STORAGE↗
DOE OSTI2026

Development of Next Generation Hierarchical Hybrid Cu-Si anode Batteries via Direct-Ink Writing Application: End of (6th) Month Report - November 2025

Sustainable renewable energy continues to be in dire need to effectively combat global warming. Emerging technology for electric vehicles/ devices remains in high demand that is not only lower in cost, more efficient, but safer in comparison to commercial materials on the market. Although first-generation lithium-ion batteries have exhibited extensive commercial application, conventional graphite no longer meets this increasing demand as an efficient anode material. Due to the fact that graphite has a subpar theoretical specific capacity (372 mAh g -1 ), thus significant limitations in rate capability (for potential faster charging at higher C-rates currently commercially available.). Alternatively, silicon has gained significant attention as a superior candidate to potentially surpass graphite. Due to silicon’s exceedingly high theoretical capacity (4,200 mAh g -1 ) in comparison to standard graphite, its abundance thus in turn it’s low-cost, in addition to exhibiting a significantly low working potential (< 0.4 V vs Li/Li + ). However, one of the main (and most detrimental) challenges is silicon’s tendency to expand in volume (> 300%) upon discharge as it begins the lithiation process. As a direct result, it causes not only for the particles to both crack and pulverize under mechanical stress as the volume continues to expand and contract during cycling. Upon assembling the cell, it needs to undergo ‘charging’ for initially discharging/ ‘activating’ the cell, otherwise commonly known as the ‘formation’ step. As a result a solid electrolyte interface (SEI) layer begins to form at the anode surface because some of the electrolyte begins to react during the formation process. However, this (SEI) layer is deemed as a ‘protective’ interlayer because in theory it prevents further reaction as the cell continues to cycle. However, due to the volume change it causes significant degradation at the interface. As cracking starts to occur at the anode surface, it results in a ‘new’ altered surface with each cycle that causes further reaction with the electrolyte as a byproduct quickly consuming active Li/ and more electrolyte. Thus, fracturing this ‘protective layer,’ causing significantly higher impedance as a result, and in turn a decline in capacity due to active Li-loss. In addition to the active material exfoliating off from the current collector, further contributing to the steady decline in capacity and overall performance. Current state of the art Si-anode batteries on the market range between a maximum content of 5-10 Si wt%. It has been previously reported Tesla has utilized SiO x -C anodes containing 5 wt% Si within their ‘Model 3/ Model X’ electric vehicles. However, more recent ‘Model 3’ vehicles have started to incorporate 10 Si wt%, in which they were able to increase their energy density upwards by approximately 30%. Recent effort has been focused on continuing to increase the wt% of Si being utilized, eventually to 100 wt% of Si, to maximize the energy density even further.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Multiscale Cryo Electron Microscopy Reveals Interfacial Degradation and Stabilization in Battery Electrodes

Electrochemical interfaces are dynamic systems, evolving based on their local environment and reactant surface structures. The electrode-electrolyte interface in Li-ion batteries can be protective, limiting parasitic reactions with the electrolyte to passivate the surface [1]. Additionally, this interphase has an impact on the Li-ion transport through that layer based on its composition, bonding environment, and thickness. These parameters are challenging to collect and may vary depending on the electrode surface site investigated relative to its spatial position in a coin cell. This study will detail a multiscale cryogenic electron microscopy approach where millimeter-scale cross-sections through the coin cell batteries were made using a cryogenic stage within a fs-laser plasma focused ion beam (laser PFIB) with complementary energy dispersive X-ray spectroscopy able to detect variations in the composition at electrode interfaces [2]. Microscale cross-sectioning and lamella sample preparation of battery electrodes was conducted at the Center for Integrated Nanotechnologies using a Ga-ion focused ion beam (FIB) with air-free and cryo-transfer [3], followed by nanoscale mapping of composition and bonding within the CEI through cryo-scanning transmission electron microscopy (cryo-STEM) electron energy loss spectroscopy [4]. This multiscale approach enabled identification of millimeter-scale features of a battery stack with visualization of degradation in electrodes such as cracks in cathode particles, gas evolution, and SEI evolution; microscale interfacial characteristics, such as heterogeneity in the SEI or barrier layer and identification of electrolyte networks to the electrode surfaces; and nanoscale measurement of the CEI thickness, mapping of transition metal bonding within the cathode particles to identify loss of active materials, and identification of beneficial electrolyte additives incorporated into the CEI structure. This multiscale approach allows for a statistical understanding of the primary mechanisms and parasitic degradation pathways that impact performance by limiting the ion transport pathways within Li+ batteries.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Chemical contributions to silicon anode calendar aging are dominant over mechanical contributions

Silicon (Si) anodes are a promising candidate for increasing the energy density of lithium (Li)-ion batteries for electric vehicles. However, they have recently been identified as having poor calendar life that is insufficient for commercial needs, in addition to the well-known issue of their poor cycle life resulting from large volume expansion. Here, a specially designed protocol with variable rest periods between intermittent cycling is used to evaluate the impact of the mechanical disruption of Si and solid electrolyte interphase (SEI) from cycling on calendar aging measurements. Si was found to undergo more mechanical degradation during calendar aging with intermittent cycling than graphite. However, Si anode capacity fade was still dominated by time, especially for rest periods greater than or equal to 1 month between cycling. Postmortem dQ/dV half-cell analysis indicated this was mainly due to Li inventory loss and an increase in electrode resistance. Isothermal microcalorimetry further demonstrated that Si passivation is more disrupted than graphite passivation with intermittent cycling and suggested that there may be a chemical buildup of a detrimental species in the electrolyte, leading to a large spike in heat after the Si and SEI are disrupted by cycling.

25 ENERGY STORAGE↗
DOE OSTI2026

Rational Electrolyte Formulation for Sodium Metal Batteries Operating in Extremely Cold Environments

Sodium metal batteries have shown considerable potential when operated at ambient temperatures. However, their performance in cold environments is constrained by increased electrolyte resistance with decreasing temperature and dendritic sodium plating associated with unstable solid electrolyte interphase (SEI), which are primarily influenced by the electrolyte composition. In this study, we present an electrolyte formulation that remains thermally stable down to −150 °C, which not only facilitates low internal resistance but also contributes to the formation of a protective SEI under cryogenic conditions. When cycled at −40 °C at 1 mA cm −2 , the sodium metal electrode exhibits a low overpotential of only 16 mV over 750 h; even at an ultra-low temperature of −80 °C, the electrode demonstrates remarkable long-term stability with a low overpotential of 54 mV sustained over 1500 h at 0.5 mA cm −2 . Furthermore, full cell evaluations when paring with Na 3 V 2 (PO 4 ) 3 cathode reveal a high average Coulombic efficiency exceeding 99.1% and a capacity retention over 83% after 100 cycles at both −40 °C and −80 °C.

Electrolyte↗
NASA NTRS1989

Mechanism for nearly ohmic behavior in annealed Au/n-GaAs Schottky diodes

The mechanism of the ohmic behavior commonly observed after annealing Au/n-GaAs 110-oriented Schottky diodes was investigated using electron-beam-induced current (EBIC) measurements, secondary electron imaging (SEI), and SEM and TEM observations. The results showed that the ohmic behavior of annealed Schottky diodes originates from a shunt current pathway at the diode periphery. The SEI, EBIC, and electrical measurements indicated that the ohmic leakage current is due to the surface recombinations at the exposed surface of GaAs between elongated Au crystallites.

Leon, R. P.↗
NASA NTRS1990

A technology assessment of alternative communications systems for the space exploration initiative

Telecommunications, Navigation, and Information Management (TNIM) services are vital to accomplish the ambitious goals of the Space Exploration Initiative (SEI). A technology assessment is provided for four alternative lunar and Mars operational TNIM systems based on detailed communications link analyses. The four alternative systems range from a minimum to a fully enhanced capability and use frequencies from S-band, through Ka-band, and up to optical wavelengths. Included are technology development schedules as they relate to present SEI mission architecture time frames.

Ponchak, Denise S.↗
NASA NTRS1990

An infrastructure assessment of alternative Mars Transfer Vehicles

Development and evolutionary paths for many space transportation elements must be considered as the United States space program embarks on the Space Exploration Initiative (SEI). A central element of the space transportation infrastructure necessary to support the SEI is Mars Transportation System (MTS). This system consists of the Mars Transfer Vehicle (MTV) and Mars Excursion Vehicle. This paper describes the process and results in evaluating the alternate MTV propulsion concepts. Primary discriminators in evaluating different options for the MTV alternatives are: requirements for earth-to-orbit delivery, on-orbit facility and assembly requirements, and mission performance. Propulsion candidates assessed in this paper include nuclear thermal propulsion, nuclear electric propulsion, solar electric propulsion, and cryogenic chemical propulsion (LO2/LH2). The primary discriminators as well as additional selection criteria will be discussed for each MTS alternative.

Holdridge, Jeffrey D.↗
NASA NTRS1991

Conceptual study of on orbit production of cryogenic propellants by water electrolysis

The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

Moran, Matthew E.↗
NASA NTRS1991

An assessment of technology alternatives for telecommunications and information management for the space exploration initiative

On the 20th anniversary of the Apollo 11 lunar landing, President Bush set forth ambitious goals for expanding human presence in the solar system. The Space Exploration Initiative (SEI) addresses these goals beginning with Space Station Freedom, followed by a permanent return to the Moon, and a manned mission to Mars. A well designed, adaptive Telecommunications, Navigation, and Information Management (TNIM) infrastructure is vital to the success of these missions. Utilizing initial projections of user requirements, a team under the direction of NASA's Office of Space Operations developed overall architectures and point designs to implement the TNIM functions for the Lunar and Mars mission scenarios. Based on these designs, an assessment of technology alternatives for the telecommunications and information management functions was performed. This technology assessment identifies technology developments necessary to meet the telecommunications and information management system requirements for SEI. Technology requirements, technology needs and alternatives, the present level of technology readiness in each area, and a schedule for development are presented.

Ponchak, Denise S.↗
NASA NTRS1991

Data compression for full motion video transmission

Clearly transmission of visual information will be a major, if not dominant, factor in determining the requirements for, and assessing the performance of the Space Exploration Initiative (SEI) communications systems. Projected image/video requirements which are currently anticipated for SEI mission scenarios are presented. Based on this information and projected link performance figures, the image/video data compression requirements which would allow link closure are identified. Finally several approaches which could satisfy some of the compression requirements are presented and possible future approaches which show promise for more substantial compression performance improvement are discussed.

Whyte, Wayne A., Jr.↗
NASA NTRS1990

The Space Exploration Initiative and NASA Langley Research Center test facilities

The NASA Exploration Technology Program (ETP) will make possible the U.S. Space Exploration Initiative (SEI), and is structured according to mission thrusts that are based on technologies to be developed and tested or that will otherwise be utilized to support SEI. Twenty-seven technology projects have thus far been established, and NASA's Langley Research Center is responsible for six lead roles and four participating roles. This report briefly defines these ten Langley-assigned ETP technology projects, and it describes both existing and proposed test facilities capable of supporting the Center's responsibilities.

Mouring, John L.↗
NASA NTRS1990

Concurrent research on the Space Station transportation node

The feasibility of integrating scientific research on Space Station Freedom (SSF) with concurrent lunar-vehicle assembly and servicing operations associated with the support of Space Exploration Initiative (SEI) is investigated. The SSF, SEI, and lunar-vehicle user resource requirements are reviewed, and a station configuration is derived which can accommodate a significant percentage of user requirements while supporting the lunar transport vehicle (LTV) processing operations. The derived station configuration will require several augmentations to the baseline configuration. Most notably, the SSF power generation will be increased by an addition of six solar dynamic arrays, crew support will be increased by adding two habitation modules, and more payloads will be accomodated by adding dual keels.

Meredith, B. D.↗