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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

High-Energy All-Solid-State Organic–Lithium Batteries Based on Ceramic Electrolytes

Recent studies have identified unique properties of organic battery electrode materials such as moderate redox potentials and mechanical softness which are uniquely beneficial for all-solid-state batteries based on ceramic electrolytes. Here, we further explore the promise of organic materials and demonstrate a sulfide electrolyte- based organic-lithium battery with a specific energy of 828 Wh kg –1 , rivaling the state-of- the-art of all-solid-state batteries. Two innovation steps are responsible for the accomplishment. First, the combination of lithium anode and the high-capacity cathode material pyrene-4,5,9,10-tetraone ensures a high theoretical specific energy. Second, the microstructure of the organic cathode is optimized with the introduction of cryomilling, a technique common to processing soft materials but not familiar to electrode fabrication. The cathode material utilization increases to 99.5% as a result, up from the 55–89% previously reported for ceramic electrolyte-based solid-state organic batteries. In conclusion, the improvement highlights the special requirements of solid-state organic electrodes for microstructural engineering while preserving the chemical integrity of components.

25 ENERGY STORAGE↗
DOE OSTI2025

Tritium Breeder Composites for Fusion Applications

Due to the short half-life of tritium, all fusion reactors planned for long-term operation using a deuterium-tritium fuel cycle must produce sufficient tritium from reactions outside the core to maintain reactor operation. Typically, the core is surrounded by a tritium breeder blanket filled with lithium-containing materials which react under a neutron flux to form tritium that can then be collected. Here, reactor designers are forced to choose between using chemically reactive liquid breeders (e.g., Pb-Li, FLiBe, Li) or solid breeders, which often have lower lithium concentrations and questionable mechanical integrity under irradiation (e.g., Li4SiO4, Li2TiO3). To expand this pool of options, this work has sought to produce composite tritium breeder materials using lithium-containing ceramics and metal reinforcements. The resultant composite tritium breeders simultaneously feature higher lithium densities and improved mechanical integrity, including tensile strength and toughness, compared to other tritium breeders previously reported in literature.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Correlating hidden local structural distortion with antiferroelectric-ferroelectric transition in PbZrO 3 -based perovskites

Externally stimulated antiferroelectric-ferroelectric (AFE-FE) transition makes AFE materials attractive for many applications ranging from energy storage to sensing. This transition-mediated macroscopic electrical characteristics have been extensively investigated, yet the underlying structural evolution remains poorly understood. Herein, we study the local- and long-range structural evolutions in the Nb-doped Pb(Zr,Sn,Ti)O 3 perovskites by in-situ X-ray total scattering and diffraction, which show three different types of AFE-FE transitions. The evolution of long-range structure from diffraction and local structure identified by atomic pair distribution function (PDF) are consistent well with the phase transition behavior indicated by macroscopic polarization/strain measurements, while discrepancies exist. Interestingly, frequently employed long-range structure picture that the uniform AFE pseudo-tetragonal to FE rhombohedral transformation is insufficient to understand the distinct composition-dependent AFE-FE transition behaviours. Instead, the reversibility of this transition correlates with the chemically sensitive local atomic displacements revealed by newly developed in-situ PDF. The critical electric field of transition is associated with the local structural differences between the AFE and FE state. The macroscopic electrostrains can be well estimated by the phase transition associated lattice strain and domain alignment from in-situ synchrotron XRD data, while the local strains calculated from in-situ PDFs are found to be much lower. Finally, these results provide a fresh insight into the AFE-FE transition, and advance the understanding of structure-property relationships in AFE materials.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Processing, structure, and thermal properties of ZrW 2 O 8 , HfW 2 O 8 , HfMgW 3 O 12 , Al(HfMg) 0.5 W 3 O 12 , and Al 0.5 Sc 1.5 W 3 O 12 negative and zero thermal expansion coefficient ceramics

Negative and zero coefficient of thermal expansion (CTE) materials are of interest for developing polymer composites in electronic circuits that match the expansion of Si and in zero CTE supports for optical components, e.g., mirrors. In this work, the processing challenges and stability of ZrW 2 O 8 , HfW 2 O 8 , HfMgW 3 O 12 , Al(HfMg) 0.5 W 3 O 12 , and Al 0.5 Sc 1.5 W 3 O 12 negative and zero thermal expansion coefficient ceramics are discussed. Al 0.5 Sc 1.5 W 3 O 12 is demonstrated to be a relatively simple oxide to fabricate in large quantity and is shown to exhibit single phase up to 1300 °C in air and inert N 2 environments. The negative and zero CTE behavior was confirmed with dilatometry. Thermal conductivity and heat capacity were reported for the first time for HfMgW 3 O 12 and Al 0.5 Sc 1.5 W 3 O 12 and thermal conductivity was found to be very low (~0.5 W/mK). Grüneisen parameter is also estimated. Methods for integration of Al 0.5 Sc 1.5 W 3 O 12 with other materials was examined and embedding 50 vol% of the ceramic powder in flexible epoxy was demonstrated with a commercial vendor.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Enhanced flexibility and thermal conductivity of HfC decorated carbon nanofiber mats

Future-generation spacecraft components allude discovery of novel materials that can withstand extreme environments (>2000 °C). The combined effect of ultra-high temperature ceramics (UHTCs) and carbon fibers (C f ) can satisfy the demanding requirements of aerospace applications. A novel, hybrid, and flexible hafnium carbide (HfC)-decorated carbon nanofiber (C nf ) mat was fabricated via electrospinning. Enhanced thermal stability of the flexible HfC decorated C nf over C nf can be elucidated from the 20-fold increment in thermal conductivity and the onset of degradation at higher temperatures (840 °C). Successful integration of multi-layered sandwich lattice using in-housed fabricated HfC decorated C nf showed retention of the fibrous structure even after extreme spark plasma sintering (SPS) process at 1850 °C. Fabricating a similar multi-layered structure using procured C f was unsuccessful due to bundled agglomeration and micron-sized fibers. High-load indentation suggests that HfC decorated C nf interlayer is stronger (~2.3 times) than the parent UHTC with no cracking at the interface. Compared with the HfC matrix, the indentation-damaged area at the interface reduced up to ~56% due to toughening mechanisms such as C nf , fiber pull-out and bridging. The synthesized HfC decorated Cnf mat is proposed as an ultra-thin filler material for joining similar or dissimilar UHTCs while maintaining similar chemistry and better mechanical integrity at the interface. Furthermore, the findings insinuate a new paradigm in designing hybrid and flexible ceramic-containing materials for thermal protection systems (TPS) of future-generation spacecraft components that can mitigate failure in extreme environments (>2000 °C).

36 MATERIALS SCIENCE↗
DOE OSTI2024

Low Thermal Conductivity and Diffusivity at High Temperatures Using Stable High–Entropy Spinel Oxide Nanoparticles

The realization of low thermal conductivity at high temperatures (0.11 W m –1 K –1 800 °C) in ambient air in a porous solid thermal insulation material, using stable packed nanoparticles of high-entropy spinel oxide with 8 cations (HESO-8 NPs) with a relatively high packing density of ≈50%, is reported. The high-density HESO-8 NP pellets possess around 1000-fold lower thermal diffusivity than that of air, resulting in much slower heat propagation when subjected to a transient heat flux. The low thermal conductivity and diffusivity are realized by suppressing all three modes of heat transfer, namely solid conduction, gas conduction, and thermal radiation, via stable nanoconstriction and infrared-absorbing nature of the HESO-8 NPs, which are enabled by remarkable microstructural stability against coarsening at high temperatures due to the high entropy. Furthermore, this work can elucidate the design of the next-generation high-temperature thermal insulation materials using high-entropy ceramic nanostructures.

thermal insulation↗
DOE OSTI2021

Pyroelectricity of Lead Sulfide (PbS) Quantum Dot Films Induced by Janus-Ligand Shells

Asymmetry is an essential property to control. To do that in nanocrystalline systems we have developed methods to produce Janus-ligand shells on otherwise symmetric PbS quantum dots (QDs). In this work, we demonstrate that control by constructing a system that exhibits pyroelectricity built from spherical PbS QDs. We observed a pyroelectric current in two different configurations. In one configuration, the QDs are self-assembled into close-packed arrays while in the second configuration, the QDs are dispersed into an electro-inactive polymer, polydimethylsiloxane. Both exhibit a pyroelectric response. In the first configuration we estimate a lower limit of the pyroelectric coefficient to be 1.97 × 10 -7 C/m 2 K, which is likely limited by the degree of QD alignment during film formation but is already on par with common pyroelectric systems. Compared with inorganic ceramic-like and polymeric pyroelectric materials, pyroelectric films self-assembled from polar QDs are easier to prepare, responsive to light with different energies based on QD exciton energy, and the polarization of each QD could be easily tuned by constructing different Janus-ligand shells.

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

Room temperature facile synthesis of olivine-Co 2 SiO 4 nanoparticles utilizing a mechanochemical method

Co 2 SiO 4 is a ceramic pigment and promising battery material of significant technological interest, as well as a model end-member of one of the most important mineral families in the Earth's crust and upper mantle. All previously developed methods for synthesis of Co 2 SiO 4 require high-temperature processing, which promotes grain growth, while the nanocrystalline form is required for some important technological applications. Here, we report a successful method for synthesizing nanocrystalline Co 2 SiO 4 via a simple and inexpensive high-energy ball milling mechanochemical process. Products of the synthesis were characterized by a combination of XRD and TEM, and their crystal structures and elemental compositions are reported.

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

Metal-Supported Solid Oxide Fuel Cells for Natural Gas

Solid oxide fuel cells (SOFCs) are high temperature energy conversion devices that produce electricity efficiently and sustainably. High operating temperatures required for SOFC function endow these devices with many advantages including fuel flexibility and high conversion efficiencies. Fuel flexibility, in particular, distinguishes SOFCs from other types of fuel cells that operate with clean H 2 only, and enables operation with natural gas (NG). LBNL has developed metal supported SOFCs (MS-SOFCs) with unique symmetrical architecture that offer several advantages over state of the art (SoA) ceramic SOFC models including inexpensive materials, rapid start up capability, increased mechanical strength and high tolerance to thermal cycling, Fig 1. These advantages make LBNL MS-SOFCs uniquely suited for fast start-up, portable, and mobile backup generator applications. Specifically motivating this work was a scenario of backup generators fueled by pipeline natural gas delivered from SoCalGas in the event of an electric grid shut down. This project investigates the feasibility of using MS-SOFCs with pre-reformed natural gas as well as direct on-cell reforming of simulated natural gas both with and without sulfur.

03 NATURAL GAS↗
DOE OSTI2022

Combining complex flow manifold with three dimensional woven lattices as a thermal management unit

The present invention is directed to a manifold for directing cooling fluid and/or gas to a heat exchanger in a flow configuration designed to optimize heat transfer from the heat exchanger. The manifold can take many different forms such as a layered construction with distributed inlet paths, local outlet paths, a central collection changer and a path for fluid removal. The manifold can be formed from a metal, plastic, rubber, ceramic, or other heat resistant material known to or conceivable by one of skill in the art. The manifold can also be combined with any type of heat exchanger known to or conceivable by one of skill in the art to form a thermal management unit. To optimize overall properties such as low pressure drop, high heat transfer, and excellent temperature uniformity of the thermal management unit, the manifold can be graded, expanded and scaled as needed.

Hemker, Kevin J.↗
DOE OSTI2023

Lead-free Zr-doped ceria ceramics with low permittivity displaying giant electrostriction

Electrostrictors, materials developing mechanical strain proportional to the square of the applied electric field, present many advantages for mechanical actuation as they convert electrical energy into mechanical, but not vice versa. Both high relative permittivity and reliance on Pb as the key component in commercial electrostrictors pose serious practical and health problems. Here we describe a low relative permittivity (<250) ceramic, Zr x Ce 1-x O 2 (x < 0.2), that displays electromechanical properties rivaling those of the best performing electrostrictors: longitudinal electrostriction strain coefficient ~10 -16 m 2 /V 2 ; relaxation frequency ≈ a few kHz; and strain ≥0.02%. Combining X-ray absorption spectroscopy, atomic-level modeling and electromechanical measurements, here we show that electrostriction in Zr x Ce 1-x O 2 is enabled by elastic dipoles produced by anharmonic motion of the smaller isovalent dopant (Zr). Unlike the elastic dipoles in aliovalent doped ceria, which are present even in the absence of an applied elastic or electric field, the elastic dipoles in Zr x Ce 1-x O 2 are formed only under applied anisotropic field. The local descriptors of electrostrictive strain, namely, the cation size mismatch and dynamic anharmonicity, are sufficiently versatile to guide future searches in other polycrystalline solids.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Lithium battery

The present disclosure describes various types of batteries, including lithium-ion batteries having an anode assembly comprising: an anode comprising a first porous ceramic matrix having pores; and a ceramic separator layer affixed directly or indirectly to the anode; a cathode; an anode-side current collector contacting the anode; and anode active material comprising lithium located within the pores or cathode active material located within the cathode; wherein, the ceramic separator layer is located between the anode and the cathode, no electrically conductive coating on the pores contacts the separator layer, and in a fully charged state, lithium active material in the anode does not contact the separator layer. Also disclosed are methods of making and methods of using such batteries.

25 ENERGY STORAGE↗
DOE OSTI2025

Critical insights into the steam electrolysis electrode in protonic ceramic cells for hydrogen production

Intermediate-temperature protonic ceramic electrolysis cells (PCECs), which combine the benefits of both lower- and higher-temperature electrolysis, are among the most efficient technologies for the production of green hydrogen. To ensure economic competitiveness and broad adoption, ongoing innovations in cell materials are essential to improve durability and reduce costs. The water oxidation half-reaction at the anode is a key area for improvement as it is a major contributor to performance degradation and efficiency loss in PCECs. Current anode designs, which are largely derived from solid oxide electrolysis cells, fail to address the specific requirements for PCECs under realistic operating conditions. Here, this Perspective highlights the unique challenges faced by PCEC anodes, focusing on the impact of high steam concentrations and the critical role of proton-coupled electron-transfer mechanisms—factors that are absent in solid oxide electrolysis cells. Furthermore, we explore design principles for advancing anodes tailored for PCECs, offering guidance for future research and development in this promising field.

Electrocatalysis↗
DOE OSTI2020

Thermal shock resistance of multilayer silicon carbide receiver tubes for 800°C molten salt concentrating solar power application

CSP power tower receiver systems during rapid transient weather periods can be vulnerable to thermal shock conditions from rain that which can facilitate the onset of leaks and failures that can have catastrophic consequences. Silicon carbide (SiC) materials have attractive receiver application characteristics for being light weight, having high-strength and excellent thermal shock resistance performance which make them a particularly good fit for receiver absorber materials in CSP. In this investigation, the performance characteristics of Ceramic Tubular Products (CTP) SiC ceramic matrix composite (CMC), multilayered tubes were explored with respect to thermal shock performance for solar receiver applications in next generation CSP plants. Here, thermal shock testing was performed at the Sandia National Laboratories (SNL) Solar Furnace facility using a dynamic stage and thermal shock tube test setup. The tubes tested under incident solar heat flux of 100 W/cm2 were heated with inner tube temperatures reaching approximately 800 °C, with outer temperatures exceeding or just reaching 1000 El for the multilayer and monolithic SiC tubes respectively. The tubes were then quenched with simulated rain. The tubes were then cooled and subjected to hoop stress analysis using an Instron device to assess their subsequent mechanical strength. Furthermore, the on-sun study experimental results indicate an average of 24.2% and 97% higher hoop strength for the CMC tubes than those composed of monolithic SiC and aluminum oxide (A1203) respectively.

14 SOLAR ENERGY↗
DOE OSTI2025

Design strategies for ion-sieving charge mosaic membranes toward sustainable lithium extraction

Membrane-based technologies are essential for realizing sustainable ion-sieving processes such as lithium extraction. Much effort was devoted to designing new membrane materials, whereas the effect of charge distribution has been largely overlooked. Here, we filled this knowledge gap by providing a quantitative transport model for selective ion diffusion through a charge mosaic membrane (CMM). Composed of alternating regions of Li-selective ceramic and anion-selective polymeric materials, CMMs offered the unique advantage of promoting the transport of both Li + and anions while blocking other cations. As a result, the membrane achieved a high Li/Mg selectivity of 62 and a high permeation rate of 59 mmol·m −2 ·h −1 at a low feeding concentration of 30 mM, without any external driving force. Systematical experiments revealed the influence of brine Mg/Li ratio and membrane ceramic/polymer ratio on the overall extraction rate, which was consistent with the prediction of our transport model. In conclusion, the model developed in this work not only presented the design strategies of CMMs for Li extraction but also provided guidance for the development of other ion-sieving processes in general.

25 ENERGY STORAGE↗
DOE OSTI2022

High-Energy Solid-State Lithium Batteries with Organic Cathode Materials (Final Report)

Organic materials made from abundant elements via low-energy processes are emerging as sustainable and low-cost alternatives to transition metal oxides as the electrode materials for high- energy batteries in the wake of supply chain and environmental issues associated with critical materials during the transition to clean energy. Organic insertion materials (OIMs) offer material- level energy comparable to transition metal oxides, but they have durability difficulties owing to dissolving in common liquid electrolytes. Combining ceramic-based solid electrolytes with organic electrode materials is one intriguing solution. The goal of this project is to design and synthesize high-energy OIMs, to understand the chemical dynamics and mechanical properties at the OIM-sulfide interface during electrochemical cycling, and to develop methods for constructing the optimum cathode microstructure, which will lead to improved electrochemical performance. The project team has accomplished the following over the last four years: (a) demonstrating that the mechanical softness of organic electrode materials is uniquely beneficial in suppressing crack formation at the electrode-electrolyte interface during cell operation; (b) understanding the interaction between cathode microstructure and the mechanical properties of individual components; and (c) establishing predictive control of cathode microstructure by tuning the mechanical properties of solid electrolytes and OIMs; (d) determining the chemical combability of sulfide electrolyte with high-energy OIMs and finally (f) laying out a road map toward a specific energy of 500 Wh kg -1 for solid-state lithium batteries. 14 publications resulted from this project.

25 ENERGY STORAGE↗