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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Low-temperature liquid-phase synthesis of lithium thiophosphate-borohydride solid electrolyte with high room-temperature ionic conductivity

Embodiments relate to a scalable liquid-phase synthesis technique of lithium thiophosphate-borohydride solid electrolytes with high ionic conductivity at room temperature and its use in all-solid-state lithium batteries. A battery comprises an anode, a cathode, and a solid electrolyte layer positioned between the anode and the cathode. The liquid-phase synthesized solid electrolyte material can be used as the solid electrolyte layer or incorporated into anodes or cathodes.

Wang, Donghai [Pennsylvania State Univ., Universit↗
DOE OSTI2013

Rietveld refinement and ionic conductivity of Ca{sub 8.4}Bi{sub 1.6}(PO{sub 4}){sub 6}O{sub 1.8}

The structure of Ca{sub 8.4}Bi{sub 1.6}(PO{sub 4}){sub 6}O{sub 1.8}, isostructural with Fluoroapatite, was determined by X-ray powder diffraction methods. The results of Rietveld refinement revealed that the formula of this compound is [Ca{sub 4}]{sup 4f}[Ca{sub 4.4}Bi{sub 1.6}]{sup 6h}(PO{sub 4}){sub 6}[O{sub 1.8}]{sup 2a}, space group P63/m (a=9.468 (3) A, c=6.957 (3) A). A total substitution of Bi{sup 3+} ions in the (6h) sites was related particularly to the high polarizability of the Bi{sup 3+} ion compared to Ca{sup 2+}. The observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses and in comparison with Fluoroapatite and other oxyapatites. The ionic conductivity over a wide range of temperature was investigated according to the complex impedance method. The highest overall conductivity values were found at {sigma}{sub 700 Degree-Sign C} =5.03 Multiplication-Sign 10{sup -7} S cm{sup -1} and E{sub a}=0.50 eV. - Graphical abstract: The final Rietveld refinement plot of the Ca{sub 8.4}Bi{sub 1.6} (PO{sub 4}){sub 6}O{sub 1.8}. Highlights: Black-Right-Pointing-Pointer The Rietveld refinement revealed that the formula of this compound is Ca{sub 8.4}Bi{sub 1.6}(PO{sub 4}){sub 6}O{sub 1.8}. Black-Right-Pointing-Pointer Vibrational spectroscopy supports the high symmetry P63/m space group for this apatite. Black-Right-Pointing-Pointer This apatite contained channels where oxygen ions were located in 2a sites. Black-Right-Pointing-Pointer The possibility of anionic conduction along these channels was considered.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Ab initio spectroscopy and ionic conductivity of water under Earth mantle conditions

The phase diagram of water at extreme conditions plays a critical role in Earth and planetary science, yet remains poorly understood. Here we report a first-principles investigation of the liquid at high temperature, between 11 GPa and 20 GPa—a region where numerous controversial results have been reported over the past three decades. Our results are consistent with the recent estimates of the water melting line below 1,000 K and show that on the 1,000-K isotherm the liquid is rapidly dissociating and recombining through a bimolecular mechanism. We found that short-lived ionic species act as charge carriers, giving rise to an ionic conductivity that at 11 GPa and 20 GPa is six and seven orders of magnitude larger, respectively, than at ambient conditions. Conductivity calculations were performed entirely from first principles, with no a priori assumptions on the nature of charge carriers. Despite frequent dissociative events, we observed that hydrogen bonding persists at high pressure, up to at least 20 GPa. Our computed Raman spectra, which are in excellent agreement with experiment, show no distinctive signatures of the hydronium and hydroxide ions present in our simulations. Instead, we found that infrared spectra are sensitive probes of molecular dissociation, exhibiting a broad band below the OH stretching mode ascribable to vibrations of complex ions.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Ionic conductivity of sodium–strontium germanate Na{sub 4}SrGe{sub 6}O{sub 15}

The electrical conductivity of sodium–strontium germanate Na{sub 4}SrGe{sub 6}O{sub 15} (sp. gr. P6{sub 3}/m) has been studied by impedance spectroscopy in the frequency range of 10{sup 2}–4 × 10{sup 4} Hz and a temperature range of 450–600 K. Na4SrGe6O15 crystals were obtained by hydrothermal technique in the Na{sub 2}O–SrO–GeO{sub 2}–H{sub 2}O system (temperature t = 300–600°C and pressure p = 1.4 × 10{sup 8} Pа in the dissolution zone). The ionic conductivity of ceramic Na{sub 4}SrGe{sub 6}O{sub 15} samples is σ = 2.2 × 10{sup –6} S/cm (at 573 K), the activation energy of Na{sup +} ion transfer is E{sub a} = 0.70 ± 0.03 eV.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Synthesis, crystal structure, and ionic conductivity of a new layered metal phosphate, Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}

A new layered metal phosphate, Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}, was synthesized in the form of either a single-crystal or polycrystalline powder using the molten hydroxide flux method or a solid-state reaction, respectively. Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} crystallizes to the P2{sub 1}/n (Z=4) monoclinic space group with lattice parameters a≈4.95 Å, b≈22.06 Å, c≈8.63 Å, and β≈91.5°. The structure is composed of stacked [LiSrAl(PO{sub 4}){sub 2}] layers alternating regularly with [LiSrPO{sub 4}] layers. In the [LiSrAl(PO{sub 4}){sub 2}] sublattice, the AlO{sub 6} octahedra and PO{sub 4} tetrahedra are tilted cooperatively to form an anionic, corrugated, two-dimensional [Al(PO{sub 4}){sub 2}]{sup 3−} framework that can be regarded as a “distorted-glaserite” structure. The [LiSrPO{sub 4}] sublattice is that of a layered block containing a six-membered ring formed from alternating linkages of LiO{sub 4} and PO{sub 4} tetrahedra. The six-membered rings show a boat-type arrangement with the up(U) or down(D) pointing sequence, UUDUUD. The interspace between the two sublattices generates a two-dimensional pathway for Li{sup +} ion conduction. The impedance measurement indicated that Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} had a moderate ion conductivity (σ≈1.30×10{sup −4} S cm{sup −1} at 667 K), with an activation energy E{sub a}≈1.02 eV. - Graphical abstract: Polyhedral view of Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3}. Li{sup +} ions are represented by green spheres, Sr atoms by white spheres, AlO{sub 6} groups by octahedra, and PO{sub 4} groups by tetrahedra. - Highlights: • New compound Li{sub 2}Sr{sub 2}Al(PO{sub 4}){sub 3} is reported. • The crystal structure is investigated by single-crystal XRD analysis. • The structure is formed by the alternate stacking of two different sublattices. • Correlation between the crystal structure and ionic conductivity is discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2019

110th Anniversary: The Dehydration and Loss of Ionic Conductivity in Anion Exchange Membranes Due to FeCl 4 – Ion Exchange and the Role of Membrane Microstructure

Anion-exchange membranes (AEMs) often dehydrate and lose ionic conductivity in ferric chloride solutions used in all-iron or iron–chromium redox flow batteries (RFB). In this work, the change in material and ionic transport properties of three AEMs with similar concentrations of ion exchange sites and hydration numbers (mol H 2 O/mol ion exchange site) upon exposure to ferric chloride/hydrochloric acid solutions were studied. Raman spectroscopy and iron sorption measurements show that FeCl 4 – occupies a fraction of the AEM ion exchange sites that depends on the ferric chloride concentration in the external solution. The AEM hydration number is linearly proportional to the amount of iron sorbed in the AEMs, suggesting that the displacement of the original hydrated Cl – counterions for unhydrated FeCl 4 – is the dominant mechanism for membrane dehydration. The ionic resistivity of the AEMs containing FeCl 4 – increased by as much as 4 orders of magnitude due to dehydration and, at high FeC l3 solution concentrations (≥1.4M), also due to nonideal solution effects. Although the three AEMs have similar ion exchange site concentrations, the AEM with the closer local spacing of ion exchange sites exhibits higher FeCl 4 – sorption, and a correspondingly greater dehydration and resistivity increase in dilute FeCl 3 solutions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

The ionic conductivity of Sm‐doped ceria

Abstract The oxygen ion conductivity of polycrystalline samples of Sm‐doped ceria and of Gd‐doped ceria is studied as a function of doping fraction and temperature using impedance spectroscopy allowing the separation of bulk and grain boundary conductivity. The introduction of a fine spacing for the Sm dopant fraction allows the clear identification of the dopant fraction leading to the largest bulk conductivity. At 267°C, the largest bulk conductivity is shown for Ce 0.93 Sm 0.07 O 1.965 . With increasing temperature, indications of an increase in the dopant fraction, which leads to the maximum in conductivity, are found. For the grain boundary conductivity, the maximum appears at larger dopant fractions compared to the bulk conductivity. The largest total conductivity for both dopants is again found for Sm‐doped ceria. In literature, different syntheses and sample preparation methods led to larger total conductivities for Gd‐doped ceria. In this work, we demonstrate that the variation of sintering conditions leads to scattering in the conductivity over one order of magnitude. Finally, we demonstrate that, in nominally pure cerium oxide, impurities dominate the ionic conductivity.

Koettgen, Julius↗
DOE OSTI2024

The persistence of memory in ionic conduction probed by nonlinear optics

Predicting practical rates of transport in condensed phases enables the rational design of materials, devices and processes. This is especially critical to developing low-carbon energy technologies such as rechargeable batteries. For ionic conduction, the collective mechanisms, variation of conductivity with timescales and confinement, and ambiguity in the phononic origin of translation, call for a direct probe of the fundamental steps of ionic diffusion: ion hops. However, such hops are rare-event large-amplitude translations, and are challenging to excite and detect. Here we use single-cycle terahertz pumps to impulsively trigger ionic hopping in battery solid electrolytes. This is visualized by an induced transient birefringence, enabling direct probing of anisotropy in ionic hopping on the picosecond timescale. The relaxation of the transient signal measures the decay of orientational memory, and the production of entropy in diffusion. We extend experimental results using in silico transient birefringence to identify vibrational attempt frequencies for ion hopping. Using nonlinear optical methods, we probe ion transport at its fastest limit, distinguish correlated conduction mechanisms from a true random walk at the atomic scale, and demonstrate the connection between activated transport and the thermodynamics of information.

25 ENERGY STORAGE↗
DOE OSTI2013

Block copolymer with simultaneous electric and ionic conduction for use in lithium ion batteries

Redox reactions that occur at the electrodes of batteries require transport of both ions and electrons to the active centers. Reported is the synthesis of a block copolymer that exhibits simultaneous electronic and ionic conduction. A combination of Grignard metathesis polymerization and click reaction was used successively to synthesize the block copolymer containing regioregular poly(3-hexylthiophene) (P3HT) and poly(ethylene oxide) (PEO) segments. The P3HT-PEO/LiTFSI mixture was then used to make a lithium battery cathode with LiFePO.sub.4 as the only other component. All-solid lithium batteries of the cathode described above, a solid electrolyte and a lithium foil as the anode showed capacities within experimental error of the theoretical capacity of the battery. The ability of P3HT-PEO to serve all of the transport and binding functions required in a lithium battery electrode is thus demonstrated.

25 ENERGY STORAGE↗
DOE OSTI2022

Ultra-Stretchable, Ionic Conducting, Pressure-Sensitive Adhesive with Dual Role for Stable Li-Metal Batteries

The practical application of lithium (Li) metal battery is impeded by the Li dendrite growth and unstable solid electrolyte interphase (SEI) layer. Herein, an ultra-stretchable and ionic conducting chemically crosslinked pressure-sensitive adhesive (cPSA) synthesized via the copolymerization of 2-ethylhexyl acrylate and acrylic acid with poly(ethyleneglycol)dimethacrylate as crosslinker (short for 70cPSA), is developed as both artificial SEI layer and solid polymer electrolyte (SPE) for stable Li-metal electrode, enabling all-solid-state Li metal batteries with excellent cycling performance. As an artificial SEI layer, the 70cPSA-modified electrodes exhibit excellent electrochemical performance in Li|70cPSA@Cu half cells and 70cPSA@Li|70cPSA@Li symmetric cells. In full cells with LiFePO 4 (LFP) as cathode, the 70cPSA@Li|LFP cell exhibits stable cycling performance over 250 cycles. Utilized as SPE, the all-solid-state Li|SPE|LFP cell delivers excellent cycling stability with a capacity retention of 86% over 500 cycles. With high-voltage LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) as cathode, the Li|SPE|NMC811 cell exhibits a discharge capacity of 124.3 mAh g -1 with a capacity retention of 71% after 200 cycles. Furthermore, the rational design of PSAs and investigation of their dual role for stable and safe Li-metal batteries may shed a light on adhesive polymers for battery applications.

25 ENERGY STORAGE↗
DOE OSTI2021

Decoding ionic conductivity and reordering in cation-disordered pyrochlores

The ordered structure A 2 B 2 O 6 O’ in pyrochlores engenders twin rows of inequivalent anion sublattices each centred on alternating cations. While it is known that cation antisite disorder augments the ionic conductivity by several orders of magnitude, the local cation environment around the anions and the dynamic anion reordering during the cation disordering are not well-elucidated. Using atomistic simulations on Gd 2 Zr 2 O 7 , we first show that the anions engage in concerted hops to the neighbouring tetrahedral sites mostly along with the $\langle$1 0 0$\rangle$ direction while completely avoiding the octahedral sites. While the initially vacant 8 a sites start accommodating oxygen ions with increasing cation disorder, they show noticeable reluctance even at significant levels of disorder. We have also tracked both the distribution of available oxygen sites following random cation disorder, which is dependent only on cation disordering, and the probability of occupation of these sites. Interestingly, the available oxygen sites show a non-monotonic dependence on the number of B ions in the nearest neighbouring shell while the occupation probability of all the available oxygen sites increases monotonically. A tetrahedral oxygen site thus has a better probability of being occupied when it has a greater number of second neighbour B ions. This article is part of the Theo Murphy meeting issue 'Understanding fast-ion conduction in solid electrolytes'.

Science & Technology - Other Topics↗
DOE OSTI2015

Ionic conductivity of YSZ/CZO multilayers with variable lattice mismatch

Heterostructured multilayers have been controversially reported to alter the oxygen ion conductivity of solid electrolytes by inducing interfacial mechanical strain. Here, we fabricated thin film multilayers composed of 9 mol% Y 2 O 3 doped ZrO 2 (YSZ) and Ce 1-x Zr x O 2 (CZO) to systematically quantify the effects of tensile strain on the oxygen-ion conduction behavior in YSZ. A significant advantage of using CZO is that its lattice parameter can be continuously varied by adjusting the Ce/Zr atomic ratio, simplifying the strain control over the neighboring YSZ layers. Three different sets of multilayers composed of YSZ with CeO 2 , or with Ce 0.70 Z r0.30 O 2 (CZO30), or with Ce 0.55 Zr 0.45 O 2 (CZO45) were prepared on Al 2 O 3 substrates with interfacial lattice mismatch of +5.2%, +3.7%, and +2.9%, respectively. When decreasing the individual layer thicknesses from 35 nm to 5 nm, all of the multilayers exhibited little change of the conductivity, with values consistently near that of bulk YSZ. X-ray diffraction results indicate that the interfacial strains were largely relaxed. In conclusion, suggestions that multilayers are unable to effect ionic conductivity changes must therefore consider the difficulties in obtaining lattice mismatch-based elastic strain, even at <3% mismatch.

36 MATERIALS SCIENCE↗
NASA NTRS2021

Introduction to the Physics of Ionic Conduction in Narrow Biological and Artificial Channels

The permeation of ions through narrow water-filled channels is essential to life and of rapidly-growing importance in technology. Reaching an understanding of the mechanisms underlying the permeation process requires an interdisciplinary approach, where ideas drawn from physics are of particular importance and have brought encouraging progress in recent years. This Introduction sets into context the several ground-breaking papers presented in the Entropy Special Issue on "The Physics of Ionic Conduction in Narrow Biological and Artificial Channels''.

ion channel↗
DOE OSTI2024

Room-temperature fabrication of garnet-type solid-electrolyte: Optimizing particle size for high ionic conductivity

Dense and uniform Li 6.25 Al 0.25 La 3 Zr 2 O 12 (Al-doped LLZO) solid-electrolyte film of ~24 µm thickness is successfully fabricated by room temperature aerosol deposition (AD) method. The process optimization study revealed that careful control of particle size and morphology is one of critical determinants in the development of a compact AD membrane. Notably, our method facilitated an impressive ionic conductivity of approximately 10 –5 S cm –1 , bypassing the necessity for post-annealing processes, a milestone in itself. However, it is hypothesized that the attained conductivity is somewhat restrained by factors such as smaller grain size and potential surface degradation due to moisture exposure during fabrication, indicating avenues for further research. Looking forward, detailed investigations into the film's microstructure and its impact on transport properties will be a focal point, alongside potential enhancements through post-annealing and particle coating strategies. Finally, this research hints at a promising trajectory for the development of high-efficiency solid-state battery technology.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Ring-opening metathesis polymerization of cobaltocenium derivative to prepare anion exchange membrane with high ionic conductivity

Abstract An efficient method to incorporate a cobaltocenium cation into polymers for anion exchange membranes is described. A cobaltocenium-containing norbornene derivative has been synthesized. It can be homopolymerized, or copolymerized with norbornene, by ring-opening metathesis polymerization (ROMP) with quantitative yields. The composition of the random copolymers can be precisely controlled by adjusting the feed ratio of the monomers. Additionally, the resulting polymers can be cast into thin robust membranes. The morphology of the membranes is characterized by humidity controlled SAXS and TEM, showing disordered interconnected cobaltocenium domains. The high ionic conductivity suggests that such membranes are good candidates for anion exchange membranes.

42 ENGINEERING↗
DOE OSTI2023

Dual Modification of MOFs Improves Dispersion and Ionic Conductivity of Mixed Matrix Membranes

Nonaqueous redox flow batteries (NARFBs) are a promising class of energy storage devices, but the lack of a chemically stable, conductive membrane that exhibits size-selectivity over redox-active species prevents their broader implementation. Recently, metal–organic frameworks (MOFs) have been implemented into mixed-matrix membranes (MMMs) for NARFBs, but the effects of the MOF linker functionality on membrane properties are not well-understood. In this work, we develop a series of MOF-based MMMs by blending postsynthetically modified variants of UiO-66-NH2 with poly(ethylene-co-vinyl acetate). The modification of UiO-66-NH2 with sulfate groups initially resulted in poor dispersion throughout the MMMs, but when dual-modified with poly(N-isopropylacrylamide), MOF dispersion throughout the MMM was improved, and ionic conductivity was significantly higher than the UiO-66-NH2 MMMs. Furthermore, the dual-modified MMMs demonstrated excellent size-selectivity by blocking redox active species transport. This work demonstrates a synergy between the MOF functional groups to improve MMM properties critical for the development of practical NARFBs.

Carey, Cassidy A.↗
DOE OSTI2013

Ionic conduction, bond valence analysis of structure–property relationships of NaHoP{sub 2}O{sub 7}

Single crystals of NaHoP{sub 2}O{sub 7} diphosphate have been prepared by the flux method and its structural and physical properties have been investigated. It crystallizes in the monoclinic system with the space group P2{sub 1}/n and its parameters are: a=8.6796(4) Å, b=5.3677(2) Å, c=13.6904(6) Å, β=106.120° (2), V=612.75 (5) Å{sup 3}, Z=4. The structure of NaHoP{sub 2}O{sub 7} consists of a three-dimensional framework of HoO{sub 6} octahedra, linked by P{sub 2}O{sub 7} diphosphate units, forming tunnels running parallel to [0 1 0], which are occupied by Na atoms. The infrared and Raman vibrational spectra have been investigated. Activation energy was obtained from Arrhenius plots (Ln σT versus 1000/T) and found to be 1.27 eV. The coupling of the structural analysis with the BVS model for NaHoP{sub 2}O{sub 7} has better interpret the measurements of the ionic conductivity and the most probably transport pathway model was determined. - Graphical abstract: Schematic representation of the structural arrangement of NaHoP{sub 2}O{sub 7} shows the sodium conduction pathway along the [0 1 0] direction. Highlights: • Single crystals of NaHoP{sub 2}O{sub 7} were prepared by flux method and characterized by single-crystal X-ray data. • The conductivity and loss spectra were analysed in order explain the mechanism of conduction. • The most probably conduction pathway are determined.

36 MATERIALS SCIENCE↗