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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 1,189 records · Page 66
All sourcesNASA NTRSDOE OSTI
NASA NTRS2009

The Effect of Electrolyte Additives upon the Lithium Kinetics of Li-Ion Cells Containing MCMB and LiNi(x)Co(1-x)O2 Electrodes and Exposed to High Temperatures

With the intent of improving the performance of lithium-ion cells at high temperatures, we have investigated the use of a number of electrolyte additives in experimental MCMB- Li(x)Ni(y)Co(1-y)O2 cells, which were exposed to temperatures as high as 80 C. In the present work, we have evaluated the use of a number of additives, namely vinylene carbonate (VC), dimethyl acetamide (DMAc), and mono-fluoroethylene carbonate (FEC), in an electrolyte solution anticipated to perform well at warm temperature (i.e., 1.0M LiPF6 in EC+EMC (50:50 v/v %). In addition, we have explored the use of novel electrolyte additives, namely lithium oxalate and lithium tetraborate. In addition to determining the capacity and power losses at various temperatures sustained as a result of high temperature cycling (cycling performed at 60 and 80 C), the three-electrode MCMB-Li(x)Ni(y)Co(1-y)O2 cells (lithium reference) enabled us to study the impact of high temperature storage upon the solid electrolyte interphase (SEI) film characteristics on carbon anodes (MCMB-based materials), metal oxide cathodes, and the subsequent impact upon electrode kinetics.

High Temperture Resilience↗
NASA NTRS2015

Compliant Electrode and Composite Material for Piezoelectric Wind and Mechanical Energy Conversions

A thin film device for harvesting energy from wind. The thin film device includes one or more layers of a compliant piezoelectric material formed from a composite of a polymer and an inorganic material, such as a ceramic. Electrodes are disposed on a first side and a second side of the piezoelectric material. The electrodes are formed from a compliant material, such as carbon nanotubes or graphene. The thin film device exhibits improved resistance to structural fatigue upon application of large strains and repeated cyclic loadings.

Chen, Bin↗
NASA NTRS2011

Reliability Evaluation of Base-Metal-Electrode (BME) Multilayer Ceramic Capacitors for Space Applications

This paper reports reliability evaluation of BME ceramic capacitors for possible high reliability space-level applications. The study is focused on the construction and microstructure of BME capacitors and their impacts on the capacitor life reliability. First, the examinations of the construction and microstructure of commercial-off-the-shelf (COTS) BME capacitors show great variance in dielectric layer thickness, even among BME capacitors with the same rated voltage. Compared to PME (precious-metal-electrode) capacitors, BME capacitors exhibit a denser and more uniform microstructure, with an average grain size between 0.3 and approximately 0.5 micrometers, which is much less than that of most PME capacitors. The primary reasons that a BME capacitor can be fabricated with more internal electrode layers and less dielectric layer thickness is that it has a fine-grained microstructure and does not shrink much during ceramic sintering. This results in the BME capacitors a very high volumetric efficiency. The reliability of BME and PME capacitors was investigated using highly accelerated life testing (HALT) and regular life testing as per MIL-PRF-123. Most BME capacitors were found to fail· with an early dielectric wearout, followed by a rapid wearout failure mode during the HALT test. When most of the early wearout failures were removed, BME capacitors exhibited a minimum mean time-to-failure of more than 10(exp 5) years. Dielectric thickness was found to be a critical parameter for the reliability of BME capacitors. The number of stacked grains in a dielectric layer appears to play a significant role in determining BME capacitor reliability. Although dielectric layer thickness varies for a given rated voltage in BME capacitors, the number of stacked grains is relatively consistent, typically between 10 and 20. This may suggest that the number of grains per dielectric layer is more critical than the thickness itself for determining the rated voltage and the life expectancy of the BME capacitor. Since BME capacitors have a much smaller grain size than PME capacitors, it is reasonable to predict that BME capacitors with thinner dielectric layers may have an equivalent life expectancy to that of PME capacitors with thicker dielectric layers.

Liu, David (Donghang)↗
NASA NTRSDate not supplied

Solvent-Free Preparation of High Energy, Binder-Free Electrodes Enabled by Dry Compressible Holey Graphene

Graphene is an atomically thick sheet consisting of a graphitic carbon network with excellent mechanical strength, electrical and thermal conductivity, and chemical stability. Holey graphene, a structural derivative of graphene, has an array of through-the-thickness holes across the lateral surface of the nanosheet. The presence of these holes has minimal detrimental effect on the graphene properties and leads to enhanced performance in applications such as electronics, sensors, and energy storage. For example, these holes allow more facile cross-plane ion and gas transport than intact graphene, making holey graphene an ideal electrode material for electrochemical energy storage. This presentation will focus on the ability of holey graphene to be compression molded into robust articles or architectures under solvent-free conditions without the need for potentially parasitic binders. The unique dry compressibility of holey graphene has enabled facile fabrication of high mass loading electrodes with both high density and high porosity, which have found use in supercapacitors and various high-energy battery systems such as lithium-oxygen, lithium-sulfur, and lithium-selenium batteries.

Yi Lin↗
NASA NTRS2021

Anion-Assisted Delivery of Multivalent Cations to Inert Electrodes

To understand and control key electrochemical processes - metal plating, corrosion, intercalation, etc. requires molecular-scale details of the active species at electrochemical interfaces and their mechanisms for de-solvation from the electrolyte. Using free energy sampling techniques we reveal the interfacial speciation of divalent cations in ether-based electrolytes and mechanisms for their delivery to an inert graphene electrode interface. Surprisingly, we find that anion solvophobicity drives a high population of anion-containing species to the interface that facilitate the delivery of divalent cations, even to negatively charged electrodes. Our simulations indicate that cation desolvation is greatly facilitated by cation-anion coupling. We propose anion solvophobicity as a molecular-level descriptor for rational design of electrolytes with increased efficiency for electrochemical processes limited by multivalent cation desolvation.

Electrochemical interfaces↗
NASA NTRSDate not supplied

Enhancing the Sensitivity of Redox Detection in Search-for-Life Missions Using Chemical Vapor Deposition (CVD) Graphene Electrodes

The primary objective for this effort is to fabricate and characterize redox-active molecules using CVD graphene as working electrodes using standard "on-chip" lithographic techniques. We then plan to move away from “on-chip” graphene electrodes and study methods for CVD graphene transfer that can also accommodate in-space manufacturing (ISM), enabling the use of this technology for crewed mission operations of the future.

graphene↗
DOE OSTI2020

Devices and methods for removing dissolved ions from water using composite resin electrodes

The present invention provides for a device useful or removing dissolved ions from water comprising or configured to comprise composite resin electrodes. The present invention provides for a device useful for removing dissolved ions from water comprising or configured to comprise composite resin electrodes. The present invention also provides for a method for removing dissolved ions from water comprising providing said device, and using it thereof.

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

Method for electrochemical roughening of thin film electrodes

The present invention relates to surface roughening methods and more particularly to a method for electrochemical roughening of thin film macro- and micro-electrodes. In one embodiment, an electrochemical etch template is formed comprising polymer particles adsorbed on a surface of a substrate to be roughened, followed by electrochemically etching of exposed regions of the substrate between the polymer particles in the electrochemical etch template so as to selectively roughen the surface of the substrate. In another embodiment, a surface of the electrode is immersed in either a adsorbing acidic solution, such as sulfuric acid, or a non-adsorbing acidic solution, such as perchloric acid, followed by electrochemically pulse etching the surface of the substrate at a narrow frequency range for adsorbing acidic solutions, or at a wide frequency range for non-adsorbing acidic solutions.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Membrane electrode assembly

Membrane electrode assembly comprising oxygen evolution reaction catalyst disposed in gas distribution layer (100, 700) or between gas distribution layer (100, 700 and gas dispersion layer (200, 600). Membrane electrode assemblies described herein are useful, for example, in electrochemical devices such as a fuel cell.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2020

Solid-state laminate electrode assemblies and methods of making

Solid-state laminate electrode assemblies and various methods for making the solid-state laminate electrode assemblies involve a lithium metal layer reactively bonded to a lithium ion conducting sulfide glass layer. During manufacture, highly reactive surfaces of the lithium metal layer and the lithium ion conducting sulfide glass layer are maintained in its substantially unpassivated state until they have been reactively bonded.

25 ENERGY STORAGE↗
DOE OSTI2020

Surface treatment for lithium battery electrode materials

Electrode materials for electrochemical cells and batteries and methods of producing such materials are disclosed herein. A method of preparing an active lithium metal oxide material suitable for use in an electrode for a lithium electrochemical cell comprises the steps of: (a) contacting the lithium metal oxide material with an aqueous acidic solution containing one or more metal cations; and (b) heating the so-contacted lithium metal oxide from step (a) to dryness at a temperature below 200° C. The metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of an alkaline earth metal ion, a transition metal ion, and a main group metal ion.

25 ENERGY STORAGE↗
DOE OSTI2020

Cobalt-stabilized lithium metal oxide electrodes for lithium batteries

An electrode material comprising a composite lithium metal oxide, which in an initial state has the formula: y[xLi2MO3.(1−x)LiM′O2].(1−y)Li1+dMn2−z−dM″zO4; wherein 0≤x≤1; 0.75≤y<1; 0<z≤2; 0≤d≤0.2; and z−d≤2. M comprises one or more metal ions that together have an average oxidation state of +4; M′ comprises one or more metal ions that together have an average oxidation state of +3; and M″ comprises one or more metal ions that together with the Mn and any excess proportion of lithium, “d”, have a combined average oxidation state between +3.5 and +4. The Li1+dMn2−z−dM″zO4 component comprises a spinel structure, each of the Li2MO3 and the LiM′O2 components comprise layered structures, and at least one of M, M′, and M″ comprises Co. Cells and batteries comprising the electrode material also are described.

25 ENERGY STORAGE↗
DOE OSTI2020

Monolithically-integrated AC switch having JBSFETs therein with commonly-connected drain and cathode electrodes

A monolithically-integrated AC switch includes a semiconductor substrate having first and second insulated-gate field effect transistors therein, which contain first and second spaced-apart and independently-controllable source terminals extending adjacent a first surface of the semiconductor substrate, yet share a common drain electrode extending adjacent a second surface of the semiconductor substrate. According to some of these embodiments of the invention, the first and second insulated-gate field effect transistors include respective first and second independently-controllable gate electrodes, which extend adjacent the first surface. The first and second insulated-gate field effect transistors may be configured as first and second vertical power MOSFETs, respectively. The semiconductor substrate may also include at least one edge termination region therein, which extends between the first and second vertical power MOSFETs.

42 ENGINEERING↗
DOE OSTI2020

Poly(9,9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester), carbon nanotubes, and sulfur nanocomposite, electrode and lithium-fulfur battery including the same

The present invention provides for a composition of matter comprising: poly(9,9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester)(PFM), carbon nanotubes (CNT), and sulfur particles nanocomposite, wherein the nanocomposite is porous. The present invention also provides for an electrode comprising: poly(9,9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester)(PFM), carbon nanotubes (CNT), and sulfur particles nanocomposite, wherein the nanocomposite is porous. The present invention also provides for a lithium sulfur (Li—S) battery comprising: an electrode comprising poly(9,9-dioctylfluorene-co-fluorenone-co-methylbenzoic ester)(PFM), carbon nanotubes (CNT), and sulfur particles nanocomposite, wherein the nanocomposite is porous.

Liu, Gao↗
DOE OSTI2020

Nitride- and oxide-modified electrode compositions and their methods of making

Compositions and methods of making compositions are provided for nitride- and/or oxide-modified electrode compositions. In certain embodiments, the nitride- and/or oxide-modified compositions have the general formula M 1-z M′ z OaF 3-x N y . Such compositions may be used as bulk or surface compositions, and used in a battery as the anode or cathode. In other embodiments, the electrode includes a surface coating composition selected from metal nitrides and metal oxides, and a core composition having the formula M 1-z M′ z OaF 3-x N y , or an oxide fluoride.

Bridges, Craig A.↗
DOE OSTI2021

Nanostructured electrode for energy storage device

Disclosed herein is electrode comprising a current collector comprising a conductor layer having at least a first surface; and elongated metal carbide nanostructures extending from the first surface; and a carbonaceous energy storage media disposed on the first surface and in contact with the elongated metal carbide nanostructures. Disclosed herein too is an ultracapacitor comprising at least one electrode comprising a current collector comprising a conductor layer having at least a first surface; and elongated metal carbide nanostructures extending from the first surface; and a carbonaceous energy storage media disposed on the first surface and in contact with the elongated metal carbide nanostructures.

Brambilla, Nicol Michele↗
DOE OSTI2021

Protective coating for lithium-containing electrode and methods of making the same

A lithium-containing electrode with a protective coating and lithium-containing electrochemical cells including the same are provided herein. The protective coating has a first layer including a first fluoropolymeric matrix and Li—F compounds and a second layer including a second fluoropolymeric matrix. Methods of preparing the protective coating on the lithium-containing electrode by applying a first fluoropolymer and/or a first fluoropolymer precursor and a second fluoropolymer and/or a second fluoropolymer precursor are also provided herein.

Xiao, Xingcheng↗