Search NASA⌕ Search

SEARCH · Search NASA

Results for “anode material”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Thermal control materials on EOIM-3

Thermal control paints, anodized aluminum, and beta cloth samples were flown on STS-46 as part of the Evaluation of Oxygen Interaction with Materials Experiment (EOIM-3). The thermal control paints flown on EOIM-3 include ceramic and polyurethane-based paints. Passively exposed samples are compared to actively heated samples and controlled exposure samples. Optical property measurements of absorptivity, emissivity, and spectrofluorescence are presented for each paint. Several variations of anodized aluminum, including chromic acid anodize, sulfuric acid anodize, and boric/sulfuric acid anodize were flown on the actively heated trays and the passive exposure trays. The post-flight optical properties are within tolerances for these materials. Also flown were two samples of yellow anodized aluminum. The yellow anodized aluminum samples darkened noticeably. Samples of aluminized and unaluminized beta cloth, a fiberglass woven mat impregnated with TFE Teflon, were flown with passive exposure to the space environment. Data from this part of the experiment is correlated to observations from LDEF and erosion of the Teflon thin film samples also flown on EOIM-3 and LDEF.

Finckenor, Miria M.↗
NASA NTRS1972

Magnetically actuated tuning method for Gunn oscillators

A tunable microwave generator based on the Gunn effect is disclosed. The generator includes a semiconductor material which exhibits the Gunn effect when current flows between anode and cathode end contacts. The material has a plurality of sides each with a scratch at a different distance from the anode contact. A magnetic field is produced by a magnet placed about the semiconductor field. The Lorentz force produced as a function of the current flow and the magnetic field drive the electrons to the surface of one of the sides to cause nucleation to occur at the scratch. A domain formed thereat travels to the anode contact to provide pulses at a frequency which is related to the distance between the scratch and the anode contact.

Sacks, B. H.↗
NASA NTRS2010

Miniature Lightweight Ion Pump

This design offers a larger surface area for pumping of active gases and reduces the mass of the pump by eliminating the additional vacuum enclosure. There are three main components to this ion pump: the cathode and anode pumping elements assembly, the vacuum enclosure (made completely of titanium and used as the cathode and maintained at ground potential) containing the assembly, and the external magnet. These components are generally put in a noble diode (or differential) configuration of the ion pump technology. In the present state of the art, there are two cathodes, one made of titanium and the other of tantalum. The anodes are made up of an array of stainless steel cylinders positioned between the two cathodes. All the elements of the pump are in a vacuum enclosure. After the reduction of pressure in this enclosure to a few microns, a voltage is applied between the cathode and the anode elements. Electrons generated by the ionization are accelerated toward the anodes that are confined in the anode space by the axial magnetic field. For the generation of the axial field along the anode elements, the magnet is designed in a C-configuration and is fabricated from rare earth magnetic materials (Nd-B-Fe or Sm-Co) possessing high energy product values, and the yoke is fabricated from the high permeability material (Hiperco-50A composed of Fe-Co-V). The electrons in this region collide with the gas molecules and generate their positive ions. These ions are accelerated into the cathode and eject cathode material (Ti). The neutral atoms deposit on the anode surfaces. Because of the chemical activity of Ti, the atoms combine with chemically active gas molecules (e.g. N2, O2, etc.) and remove them. New layers of Ti are continually deposited, and the pumping of active gases is thus accomplished. Pumping of the inert gases is accomplished by their burial several atomic layers deep into the cathode. However, they tend to re-emit if the entrapping lattice atoms are sputtered away. For stable pumping of inert gases, one side of the cathode is made of Ta. Impaction on Ta produces energetic, neutral atoms that pump the inert gases on the anode structure at the peripheral areas of the cathodes (between anode rings). For inert gases stability, a post design has been implemented. Here, posts of cathode material (Ti) are mounted on the cathode. These protrude into the initial part of the anode elements. Materials sputtered from the posts condense on the anode assembly and on the cathode plane at higher rates than in the normal diodes due to enhanced sputtering at glancing angles from geometrical considerations. This increases pumping by burial. This post design has enhanced pumping rates for both active and inert gases, compared with conventional designs.

Sinha, Mahadeva P.↗
NASA NTRS2001

Effects of Surface Oxygen on the Performance of Carbon as an Anode in Lithium-Ion Batteries

Carbon materials with similar bulk structure but different surface oxygen were compared for their performance as anodes in lithium-ion battery. The bulk structure was such that the graphene planes were perpendicular to the surface. Three types of surfaces were examined: surface containing C=O type oxygen. surface containing -O-C type oxygen, and surface containing high concentration of active sites. The test involved cycles of lithium insertion into and release from the carbon materials, which was in the half cells of carbon/saturated LiI-50/50 (vol %) EC and DMC/lithium. During the first cycle of lithium insertion, the presence of adsorbed oxygen, -O-C type oxygen, active carbon sites, and C=O type oxygen resulted in the formation of solid-electrolyte interface (SEI) when the carbon's voltage relative to lithium metal was >1.35, 1 to 1.35, 0.5 to 1, and 0.67 to 0.7 V, respectively. An optimum -O-C type oxygen and a minimum C=O type oxygen was found to increase the reversible and decrease the irreversible capacity of carbon. Active sites on the carbon surface result in a large irreversible capacity and a second lithium insertion-release mechanism. However, this new mechanism has a short cycle life.

Hung, Ching-Cheh↗
DOE OSTI2024

Comprehensive evaluation of commercially scalable atomic-layer-deposited alumina coating impact on full cell battery performance across varied test conditions

Atomic Layer Deposition (ALD) has emerged as a strategic enhancement method for lithium-ion battery (LIB) materials offering potential benefits and durability benefits for industrial battery production. However, the translation from laboratory achievements to commercial-scale applications has been limited. Here, this study aims to bridge this gap by comprehensively evaluating the effects of commercially scalable Al 2 O 3 ALD coatings using full pouch cell performance as a means to assess the ALD impact. We utilized large-scale slot-die coating techniques to ensure consistent electrode quality and tested four configurations of pouch cells to analyze the individual effects of ALD coating on anode and cathode electroactive materials. Our extensive testing matrix included long-term cycling, fast discharge, fast charge, leakage current, and high voltage tests. While at lower C-rates (<~1C), the influence of Al 2 O 3 coatings on cell performance is not significant. Fast charging conditions reveal that the anode ALD coating significantly enhances performance via a passivating effect, while on the cathode, it is detrimental, potentially due to increased resistance of the thin interfacial layer formed during the ALD processing. Leakage current and high-voltage tests show that the application of ALD coatings on either anode or cathode effectively minimizes side reactions at the electrode-electrolyte interface. Additionally, ALD coatings significantly mitigate concentrated and localized lithium plating on the anodes. These insights provide a valuable understanding of the potential of ALD technologies in LIB manufacturing to tailor cell performance, paving the way for safer, more efficient, and cost-effective battery solutions.

25 ENERGY STORAGE↗
NASA NTRS2004

Thermal characteristics of Lithium-ion batteries

Lithium-ion batteries have a very promising future for space applications. Currently they are being used on a few GEO satellites, and were used on the two recent Mars rovers Spirit and Opportunity. There are still problem that exist that need to be addressed before these batteries can fully take flight. One of the problems is that the cycle life of these batteries needs to be increased. battery. Research is being focused on the chemistry of the materials inside the battery. This includes the anode, cathode, and the cell electrolyte solution. These components can undergo unwanted chemical reactions inside the cell that deteriorate the materials of the battery. During discharge/ charge cycles there is heat dissipated in the cell, and the battery heats up and its temperature increases. An increase in temperature can speed up any unwanted reactions in the cell. Exothermic reactions cause the temperature to increase; therefore increasing the reaction rate will cause the increase of the temperature inside the cell to occur at a faster rate. If the temperature gets too high thermal runaway will occur, and the cell can explode. The material that separates the electrode from the electrolyte is a non-conducting polymer. At high temperatures the separator will melt and the battery will be destroyed. The separator also contains small pores that allow lithium ions to diffuse through during charge and discharge. High temperatures can cause these pores to close up, permanently damaging the cell. My job at NASA Glenn research center this summer will be to perform thermal characterization tests on an 18650 type lithium-ion battery. High temperatures cause the chemicals inside lithium ion batteries to spontaneously react with each other. My task is to conduct experiments to determine the temperature that the reaction takes place at, what components in the cell are reacting and the mechanism of the reaction. The experiments will be conducted using an accelerating rate calorimeter (ARC), which uses a heat-wait-search mode until an exothermic reaction is detected. After an exotherm is found the calorimeter maintains an adiabatic environment around a bomb which holds the test sample. The ARC will help identify important reactions and what temperature these exothermic reactions take place at. In order fully understand the battery, we are first going to take apart the battery and test the individual components of the battery using the ARC. I will first conduct a test on the electrolyte solution by itself. We will then test the electrolyte solution with the anode. We would like to see how the electrolyte solution reacts with the anode and its binder material. The next would be the same test using the cathode instead of the anode. By comparing the results of the electrolyte, electrolyte with anode, and the electrolyte with the cathode we can determine the reactions that are taking place due to each component. Using the heat capacity of the each individual sample and the temperature by which the sample increases, kinetic and thermo-dynamical information can then be found. A Gas chromatograph could be used to help with the task of identifying the by-products at the end of each test. One way of increasing the cycle life is to increase the stability of the materials inside the

Hauser, Dan↗
NASA NTRS1991

Survey of results from the Boeing modules on the M0003 experiment on LDEF

The Boeing modules on the M0003 experiment included fiber optics, ceramic materials, a variety of electronic piece parts, composites and thermal control paints, fasteners, thin film lubricants, anodized surfaces, and adhesives. These materials were flown on the leading and trailing edge exteriors, and on the interior portion of LDEF M0003 providing exposure under three distinct environments. The condition of each of these material types is described. Results of optical, surface, and mechanical properties are presented.

Pippin, H. Gary↗
DOE OSTI2025

Compositionally Complex Spinel Oxides as Conversion Anodes for Lithium-Ion Batteries

Four different compositionally complex multicomponent M 3 O 4 spinels containing 5–8 distinct metals were prepared by a rapid combustion synthesis method or solvothermal synthesis. High resolution synchrotron X-ray diffraction patterns show that the materials consist primarily of spinel phases with small amounts of rock salt impurities, and, in several samples, a minor amount of contracted spinel phase. Materials were investigated as conversion anodes in lithium half-cells and delivered significantly higher capacities than two-component MgFe 2 O 4 made by combustion synthesis. X-ray absorption near-edge structure (XANES) was used to estimate the oxidation states of the metals in the pristine, lithiated (discharged) and delithiated (charged) materials to better understand the redox processes in half cells that led to the improvement. Co, Ni, and Zn are reduced to low oxidation states during lithiation (cell discharge) but are only partially oxidized. The presence of a conductive metallic network that forms after lithiation is thought to account for the improved electrochemical characteristics. Interestingly, in most of the samples, iron is not fully reduced during initial lithiation unlike what happens with a set of related high entropy spinel ferrites studied previously. Finally, the improved electrochemical properties of these materials illustrates both the advantages of complexity and the difficulties in predicting their behavior.

25 ENERGY STORAGE↗
DOE OSTI2026

Prelithiated SiO x /Graphite-NMC811 Cells: Capacity Loss, Impedance Rise and Hidden Degradation Pathways Revealed Using Three-Electrode Diagnostics

Electrodes containing SiO x /graphite (Gr) materials are attractive as anodes for high-energy lithium-ion batteries. However, their mechanical deformation, electrochemical response, and impedance evolution during long-term cycling are strongly coupled, complicating accurate diagnosis of performance fade mechanisms. In this work, the behavior of electrochemically prelithiated SiO x /Gr anodes paired with NMC811 cathodes is systematically investigated using techniques that include in-situ dilatometry, three-electrode electrochemistry, and multiscale post-cycling microscopy. The SiO x /Gr electrode exhibits a maximum expansion of 49% upon lithiation to 10 mV vs Li + /Li, with 84% of the expansion and 91% of the capacity being reversible. In full cells, relatively stable cycling with only 12% capacity fade over 500 cycles is observed. Three-electrode experiments reveal cell-level impedance growth, which is dominated by the NMC811 cathode: the SiO x /Gr anode exhibits minimal net impedance rise and an initial impedance decrease at low potentials. Despite this apparent electrochemical stability, cross-sectional SEM, PFIB tomography, and cryo-STEM reveal irreversible anode thickening caused by the accumulation of an inorganic-rich solid electrolyte interphase (SEI) permeating the anode bulk. Electrode potential-shift analysis further demonstrates that Li + ions released from lithium reservoirs in the prelithiated anode mask true lithium inventory loss during aging. These results demonstrate that low-expansion SiO x /Gr anodes can simultaneously exhibit favorable cycling and impedance metrics while undergoing substantial, hidden degradation, underscoring the importance of electrode-resolved diagnostics for evaluating prelithiated silicon-based anodes.

25 ENERGY STORAGE↗
DOE OSTI2026

Roll-to-Roll Manufacturing of Solid Oxide Fuel Cells

The overall goal of this project is to develop a high-volume electrode electrolyte assembly (EEA) production capability to significantly increase throughput of solid oxide fuel cell (SOFC) manufacturing and reduce the cost while maintaining the same level of performance. Specifically, four approaches will be adopted: 1) optimization of the lamination process and correlation of the EEA properties and performance with the lamination conditions; 2) scale up of the lamination process and demonstration of >10 ft of EEA; 3) further increase of the EEA throughput via slot-die coating and demonstration of > 5 m/min in coating the thick anode layer; and 4) minimization of the anode thickness to reduce material cost.

30 DIRECT ENERGY CONVERSION↗
NASA NTRS1975

Emission spectrometric arcing procedure with minimal effect of chemical form of sample

Matrix effects related to the chemical form of analyzed materials were studied. An arc in argon was used which was buffered with silver chloride. The effect of chemical form was minimal for a variety of metals, oxides, and carbides representing the most refractory compounds and thermally stable metal-containing molecules. Only four of the most refractory materials known showed significant emission depressions due to incomplete volatilization in the arc system. These results are discussed in terms of vapor pressures of the solid materials placed on the anodes and dissociation reactions of the molecules in the gaseous environment.

Gordon, W. A.↗
NASA NTRS1975

Design and fabrication of silver-hydrogen cells

The design and fabrication of silver-hydrogen secondary cells capable of delivering higher energy densities than comparable nickel-cadmium and nickel-hydrogen cells and relatively high cycle life is presented. An experimental task utilizing single electrode pairs for the optimization of the individual electrode components, the preparation of a design for lightweight 20Ahr cells, and the fabrication of four 20Ahr cells in heavy wall test housing containing electrode stacks of the lightweight design are described. The design approach is based on the use of a single cylindrical self-contained cell with a stacked disc sequence of electrodes. The electrode stack design is based on the use of NASA- Astropower Separator Material, PPF fuel cell anodes, an intercell electrolyte reservoir concept and sintered silver electrodes. Results of performance tests are given.

Klein, M. G.↗
NASA NTRS1976

Emission spectrometric arcing procedure with minimal effect of chemical form of sample

This paper describes a study of matrix effects related to the chemical form of materials analyzed. The study was made using an arc in argon buffered with silver chloride. The effect of chemical form was minimal for a variety of metals, oxides, and carbides representing the most refractory compounds and thermally stable metal-containing molecules. Among these, only four of the most refractory materials known showed significant emission depressions due to incomplete volatilization in the arc system. These results are discussed in terms of vapor pressure of the solid materials placed on the anodes and dissociation reactions of the molecules in the gaseous environment.

Gordon, W. A.↗
NASA NTRS1984

Low-Noise Submillimeter-Wave Diode

Low noise achieved without usual high resistance. Barrier of p-type material placed between metal anode and heavily-doped gallium arsenide. Ntype epitaxial layer eliminated. Barrier prevents quantum tunneling of electrons between semiconductor and metal. Higher breakdown structure provided.

Mattauch, R. J.↗
NASA NTRS1988

Carbon dioxide electrolysis with solid oxide electrolyte cells for oxygen recovery in life support systems

The direct electrochemical reduction of carbon dioxide (CO2) is achieved without catalysts and at sufficiently high temperatures to avoid carbon formation. The tubular electrolysis cell consists of thin layers of anode, electrolyte, cathode and cell interconnection. The electrolyte is made from yttria-stabilized zirconia which is an oxygen ion conductor at elevated temperatures. Anode and cell interconnection materials are complex oxides and are electronic conductors. The cathode material is a composite metal-ceramic structure. Cell performance characteristics have been determined using varying feed gas compositions and degrees of electrochemical decomposition. Cell test data are used to project the performance of a three-person CO2-electrolysis breadboard system.

Isenberg, Arnold O.↗
NASA NTRS2004

Lithium Polymer Electrolytes and Solid State NMR

Research is being done at the Glenn Research Center (GRC) developing new kinds of batteries that do not depend on a solution. Currently, batteries use liquid electrolytes containing lithium. Problems with the liquid electrolyte are (1) solvents used can leak out of the battery, so larger, more restrictive, packages have to be made, inhibiting the diversity of application and decreasing the power density; (2) the liquid is incompatible with the lithium metal anode, so alternative, less efficient, anodes are required. The Materials Department at GRC has been working to synthesize polymer electrolytes that can replace the liquid electrolytes. The advantages are that polymer electrolytes do not have the potential to leak so they can be used for a variety of tasks, small or large, including in the space rover or in space suits. The polymers generated by Dr. Mary Ann Meador's group are in the form of rod -coil structures. The rod aspect gives the polymer structural integrity, while the coil makes it flexible. Lithium ions are used in these polymers because of their high mobility. The coils have repeating units of oxygen which stabilize the positive lithium by donating electron density. This aids in the movement of the lithium within the polymer, which contributes to higher conductivity. In addition to conductivity testing, these polymers are characterized using DSC, TGA, FTIR, and solid state NMR. Solid state NMR is used in classifying materials that are not soluble in solvents, such as polymers. The NMR spins the sample at a magic angle (54.7') allowing the significant peaks to emerge. Although solid state NMR is a helpful technique in determining bonding, the process of preparing the sample and tuning it properly are intricate jobs that require patience; especially since each run takes about six hours. The NMR allows for the advancement of polymer synthesis by showing if the expected results were achieved. Using the NMR, in addition to looking at polymers, allows for participation on a variety of other projects, including aero-gels and carbon graphite mat en als. The goals of the polymer electrolyte research are to improve the physical properties of the polymers. This includes improving conductivity, durability, and expanding the temperature range over which it is effective. Currently, good conductivity is only present at high temperatures. My goals are to experiment with different arrangements of rods and coils to achieve these desirable properties. Some of my experiments include changing the number of repeat units in the polymer, the size of the diamines, and the types of coil. Analysis of these new polymers indicates improvement in some properties, such as lower glass transition temperature; however, they are not as flexible as desired. With further research we hope to produce polymers that encompass all of these properties to a high degree.

Berkeley, Emily R.↗
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↗