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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
NASA NTRS2004

Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical biosensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

Cassell, Alan M.↗
NASA NTRS2007

High Temperature Protonic Conductors

High Temperature Protonic Conductors (HTPC) with the perovskite structure are envisioned for electrochemical membrane applications such as H2 separation, H2 sensors and fuel cells. Successive membrane commercialization is dependent upon addressing issues with H2 permeation rate and environmental stability with CO2 and H2O. HTPC membranes are conventionally fabricated by solid-state sintering. Grain boundaries and the presence of intergranular second phases reduce the proton mobility by orders of magnitude than the bulk crystalline grain. To enhanced protonic mobility, alternative processing routes were evaluated. A laser melt modulation (LMM) process was utilized to fabricate bulk samples, while pulsed laser deposition (PLD) was utilized to fabricate thin film membranes . Sr3Ca(1+x)Nb(2-x)O9 and SrCe(1-x)Y(x)O3 bulk samples were fabricated by LMM. Thin film BaCe(0.85)Y(0.15)O3 membranes were fabricated by PLD on porous substrates. Electron microscopy with chemical mapping was done to characterize the resultant microstructures. High temperature protonic conduction was measured by impedance spectroscopy in wet air or H2 environments. The results demonstrate the advantage of thin film membranes to thick membranes but also reveal the negative impact of defects or nanoscale domains on protonic conductivity.

Dynys, Fred↗
DOE OSTI2021

Tutorial: Machine Learning and Artificial Intelligence in Batteries

Machine learning (ML) promises to compress the time needed to characterize battery performance, lifetime and safety. By coupling ML with physical models and metrics, that learning can bridge across materials, chemistries and cell designs. This tutorial will discuss the most popular ML techniques and resources and review recent work in the electrochemical literature. Applications include materials discovery, image recognition for quantitative microscopy analysis, fast charge algorithm development and life prediction.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

Solvent independent reference electrodes for use with non-aqueous electrolytes

The present disclosure relates to a method for forming a reference electrode for use in electrochemical testing applications. The method may involve positioning a porous frit against one end of a hollow tube, and securing the frit and the hollow tube to one another to form an assembly. The method may further involve forming a silver sulfide coating on a silver wire to produce a silver sulfide coated silver wire. The method may further involve filling the hollow tube with a non-aqueous solution, and inserting at least a portion of the silver sulfide coated silver wire into the non-aqueous solution in the hollow tube.

Horwood, Corie↗
NASA NTRS2007

Electrochemically Controlled Reconstitution of Immobilized Ferritins for Bioelectronic Applications

Site-specific reconstituted nanoparticles were fabricated via electrochemically-controlled biomineralization through the immobilization of biomolecules. The work reported herein includes the immobilization of ferritin with various surface modifications, the electrochemical biomineralization of ferritins with different inorganic cores, and the electrocatalytic reduction of oxygen on the reconstituted Pt-cored ferritins. Protein immobilization on the substrate is achieved by anchoring ferritins with dithiobis-N-succinimidyl propionate (DTSP). A reconstitution process of site-specific electrochemical biomineralization with a protein cage loads ferritins with different core materials. The ferritin acts as a nano-scale template, a biocompatible cage, and a separator between the nanoparticles. This first demonstration of electrochemically controlled site-specific reconstitution of biomolecules provides a new tool for biomineralization and opens the way to produce the bio-templated nanoparticles by electrochemical control. The nanosized platinum-cored ferritins on gold displayed good catalytic activity for the electrochemical reduction of oxygen, which is applicable to biofuel cell applications. This results in a smaller catalyst loading on the electrodes for fuel cells or other bioelectronic devices.

Kim, Jae-Woo↗
NASA NTRS1988

Advanced EMU electrochemically regenerable CO2 and moisture absorber module breadboard

The applicability of the Electrochemically Regenerable Carbon Dioxide and Moisture Absorption Technology to the advanced extravehicular mobility unit was demonstrated by designing, fabricating, and testing a breadboard Absorber Module and an Electrochemical Regenerator. Test results indicated that the absorber module meets or exceeds the carbon dioxide removal requirements specified for the design and can meet the moisture removal requirement when proper cooling is provided. CO2 concentration in the vent gas stream was reduced from 0.52 to 0.027 kPa (3.9 to 0.20 mm Hg) for the full five hour test period. Vent gas dew point was reduced from inlet values of 294 K (69 F) to 278 K (41 F) at the outlet. The regeneration of expended absorbent was achieved by the electrochemical method employed in the testing. An absorbent bed using microporous hydrophobic membrane sheets with circulating absorbent is shown to be the best approach to the design of an Absorber Module based on sizing and performance. Absorber Module safety design, comparison of various absorbents and their characteristics, moisture absorption and cooling study and subsystem design and operation time-lining study were also performed.

Lee, M. C.↗
NASA NTRS1987

Air Force electrochemical power research and technology program for space applications

An overview is presented of the existing Air Force electrochemical power, battery, and fuel cell programs for space application. Present thrusts are described along with anticipated technology availability dates. Critical problems to be solved before system applications occur are highlighted. Areas of needed performance improvement of batteries and fuel cells presently used are outlined including target dates for key demonstrations of advanced technology. Anticipated performance and current schedules for present technology programs are reviewed. Programs that support conventional military satellite power systems and special high power applications are reviewed. Battery types include bipolar lead-acid, nickel-cadmium, silver-zinc, nickel-hydrogen, sodium-sulfur, and some candidate advanced couples. Fuel cells for pulsed and transportation power applications are discussed as are some candidate advanced regenerative concepts.

Allen, Douglas↗
DOE OSTI2024

Elucidating the complex interplay between thermodynamics, kinetics, and electrochemistry in battery electrodes through phase-field modeling

Abstract This article highlights applications of phase-field modeling to electrochemical systems, with a focus on battery electrodes. We first provide an overview on the physical processes involved in electrochemical systems and applications of the phase-field approach to understand the thermodynamic and kinetic mechanisms underlying these processes. We employ two examples to highlight how realistic thermodynamics and kinetics can naturally be incorporated into phase-field modeling of electrochemical processes. One is a composite battery cathode with an intercalation compound (Li x FePO 4 ) as the electrochemically active material, and the other is a displacement reaction compound (Li–Cu–TiS 2 ). With the input parameters mostly from atomistic calculations and experimental measurements, phase-field simulations allowed us to untangle the interactions among transport, reaction, electricity, chemistry, and thermodynamics that lead to highly complex evolution of the materials within battery electrodes. The implications of these observations for battery performance and degradation are discussed. Graphical abstract

Andrews, W. Beck (ORCID:0000000287824621)↗
DOE OSTI2020

Precautions of Using Three-Electrode Configuration to Measure Electrode Overpotential in Solid Oxide Electrochemical Cells: Insights from Finite Element Modeling

Accurate determination of electrode overpotentials is essential to assess the performance of the electrode and understand the rate-limiting steps involved. Three-electrode configuration with the use of a reference electrode at a fixed potential is a standard way to measure overpotential of a specific electrode in liquid electrochemical systems. However, application of such three-electrode configuration to solid electrochemical cells for overpotential determination is not straightforward and requires extra caution. Here we report a theoretical Finite Element Analysis on the geometrical requirements for which the reference electrode can be applied to anode- or electrolyte-supported solid oxide button cells. The modeling results suggest that the symmetry of the working and counter electrodes is the key factor determining if a reference electrode is suitable to use. For anode-supported fuel cells with asymmetrical working and counter electrodes, reference electrode cannot be used under all circumstances. To use reference electrode for overpotential measurements, electrolyte-supported cells with symmetrical semicircular-shaped electrodes are preferred. A data processing procedure has also been presented to obtain the electrode overpotential from the measured potential using the three-electrode scheme in solid oxide electrochemical cells.

25 ENERGY STORAGE↗
DOE OSTI2023

Application of Principal Component Analysis to Electrochemical Reprocessing PM and NMAC

In this report, data from an electrorefiner (ER) for nuclear fuel reprocessing is evaluated for process monitoring (PM) conclusions. This data comes from tests performed at the Idaho National Laboratory in 2022. Multivariate approaches utilizing methods of Principal Component Analysis (PCA) is applied. This is based off established work in process monitoring for fault detection in industrial facilities. This report will discuss the background, methods, and results of the application and some of the conclusions and applications that can be drawn from them. PCA is applied to two different electrorefiner (ER) operations that occurred at Idaho National Laboratory between August and October 2022. The first operation occurred with little incident while the second had several noted faults in the equipment in operational logs. The data from the first run was used to train the data for “normal” operations and applied to both sets of data to determine when operations were in an “off-normal” condition and identify where the fault occurs through PCA. PCA was able to identify off-normal events and identify the cause for off-normal operations. These identified off-normal events matched with the events and their causes in the operational logs. However, small amounts of variance in the data led to false detection of “off-normal” events. Thus, careful selection of training data and a-posteriori conclusions based off operator assessments will both be required for application of PCA to PM applications. This work demonstrated that multivariate approaches and latent variables are applicable to pyroprocessing PM applications and can be further expanded in future work as quality variables such as salt concentration from sensors and sampling become available.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

Impact of Cation Insertion on Semiconducting Polymer Thin Films toward Electrochemical Energy Conversion

Semiconducting polymers are being explored for electrochemical and photoelectrochemical energy transformation and storage applications. For these applications, it is critical to understand how ion insertion from the electrolyte into polymer electrodes modulates the polymer electronic structure and electron doping levels. Here, this study explores electrochemical cation insertion in the n-type conjugated redox polymer P90, composed of alternating naphthalene diimide (NDI) acceptor and bithiophene (T2) donor units, where the NDI units are functionalized with heptaethylene glycol (HEG, 90%) and 2-octyl dodecyl (OD, 10%) side chains. By combining in situ techniques (UV-vis absorption and Raman spectroscopies with electrochemistry), structural analysis using ex situ grazing-incidence wide-angle X-ray scattering (GIWAXS), and density functional theory (DFT) calculations, we reveal that dications enable negative polaron and bipolaron formation in the P90 at less reducing potentials while supporting more bipolaron formation than the monocations; moreover, larger dications with smaller hydrated radii increase the maximum P90 electron doping level. We also determine that the monocations lead to more thermodynamically stabilized polarons compared with the dications. These findings highlight the critical role of cation identity in tuning electrochemical charging, charge stabilization, and electronic structure of n-type conjugated redox polymers, providing guidance on the rational design of polymer-based (photo)electrochemical applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2008

PH and Electrochemical Responsive Materials for Corrosion Smart Coating Applications

Corrosion is a costly issue for military operations and civil industries. While most corrosion initiates from localized corrosion form, such as pitting, failure directly caused by localized corrosion is the most dangerous kind, because it is difficult to anticipate and prevent, occurs very suddenly and can be catastrophic. One way of preventing these failures is with a coating that can detect and heal localized corrosion. pH and other electrochemical changes are often associated with localized corrosion, so it is expected that materials that are pH or otherwise electrochemical responsive can be used to detect and control corrosion. This paper will review various pH and electrochemical responsive materials and their potential applications in corrosion smart coatings. Current research results in this field will also be reported.

Li, Wenyan↗