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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Binder model system to be used for determination of prepolymer functionality

Development of a method for determining the functionality distribution of prepolymers used for rocket binders is discussed. Research has been concerned with accurately determining the gel point of a model polyester system containing a single trifunctional crosslinker, and the application of these methods to more complicated model systems containing a second trifunctional crosslinker, monofunctional ingredients, or a higher functionality crosslinker. Correlations of observed with theoretical gel points for these systems would allow the methods to be applied directly to prepolymers.

Martinelli, F. J.↗
NASA NTRS2003

Organic Binder Developments for Solid Freeform Fabrication

A number of rapid prototyping techniques are under development at Marshall Space Flight Center's (MSFC) National Center for Advanced Manufacturing Rapid Prototyping Laboratory. Commercial binder developments in creating solid models for rapid prototyping include: 1) Fused Deposition Modeling; 2) Three Dimensional Printing; 3) Selective Laser Sintering (SLS). This document describes these techniques developed by the private sector, as well as SLS undertaken by MSFC.

Cooper, Ken↗
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↗
DOE OSTI2021

Crosslinked polymer binders for electrochemical energy storage devices

An electrochemical storage device including a conductive material and an electrochemical storage device material held together by a covalently crosslinked binder matrix. A method of forming an electrode for an electrochemical storage device, the method including the steps of: mixing electrochemical storage device material, conductive material, linear polymer, and crosslinker with one or more solvents, the resultant mixture forming an electrode slurry, crosslinking the linear polymer with the crosslinker to thereby create a covalently crosslinked polymer network of the polymer and crosslinker, the crosslinked polymer network physically or chemically binding together the electrochemical storage device material and the conductive material.

Zhu, Yu↗
DOE OSTI2022

Phosphonated polymers, and methods of production thereof, for use as polymer electrolyte membranes (PEMs) and/or catalyst ionomeric binders for electrodes in PEM fuel cells

The present disclosure provides phosphonated polymers that can be used, for example, as polymer electrolyte membranes (PEMs) and/or catalyst ionomeric binders for electrodes in PEM fuel cells, and more particularly for high-temperature PEM fuel cells. High-temperature PEM fuel cells that use phosphonated polymers of the present disclosure suffer from reduced or no acid leaching because, in at least some examples, phosphonic acid moieties are covalently bound to the backbone of the polymers. A phosphonated polymer include a backbone having one or more aromatic monomers, with each aromatic monomer having one or more phosphonic acid groups. A phosphonic acid group may include phosphonic acid or a functional group that is hydrolysable into phosphonic acid.

Park, Eun Joo↗
DOE OSTI2022

Binders for silicon electrodes in lithium-ion batteries

An electrode for a lithium-ion electrochemical cell comprises silicon particles and carbon particles coated on a conductive current collector. The silicon and carbon particles being bound to each other and to the current collector by a cross-linked binder formed from a combination of a poly(carboxylic acid) such as poly(acrylic acid) and a branched polyethyleneimine. A method of preparing the anode also is described.

Shi, Zhangxing↗
DOE OSTI2023

Hyperelastic binder for printed, stretchable electronics

Disclosed are compositions, devices, systems and fabrication methods for stretchable composite materials and stretchable electronics devices. In some aspects, an elastic composite material for a stretchable electronics device includes a first material having a particular electrical, mechanical or optical property; and a multi-block copolymer configured to form a hyperelastic binder that creates contact between the first material and the multi-block copolymer, in which the elastic composite material is structured to stretch at least 500% in at least one direction of the material and to exhibit the particular electrical, mechanical or optical property imparted from the first material. In some aspects, the stretchable electronics device includes a stretchable battery, biofuel cell, sensor, supercapacitor or other device able to be mounted to skin, clothing or other surface of a user or object.

Wang, Joseph↗
DOE OSTI2020

Self-supported MoO 2 /MoS 2 nano-sheets embedded in a carbon cloth as a binder-free substrate for high-energy lithium–sulfur batteries

As one of the most prospective candidates for next-generation rechargeable batteries, lithium-sulfur (Li-S) batteries currently still encounter great challenges associated with the low conductivity, severe shuttle effects, and sluggish redox kinetics. Herein, a self-supported sulfur host is fabricated by an in-situ growth of MoO 2 /MoS 2 nano-sheets on a carbon cloth (CC). First, carbon cloth serves as a good template for the morphology-controlled synthesis of nanostructured materials, which not only alleviates the agglomeration of MoO2/MoS2, but also enhances the flexibility and mechanical strengthen of the hybrid architecture as a free-standing host. Second, the polysulfide-trapping ability can be greatly enhanced by both physical and chemical adsorption from the MoO 2 /MoS 2 -anchored carbon cloth. Moreover, the partially sulfurized MoO 2 /MoS 2 nano-sheets integrate the benefits of conductive MoO 2 and sulfiphilic MoS 2 , thus facilitating fast charge transfer and redox kinetics of polysulfide conversion. As a result, these attributes enable the host to hold a high sulfur loading (up to 7.6 mg cm -2 ), which exceeds most of the reported carbon cloth-related cathode work in the literature. Furthermore, the Li-S cells can achieve a high peak capacity of 1350 mA h g -1 , excellent rate capability (C/20 - 2C rate), impressive areal capacity (up to 6.3 mA h cm -2 ), and a high capacity retention of 85% after 100 cycles.

25 ENERGY STORAGE↗
NASA NTRS1961

Sintering of Hafnium Carbide With A Fugitive Metal Binder

The sintering behavior of a mixture of hafnium carbide and 10 weight percent cobalt powders is presented. Compacts were heated in a vacuum at elevates temperatures for densification and removal of the cobalt. Densities of 99 percent of theoretical for the hafnium carbide were achieved with a maximum sintering temperature of 2200' C. Retained cobalt, grain size, microhardness, and weight loss were determined.

SINTERING↗
DOE OSTI2020

Ending the Chase for a Perfect Binder: Role of Surface Chemistry Variation and its Influence on Silicon Anodes

In this work we examine the influence of the type of silicon source material (two milled and two plasma enhanced chemical vapor deposition) on the electrochemical performance of silicon-based anodes for Li-ion batteries. The four representative Si sources were previously identified in literature but have never been compared side by side, which is critical to understanding the wide variation in performance reported for silicon-based electrodes. These particles display unique surface features associated with surface oxides and residual precursor species (Si-N, Si-C, Si-H) which impact processability by changing interactions within the electrode slurry and the resulting electrochemical performance. These properties should be taken into consideration when utilizing “off-the-shelf” Si powders for investigations and would be good variables to explore to understand why certain chemistries display suitable performance, while others “don't work.”

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗