Materials

Li-Ion Electrolytes With Improved Safety and Tolerance to High-Voltage Systems

Promising electrolytes are identified. Given that lithium-ion (Li-ion) technology is the most viable rechargeable energy storage device for near-term applications, effort has been devoted to improving the safety characteristics of this system. Therefore, extensive effort has been devoted to developing non-flammable electrolytes to reduce the flammability of the cells/battery. A number of promising electrolytes have been developed incorporating flame-retardant additives, and have been shown to have good performance in a number of systems. However, these electrolyte formulations did not perform well when utilizing carbonaceous anodes with the high-voltage materials. Thus, further development was required to improve the compatibility.

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Composite Aerogel Multifoil Protective Shielding

These composites are also suitable for environments containing an atmosphere. New technologies are needed to survive the temperatures, radiation, and hypervelocity particles that exploration spacecraft encounter. Multilayer insulations (MLIs) have been used on many spacecraft as thermal insulation. Other materials and composites have been used as micrometeorite shielding or radiation shielding. However, no material composite has been developed and employed as a combined thermal insulation, micrometeorite, and radiation shielding.

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Polymer-Reinforced, Non-Brittle, Lightweight Cryogenic Insulation

The primary application for cryogenic insulating foams will be fuel tank applications for fueling systems. It is crucial for this insulation to be incorporated into systems that survive vacuum and terrestrial environments. It is hypothesized that by forming an open-cell silica-reinforced polymer structure, the foam structures will exhibit the necessary strength to maintain shape. This will, in turn, maintain the insulating capabilities of the foam insulation. Besides mechanical stability in the form of crush resistance, it is important for these insulating materials to exhibit water penetration resistance. Hydrocarbon-terminated foam surfaces were implemented to impart hydrophobic functionality that apparently limits moisture penetration through the foam. During the freezing process, water accumulates on the surfaces of the foams. However, when hydrocarbon-terminated surfaces are present, water apparently beads and forms crystals, leading to less apparent accumulation.

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Sprayable Aerogel Bead Compositions With High Shear Flow Resistance and High Thermal Insulation Value

This aerogel insulation could be used in fuel cell systems, oil and gas pipelines, and in building and construction applications. A sprayable aerogel insulation has been developed that has good mechanical integrity and lower thermal conductivity than incumbent polyurethane spray-on foam insulation, at similar or lower areal densities, to prevent insulation cracking and debonding in an effort to eliminate the generation of inflight debris.

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Controlled, Site-Specific Functionalization of Carbon Nanotubes With Diazonium Salts

Possible applications include molecular switches and molecular wires. This work uses existing technologies to prepare a crossbar architecture of nanotubes, wherein one nanotube is fixed to a substrate, and a second nanotube is suspended a finite distance above. Both nanotubes can be individually addressed electrically. Application of opposite potentials to the two tubes causes the top tube to deform and to essentially come into contact with the lower tube. Contact here refers not to actual, physical contact, but rather within an infinitesimally small distance referred to as van der Walls contact, in which the entities may influence each other on a molecular and electronic scale.

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A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries

A document discusses a thin layer of composite material, made from nano scale particles of nickel and Teflon, placed within a battery cell as a layer within the anode and/or the cathode. There it conducts electrons at room temperature, then switches to an insulator at an elevated temperature to prevent thermal runaway caused by internal short circuits. The material layer controls excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect.

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Non-Toxic, Non-Flammable, –80 ºC Phase Change Materials

The objective of this effort was to develop a non-toxic, non-flammable, –80 °C phase change material (PCM) to be used in NASA’s ICEPAC capsules for biological sample preservation in flight to and from Earth orbit. A temperature of about –68 °C or lower is a critical temperature for maintaining stable cell, tissue, and cell fragment storage.

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