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This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 1 November 2010, was one of a series of advanced technology reports produced in FY 2010 under the Advanced Aerospace Weapons System Applications (AAWSA) Program. It reviews ultracapacitors as energy and power storage devices. It covers how they work, their materials, their commercial and military uses, and new developments such as carbon nanotubes, thin films and magnetic capacitors. It concludes that the U.S. government must understand and adopt advanced ultracapacitors.
“Lockheed”3 pages
UNCLASSIFIED//P81il 8ffllil.t.k WE&i 811L>C ,s IJ Ill II Figure 9. Relationship Between Average Pore Size and Normalized Specific Capacitance. As the average pore size decreases below 1 nm, the specific capacitance increases due to distorted electrolyte ion salvation. THIN FILMS CNT films have been used in 2D thin-film ultracapacitors having respectable gravimetric and volumetric capacitance. Activated carbon powders have a better performance in terms of energy per unit area, 35 but they need to be processed into films before use, and this limits their choice for microdevice fabrication, which allows mass production of capacitors on semiconductor wafers. Carbide-derived carbon (CDC) is a class of carbon materials produced by selectively etching metals from metal carbides using chlorine at elevated temperatures in a process similar to current dry-etching techniques used in MEMS and microchip fabrication. CDC has been shown to have excellent performance as the active material in traditionally processed ultracaps36 since it can have its microstructure precisely tuned by tailoring the synthesis conditions for a particular electrolyte. 37 For microfabricated supercapacitors, CDC is attractive for several reasons. The precursor carbides are conductive and can be deposited in uniform thin and thick films by well-known chemical and physical vapor deposition (CVD and PVD) techniques. 38 In addition, the chlorination process can be performed at temperatures at least as low as 200°C, 39 and the resulting coatings are well-adhered with an atomically perfect interface, 40 which minimizes device impedance. This technology can be used to produce the microfabricated ultracaps on the same chip as the integrated circuits, which they are powering (shown in Figure 10). 41 Chlorine-containing plasma etching of materials in semiconductor manufacturing is a well-established technique and is similar to the chlorination procedure in CDC manufacturing. Continuous porous carbon films cannot be produced by conventional CVD, PVD, or other techniques, and the high-temperature activation needed to produce the microstructures necessary for ultracapacitor performance in CVD carbons would destroy the devices they were intended to power. 20 UNCLASSIFIED,' }Flilll. lilFFUilAle lal!il! 8Hl!V
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 34 pages are in the text index: search them above, or from the library's search.