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This Defense Intelligence Reference Document was prepared by the Defense Intelligence Agency's Defense Warning Office and dated 1 November 2010. It is one of a series of advanced technology reports produced under the Advanced Aerospace Weapons System Applications Program. The report reviews how ultracapacitors work, how they compare with batteries, their history and materials, and their commercial, military and aerospace uses. It concludes that new materials and cell designs will raise energy density and that the U.S. government must understand the devices' spectral signatures.
From the source: Release of 2026-09-18 Incident: 11/1/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys ultracapacitors as high-power energy-storage devices and argues that their main value lies in extremely rapid charge and discharge, very long cycle life, and usefulness in systems that need short bursts of power rather than sustained energy delivery. The report explains how ultracapacitors differ from batteries, reviews the materials and cell designs that determine their performance, and emphasizes that they are especially useful for power stabilization, backup power, load leveling, regenerative braking, and other applications where fast energy transfer matters more than total stored energy. It also notes their drawbacks, including lower energy density, self-discharge, and voltage-management requirements that limit their usefulness as stand-alone replacements for batteries in many applications. The document presents ultracapacitors as a maturing and increasingly important technology whose most credible aerospace and military uses lie in pulsed-power, missile and munitions systems, electric propulsion support, and other hybrid power architectures rather than in long-duration primary energy storage.
UNCLASSIFIED1fFOR 8ffl@IAL tt.!! e"t I Activated carbons are synthesized by a heat treatment of carbon-rich organ ic precursors in a controlled atmosphere. This carbon ization process can be performed from natural sources, such as fru it shells, wood, pitch, or coke. Activated carbons can also be produced from synthetic precursors, such as select polymers. The heat treatment process uses a controlled partial oxidation of the precursor combined with a high-temperature processing. The high-temperature processing can be done in an inert atmosphere, an oxidizing environment, or with a chemical modification. The activated carbons conta in a distributed porous network throughout, as shown in Figure 5.17 These materials can have an extremely high surface area, upward of 3,000 m 2/g, but process conditions to create activated carbons have little control over pore size distribution, resulting in incomplete utilization of the surface area. Carbon cloth electrodes use processi ng conditions sim ilar to those used to create activated carbons. The advantage with a fabric composed of activated carbon is t hese materials are directly used as active electrodes, requiring no binder or additional processing. However, these tend to be expensive to produce, which has thus far limited their use to specialized applications. rnacroporcs >50 run ~ -1-- mi r pre <2nm mesopore 2-50nm Figure 5. Activated Carbon Porosity. These can be produced with a distribution of pore sizes ranging from less than 2 nm to greater than SO nm . Continued improvements to the carbon electrodes are expected to provide additional performance enhancement to ultracaps. Current research is leading toward carbon materials with higher specific capacitance (F/g). Improved materials, such as carbon nanotubes and tailored porous carbons show promise as the next generation of carbon materials. Graphene is another advanced carbon material that shows promise to providing increased capacitance. One of the key design issues revolves around improved understanding of the relationship between the carbon pore size and the electrolyte ion. The nanostructured materials allow fine tuning of the porous structure to increase capacitance. Ca rbon nanotubes (CNTs) are commonly produced as powders where they can be cast as a distributed network to form an electrode, and they can be used as an additive to increase conductivity. Additionally, CNTs can be grown as a "forest," where the CNTs are grown perpendicu lar to a substrate. These forests can be used as is or can be modified or coated to change specific structural or electronic properties. CNTs are grown by a number of methods, but most methods used currently are a derivative of a chemical vapor deposition (CVD) process. The specific properties of the nanotubes are extremely tailorable. CNT length, diameter, the number of tubes, and t he electronic properties can all be tailored by growth conditions. The catalysts used to grow CNTs can affect tube properties, as well as CNT temperature and precursor variables. Carbon nanotubes are finding utility in both battery and ultracapacitor applications, where they are used for conductivity enhancement and energy storage. Their capacitive behavior suggests they may have a fundamentally different storage mechanism than traditional carbon. Storage potential includes CNT outer walls, inner diameter, and interwall spaces UNCLASSIFIEO/fFOA OFFI&I:.l.b YS& ONLY 10
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Official release, from the pursue 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.