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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.
UNCLASSIFIED1/FOR 8ffl@IAL tt91! e"t I there is room for improvement on these values. Optimization of graphene synthesis to produce finer control is an area receiving increased attention in research and development activities in universities, national labs, and industria l research facilities. Lockheed Martin is actively engaged in research investigating graphene and appl ications where graphene could be a critical differentiator. There are a number of companies that supply graphene made from various methods, as well as emerging startups geared toward producing graphene-based ultracapacitors or materials designed for ultracaps. Figure 8. Transmission Electron Microscope Image of Graphene. This could be an excellent ultracapacitor electrode material with its hig h surface area and excellent conductivity. 33 Manipulation of the porosity of high surface area carbons leads to the largest difference in specific capacitance . Understanding the relationship between the electrolyte ion size and the carbon pore size is critical to improving performance. There are a number of strategies being investigated for fine control over the pore-size distribution to increase the specific capacitance. The most common methods used currently are template methods and carbide-derived carbons. Template methods create a controlled mesoporous structure with a fairly narrow range. These structures have pores that range from 2 to 10 nanometers and are maximized to pore sizes roughly twice that of the solvated ions. The template process involves filling the pores of an inorganic template host with a carbon precursor (such as an alumina template). The template is removed after carbonization by acid treatment . The pore size is then dictated by the template as t he pores are the remaining void space once occupied by the template . Similar methods have shown that smaller pores, including those less than two nanometers, may provide high specific capacitance. The realizati on t hat smaller pores contribute to charge storage in an electric double layer has led to the need to develop a better understand ing of the charge storage mechanism. Carbide-derived carbons have a unique pore-size distribution that is tunable with sub angstrom accuracy. These have served as models to study the charge storage behavior and ion adsorption in pore sizes ranging from 0.6 nm to 1.1 nm. 34 The normalized capacitance decreases with decreasing pore size until a critical value is reached. Figure 9 shows t he relationship between average pore size and the normalized specific capacitance. Pore sizes smaller than one nanometer significantly contribute to the charge storage despite the fact that the solvated ion size is larger than the pore diameter. The capacitance increase is explained by a distorted ion shell model. The ion salvation shell is perturbed such that it is capable of a closer approach of the ion and the carbon surface. The discoveries at Drexel University that util ize the fine control to create tailored porous carbon structures can maximize specific capacitance for a given ultracapa citor system. UNCLASSIFIEO/fFOA OFFI&I:.l.b YS& ONLY 19
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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.