Documents / Official release
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.
UNCLASSIFIED11FOR. 8FFl@IAL tt.!! e"t I of some CNT types. Carbon nanotubes have been a rich area of study for many applications, which has translated to a broad understanding of synthesis techniques to produce CNTs with tailorable properties. Graphene can be thought of as a sheet of graphite, either a single layer or a few layers thick. The two-dimensional nature of graphene leads to extremely high electron transport across the surface, interesting magnetic properties, high strength, and a large accessible surface area. 18 Graphene is generally made by exfoliation/separation of graphite or grown by CVD processes. Derivations from both of these methods can produce single-layer graphene or few-layer graphene. These methods include, but are not limited to, CVD methods, epitaxia l growth, solvothermal synthesis, micromechanical exfoliation, and colloidal synthesis. 19 Graphene has generated an enormous amount of attention due to its potential for transforming electronics. A number of approaches to graphene synthesis are being used that consider purity, scalability, and cost. Carbide-derived carbons are a unique class of porous carbons with extremely fine control over pore size. 20 These porous carbons are derived by chlorination of metal carbides at very high temperatures. At temperatures of 500-1000°C, metals and metalloids are removed as chlorides, leaving behind a finely tunable nanoporous carbon. These porous carbons have a pore-size distribution that is tunable within 0.05 nm. The extremely accurate tunability has allowed these systems to serve as a model for the relationship of pore size and capacitance, thereby allowing for design of materials to be tailored for maximum capacitance within a specific system. The local maximum in capacitance is dependent on the ion salvation sphere, which is a product of the electrolyte ion, solvent, and interaction with the pores of the electrode. These findings will lead to new electrode materials and designs. Activated carbon and other porous carbon derivatives are commonly used for symmetric ultracapacitors. Metal oxides such as ruthenium oxide and conductive polymers replace one of the electrodes to create an asymmetric system. Asymmetric electrodes greatly increase the storage capacity of ultracapacitors. These are a different class of capacitor, as they store their charge both in the electrica l double layer and using a surface redox (faradaic) reaction (in the same manner as a battery). While these undergo electron transfer reactions, they behave in a capacitive fashion. Often termed pseudocapacitor, this class of materials includes a variety of metal oxides and conductive polymers. The capacitance of an asymmetric electrode is twice that of a symmetric design. The electron transfer electrode essentially has a fixed potential, whereas the potential of the carbon electrode changes with state of charge. Add itional storage capacity arises from the higher working voltage, due to the different rest potentials of the different electrodes. Asymmetric electrodes are becoming increasingly common due to the increased energy storage capability. As energy is proportional to the voltage squared, the higher operating voltage has profound effects on the capacity. Ruthenium oxide (RuO2) has been shown to give capacitance of as high as 1300 F/cm 3 • By comparison, carbonaceous materials in an aqueous electrolyte have a capacitance of 110-125 F/cm 3 . There are many additional metal oxides being investigated for insertion into the ultracapacitor system. Many of these have their roots in lithium ion battery cathode materials. As ultracaps gain wider acceptance, market size is increasing rapidly and is expected to grow at an increasing pace. Investigations are being conducted into alternative metal oxide systems to ensure that cost, supply, and performance can be met on a global scale. Manganese oxide (MnO2) and nickel metal oxides/hydroxides are UNCLASSIFIEO/;LFOA OFFI&il:.l.b YS& OrtLY 11
Not linked to a story yet.
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.