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AAWSAP DIRD, Ultracapacitors as Energy and Power Storage Devices, November 2010

U.S. Department of War · 2010-11-01 · 34 pages · text from the file's own layer

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
r------- /
MCap nanocell / /
1.6μm
o.55μmJ• •I / /
Magnetic materials "'i / /
Dielectric layer -- / MCap cell
Magnetic materials ,----,•...____ / Made up of millions
(all proprietary compositions) / / MCap nanocells
~- - - - - - - - ../
Figure 12. MCap Structure. MCap nanocell and MCap cell are fabricated using traditional semiconductor
fabrication processes .
MCap cells are then packaged into larger MCap modules. The capacitance of the device
is given by the equation , C = so k A/d, where A is the area of the plate, d is the
separation between plates, so the permittivity of free space, and k is t he dielectric
constant (or relative permittivity) of the material. The MCap increases capacitance by
increasing the dielectric constant k through the GMC effect (fGMc) given by t he
relationship, k' = k*fGMc- GMC acts like a charge trap that brings electrons closer, thus
increasing electron densities at the plates. Based on quantum theory, GMC brings about
a capacitance which, to date, has been measured to be 109 times larger than that
observed in electrostatic capacitors. As shown earlier in equation (2), energy is
proportional to the capacitance and the voltage squared. Moreover, capacitor leakage
and self-discharge are essentially eliminated as electrons are "trapped" in the magnetic
field.
Due to the above effects, the available energy for a large range of storage devices, like
smart cards and other products, can be increased substantially by simply packaging
them in series-parallel connected modules to meet the energy and voltage
requirements. Coupled with Lockheed Martin's extensive nanomaterials and device
physics experience, it is likely that NLSC will be able to use its MRAM development
expertise to accomplish this.
Experimental Results
Over the last year, NLSC has had MCap structures and nanocells tested by independent
parties with results shown in Figure 13. These unbiased tests demonstrate the validity
of the high-capacitance claims. Figure 14 quantifies the progress in improved
performance throughout the development of the device. The number of devices that
demonstrate the GMC behavior has increased substantially in 2009, which is reportedly
due to improved materials development rather than an increased production load. The
performances of the nanocells as well as the variability are plotted, which shows that
potential improvement in the materials could lead to an increased GMC factor. There is
promising evidence that improvements may allow a higher level of performance, which
could match lithium ion batteries at ambient temperature and perhaps exceed them at
low and high temperatures.
UNCLASSIFIEO/fFOA OFFI&I:.l.b YS& ONLY
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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.