MURI - Three Dimensional Architectures
for
Electrochemical Power Sources
ABSTRACT
Thin film batteries have demonstrated rather impressive performance
with respect to lithium capacity, cycle life and energy density. Despite
their excellent characteristics, these batteries underscore the inherent
limitations in 2-D battery systems; thin film batteries are unable to
provide meaningful power levels for reasonable periods of time.
We propose to overcome the size and energy density deficiencies of thin
film batteries by creating cubic-millimeter sized power supplies based
on three-dimensional (3-D) geometries. 3-D configurations offer a means
of keeping the diffusion distances "short" and yet provide
enough active material such that the 3-D batteries will be capable of
powering MEMS devices and microelectronic circuits for extended periods
of time. We have assembled an interdisciplinary team combining research
Universities with the Naval Research Laboratory in a program that will
provide the 3-D nanoarchitecture designs, fabrication approaches and
enabling science for a new generation of electrochemical power sources.
Our program will proceed along dual fronts:
1) One activity will focus on the fabrication, testing and analysis
of 3-D batteries in which the electroactive components are of micrometer
length scale;
2) In parallel, we will establish the basic 3-D architectures and fabrication
strategies for creating electroactive structures at the nanometer
length scale.
At the micrometer length scale, the ability to design and fabricate
a functioning 3-D battery currently exists, but has yet to be exploited.
Our program takes advantage of the extensive advances in micromachining
and other technical areas that are well away from the power sources
field to demonstrate a functional 3-D battery architecture. The
outcome here is a tangible device that not only powers a MEMS microactuator
but also establishes an important paradigm shift to the power sources
field - from 2-D to 3-D. The research in support of this goal
includes numerical modeling and scientific studies of colloidal materials
synthesis and processing.
The second research activity is directed at the dimensional regime of
100 nm and below, where 3-D design and fabrication strategies are still
evolving. The MURI team will address the key materials synthesis
and fabrication issues that will provide the enabling science and technology
for producing 3-D nanostructured batteries. Three complementary
approaches are identified for synthesizing electroactive nanoscale building
blocks. An important component of this work will be model simulations
which consider transport and electrode kinetics at the nanoscale.
We believe that our "two-level" strategy, of an integrated
device/fundamental science program, is designed to meet the challenge
of creating revolutionary approaches to electrochemical power sources.
Charles R. Sides
and Prof. Martin's work on nanostructured electrodes is selected as
cover art for
