A
repository developed by Duke University engineers that they call a
“materials genome” will allow scientists to stop using trail-and-error
methods for combining electricity-producing materials called
“thermoelectrics.”
Thermoelectric
materials produce electricity by taking advantage of temperature
differences on opposite sides of a material. They are currently being
used in deep space satellites and camp coolers. But until now,
scientists have not had a rational basis for combining different
elements to produce these energy-producing materials.
The
project developed by the Duke engineers covers thousands of compounds,
and provides detailed “recipes” for creating most efficient combinations
for a particular purpose, much like hardware stores mix different
colors to achieve a particular tint of paint. The database is free and
open to all (aflowlib.org).
“We
have calculated the thermoelectric properties of more than 2,500
compounds and have calculated all their energy potentials in order to
come up with the best candidates for combining them in the most
efficient ways,” said Stefano Curtarolo, associate professor of
mechanical engineering and materials sciences and physics at Duke’s
Pratt School of Engineering. “Scientists will now have a more rational
basis when they decide which elements to combine for their
thermoelectric devices.”
The results of the Duke team’s work were published online in the journal Physics Review X.
A
thermoelectric device takes advantage of temperature differences on
opposite sides of a material – the greater the temperature difference,
the greater energy potential.
Thermoelectric
devices are currently used, for example, to provide power for
deep-space satellites. The side of the device facing the sun absorbs
heat, while the underside of the device remains extremely cold. The
satellite uses this temperature difference to produce electricity to
power the craft.
Different
material combinations may be a more efficient method of turning these
temperature differences into power, according to Shidong Wang, a
post-doctoral fellow in Curtarolo’s lab and first author of the paper.
Thermoelectric
materials can be created by combining powdered forms of different
elements under high temperatures – a process known as sintering. Not
only does the new program provide the recipes, but it does so for the
extremely small versions of the particular elements, known as
nanoparticles. Because of their miniscule size and higher surface areas,
nanoparticles have properties unlike their bulk counterparts.
“Having
this repository could change the way we produce thermoelectric
materials,” Wang said. “With the current trial-and-error method, we may
not be obtaining the most efficient combinations of materials. Now we
have a theoretical background, or set of rules, for many of the
combinations we now have. The approach can be used to tackle many other
clean energy related problems.”
The
Duke researchers believe that the use of thermoelectric devices—which
the new database should help fuel—could prove especially effective in
cooling microdevices, such as laptop computers.
Wang
and Curtarolo made use of data collected by the aflowlib.org
consortium, a cloud-distributed repository for materials genomics. It
currently comprises electronic structures, magnetic and thermodynamic
characterization of inorganic compounds. The project, started by Duke
scientists, is sponsored by the Office of Naval Research, the National
Science Foundation and the U.S. Department of Homeland Security.
Duke’s
Wahyu Setyman, as well as Zhao Wang and Natalio Mingo of France’s
Atomic Energy and Alternative Energies Commission, were also part of the
research team.