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A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A R C H 2 0 1 5
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BRIEFS
The Global Climate and Energy Project
(GCEP) at
Stanford University,
Calif., awarded $10.5 million for seven research projects
designed to advance a broad range of renewable energy technologies. The funding will be shared by six Stanford research teams
and an international group from the U.S. and Europe. These new awards bring the total number of GCEP-supported programs to
117 since the project’s launch in 2002. GCEP has awarded $161 million to researchers at Stanford and 40 other institutions world-
wide.
gcep.stanford.edu.PEROVSKITE SOLAR CELLS
CLOSER TO REALITY
Researchers at DOE’s Los Alamos
National Laboratory, N.M., fabricat-
ed planar solar cells from perovskite
materials with large crystalline grains
that had efficiencies approaching 18%,
among the highest reported in the field
of perovskite-based light-to-energy con-
version devices. The cells demonstrate
little cell-to-cell variability, resulting in
devices showing a hysteresis-free pho-
tovoltaic response, which had been a
fundamental bottleneck for stable op-
eration of perovskite devices. “Charac-
terization and modeling attribute the
improved performance to reduced bulk
defects and improved charge-carrier
mobility in large-grain perovskite ma-
terials,” says Aditya Mohite, lead scien-
tist, “and we’ve demonstrated that the
crystalline quality is on par with that
observed for high-quality semiconduc-
tors like silicon and gallium arsenides.”
For more information: Aditya Mohite,
amohite@lanl.gov, www.lanl.gov.BUILDING BETTER
CAR BATTERIES
Smaller, lighter electric car batter-
ies that don’t have to sacrifice longev-
ity to be petite could be one benefit of
basic research into lithium-ion battery
nanomaterials at The University of Al-
abama in Huntsville. A $502,000 Na-
tional Science Foundation Faculty Early
Career Development Program grant
is funding research into nanomaterial
cathodes for the batteries by George
Nelson, assistant professor of mechan-
ical and aerospace engineering. Nano-
materials may make the trade-off be-
tween high battery power and smaller
size a more favorable one over the wide
temperature variations experienced by
cars and other devices.
Traditionally, cathodes are made
of larger materials on the micron scale
that fit together more loosely than
smaller nanomaterials. Nanomaterials
have much greater surface area for the
chemical interactions that create elec-
tric current, resulting in more power for
their size. However, that can be a draw-
back when it comes to lifespan over a
wide temperature range.
“We suspect that increased tem-
perature will shorten battery life for
these materials, more so than tradi-
tional materials,” says Nelson. There-
fore, researchers are charging and dis-
charging batteries made with different
cathode compositions at various tem-
peratures and using x-ray nanotomog-
raphy to observe changes in the cath-
ode structure to help determine which
higher-power nanomaterial has the
longest lifespan.
For more information:
George Nelson,
george.nelson@uah.edu,
www.uah.edu.Scientists Aditya Mohite, left, and Wanyi Nie are perfecting a crystal production tech-
nique to improve perovskite crystal production for solar cells at Los Alamos National
Laboratory.
Batteries made with different cathode
compositions are being charged and
discharged at various temperatures using
x-ray nanotomography to help determine
which nanomaterials have the longest
lifespan.
ENERGY TRENDS