W. Craig Carter - Fostering U.S.-Russia energy innovation
Center for Electrochemical Energy Storage brings together researchers
from MIT and two Russian institutes to develop advanced batteries and
Denis Paiste | Materials Processing Center
April 10, 2015
ion batteries are popular for powering portable electronic devices but
remain expensive for larger applications such as all-electric vehicles.
"All the technology that wows us, all the portability that we have
quickly gotten used to, is based on lithium ion batteries. There is an
intense interest in still higher capacity batteries," says Carl V.
Thompson, co-director of the Skoltech Center for Electrochemical Energy
Research into lithium ion batteries is a key area for CEES,
which is a partnership between the MIT Materials Processing Center and
Lomonosov Moscow State University. CEES is a Center for Research,
Education and Innovation (CREI) under the umbrella of the Skolkovo
Institute of Science and Technology (Skoltech).
"It's a great team and we're making rapid progress. We've got some
good collaborations going on. Things are up and running at Skoltech, and
we're enthusiastic about the future," Thompson says.
CEES has three main research thrusts:
• advanced lithium ion and multivalent ion batteries, led by Yet-Ming
Chiang, the Kyocera Professor Department of Materials Science and
Engineering at MIT, and Evgeny Antipov, professor and electrochemistry
chair at Moscow State;
• rechargeable metal-air batteries, led by MIT Professor Yang
Shao-Horn and Evgeny Goodilin, professor and deputy dean of materials
science at Moscow State; and
• reversible fuel-electrolysis cells, led by Harry Tuller, professor
of ceramics and electronic materials at MIT, and Evgeny Antipov at
Research in electrochemical energy storage is highly
interdisciplinary. Key scientific issues involve the chemistry of the
electrolyte and electrodes, their interactions, and the structure and
surface properties of these materials. "It's right at the intersection
of physics, chemistry, materials and engineering," Thompson explains.
Altogether, eight MIT faculty members and eight Moscow State
University faculty members are engaged in CEES-related research. "Within
MIT, there are people from materials engineering, mechanical
engineering, chemical engineering and chemistry," says Thompson, who is
the Stavros Salapatas Professor of Materials Science and Engineering at
MIT as well as director of the Materials Processing Center. Thompson
previously served from 2000 to 2014 as co-chair of the MIT Singapore
Alliance's Program in Advanced Materials for Micro- and Nano-Systems.
Director Keith J. Stevenson joined CEES in Moscow from
the University of Texas at Austin, where he served as
professor of chemistry. "He's an outstanding scientist," Thompson says.
Raising energy storage density
Chiang, MIT colleague W. Craig Carter, with their associates, published a study on March 4 in Advanced Energy Materials showing
use of aluminum ions as an energy-storage mechanism in a capacitor.
Aluminum is more abundant and less costly than lithium.
The aluminum ion research fits into a quest to find battery materials
that pack higher charge density than lithium. The advantage of aluminum
is that it carries three charges per ion compared with lithium, which
carries just one. This allows storage of charge at a higher volumetric
or gravimetric density, which translates to a higher stored energy
density or storage capacity for a given size or weight. Other work
focuses on sodium as an earth-abundant alternative to lithium, but while
it could lower cost, sodium ions also carry just a single charge.
The metal-air thrust is examining whether a metal-air battery that stores lithium in the form of its oxide, lithium peroxide (Li2O2),
with potential for greatly enhanced energy storage density, can be made
to function reversibly. "If you have a chunk of lithium peroxide, half
of the atoms are lithium. That's a very high storage density," Thompson
explains. "The ideal is to have a metal air battery that is reversible,
that can cycle back and forth, discharge and recharge."
Storing intermittent energy
High-temperature solid-oxide fuel cells and solid-oxide electrolysis
cells have potential over the intermediate term to double energy
efficiency from fossil fuels and reduce greenhouse gas emissions as well
as over the long-term to enable the shift to renewable energy sources
such as solar and wind. The solid oxide fuel cell-electrolysis thrust
aims to optimize conversion efficiency between chemical and electrical
energy, lower operating temperatures to increase the lifetime of these
devices, and bring down costs.
The project is examining how to combine electrolysis, or
electrochemical water splitting, with a fuel-cell-like design. "You can
split water to make hydrogen and then use the fuel cell to convert the
hydrogen into electrical energy. You store the energy by storing the
hydrogen. It becomes an energy storage system when you couple
electrolysis and fuel cells," Thompson says.
"We need a way of producing alternative cleaner fuels, minimizing use
of hydrocarbons, or at a minimum recycling the carbon dioxide to form
these more useful fuels. High-temperature systems really offer a number
of advantages in terms of actually being able to do that, particularly
decomposing carbon dioxide, but also doing so with less costly materials
and more efficiently," fuel cell thrust leader Tuller says. Using fuel
cells to convert hydrocarbon fuels directly to electricity could double
extraction efficiency, from about 30 percent to about 70 percent, while
at the same time cutting carbon dioxide (CO2) emissions by half.
Because solar and wind energy are intermittent, producing energy only
when the sun shines or the wind blows, a method to capture and store
energy for later use is needed. Fuel cells, coupled with electrochemical
electrolysis, have potential to serve that role. One way is to generate
hydrogen by splitting water and storing the hydrogen. "The challenge
with hydrogen is that while it has a high energy density on a weight
basis, it has a very low energy density based on a volume basis, and the
infrastructure that we now have is not particularly designed to
transmit that hydrogen over long distances. So ideally what you'd prefer
is something that more closely resembles conventional fuels," Tuller
"If we could take CO2 which is now problematic, and
use some sort of technique to decompose CO2 back into, for example,
carbon monoxide [CO], then there are a variety of different ways in
which you can react hydrogen and the CO to produce gaseous fuels like
methane or liquid hydrocarbon fuels," he says. "The big advantage there
is if you can convert that back into synthetic gas, which resembles
natural gas, or a liquid fuel, like gasoline, then we have this enormous
infrastructure already available nationwide and world-wide where we can
store it, transmit it and use it in many different ways, including for
transportation. We can use it in vehicles, we can use it in aircraft,
and so forth," he says.
Electrolyzers operating in the 100-degrees Celsius range, such as
polymer electrolyte-based cells, can split water, but they can't very
efficiently decompose CO2, Tuller says. Likewise polymer electrolyte membrane (PEM) fuel cells operate only with H2 as
the fuel and only then with platinum electrodes. Solid-oxide-based
cells operating at high temperature are more efficient and can operate
with lower-cost metal oxide catalysts versus more expensive platinum.
But the solid-oxide materials are more difficult to fabricate, which
increases cost, and higher temperatures accelerate certain reactions
that shorten operating life.
"We're looking to try to understand in more detail what are the
sources of degradation and what are the factors which limit performance
at lower temperatures," Tuller explains. The researchers are creating
model systems for fuel cell structures to do a better job of isolating
factors that contribute to performance and investigating novel materials
with promising features in terms of both endurance and performance.
In particular, the researchers are looking at modifying the
morphology, or physical structure, of the electrode materials, to
enhance transport of gas molecules through their pores, flow of ions and
electrons through the solid part of the electrode, and catalytic
activity at the electrode interface.
A patent disclosure related to the electrode material morphology work
is expected in the next month or so, Tuller says. One of the explicit
objectives of the Skoltech program is to create new technology and
perhaps spinoff companies, he notes. "MIT is noted for its
entrepreneurship and they want to get a better sense of how this is done
and how do we translate that into something similar in the Russian
environment," Tuller says.
A Feb. 5 report
in the Journal of Physical Chemistry by Shao-Horn and colleagues
at MIT, Oak Ridge National Laboratory, and the University of Wisconsin
at Madison examined the role of tensile strain and electronic
conductivity in oxide materials for oxygen electrocatalysis, focusing on
the catalytic activity of LaCoO3 (LCO) thin films. The
study uncovered an unequal influence of charge-transfer resistance, with
a greater influence on the oxygen-reduction reaction and a lesser
influence on the oxygen-evolution reaction. The new understanding can
help incorporate the effects of strain to guide the design of highly
active catalysts, the researchers say.
A different collaboration between Shao-Horn and researchers at SLAC
National Accelerator Laboratory and the Advanced Light Source further
explored new methods for studying the influence of chemistry on oxide
electronic properties in a paper published in the Journal of Physical Chemistry C.
Combining techniques from synchrotron X-ray spectroscopy, they
developed a method for studying trends in the energy of electronic
states on an absolute scale. Insights from this approach can shed light
on the catalytic properties of oxides for fuel cells, electrolyzers, and
Student, faculty visits
Skoltech MIT Center for Electrochemical Energy Storage got started in
October 2013 and completed its first full year in 2014. So far, just a
small number of students from Skoltech have come to MIT, usually
first-year master's degree students, but Thompson anticipates that over
time more master's and PhD students will be doing research at MIT. "We
have had short-time visitors at the post doc and research staff level
from Moscow State and that will be happening all the time. The
presumption is some of our students will spend time at Moscow State and
Skoltech as it comes on line," he says. As collaborations deepen between
Skoltech and MIT researchers, among both faculty and students,
communications grow and group members will spend more time with each
Visits to MIT by Skoltech CEES Director Keith Stevenson and Moscow
State University faculty have yielded insights into different materials
that operate better at much lower temperatures for different
applications and optimizing material properties by manipulating complex
crystal chemistries, Tuller says.
CEES also has a Russian co-director, Alexei Khokhlov, who is
professor and head of polymer physics as well as vice-rector at Moscow
State University. He leads the research team at Moscow State. MIT CEES
Assistant Director Jack Kosek is responsible for budgeting, reporting,
and managing timetables.
The Skoltech-MIT CEES partnership is expected to run for five years.
CEES is part of the larger Skoltech effort to create a Silicon
Valley-like innovation hub in Russia by pairing the fledging
graduate-level institute with an industrial and commercial park setting.
The Russian economy is heavily dependent on selling carbon-based fossil
fuels, principally oil and gas. "For Russia to have economic stability
and balanced relationships with other nations, it's important for its
economy to become more diverse and more broadly integrated with the rest
of the world," Thompson says.