Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




ENERGY TECH
New rechargeable flow battery enables cheaper, large-scale energy storage
by Jennifer Chu, MIT News Office
Boston MA (SPX) Aug 20, 2013


Low-cost energy storage has the potential to foster widespread use of renewable energy, such as solar and wind power.

MIT researchers have engineered a new rechargeable flow battery that doesn't rely on expensive membranes to generate and store electricity. The device, they say, may one day enable cheaper, large-scale energy storage.

The palm-sized prototype generates three times as much power per square centimeter as other membraneless systems - a power density that is an order of magnitude higher than that of many lithium-ion batteries and other commercial and experimental energy-storage systems.

The device stores and releases energy in a device that relies on a phenomenon called laminar flow: Two liquids are pumped through a channel, undergoing electrochemical reactions between two electrodes to store or release energy. Under the right conditions, the solutions stream through in parallel, with very little mixing. The flow naturally separates the liquids, without requiring a costly membrane.

The reactants in the battery consist of a liquid bromine solution and hydrogen fuel. The group chose to work with bromine because the chemical is relatively inexpensive and available in large quantities, with more than 243,000 tons produced each year in the United States.

In addition to bromine's low cost and abundance, the chemical reaction between hydrogen and bromine holds great potential for energy storage. But fuel-cell designs based on hydrogen and bromine have largely had mixed results: Hydrobromic acid tends to eat away at a battery's membrane, effectively slowing the energy-storing reaction and reducing the battery's lifetime.

To circumvent these issues, the team landed on a simple solution: Take out the membrane.

"This technology has as much promise as anything else being explored for storage, if not more," says Cullen Buie, an assistant professor of mechanical engineering at MIT. "Contrary to previous opinions that membraneless systems are purely academic, this system could potentially have a large practical impact."

Buie, along with Martin Bazant, a professor of chemical engineering, and William Braff, a graduate student in mechanical engineering, have published their results this week in Nature Communications.

"Here, we have a system where performance is just as good as previous systems, and now we don't have to worry about issues of the membrane," Bazant says. "This is something that can be a quantum leap in energy-storage technology."

Possible boost for solar and wind energy
Low-cost energy storage has the potential to foster widespread use of renewable energy, such as solar and wind power. To date, such energy sources have been unreliable: Winds can be capricious, and cloudless days are never guaranteed. With cheap energy-storage technologies, renewable energy might be stored and then distributed via the electric grid at times of peak power demand.

"Energy storage is the key enabling technology for renewables," Buie says. "Until you can make [energy storage] reliable and affordable, it doesn't matter how cheap and efficient you can make wind and solar, because our grid can't handle the intermittency of those renewable technologies."

By designing a flow battery without a membrane, Buie says the group was able to remove two large barriers to energy storage: cost and performance. Membranes are often the most costly component of a battery, and the most unreliable, as they can corrode with repeated exposure to certain reactants.

Braff built a prototype of a flow battery with a small channel between two electrodes. Through the channel, the group pumped liquid bromine over a graphite cathode and hydrobromic acid under a porous anode. At the same time, the researchers flowed hydrogen gas across the anode. The resulting reactions between hydrogen and bromine produced energy in the form of free electrons that can be discharged or released.

The researchers were also able to reverse the chemical reaction within the channel to capture electrons and store energy - a first for any membraneless design.

In experiments, Braff and his colleagues operated the flow battery at room temperature over a range of flow rates and reactant concentrations. They found that the battery produced a maximum power density of 0.795 watts of stored energy per square centimeter.

More storage, less cost
In addition to conducting experiments, the researchers drew up a mathematical model to describe the chemical reactions in a hydrogen-bromine system. Their predictions from the model agreed with their experimental results - an outcome that Bazant sees as promising for the design of future iterations.

"We have a design tool now that gives us confidence that as we try to scale up this system, we can make rational decisions about what the optimal system dimensions should be," Bazant says. "We believe we can break records of power density with more engineering guided by the model."

Yury Gogotsi, a professor of materials science and engineering at Drexel University, says eliminating the membrane is the next step toward scalable, inexpensive energy storage. The group's design, he says, will help engineers better understand the physics of membraneless systems.

"You cannot have an inexpensive energy-storage system by piling up tens of thousands of individual small cells, like cellphone or computer batteries," says Gogotsi, who did not contribute to the research. "As any new technology, the laminar flow battery will need time to prove its viability. It's like a newborn baby - we'll only know what the technology is good for after a few years."

According to preliminary projections, Braff and his colleagues estimate that the membraneless flow battery may produce energy costing as little as $100 per kilowatt-hour - a goal that the U.S. Department of Energy has estimated would be economically attractive to utility companies.

"You can do so much to make the grid more efficient if you can get to a cost point like that," Braff says. "Most systems are easily an order of magnitude higher, and no one's ever built anything at that price."

.


Related Links
MIT
Powering The World in the 21st Century at Energy-Daily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ENERGY TECH
Fuel Cell Innovation By UNIST Researchers
Ulsan, South Korea (SPX) Aug 14, 2013
Research team of Ulsan National Institute of Science and Technology (UNIST), Georgia Institute of Technology, and Dong-Eui University developed a novel cathode material which has outstanding performance and robust reliability even at the intermediate temperature range. As high power density devices, fuel cells can convert chemical energy directly into electric power very efficiently and en ... read more


ENERGY TECH
NASA Prepares for First Virginia Coast Launch to Moon

NASA Selects Launch Services Contract for OSIRIS-REx Mission

Environmental Controls Move Beyond Earth

Bad night's sleep? The moon could be to blame

ENERGY TECH
International Space Agencies Outline Steps to Take Humans to Mars

Snapping Pictures of the Martian Moons

Mars Rover Opportunity Working at Edge of 'Solander'

MRO Swapping Motion-Sensing Units

ENERGY TECH
NSBRI and NASA Reduce Space Radiation Risks by Soliciting for Center of Space Radiation Research

Next Generation of Explorers Takes the Stage

Has Voyager 1 Left The Solar System?

Groundbreaking space exploration research at UH

ENERGY TECH
China launches three experimental satellites

Medical quarantine over for Shenzhou-10 astronauts

China's astronauts ready for longer missions

Chinese probe reaches record height in space travel

ENERGY TECH
Cosmonauts Complete Spacewalk, Unfold Russian Flag in Space

Italian astronaut recounts spacewalk drowning terror

ISS Boosting Biological Research in Orbit

Japanese Cargo Craft Captured, Berthed to ISS

ENERGY TECH
NASA Explores New Uses for Historic Launch Structures

Telemetry data confirms launch of South Korean satellite

ISRO pins hopes on GSLV-D5

Lockheed Martin Selects CubeSat Integrators for Athena to Enhance Launch Systems Integration

ENERGY TECH
Study: Planets might be 'born free' without a parent star

Distant planet sets speed record by orbiting its star every 8.5 hours

Kepler planet hunter spacecraft is beyond repair: NASA

Astronomers Image Lowest-mass Exoplanet Around a Sun-like Star

ENERGY TECH
U.S. firm releases $1,400 scanner to create 3-D printing files

Boeing Communications Relay Satellites Complete Space, Earthly Testing

Mobius strip ties liquid crystal in knots to produce tomorrow's materials and photonic devices

The world's future tallest skyscrapers: who will be first to break the 1,000-meter mark?




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement