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How a Single Chemical Bond Balances Cells Between Life and Death

With SLAC's X-ray laser and synchrotron, scientists measured exactly how much energy goes into keeping a crucial chemical bond from triggering a cell's death spiral.

New Efficient, Low-Temperature Catalyst for Converting Water and CO to Hydrogen Gas and CO2

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Study Sheds Light on How Bacterial Organelles Assemble

Scientists at Berkeley Lab and Michigan State University are providing the clearest view yet of an intact bacterial microcompartment, revealing at atomic-level resolution the structure and assembly of the organelle's protein shell. This work can help provide important information for research in bioenergy, pathogenesis, and biotechnology.

A Single Electron's Tiny Leap Sets Off 'Molecular Sunscreen' Response

In experiments at the Department of Energy's SLAC National Accelerator Laboratory, scientists were able to see the first step of a process that protects a DNA building block called thymine from sun damage: When it's hit with ultraviolet light, a single electron jumps into a slightly higher orbit around the nucleus of a single oxygen atom.

Researchers Find New Mechanism for Genome Regulation

The same mechanisms that separate mixtures of oil and water may also help the organization of an unusual part of our DNA called heterochromatin, according to a new study by Berkeley Lab researchers. They found that liquid-liquid phase separation helps heterochromatin organize large parts of the genome into specific regions of the nucleus. The work addresses a long-standing question about how DNA functions are organized in space and time, including how genes are silenced or expressed.

The Rise of Giant Viruses

Research reveals that giant viruses acquire genes piecemeal from others, with implications for bioenergy production and environmental cleanup.

Grasses: The Secrets Behind Their Success

Researchers find a grass gene affecting how plants manage water and carbon dioxide that could be useful to growing biofuel crops on marginal land.

SLAC Experiment is First to Decipher Atomic Structure of an Intact Virus with an X-ray Laser

An international team of scientists has for the first time used an X-ray free-electron laser to unravel the structure of an intact virus particle on the atomic level. The method dramatically reduces the amount of virus material required, while also allowing the investigations to be carried out several times faster than before. This opens up entirely new research opportunities.

New Perspectives Into Arctic Cloud Phases

Teamwork provides insight into complicated cloud processes that are important to potential environmental changes in the Arctic.

Illuminating a Better Way to Calculate Excitation Energy

In a new study appearing this week in The Journal of Chemical Physics, researchers demonstrate a new method to calculate excitation energies. They used a new approach based on density functional methods, which use an atom-by-atom approach to calculate electronic interactions. By analyzing a benchmark set of small molecules and oligomers, their functional produced more accurate estimates of excitation energy compared to other commonly used density functionals, while requiring less computing power.


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Chicago Quantum Exchange to Create Technologically Transformative Ecosystem

The University of Chicago is collaborating with the U.S. Department of Energy's Argonne National Laboratory and Fermi National Accelerator Laboratory to launch an intellectual hub for advancing academic, industrial and governmental efforts in the science and engineering of quantum information.

Department of Energy Awards Six Research Contracts Totaling $258 Million to Accelerate U.S. Supercomputing Technology

Today U.S. Secretary of Energy Rick Perry announced that six leading U.S. technology companies will receive funding from the Department of Energy's Exascale Computing Project (ECP) as part of its new PathForward program, accelerating the research necessary to deploy the nation's first exascale supercomputers.

Cynthia Jenks Named Director of Argonne's Chemical Sciences and Engineering Division

Argonne has named Cynthia Jenks the next director of the laboratory's Chemical Sciences and Engineering Division. Jenks currently serves as the assistant director for scientific planning and the director of the Chemical and Biological Sciences Division at Ames Laboratory.

Argonne-Developed Technology for Producing Graphene Wins TechConnect National Innovation Award

A method that significantly cuts the time and cost needed to grow graphene has won a 2017 TechConnect National Innovation Award. This is the second year in a row that a team at Argonne's Center for Nanoscale Materials has received this award.

Honeywell UOP and Argonne Seek Research Collaborations in Catalysis Under Technologist in Residence Program

Researchers at Argonne are collaborating with Honeywell UOP scientists to explore innovative energy and chemicals production.

Follow the Fantastic Voyage of the ICARUS Neutrino Detector

The ICARUS neutrino detector, born at Gran Sasso National Lab in Italy and refurbished at CERN, will make its way across the sea to Fermilab this summer. Follow along using an interactive map online.

JSA Awards Graduate Fellowships for Research at Jefferson Lab

Jefferson Sciences Associates announced today the award of eight JSA/Jefferson Lab graduate fellowships. The doctoral students will use the fellowships to support their advanced studies at their universities and conduct research at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) - a U.S. Department of Energy nuclear physics laboratory managed and operated by JSA, a joint venture between SURA and PAE Applied Technologies.

Muon Magnet's Moment Has Arrived

On May 31, the 50-foot-wide superconducting electromagnet at the center of the Muon g-2 experiment saw its first beam of muon particles from Fermilab's accelerators, kicking off a three-year effort to measure just what happens to those particles when placed in a stunningly precise magnetic field. The answer could rewrite scientists' picture of the universe and how it works.

Seven Small Businesses to Collaborate with Argonne to Solve Technical Challenges

Seven small businesses have been selected to collaborate with researchers at Argonne to address technical challenges as part of DOE's Small Business Vouchers Program.

JSA Names Charles Perdrisat and Charles Sinclair as Co-Recipients of its 2017 Outstanding Nuclear Physicist Prize

Jefferson Science Associates, LLC, announced today that Charles Perdrisat and Charles Sinclair are the recipients of the 2017 Outstanding Nuclear Physicist Prize. The 2017 JSA Outstanding Nuclear Physicist Award is jointly awarded to Charles Perdrisat for his pioneering implementation of the polarization transfer technique to determine proton elastic form factors, and to Charles Sinclair for his crucial development of polarized electron beam technology, which made such measurements, and many others, possible.


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Oxygen: The Jekyll and Hyde of Biofuels

Scientists are devising ways to protect plants, biofuels and, ultimately, the atmosphere itself from damage caused by an element that sustains life on earth.

The Rise of Giant Viruses

Research reveals that giant viruses acquire genes piecemeal from others, with implications for bioenergy production and environmental cleanup.

Grasses: The Secrets Behind Their Success

Researchers find a grass gene affecting how plants manage water and carbon dioxide that could be useful to growing biofuel crops on marginal land.

New Perspectives Into Arctic Cloud Phases

Teamwork provides insight into complicated cloud processes that are important to potential environmental changes in the Arctic.

Mountaintop Plants and Soils to Become Out of Sync

Plants and soil microbes may be altered by climate warming at different rates and in different ways, meaning vital nutrient patterns could be misaligned.

If a Tree Falls in the Amazon

For the first time, scientists pinpointed how often storms topple trees, helping to predict how changes in Amazonia affect the world.

Turning Waste into Fuels, Microbial Style

A newly discovered metabolic process linking different bacteria in a community could enhance bioenergy production.

Department of Energy Awards Six Research Contracts Totaling $258 Million to Accelerate U.S. Supercomputing Technology

Today U.S. Secretary of Energy Rick Perry announced that six leading U.S. technology companies will receive funding from the Department of Energy's Exascale Computing Project (ECP) as part of its new PathForward program, accelerating the research necessary to deploy the nation's first exascale supercomputers.

Electrifying Magnetism

Researchers create materials with controllable electrical and magnetic properties, even at room temperature.

One Step Closer to Practical Fast Charging Batteries

Novel electrode materials have designed pathways for electrons and ions during the charge/discharge cycle.


A Seaweed Derivative Could Be Just What Lithium-Sulfur Batteries Need

Article ID: 676317

Released: 2017-06-13 13:05:22

Source Newsroom: Lawrence Berkeley National Laboratory

  • Credit: Berkeley Lab

    Berkeley Lab battery scientist Gao Liu

Lithium-sulfur batteries have great potential as a low-cost, high-energy, energy source for both vehicle and grid applications. However, they suffer from significant capacity fading. Now scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have made a surprising discovery that could fix this problem.

In research led by Gao Liu, the team unexpectedly found that carrageenan, a seaweed derivative, acts as a stabilizer in lithium-sulfur batteries. Better stability allows for more cycling and an extended lifetime. Their study was published in the journal Nano Energy in a paper titled, “Nucleophilic substitution between polysulfides and binders unexpectedly stabilizing lithium sulfur battery.”

“There’s a lot of demand for energy storage, but there’s very little chemistry that can meet the cost target,” said Liu, the corresponding author of the paper. “Sulfur is a very low-cost material—it’s practically free. And the energy capacity is much higher than that of lithium-ion. So lithium-sulfur is one chemistry that can potentially meet the target.”

Rechargeable lithium-sulfur batteries have some limited commercial applications currently, but the “critical killer” in the chemistry is that the sulfur starts to dissolve, creating what is called the polysulfide shuttling effect. In trying to address this problem, Liu was experimenting with the binder, which is the substance that holds all the active materials in a battery cell together.

“A binder is like glue, and normally battery designers want a glue that is inert,” Liu said. “This binder we tried worked really well. We asked why, and we discovered it’s reacting­—it reacted immediately with the polysulfide. It formed a covalent bonding structure.”

By chemically reacting with the sulfur, the binder was able to stop it from dissolving. Once the researchers figured that out, they looked around for a naturally occurring material that would do the same thing. They landed upon carrageenan, a substance extracted from red seaweeds and in the same functional group (or group of atoms, with similar chemical reactivity) as the synthetic polymer they used in their initial experiments.

“We looked for something that was economical and readily available,” Liu said. “It turns out carrageenan is used as a food thickener. And it actually worked just as well as the synthetic polymer—it worked as a glue and it immobilized the polysulfide, making a really stable electrode.”

Visualizing in situ reactions

Liu worked with Jinghua Guo of Berkeley Lab’s Advanced Light Source, one of the world’s brightest sources of ultraviolet and soft X-ray beams, to make his discovery. “The light source provides unique X-ray based tools,” Guo said. “We want the tool to monitor the electrochemistry simultaneously while the battery is charging. In this case, we made a dedicated battery cell with the materials, then used X-rays to monitor the process under in situ conditions.”

Liu added: “You can’t do this kind of experiment anywhere else. In this case we have a unique beamline to detect sulfur. It’s always a lot of effort to design the tool for in situ. Ex situ is easy, but in this case, ex situ didn’t give you the result. With the in situ cell, we were able to watch where the sulfur goes. Turns out, it doesn’t go anywhere. That was really cool.”

General Motors, an industry research partner of Berkeley Lab’s Energy Storage & Distributed Resources Division, confirmed Liu’s research findings. “They independently tested it and saw the same effect we saw—in fact the stability was even better,” Liu said.

Radical departure

The results open up an entirely new way of thinking about battery chemistry, Liu noted. “Scientifically, it’s a totally different concept, of a binder that is reactive rather than inert,” he said. “People don’t think that way. They think a binder’s function is to physically hold things together. We found, no, we need a way to chemically bind the polysulfide.”

Liu and his group have been working on lithium-sulfur batteries for several years. They published a paper in Nano Letters last year on a novel lithium-sulfur electrode structure based on nature’s own superefficient ant nest.

With this breakthrough to stabilize lithium-sulfur batteries­ Liu is now seeking to improve the lifetime of lithium-sulfur batteries even further. “We want to get to thousands of cycles,” he said.

Lithium-sulfur batteries have more than twice the energy density of lithium-ion batteries, which now dominate the market. They are also much more lightweight so they have potential application in airplanes and drones. In fact, lithium-sulfur batteries provided nighttime power in the record-setting 14-day solar-powered flight of the Zephyr, an unmanned aircraft, in 2010.

Liu, Guo, and their team will continue to work on understanding the chemical reactions in the cell. “After this polymer binds with sulfur, what happens next? How does it react with sulfur, and is it reversible?” Liu said. “Understanding that will allow us to be able to develop better ways to further improve the life of lithium-sulfur batteries.”

The research was supported by DOE’s Office of Energy Efficiency and Renewable Energy. Other co-authors on the paper were Min Ling, Liang Zhang, Tianyue Zheng, and Jun Feng of Berkeley Lab, and Liqiang Mai of the Wuhan University of Technology. The Advanced Light Source and Molecular Foundry, both DOE Office of Science User Facilities at Berkeley Lab, were used in the research.

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Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel Prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.