Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Battery development may extend range of electric cars

10.01.2014
New anode quadruples life of lithium-sulfur battery, could also help store renewable energy more cheaply

It's known that electric vehicles could travel longer distances before needing to charge and more renewable energy could be saved for a rainy day if lithium-sulfur batteries can just overcome a few technical hurdles. Now, a novel design for a critical part of the battery has been shown to significantly extend the technology's lifespan, bringing it closer to commercial use.


Pacific Northwest National Laboratory researchers have developed a hybrid anode made of graphite and lithium that could quadruple the lifespan of lithium-sulfur batteries.

Credit: Image courtesy of Huang et al, Nature Communications 2014

A "hybrid" anode developed at the Department of Energy's Pacific Northwest National Laboratory could quadruple the life of lithium-sulfur batteries. Nature Communications published a paper today describing the anode's design and performance.

"Lithium-sulfur batteries could one day help us take electric cars on longer drives and store renewable wind energy more cheaply, but some technical challenges have to be overcome first," said PNNL Laboratory Fellow Jun Liu, who is the paper's corresponding author. "PNNL's new anode design is helping bringing us closer to that day."

Today's electric vehicles are commonly powered by rechargeable lithium-ion batteries, which are also being used to store renewable energy. But the chemistry of lithium-ion batteries limits how much energy they can store. One promising solution is the lithium-sulfur battery, which can hold as much as four times more energy per mass than lithium-ion batteries. This would enable electric vehicles to drive longer on a single charge and help store more renewable energy. The down side of lithium-sulfur batteries, however, is they have a much shorter lifespan because they can't be charged as many times as lithium-ion batteries.

Most batteries have two electrodes: one is positively charged and called a cathode, while the second is negative and called an anode. Electricity is generated when electrons flow through a wire that connects the two. Meanwhile, charged molecules called ions shuffle from one electrode to the other through another path: the electrolyte solution in which the electrodes sit.

The lithium-sulfur battery's main obstacles are unwanted side reactions that cut the battery's life short. The undesirable action starts on the battery's sulfur-containing cathode, which slowly disintegrates and forms molecules called polysulfides that dissolve into the battery's electrolyte liquid. The dissolved sulfur eventually develops into a thin film called the solid-state electrolyte interface layer. The film forms on the surface of the lithium-containing anode, growing until the battery is inoperable.

Most lithium-sulfur battery research to date has centered on stopping sulfur leakage from the cathode. But PNNL researchers determined stopping that leakage can be particularly challenging. Besides, recent research has shown a battery with a dissolved cathode can still work. So the PNNL team focused on the battery's other side by adding a protective shield to the anode.

The new shield is made of graphite, a thin matrix of connected carbon molecules that is already used in lithium-ion battery anodes. In a lithium-sulfur battery, PNNL's graphite shield moves the sulfur side reactions away from the anode's lithium surface, preventing it from growing the debilitating interference layer. Combining graphite from lithium-ion batteries with lithium from conventional lithium-sulfur batteries, the researchers dubbed their new anode a hybrid of the two.

The new anode quadrupled the lifespan of the lithium-sulfur battery system the PNNL team tested. When equipped with a conventional anode, the battery stopped working after about 100 charge-and-discharge cycles. But the system worked well past 400 cycles when it used PNNL's hybrid anode and was tested under the same conditions.

"Sulfur is still dissolved in a lithium-sulfur battery that uses our hybrid anode, but that doesn't really matter," Liu said. "Tests showed a battery with a hybrid anode can successfully be charged repeatedly at a high rate for more 400 cycles, and with just an 11-percent decrease in the battery's energy storage capacity."

This and most other lithium-sulfur battery research is conducted with small, thin-film versions of the battery that are ideal for lab tests. Larger, thicker batteries would be needed to power electric cars and store renewable energy. Liu noted tests with a larger battery system would better evaluate the performance of PNNL's new hybrid anode for real-world applications.

This study was primarily supported by the Department of Energy's Office of Science (BES), with additional support from DOE's Advanced Research Projects Agency-Energy, and DOE's Office of Energy Efficiency and Renewable Energy. Some of this research was performed at EMSL, DOE's Environmental and Molecular Sciences Laboratory at PNNL.

REFERENCE: Cheng Huang, Jie Xiao, Yuyan Shao, Jianming Zheng, Wendy D. Bennett, Dongping Lu, Saraf V. Laxmikant, Mark Engelhard, Liwen Ji, Jiguang Zhang, Xiaolin Li, Gordon L. Graff & Jun Liu, Manipulating surface reactions in lithium-sulfur batteries using hybrid anode structures, Nature Communications, Jan. 9, 2014,DOI: 10.1038/ncomms/4015, http://dx.doi.org/10.1038/ncomms4015.

Interdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,300 staff and has an annual budget of about $950 million. It is managed by Battelle for the U.S. Department of Energy. For more information, visit the PNNL News Center, or follow PNNL on Facebook, Google+, LinkedIn and Twitter.

The Department of Energy'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.

EMSL, the Environmental Molecular Sciences Laboratory, is a national scientific user facility sponsored by the Department of Energy's Office of Science. Located at Pacific Northwest National Laboratory in Richland, Wash., EMSL offers an open, collaborative environment for scientific discovery to researchers around the world. Its integrated computational and experimental resources enable researchers to realize important scientific insights and create new technologies. Follow EMSL on Facebook, LinkedIn and Twitter.

Franny White | EurekAlert!
Further information:
http://www.pnnl.gov

More articles from Power and Electrical Engineering:

nachricht Researchers take next step toward fusion energy
16.11.2017 | Texas A&M University

nachricht Desert solar to fuel centuries of air travel
16.11.2017 | SolarPACES

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Antarctic landscape insights keep ice loss forecasts on the radar

20.11.2017 | Earth Sciences

Filling the gap: High-latitude volcanic eruptions also have global impact

20.11.2017 | Earth Sciences

Water world

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>