Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers report breakthrough in magnesium batteries

25.08.2017

Nanostructured cathode, understanding of new electrolyte lead to greater efficiency

Magnesium batteries offer promise for safely powering modern life -- unlike traditional lithium ion batteries, they are not flammable or subject to exploding -- but their ability to store energy has been limited.


This is a schematic of the structural evolution of titanium disulfide at different stages of intercalation. Interlayers are expanded or distorted as different amounts of pillaring molecules, complex cations and solvents are intercalated into the van der Waals gap of a host material at each stage.

Credit: University of Houston, Department of Electrical and Computer Engineering

Researchers reported Aug. 24 in the journal Nature Communications the discovery of a new design for the battery cathode, drastically increasing the storage capacity and upending conventional wisdom that the magnesium-chloride bond must be broken before inserting magnesium into the host.

"We are combining a nanostructured cathode and a new understanding of the magnesium electrolyte," said Yan Yao, associate professor of electrical and computer engineering at the University of Houston and lead author on the paper. "That's new."

The work was first conceived by Yao and postdoctoral fellow Hyun Deog Yoo in 2014; the project spanned several years and involved scientists from three universities and three national laboratories, working both experimentally and theoretically.

"Magnesium ion is known to be hard to insert into a host," said Yoo, first author on the paper. "First of all, it is very difficult to break magnesium-chloride bonds. More than that, magnesium ions produced in that way move extremely slowly in the host. That altogether lowers the battery's efficiency."

The new battery stores energy by inserting magnesium monochloride into a host, such as titanium disulfide. By retaining the magnesium-chloride bond, Yao said, the cathode demonstrated much faster diffusion than traditional magnesium versions.

The researchers report the new battery has storage capacity of 400 mAh/g, compared with 100 mAh/g for earlier magnesium batteries. Commercial lithium ion batteries have a cathode capacity of about 200 mAh/g, said Yao, who is also a principal investigator with the Texas Center for Superconductivity at UH.

Voltage of the new battery remains low at about one volt. That compares to three to four volts for lithium batteries.

The high voltage, coupled with their high energy density, has made lithium ion batteries the standard. But lithium is expensive and can develop breaches in its internal structure, a condition known as dendrite growths, which can cause the batteries to catch fire. As an earth-abundant resource, magnesium is cheaper and does not form dendrites. Until now, however, it has been held back by the need for a better cathode -- the electrode from which the current flows -- and more efficient electrolytes, the medium through which the ionic charge flows between cathode and anode.

This work suggests a solution.

The key, Yoo said, is to expand the titanium disulfide to allow magnesium chloride to be inserted -- a four-step process called intercalation -- rather than breaking the magnesium-chloride bonds and inserting the magnesium alone. Retaining the magnesium-chloride bond doubled the charge the cathode could store.

The magnesium monochloride molecules are too large to be inserted into the titanium disulfide using conventional methods. Building upon their earlier work, the researchers created an open nanostructure by expanding the gaps in the titanium disulfide by 300 percent, using organic "pillars."

The opening still was small, increased from 0.57 nanometers to 1.8 nanometers, but Yao said that allowed for the magnesium chloride to be inserted.

"Combined theoretical modeling, spectroscopic analysis, and electrochemical study reveal fast diffusion kinetics of magnesium monochloride cations without scission of magnesium chloride bond," the researchers wrote. "... The large capacity accompanies excellent rate and cycling performances even at room temperature, opening up possibilities for a variety of effective intercalation hosts for multivalent-ion batteries."

"We hope this is a general strategy," Yoo said. "Inserting various polyatomic ions in higher voltage hosts, we eventually aim to create higher-energy batteries at a lower price, especially for electric vehicles."

###

In addition to Yao and Yoo, authors on the paper include Yanliang Liang, Hui Dong, Yifei Li, Qiang Ru, Yan Jing and Qinyou An, all of UH; Junhao Lin and Sokrates T. Pantelides of Vanderbilt University and the Oak Ridge National Laboratory; Wu Zhou of Oak Ridge National Laboratory; Hua Wang and Xiaofeng Qian of Texas A&M University; Yisheng Liu and Jinghua Guo of Lawrence Berkeley National Laboratory; Lu Ma, Tianpin Wu and Jun Lu of Argonne National Laboratory.

Media Contact

Jeannie Kever
jekever@uh.edu
713-743-0778

 @UH_News

http://www.uh.edu/news-events 

Jeannie Kever | EurekAlert!

More articles from Materials Sciences:

nachricht Machine-learning predicted a superhard and high-energy-density tungsten nitride
18.07.2018 | Science China Press

nachricht In borophene, boundaries are no barrier
17.07.2018 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>