Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Tin nanocrystals for the battery of the future

Monodisperse tin nanodroplets in an electron microscopic image.Image: Maksym Kovalenko / ETH Zürich
Monodisperse tin nanodroplets in an electron microscopic image.

Image: Maksym Kovalenko / ETH Zürich

Abstract:
More powerful batteries could help electric cars achieve a considerably larger range and thus a breakthrough on the market. A new nanomaterial for lithium ion batteries developed in the labs of chemists at ETH Zurich and Empa could come into play here.

Tin nanocrystals for the battery of the future

Zurich, Switzerland | Posted on April 8th, 2013

They provide power for electric cars, electric bicycles, smartphones and laptops; nowadays, rechargeable lithium ion batteries are the storage media of choice when it comes to supplying a large amount of energy in a small space and light weight. All over the world, scientists are currently researching a new generation of such batteries with an improved performance. Scientists headed by Maksym Kovalenko from the Laboratory of Inorganic Chemistry at ETH Zurich and Empa have now developed a nanomaterial which enables considerably more power to be stored in lithium ion batteries.

The nanomaterial is composed of tiny tin crystals, which are to be deployed at the minus pole of the batteries (anode). When charging the batteries, lithium ions are absorbed at this electrode; while discharging, they are released again (see box). "The more lithium ions the electrodes can absorb and release - the better they can breathe, as it were - the more energy can be stored in a battery," explains Kovalenko.
Uniform crystals

The element tin is ideal for this: every tin atom can absorb at least four lithium ions. However, the challenge is to deal with the volume change of tin electrodes: tin crystal becomes up to three times bigger if it absorbs a lot of lithium ions and shrinks again when it releases them back. The scientists thus resorted to nanotechnology: they produced the tiniest tin nanocrystals and embedded a large number of them in a porous, conductive permeable carbon matrix. Much like how a sponge can suck up water and release it again, an electrode constructed in this way can absorb lithium ions while charging and release them when discharging. If the electrode were made of a compact tin block, this would practically be impossible.

During the development of the nanomaterial, the issue of the ideal size for the nanocrystals arose, which also carries the challenge of producing uniform crystals. "The trick here was to separate the two basic steps in the formation of the crystals - the formation of as small as a crystal nucleus as possible on the one hand and its subsequent growth on the other," explains Kovalenko. By influencing the time and temperature of the growth phase, the scientists were able to control the size of the crystals. "We are the first to produce such small tin crystals with such precision," says the scientist.

Larger cycle stability

Using uniform tin nanocrystals, carbon, and binding agents, the scientists produced different test electrodes for batteries. "This enables twice as much power to be stored compared to conventional electrodes," says Kovalenko. The size of the nanocrystals did not affect the storage capacity during the initial charging and discharging cycle. After a few charging and discharging cycles, however, differences caused by the crystal size became apparent: batteries with ten-nanometre crystals in the electrodes were able to store considerably more energy than ones with twice the diameter. The scientists assume that the smaller crystals perform better because they can absorb and release lithium ions more effectively. "Ten-nanometre tin crystals thus seem to be just the ticket for lithium ion batteries," says Kovalenko.

As the scientists now know the ideal size for the tin nanocrystals, they would like to turn their attention to the remaining challenges of producing optimum tin electrodes in further research projects. These include the choice of the best possible carbon matrix and binding agent for the electrodes, and the electrodes' ideal microscopic structure. Moreover, an optimal and stable electrolyte liquid in which the lithium ions can travel back and forth between the two poles in the battery also needs to be selected. Ultimately, the production costs are also an issue, which the researchers are looking to reduce by testing which cost-effective base materials are suitable for electrode production. The aim is to prepare batteries with an increased energy storage capacity and lifespan for the market, in collaboration with a Swiss industrial partner.

How lithium ion batteries work

In lithium ion batteries, the energy is stored in the form of positively charged lithium atoms (ions) that are found at the minus pole in a charged battery. If energy is taken from the battery, negatively charged electrons flow from the minus pole to the plus pole via the external circuit. To balance the charge, positively charged lithium ions also flow from the minus pole to the plus pole. However, these travel in the electrolyte fluid inside the battery. The process is reversible: lithium ion batteries can be recharged with electricity. In most lithium ion batteries these days, the plus pole is composed of the transition metal oxides cobalt, nickel, and manganese, the minus pole of graphite. In more powerful lithium ion batteries of the next generation, however, elements such as tin or silicon may well be used at the minus pole.

####

For more information, please click here

Contacts:
Maksym Kovalenko

41-446-334-156

Copyright © ETH Zurich

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Literature reference

Related story "Tortuous paths hamper ion transport":

Related News Press

News and information

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Laboratories

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Drexel materials scientists putting a new spin on computing memory April 22nd, 2015

Phonons, arise! Small electric voltage alters conductivity in key materials April 22nd, 2015

Chemistry

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Discoveries

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Announcements

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Automotive/Transportation

Nanoparticles Used to Improve Mechanical, Thermal Properties of Cellulose Fibers April 23rd, 2015

'Holey' graphene for energy storage: Charged holes in graphene increase energy storage capacity April 22nd, 2015

Expanding the reach of metallic glass April 22nd, 2015

Nanocomposites Play Effective Role in Production of Smart Fibers April 18th, 2015

Battery Technology/Capacitors/Generators/Piezoelectrics/Thermoelectrics/Energy storage

Phonons, arise! Small electric voltage alters conductivity in key materials April 22nd, 2015

New class of 3D-printed aerogels improve energy storage April 22nd, 2015

'Holey' graphene for energy storage: Charged holes in graphene increase energy storage capacity April 22nd, 2015

‘Oxford Instruments Young Nanoscientist India Award 2015’ to Prof. Arindam Ghosh April 20th, 2015

Research partnerships

Pseudoparticles travel through photoactive material: KIT scientists measure important process in the conversion of light energy -- publication in Nature Communications April 24th, 2015

Electron spin brings order to high entropy alloys April 23rd, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Drexel materials scientists putting a new spin on computing memory April 22nd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project