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nanotimes News in Brief
Akbar Jafari, Denis V. Vyalikh, Dmitry Usachov, Xianjie Liu, Uwe Treske, Mandy Grobosch, Oleg Vilkov, Vera K. Adamchuk, Stephan Irle, S. Ravi P. Silva, Martin Knupfer, Bernd Büchner and Alexander Grueneis: Graphene: Evi- dence for a New Two-Dimensional C4H-Type Polymer Based on Hydrogenated Graphene, In: Advanced Mate- rials, Vol. 23(2011), Issue 39, October 18, 2011, Pages 4497-4503, DOI:10.1002/adma.201190157: http://dx.doi.org/10.1002/adma.201190157
11-10 :: October 2011
said. “There‘s an internal kind of plasticity to the system that allows it to change as the battery gets cycled.”
According to Argonne nanoscientist Hui Xiong, who worked with Rajh to develop the new anode material, titanium dioxide seemed like it would be unlikely to adequately substitute for graphite. “We started with a material that we never thought would have provided a functional use, and it turned into something that gave us the best result possible,” she said.
A team of researchers at the U.S. Department of Energy‘s Argonne National Laboratory, led by Argonne nanoscientist Tijana Rajh and batte- ry expert Christopher Johnson, discovered that nanotubes composed of titanium dioxide can switch their phase as a battery is cycled, gradual- ly boosting their operational capacity. Laboratory tests showed that new batteries produced with this material could be recharged up to half of their origi- nal capacity in less than 30 seconds.
By switching out conventional graphite anodes for ones composed of the titanium nanotubes, Rajh and her colleagues witnessed a surprising phenomenon. As the battery cycled through several charges and discharges, its internal structure began to orient its- elf in a way that dramatically improved the battery‘s performance.
“We did not expect this to happen when we first started working with the material, but the anode spontaneously adopted the best structure,” Rajh
http://www.youtube.com/watch?feature=player_ embedded&v=NSSUnWhmJ70
Argonne nanoscientist Tijana Rajh holds a strip of materi- al created from titanium dioxide nanotubes. © George Joch / ANL