GM and HRL team use vertically aligned graphene nanosheets to increase Li-ion electrode high rate capability
25 December 2010
Researchers from General Motors Global Research & Development Center and HRL Labs report enhancing the high rate capability of Li-ion anode materials through the used of vertically aligned graphene nanosheets on the current collector. Their paper is in press in the journal Electrochemistry Communications.
In this paper, we demonstrated that the high rate capability of electrode can be achieved by engineering the existing electrode materials. A simple approach has been developed to align the graphene nanosheet vertically on current collector, which not only facilitates both lithium ion and electron transport, but also simplifies the electrode fabrication without involving binder and conductive additives.
The charging rate for the optimized electrode structure can be significantly increased while the graphitic feature of the electrode still retains. We envision the use of this highly stable structure as an integral addition to high capacity anode materials for lithium ion batteries of high power and energy density.
—Xiao et al.
Resources
Xingcheng Xiao, Ping Liu, John S. Wang, M.W. Verbrugge and Michael P. Balogh (2010) Vertically aligned graphene electrode for lithium ion battery with high rate capability. Electrochemistry Communications doi: 10.1016/j.elecom.2010.12.016
This is another interesting demonstration that properly aligned nano-structures can greatly enhance electrodes functionality. Next generation lithium batteries using improved electrodes could multiply energy density and power handling. That's what is required for lighter extended e-range PHEVs and highway capable BEVs. Cost per Kwh should also go down.
Almost simultaneously, solid states batteries will make their way and be very competitive by 2015/16. They will be inherently more rugged and safer and should cost even less when mass produced.
Post 2015 will see batteries with high performances that we only dreamed of a few months ago.
Posted by: HarveyD | 25 December 2010 at 09:35 AM
What % improvement? It's the time of year we hear 1000% improvements from EEStor, Prieto, http://news.stanford.edu/news/2008/january9/nanowire-010908.html?PHPSESSID=dcd18b32620f332b5ad2ddeeace2c993 etc..
Posted by: kelly | 25 December 2010 at 03:31 PM
Good question kelly. We've seen other graphene nanocomposites like Fe3O4 with a graphene content of 38.0 wt % exhibit a stable capacity of about 650 mAh g-1 with no noticeable fading for up to 100 cycles in the voltage range of 0.0–3.0 V.
But 100 cycles is unusable for EV purposes.
Posted by: Reel$$ | 25 December 2010 at 04:32 PM
This is the nature of research. Go one way there is more power, go another there is more energy, go another there is more longevity at deeper cycles. Each one tells the researchers something and when they add all that up they can make progress.
Posted by: SJC | 26 December 2010 at 12:45 PM
K & R$$ will not stop the world from developing improved lower cost e-storage units. Future solid states batteries will be more rugged, cost less per Kwh and have higher performance. The first units may be around as soon as 2015/16. Worldwide mass production will be well established by 2020.
Lower cost extended e-range PHEVs and highway capable BEVs will follow.
Posted by: HarveyD | 27 December 2010 at 09:46 AM