There is a lot of interesting technical information here, about Graphene (which you will hear more and more about as time goes on…), of Nanotubes (you’ll be hearing more about this too…), and an overview of why batteries are a bit different from capacitors…even ultracapacitors.
The bottom line is that these technologies are becoming more important every day. This is as good a place and time as any to learn about our future.
Graphite + water = the future of energy storage
http://www.monash.edu.au/news/show/graphite-water-the-future-of-energy-storage
A combination of two ordinary materials – graphite and water – could produce energy storage systems that perform on par with lithium ion batteries, but recharge in a matter of seconds and have an almost indefinite lifespan.
Dr Dan Li, of the Monash University Department of Materials Engineering, and his research team have been working with a material called graphene, which could form the basis of the next generation of ultrafast energy storage systems.
“Once we can properly manipulate this material, your iPhone, for example, could charge in a few seconds, or possibly faster.” said Dr Li.
Graphene is the result of breaking down graphite, a cheap, readily available material commonly used in pencils, into layers one atom thick. In this form, it has remarkable properties.
Graphene is strong, chemically stable, an excellent conductor of electricity and, importantly, has an extremely high surface area.
Dr Li said these qualities make graphene highly suitable for energy storage applications.
“The reason graphene isn’t being used everywhere is that these very thin sheets, when stacked into a usable macrostructure, immediately bond together, reforming graphite. When graphene restacks, most of the surface area is lost and it doesn’t behave like graphene anymore.”
Now, Dr Li and his team have discovered the key to maintaining the remarkable properties of separate graphene sheets: water. Keeping graphene moist – in gel form – provides repulsive forces between the sheets and prevents re-stacking, making it ready for real-world application.
“The technique is very simple and can easily be scaled up. When we discovered it, we thought it was unbelievable. We’re taking two basic, inexpensive materials – water and graphite – and making this new nanomaterial with amazing properties,” said Dr Li.
When used in energy devices, graphene gel significantly outperforms current carbon-based technology, both in terms of the amount of charge stored, and how fast the charges can be delivered.
Dr Li said the benefits of developing this new nanotechnology extend beyond consumer electronics.
“High-speed, reliable, and cost-effective energy storage systems are critical for the future viability of electricity from renewable resources. These systems are also the key to large-scale adoption of electrical vehicles.
‘Amplified’ Nanotubes May Power the Future
http://www.sciencedaily.com/releases/2011/07/110714191533.htm
Scientists have achieved a pivotal breakthrough in the development of a cable that will make an efficient electric grid of the future possible. Armchair quantum wire (AQW) will be a weave of metallic nanotubes that can carry electricity with negligible loss over long distances. It will be an ideal replacement for the nation’s copper-based grid, which leaks electricity at an estimated 5 percent per 100 miles of transmission, said Rice chemist Andrew R. Barron, author of a paper about the latest step forward published online by the American Chemical Society journal Nano Letters.
A prime technical hurdle in the development of this "miracle cable," Barron said, is the manufacture of massive amounts of metallic single-walled carbon nanotubes, dubbed armchairs for their unique shape. Armchairs are best for carrying current, but can’t yet be made alone. They grow in batches with other kinds of nanotubes and have to be separated out, which is a difficult process, given that a human hair is 50,000 times larger than a single nanotube.
Barron’s lab demonstrated a way to take small batches of individual nanotubes and make them dramatically longer. Ideally, long armchair nanotubes could be cut, re-seeded with catalyst, and re-grown indefinitely.
The paper was written by graduate student and first author Alvin Orbaek, undergraduate student Andrew Owens and Barron, the Charles W. Duncan Jr.-Welch Professor of Chemistry and a professor of materials science.
Amplification of nanotubes was seen as a key step toward the practical manufacture of AQW by the late Rice professor, nanotechnology pioneer and Nobel laureate Richard Smalley, who worked closely with Barron and Rice chemist James Tour, the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science, to lay out a path for its development.
How ultracapacitors work (and why they fall short)
http://gigaom.com/cleantech/how-ultracapacitors-work-and-why-they-fall-short
Hang around the energy storage crowd long enough, and you’ll hear chatter about ultracapacitors. Tesla Motors chief executive Elon Musk has said he believes capacitors will even “supercede” batteries.
What is it that makes ultracapacitors such a promising technology? And if ultracapacitors are so great, why have they lost out to batteries, so far, as the energy storage device of choice for applications like electric cars and the power grid?
Put simply, ultracapacitors are some of the best devices around for delivering a quick surge of power. Because an ultracapacitor stores energy in an electric field, rather than in a chemical reaction, it can survive hundreds of thousands more charge and discharge cycles than a battery can.
A more thorough answer, however, looks at how ultracapacitors compare to capacitors and batteries. From there we’ll walk through some of the inherent strengths and weaknesses of ultracaps, how they can enhance (rather than compete with) batteries, and what the opportunities are to advance ultracapacitor technology.
