Posted on 08/03/2011 12:16:01 AM PDT by neverdem
Energy-harvesting windows are a step closer with the development of a transparent lithium ion battery, created by US researchers at Stanford University. The electrodes are confined to a grid 35µm wide, making them too narrow to be perceived by the naked eye.
The electrodes pose the biggest challenge to transparent lithium ion batteries, as both anode and cathode materials are typically opaque. Yi Cui's team solved this problem by making them very thin. They set the electrode materials into a grid of trenches in clear polydimethylsiloxane (PDMS). By stacking and aligning the grids with additional layers of electrodes, it is possible to increase the battery's energy storage without sacrificing its transparency.
The Stanford team deposited a 100nm thick gold layer onto the PDMS to collect the current generated. The researchers took advantage of capillary action to pull slurries of water and electrode material - LiMn2O4 nanorods for the cathode and Li4Ti5O12 nanopowder for the anode - through the grids to create the battery's structure.
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By producing extremely fine electrodes researchers were able to produce transparent batteries
© Proc. Natl Acad. Sci. USA
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The team then sandwiched a layer of clear electrolyte between the two electrodes, aligning the grids by hand under an optical microscope. Finally, the whole device was enclosed in a clear polymer bag, with two strips of aluminium for terminals. By varying the spacing between the trenches, the researchers achieved transparencies of 78, 60 and 30 per cent. These yielded energy densities of 5, 10, and 20 Watt hours per litre (Wh/L), respectively.
Jongseung Yoon, a nanoelectronics expert at the University of Southern California, US, says the team's approach 'is particularly attractive as it is scalable to large areas as well as to multiple device stacks'.
This would allow a thin, energy-storing layer to extend all the way across 'smart windows'. According to Luis Sánchez of the University of Córdoba in Spain, whose team made the first transparent electrode, this would be the chief application for transparent batteries. These devices could be combined with transparent solar cells, which have already been developed, to absorb some of the sun's energy as it passes into a building, storing it during the day so that it can be used for low power consumption lighting after dark.
The 60 per cent transparent battery has about one tenth the energy density of the average smart phone battery, which group leader Yi Cui says can get around 100 Wh/L. 'By simple optimisation and utilisation of industrial approaches, 50 Wh/L is achievable at current stages,' he adds.
With advanced electrode materials, he thinks it may be possible reach 150 Wh/L. And because the transparent design allows chemists to watch the reaction taking place inside the battery, studying new electrodes has never been easier.
Y Yang et al, Proc. Natl Acad. Sci. USA, 2011, DOI:10.1073/pnas.1102873108
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The PDF is open access, i.e. a FReebie.
What, innovation taking place in America?
How long till the Chinese buy or seize the patent?
Looks a good argument for “Tinted” glass, the efficiency is higher.
*ping* to “free” energy.
What buy?
We don’t need no stinkin buy!
We make batteries a lot.
No buy.
Fascinating.
Forget about that. Big brother wants us to use windmills and pedal cars.
What happens when the battery wears out and each window costs $100,000?
UNH researchers help find natural products potential of frankia
Why Diets Don't Work: Starved Brain Cells Eat Themselves, Study Finds
Today's playgrounds may be too safe, critics warn Fort Tryon Park was one of my hangouts for decades from the playground to the Cloiters.
FReepmail me if you want on or off my health and science ping list.
You use your ‘Carbon Credits” to buy another?
Oh, that probably only applies to big office buildings, so sorry, maybe you can put a claim on your homeowners policy? :-(
UNH researchers help find natural products potential of frankia
Why Diets Don't Work: Starved Brain Cells Eat Themselves, Study Finds
Today's playgrounds may be too safe, critics warn Fort Tryon Park was one of my hangouts for decades from the playground to the Cloiters.
FReepmail me if you want on or off my health and science ping list.
Or a rocks hits your window.
Some science is done to learn about the physics or chemistry. This sounds an appeal to the green Marxists currently overseeing the NSF budget to help soak what remains of the private sector and hurry us only on the road to economic disaster and socialist dictatorship. To charge emergency batteries or low power LEDs is a business decision. To really invest in energy why not bribe all the environmental lawyers so that they will have no incentive to obstruct real energy production. Pay them each a million dollars a year to shut up and move to Aspen. Then the talent of our nation can return to what we have taught France, China, Japan, and India to do. Those nations, of course, now own much of our intellectual property in patents and manufacturing expertise, but with a free society we have “The Ultimate Resource” (the name of a study much maligned by Marxists Obama and Ehrlich, written by economist Julian Simon), great minds, whether born here or from China, India or Russia, the ones who chose to become citizens will produce for their chosen nation, unlike Obama, whose goal appears to be to destroy us, and who has never produced anything in his life but a confidence man's hustle.
Just remember not to use Windex on them!
Even so, it’s still an infant technology.
The biggest step in any new technology has always been the innovations that follow its discovery. After that, things can be improved upon.
For example, the Toyota hybrid technology. When it first came out, Popular Mechanics at the time said that it wasn’t worth buying because it would take 150 000 miles before the savings would pay for the technology. With the price of the technology having probably decreased, because the cost of technology is always decreasing, the improved performance, and the strong increase of the price of gasoline, I’d be willing to bet that it’s nowhere near the 150k miles before the technology has paid for itself now.
Even if the technology won’t be ready for another twenty years, it’s nice to know that they are working on it.
Or spill your juice or coffee onto it, like I’ve done to my keyboard from time to time.
Yeah. This is neat, geeky stuff. But somebody really serious about solar power in a building is still likely to want to put conventional high efficiency cells on the roof and have them move to track the sun, not goof around with windows.
Gotta be a real klutz to do that to a window!
The window probably would be laminated inside a layer that is safe to clean conventionally.
It’s easy when you have a cat.
I would like to see this come to fruition. According to the designer, if it replaced the current roadways in the US, it would provide three times the electrical energy needed by the country.
It might be pie in the sky, but with that type of surplus, an electric bill might be a thing of the past, and with the advent of electric cars, fuel cost as well. Citizen consumer wins.
http://solarroadways.com/intro.shtml
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