By dipping an ordinary piece of paper into ink infused with carbon nanotubes and silver nanowires, scientists have been able to create a low-cost battery or supercapacitor that is ultra-lightweight, bendable and very durable. The paper can be crumpled, folded or even soaked in acidic or basic solutions and still will work.
Stanford University scientist Yi Cui had previously created nanomaterial energy storage devices using plastics, but his new research showed that a paper battery is more durable because the ink adheres more strongly to paper. Coating a sheet of paper with ink made of carbon nanotubes and silver nanowires produced a highly conductive storage device that could be used in a multitude of applications.
"These nanomaterials are special," Cui said. "They're a one-dimensional structure with very small diameters. "The small diameter helps the nanomaterial ink stick strongly to the fibrous paper, making the battery and supercapacitor very durable. The paper supercapacitor may last through 40,000 charge-discharge cycles – at least an order of magnitude more than lithium batteries. The nanomaterials also make ideal conductors because they move electricity along much more efficiently than ordinary conductors, Cui said.
The flexibility of paper allows for many clever applications. "If I want to paint my wall with a conducting energy storage device," Cui said, "I can use a brush." In his lab, he demonstrated the battery by connecting it to an LED (light-emitting diode), which glowed brightly.
Like batteries, capacitors hold an electric charge, but for a shorter period of time. However, capacitors can store and discharge electricity much more rapidly than a battery. A paper supercapacitor has the advantage of a high surface-to-volume ratio and may be especially useful for applications like electric or hybrid cars, which depend on the quick transfer of electricity.
Cui predicts the biggest impact may be in large-scale storage of electricity on the distribution grid. Excess electricity generated at night, for example, could be saved for peak-use periods during the day, while wind farms and solar energy systems could also employ the new storage technology.
"This technology has potential to be commercialized within a short time," said Peidong Yang, professor of chemistry at the University of California, Berkeley. "I don't think it will be limited to just energy storage devices," he said. "This is potentially a very nice, low-cost, flexible electrode for any electrical device."
Cui's work appears in the paper Highly Conductive Paper for Energy Storage Devices, published in the Proceedings of the National Academy of Sciences.
Using silver is not going to be low cost. Silver batter plates tend to grow together, shorting out so short lived.
Supercaps hold little energy and 40k cycles is not much at 60cycles/second!
I can stick a piece of silver and carbon in a potato and light an LED. My guess thy are trolling for grants.
BTW, how many potatoes does it take to power your car?
Dr.A.Jagadeesh Nellore (AP), India 9 April 2010
The super capacitor is different. 2 in series will double the voltage, but HALVE the capacity, thus you need another set. If you had a bunch of (these supposedly cheap paper) capacitors and wanted to store, say, 36 volts for a motorized bike... Let\'s assume 2.7 volts and 100F (or 100 amp seconds or about 1/75th of a typical AA)... You would need about 15 in series which would reduce capacity by down to just 6.6 amp seconds. Now times all that by whatever it takes to build a decent capacity, say, 50 Ah (or 180,000 amp second)....
You would need like 27,000 x 15 or about 400,000 individual 100F, 2.7V capacitors! Being that EACH are like $10 dollars means that this paper deal HAS TO BE VERY, VERY CHEAP. (How dare they say \"...for utilities, wind farms, solar and what not)!
Now, I could be wrong (hopefully). If each paper capacitor was 2.7 volts (assuming typical 100F) but like 10,000 F, then it would take just about 4,000. Obviously, each would still have to cost just a few pennies (and imagine all that wiring!).
Imagine a piece of(really super thin, like nanoscale, thin) paper 100 feet long and a few feet wide rolled up to make a one billion F (or 277,000 Ah) and imagine it still having to be just 2.7 volts. We want utility scale storage for the very cheap solar PV panels... (that the oil companies finally made in 2021 when shale oil extraction became too difficult and because global warming was proven true beyond a doubt and obvious to all)... So we have to put just 44 in series to get 120 volts (next to a high voltage transformer) which gives us over 6 kWh of storage - typical for just one day\'s usage for the average family... Definitely worth a few thousand dollars! Obviously, these too, would have to be mass produced by robotic factories out of elements that have NO raw materials supply issues. (Apologies if math wrong...)
With God (and science) all things are possible...