Posted on 12/29/2015 9:55:30 AM PST by Red Badger
Fabrication schematic of ordered mesoporous fewlayer carbon (OMFLC). Credit: Science (2015). DOI: 10.1126/science.aab3798
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(Phys.org) - A team of researchers working in China has found a way to dramatically improve the energy storage capacity of supercapacitors - by doping carbon tubes with nitrogen. In their paper published in the journal Science, the team describes their process and how well the newly developed supercapacitors worked, and their goal of one day helping supercapacitors compete with batteries.
Like a battery, a capacitor is able to hold a charge, unlike a battery, however, it is able to be charged and discharged very quickly - the down side to capacitors is that they cannot hold nearly as much charge per kilogram as batteries. The work by the team in China is a step towards increasing the amount of charge that can be held by supercapacitors (capacitors that have much higher capacitance than standard capacitors - they generally employ carbon-based electrodes) - in this case, they report a threefold increase using their new method - noting also that that their supercapacitor was capable of storing 41 watt-hours per kilogram and could deliver 26 kilowatts per kilogram to a device.
The new supercapacitor was made by first forming a template made of tubes of silica. The team then covered the inside of the tubes with carbon using chemical vapor deposition and then etched away the silica, leaving just the carbon tubes, each approximately 4 to 6 nanometers in length. Then, the carbon tubes were doped with nitrogen atoms. Electrodes were made from the resulting material by pressing it in powder form into a graphene foam. The researchers report that the doping aided in chemical reactions within the supercapacitor without causing any changes to its electrical conductivity, which meant that it was still able to charge and discharge as quickly as conventional supercapcitors. The only difference was the dramatically increased storage capacity.
Because of the huge increase in storage capacity, the team believes they are on the path to building a supercapacitor able to compete directly with batteries, perhaps even lithium-ion batteries. They note that would mean being able to charge a phone in mere seconds. But before that can happen, the team is looking to industrialize their current new supercapacitor, to allow for its use in actual devices.
Explore further: Researchers find ordinary pen ink useful for building a supercapacitor
More information: T. Lin et al. Nitrogen-doped mesoporous carbon of extraordinary capacitance for electrochemical energy storage, Science (2015). DOI: 10.1126/science.aab3798
ABSTRACT Carbon-based supercapacitors can provide high electrical power, but they do not have sufficient energy density to directly compete with batteries. We found that a nitrogen-doped ordered mesoporous few-layer carbon has a capacitance of 855 farads per gram in aqueous electrolytes and can be bipolarly charged or discharged at a fast, carbon-like speed. The improvement mostly stems from robust redox reactions at nitrogen-associated defects that transform inert graphene-like layered carbon into an electrochemically active substance without affecting its electric conductivity. These bipolar aqueous-electrolyte electrochemical cells offer power densities and lifetimes similar to those of carbon-based supercapacitors and can store a specific energy of 41 watt-hours per kilogram (19.5 watt-hours per liter).
Journal reference: Science
Tech PinG!...................
I always heard my whole life about “those people” from third world countries. With the inflection that we were so superior. Slowly, Americans must ask themselves what is our place in the world now that the most of the rest of the world has become connected to the internet and has a good educational system. The literacy rate for the young in China and India are high. They will be the ones doing more and more of this stuff in the future.
The Chinese invented gunpowder.
The Indians invented the Kama Sutra.
What could possibly go wrong?....................
And Alfred Nobel invented dynomite.
Are you sure?
I coulda sworn Jimmie JJ Walker did!..................
But, but, but.... Carbon is bad! Barry and the EPA said so.
How dare they use evil carbon!
Why does the drawing show nickel?
They meant NITROGEN. I don’t think the drawing meant to use the NICKEL symbol......................
We’re becoming a third world country while they are taking our place.
I wouldn’t mind having a phone that was powered by half-supercap/half-battery. Be able to charge it quickly whenever near power, and have the supercap charge the battery while being carried around.
Another factor is a political/social climate that is friendly to science. Germany was once on the cusp of this, which is why a lot of great scientists, including Einstein, hailed from Germany. Another key motivation is profit incentive. The Middle East is in general short supply of these motivations unless oil is the source of profit, which doesn’t require too much effort anyway since someone else built most of the infrastructure. Consider Africa another basket case. Europe and the U.S. seem to be focusing more on socialism and “down with the corporations” that you’d expect in communist countries, while ironically China is focusing more on how the real world works.
Probably a very useful invention but I would like to see something good for transportation. Basically 220 pounds of this stuff would let me drive about 40 miles around town, and less on the highway.
Chinese government-backed hacking has its benefits, I see!
Wasn’t this one of the technologies that the Chinese Communist Party targeted, and acquired, from the US during the Obama open house?
I seem to remember them giving A123 battery company all kinds of Energy Dept research grants and DoD contracts, only to sell it to the Chinese for pennies on the dollar.
Thanks Red Badger.
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