printed supercapacitor could feed power-hungry gadgets - energy storage devices

Colin barlasa super capacitor-a device that can quickly release a large amount of charge-was first made using printing technology.
This progress will pave the way for "printed" power supplies that can be useful as gadgets become thinner, lighter, or even flexible.
Advances in electronic technology mean that the volume of portable electronic devices is shrinking, but the demand for energy is growing, and traditional batteries are difficult to cope.
The batteries are slow to charge because they store energy in a chemical way.
In contrast, the capacitors common in electronic products are very short
Long-term storage of electric energy that is almost instantly charged but has little energy.
In recent years, capacitors that can store thousands of times the energy of standard capacitors have been developed, called super capacitors.
They are charged by applying voltage to the two electrodes suspended in the solution so that positive ions move to one electrode and negative ions move to the other.
Now, a team led by the University of California, Los Angeles, George greenner, printed the super capacitor for the first time, building on early theoretical work, providing the fast power needed for today's electronic devices.
Members of the research team sprayed carbon nanotubes on a plastic film-two such films act both as electrodes for the device and as charge collectors.
Between the two films, the research team clipped a gel electrolyte made of a water mix together
Soluble synthetic polymer of phosphate and water.
The power density of the super capacitor is 70 KW per kilogram, which can be charged and discharged quickly.
The energy density is 9 watts per kilogram, which means that 1 kg can hold about 32 kilojoules.
Both numbers are significantly higher than commercial equipment, grüner told New Scientist.
"Personal digital devices will certainly benefit from this Printable Super capacitor," said George Chen of the University of Nottingham, UK . ".
But he believes there is still a way to go before flexible capacitors are ready to compete in the commercial market.
This is because the new tests show that, despite the high power density of the super capacitor, it is relatively inefficient.
It has high internal resistance, so it loses a lot of stored energy, not all as a power supply, Chen said.
He believes that the real progress of this new work is in engineering-many researchers have studied the electrolysis of potentially flexible super capacitor components, but no one has built working flexible equipment before.
"It's not just chemistry that's going to be considered here-but manufacturing and material selection issues that need to be considered," Chen said . ".
Both Grüner and Chen believe that portable devices will eventually carry batteries and super capacitors to provide the high energy storage and rapid energy discharge needed for modern devices.
But Chen pointed out that experimental batteries show some hope in filling these two roles.
They have the energy storage of ordinary batteries, but they also have the power density equivalent to the super capacitor, which means that they can charge and release energy 100 times as fast as ordinary lithium-ion batteries.
Magazine reference and colon; Nano Letters (DOI: 10. 1021/nl8038579)