Tag: supercapacitor

Graphene gel means high speed, long lasting batteries

Graphene – is there anything it can’t do?

Probably. It’ll never score a top ten hit, but following a discovery by researchers at Monash University, the wonder material has added yet another string to its bow.

The team of scientists has developed a method of using the material to recharge batteries at lightning speed, with the mere addition of a splash of tap water.

According to Dr Dan Li, the lead researcher, the graphene discovery means that with some tweaking it could be possible to charge up an iPhone in seconds, or even less.

This means performing on par with lithium ion batteries, as well as the potential for it to last indefinitely.

Having been discovered by two scientists at the University of Manchester mucking around with sticky tape, the Nobel prize winning material’s astounding properties have already seen it used in some fascinating ways.

For example it could be used to create modulators for ‘extremeband’ internet speeds, or a new generation of supercapacitors, while IBM has already begun to use graphene in computer chip design.

And now the material could be used in energy storage applications thanks to its extremely high surface area and conductivity.

These properties are a result of breaking down cheap and readily available graphite into one atom thick layers.

However, as the researchers were aware, problems arise when the material is restacked.

According to Dr Li, when the material is combined into a macrostructure it loses much of its surface area and ceases to behave like graphene any more.

However, they were able to solve this problem by simply adding water.

By keeping the graphene moist the team was, crucially, able to prevent the sheets from restacking, meaing its original properties remain.

The resulting graphene gel nanomaterial has a range of potential applications in energy storage, holding a large amount of charge and expending it at high speeds.

Dr Li believes that it could be beneficial for more effective delivery of renewable energy sources, and could push large scale adoption of electrical vehicles.

There are also possible uses for the gel in water purification membranes, and biomedical devices and sensors.

'Activated graphene' provides supercapacitor energy storage boost

Another day, another fascinating use for super-material graphene.

Scientists at the US Department of Energy’s Brookhaven National Laboratory and University of Texas – Austin have devised a method of using the atom thin carbon sheets that is a massive boost in the search for practical supercapacitor materials.

The new form of carbon can be incorporated into supercapacitor devices that are able to store massive amounts of energy while also being able to release it at a quick rate, as well as offering quick recharge time and 10,000 charge/discharge lifecycle.

Basically this is everything that is desirable in a battery, but which is difficult to do with traditional batteries as they store energy through chemical reactions which take considerably more time to react than supercapacitors which rely on charges stored in the form of ions on the surface of electrodes.

According to one researcher,  such properties make the new form of carbon highly useful for energy requirements where a substantial amount is needed at a quick rate, giving electric cars as an example.

So far applications of supercapacitors have been limited to smaller devices such as mobile electronics, though the new form of carbon apparently means that higher energy storage comparable to a battery is possible while still retaining the attributes of supercapacitors, and essentially offering the best of both storage types.

The discovery was made by the team at the University of Texas which had originally attempted to create a porous form of carbon by restructuring “graphene platelets”  and were able to correctly hypothesise the structure of three dimensional networks of atom-thick walls that are able to make the material act like a sponge in soaking up electrical current much more effectively.

The scientists are now looking at how they can manipulate the material to form into structures for specificed functions such as fuel cells, and though this is certainly at the development stage at the moment the team appear confident that they will be able to upscale to industrial production.