Will Graphene Change How Mobile Devices Get Their Power?
Graphene is the most conductive material known to man. But the processes for making graphene and using it to store and dispense electricity were cumbersome until Dr. Richard Kaner of UCLA and PhD candidate Maher El-Kady realized that they coud create graphene supercapacitors using very humble materials.
First Dr. Kaner and Mr. El-Kady smeared graphite oxide — a cheap biodegradable material — onto blank DVDs. Then they placed those DVD's into an ordinary DVD burner, where the laser burned off the liquid, turning the graphite oxide into pure graphene. That layer of graphene was then peeled off and placed on a flexible substrate and then cut into pieces to form electrodes. Two electrodes were then sandwiched together on either side of a flexible layer of electrolyte and a high-density capacitor, or supercapacitor, was made.
Why are graphene supercapacitors better than batteries?
Batteries store energy in chemical form and those chemicals can be toxic: Capacitors store energy by simply piling up electrical charge on two electrodes. And, while batteries take a relatively long time to charge, supercapacitors can be charged in seconds and can withstand hundreds of thousands of charging cycles - which means supercapacitors may make the next generation of mobile devices (including cameras, cellphones and tablets) more convenient.
If the processes for commercial production of graphene and the claims for graphene's functionality and environmental friendliness can be borne out, graphene supercapacitors may be powering us into a new age of mobile devices.