Electric vehicles are coming, ready or not. And one of the enabling technologies that is making them more driver friendly is the humble battery, particularly lithium-ion versions which can store enough energy to give these cars a reasonable range for city driving.
Of course, car makers are always searching for ways to improve the efficiency, and therefore the range, of these vehicles. And one way to do this is to recover and reuse the energy that would normally be wasted when the brakes slow down a vehicle.
There is a problem doing this with conventional batteries, however. Braking occurs over timescales measured in seconds but that’s much too fast for batteries which generally take many hours to charge. So car makers have to find other ways to store this energy.
One of the more promising is to use supercapacitors because they can charge quickly and then discharge the energy just as fast. Indeed, many car makers are experimenting with just this technology.
But supercapacitors are not yet ready for the open road. That’s because, although they charge and discharge quickly, they do not store much energy.
What’s more, they tend to wear out with repeated use as the materials inside them break down with the constant flow of charge in and out of their structure. That’s is a significant drawback in a device that would have to be used many millions of times over a car’s life time.
Now Santhakumar Kannappan at the Gwangju Institute of Science and Technology in Korea and a few pals say they have a solution based on the wonder material of the moment–graphene. These guys have built high-performance supercapacitors out of graphene that store almost as much energy as a lithium-ion battery, can charge and discharge in seconds and maintain all this over many tens of thousands of charging cycles.
The South Koreans have really taken graphene research and development and ran with with it. To read more, click here.