Current supercapacitors (rechargeable energy storage) are unable to store enough energy for them to be used in small cars and replace batteries.
Fortunately, this piece of the puzzle may have finally been solved with a new material called Graphene.
Researcher Santahkumar Kannappan, of the Gwagju Institute of Science and Technology in South Korea, has been able to create high-performance supercapacitors out of graphene which store almost as much energy as a traditional lithium-ion battery, but go beyond the current standard by charging and discharging in a matter of seconds, all while maintaining this rigorous process for tens of thousands of charging cycles.
The catalyst behind these impressive results came from Kannappan and his team successfully creating a highly porous form of graphene with a massive internal surface area. This graphene powder was then packed into a circular, coin-shaped cell, and dried to 140 degrees C at a pressure level of 300/kg/cm for 5 hours.
The result was a permeable electrode which offers a surface area larger than a basketball court, all contained within one gram. What this does is allow the electrode to accommodate more electrolyte (which is an ionic liquid called EBIMF 1), and in doing so, offering a much greater charge.
The evidence gathered during the tests showed that the supercapacitors have a specific capacitance of over 150 Farrads per gram, and can store energy at a density of more than 64 Watt hours per kilogram at a current density of 5 Amps per gram.
As a point of reference, these results are comparable with lithium-ion batteries that currently have an energy density of between 100 and 200 Watt hours per kilogram.
Technical mumbo-jumbo aside, the most notable advantage stemming from the findings is the fact that they can fully charge graphene supercapacitors in just 16 seconds. To test the efficacy, they repeated the process well over 10,000 times, with insignificant reductions in capacity.
The upshot of the study was that these “supercapacitor energy storage devices…can be scaled up for manufacturing in the near future for electric vehicle applications.”
Ideally, this means that we will see large-scale production of electric vehicle batteries that can harvest previously wasted energy from braking and other automobile functions…a vital process which will exponentially increase the energy efficiency of our future electric fleet.