An international team of researchers has succeeded in a numerical simulation of the interactions that take place at the molecular level within the electrodes of supercapacitors. This is an important advance in the understanding of the energy storage mechanisms and this experience opens prospects for significant improvements of ultracapacitors.
The operation of a supercapacitor is very different from that of an electrochemical battery. Supercapacitors have the ability to store and deliver more power than batteries. They do not operate on the basis of chemical reactions and can charge or discharge very quickly and last up to a million charge-discharge cycles.
The interactions that occur at the molecular level within the electrodes of supercapacitors are unobservable by experimental techniques. But thanks to a numerical simulation, the researchers produced the first quantitative picture of the ionic structure absorbed in nanoporous carbon electrode of a supercapacitor.
According to researchers, the excellent performance of supercapacitors is due to ion adsorption in porous carbon electrodes. The molecular mechanism of ion behavior in the pores of less than a nanometer (one billionth of a meter) remains poorly understood. The mechanism proposed in this research opens the door to the design of materials with improved energy storage capabilities.
To improve the storage capacity of supercapacitors, researchers indicate that it must also accurately determine if the energy storage increase is due only to a large area or the pore size and geometry of the carbon also play a role.
The results of this study provide guidance for the development of improved electrical energy storage devices that will eventually allow a wider use of renewable energy sources.
The characteristics of the supercapacitor make it the ideal storage medium for electricity from renewable energy from intermittent nature. Improving its electricity storage capacity is a huge challenge, particularly advantageously replace the batteries storing photovoltaic energy.
This work is the result of international cooperation of four universities in three countries. Gogotsi, professor at Drexel University and director of the AJ Drexel Nanotechnology Institute, teamed with Mathieu Salanne, Céline Merlet and Benjamin Rotenberg from the Université Paris 06, Paul A. Madden of the University of Oxford and Patrice Simon and Pierre-Louis Taberna of Université Paul Sabatier.