Graphene super capacitors for the storage of electric energy

G-ONET
© Photo Fraunhofer IAF

Using suitable methods, graphene (bottom right) can be produced from a rich and natural resource: graphite flakes (top left).

Being able to save large amounts of electric energy and making them available for mobile access are important prerequisites for the further development of renewable energies. Within the framework of the »Sustainability Center«, Fraunhofer IAF, together with partners from the University of Freiburg, is working on the development of super capacitors based on graphene. Such devices promise many advantages for application in mobile electrical power supply systems, for instance in electric cars.

Super capacitors play an important role as energy storage systems in electric cars: They can even balance peaks which occur while accelerating or breaking. Additionally, the run time and life span of batteries can be prolonged through the application of super capacitors. Recent results show an increase in the life span of batteries in electric cars by 76 percent through the use of super capacitors. Fraunhofer IAF is conducting research on high-performance materials for super capacitors which are environmentally friendly and whose production is cost-efficient. Materials based on graphene appear to be very promising for this purpose.

Graphene – sustainable, environmentally friendly and energy-efficient

Graphene possesses a great potential for the application in super capacitors, battery technologies or (bio)fuel cells: Its material properties can result in a lower series resistance, a higher power density and a prolonged life span. Natural graphite – a rich, natural resource – serves as the starting material. Furthermore, the disposal and environmental compatibility of the carbon material is classified as noncritical. Therefore, these super capacitors will meet all standards of »green chemistry«.

G-ONET: Interdisciplinary cooperation within the framework of the »Sustainability Center«

In the »G-ONET« project, Fraunhofer IAF, together with the Institute for Macromolecular Chemistry (MAKRO) and the Department of Microsystems Engineering (IMTEK) of the University of Freiburg, is working on graphene-organic materials for super capacitors. Fraunhofer IAF is developing a method for the production of graphene flakes based on the chemisorption of hydrogen. MAKRO will cross-link these flakes by using innovative organic chemistry to create an electrode material with controlled porosity. IMTEK is then building and testing super capacitors based on these optimized electrode materials. The project »G-ONET« is one of the pilot projects of the newly established »Sustainability Center«. Within this initiative, the five Freiburg Fraunhofer institutes as well as the University of Freiburg pool their competencies and work together in twelve pilot projects in order to find solutions for a sustainable development of society.