Graphene aerogels promise enhanced energy storage performance
The team’s graphene aerogel-based supercapacitor electrodes are suitable for the electric vehicle applications because they feature high surface area, good electrical conductivity, chemical inertness and long-term cycling stability.
Energy storage systems for electric vehicles have especially demanding requirements because they must combine high power and energy density, cyclability, safety and low cost. Supercapacitors can help to meet these requirements due to their high power density and excellent cycling stability.
"Commercial carbon-based supercapacitors are used to recover braking energy in numerous vehicles (cars, buses, trains, etc.) and to open the emergency exits of the
Airbus A380," said LLNL’s Patrick Campbell. "Our materials can potentially improve on the performance of the commercial supercapacitors by more than 100 percent."
Compared to traditional carbon-based supercapacitor electrodes fabricated from carbon black and binder materials, graphene aerogels offer many advantages such as
control of density and pore size distribution, and increased conductivity due to carbon linkers between the active carbon sheets and the absence of binder materials.
"Graphene aerogels are a relatively new type of aerogel that are ideal for energy storage applications because of their extremely high surface area, excellent mechanical properties and very high electrical conductivity," said Campbell. "We have been exploring various ways to enhance their energy storage properties such as
increasing electrode density through mechanical compression. The non-covalent modification strategy is simply another route to increase the electrical energy storage
While use in personal electronics or other high-power applications where the energy needs to be stored and released quickly has yet to be tested, the outlook is promising, said Juergen Biener, LLNL’s team leader.
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