Supercapacitors have the potential to replace Li ion batteries as the next-generation electrical energy storage technology in demanding applications due to their high power density and excellent cycling stability. Graphene-based supercapacitor electrodes are particularly promising because they feature high surface area, good electrical conductivity, and chemical inertness. Researchers at Lawrence Livermore National Laboratory have developed tailored fullerene-grafted 3D mesoporous graphene macro-assemblies (GMAs) (Figure 1) for electrical energy storage applications by anchoring fullerene molecules to the 3D graphene backbone. Fullerene-grafted graphene (C₆₀-GMA) materials promise to overcome the current charge storage limitations of carbon-based supercapacitors by combining the high charge storage capacitance of fullerenes with the high electrical conductivity of 3D-GMAs. In fact, the charge storage capacitance of fullerene (223 mAh/g) is similar or higher than that of today’s standard lithium ion battery electrode materials (177 mAh/g for LiFePO₄).

Funding was provided by Lawrence Livermore National Laboratory Directed Research and Development (LDRD) Grant 17-ERD-017. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344. IM Release Number LLNL-ABS-716277.

Figure 1. Fullerene-grafted 3D graphene bulk material