Graphene beads fabricated by an emulsion process for supercapacitor electrode materials

•Graphene beads were fabricated by a simple emulsion process.•PVP was used as the binder of graphene oxide sheets to keep spherical shape stable.•Hollow or solid graphene beads can be obtained through adjusting the stirring rate.•Graphene beads had electric double-layer capacitance and pseudocapacitance.

Hollow or solid graphene beads were fabricated via a simple emulsion process by using polyvinylpyrrolidone as the binder of graphene oxide sheets to keep spherical shape stable. The stirring rate played an important role in the diameters of graphene beads and internal morphologies. The graphene beads with wrinkled structure were applied for supercapacitor electrode materials and exhibited a specific capacitance of 237 F g−1 at 1 A g−1 in 6 M KOH.

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