Mass production of graphene nanoscrolls and their application in high rate performance supercapacitors

Mass production of graphene nanoscrolls and their application in high rate performance supercapacitors

Bingna Zheng,   Zhen Xu and   Chao Gao

The output of graphene nanoscrolls (GNSs) has been greatly enhanced to the gram-level by using an improved spray-freeze-drying method without damaging the high transforming efficiency (>92%). The lowest bulk density of GNS foam reaches 0.10 mg cm−3. Due to the unique morphology and high specific surface area (386.4 m2 g−1), the specific capacitances of the GNSs (90–100 F g−1 at 1 A g−1) are all superior to those of multiwalled carbon nanotubes meanwhile maintaining excellent rate capabilities (60–80% retention at 50 A g−1). For the first time, all-graphene-based films (AGFs) are fabricated via the intercalation of GNSs into graphene layers. The AGF exhibits a capacitance of 166.8 F g−1 at 1 A g−1 and rate capability (83.9% retention at 50 A g−1) better than those of pure reduced graphene oxide (RGO) films and carbon nanotubes/graphene hybrid films (CGFs).

Graphical abstract: Mass production of graphene nanoscrolls and their application in high rate performance supercapacitors