Boosting the performance of Zn ion hybrid supercapacitors by regulating the chemically and physically active sites of graphene films

Reduced graphene oxide (RGO) is an ideal material as an electrode used in the electrochemical energy storage field. However, the serious aggregation of graphene sheets and fewer chemically active sites limit it from exhibiting higher performance. Herein, we introduce a facile solvothermal reaction method to simultaneously regulate the functional groups on RGO, balance the aggregation and connection of graphene sheets, and dope the nitrogen element in a graphene network. The obtained electrode (RGO-N(DMF)) has a high content of carbonyl and nitrogen functional groups, and shows a fluffy structure as well as good electron conductivity, exhibiting both high chemically and physically actives sites. Benefiting from these advantages, RGO-N(DMF) shows a high specific capacity of 135 mA h g