MnO2/graphene/nickel foam composite as high performance supercapacitor electrode via a facile electrochemical deposition strategy

A novel MnO2/graphene (G)/nickel foam (NF) composite as supercapacitor electrode was fabricated by a facile electrochemical deposition approach for the first time. The approach includes electrophoretic deposition of G on NF (EPD-G/NF) and electrodeposition of MnO2 on EPD-G/NF (MnO2/EPD-G/NF). Compared with other methods for preparing MnO2/G composite, our green strategy avoids using harsh chemicals (e.g. hydrazine) or high temperature treatment for reducing graphene oxide. Owing to unique structure, specific capacitance (Cs) of the MnO2/EPD-G/NF electrode is as high as 476 F g− 1 at high current density of 1 A g− 1 in 0.5 M Na2SO4 solution, which is the highest Cs for MnO2/G composites to date, and the Cs is higher than that of MnO2/NF electrode. Furthermore, it also exhibits high rate capacity, such as 216 F g− 1 of Cs at 10 A g− 1. On the other hand, our strategy provides a versatile method for fabrication of other G-based composites with metal oxide/hydroxide or conducting polymer as supercapacitor electrode.

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► MnO2/graphene (G)/nickel foam composite was fabricated for the first time.
► The composite possesses unique porous structure.
► The composite shows the highest specific capacitance for MnO2/G composites to date.
► The composite exhibits high rate capacity (476 F g− 1 at 1 A g− 1, 216 F g− 1 at 10 A g− 1).
► Our strategy provides a versatile method for fabrication of other G-based composites.