Improved performance of a MnO2@PANI nanocomposite synthesized on 3D graphene as a binder free electrode for supercapacitors

Abstract

In the current study, we have synthesized a binder free nickel foam graphene MnO₂@PANI (MnO₂@PANI/graphene) nanocomposite by simple hydrothermal method followed by in situ polymerization. The graphene grown on nickel foam is used as a 3D scaffold conducting substrate for binder free nanocomposite electrode synthesis. Morphological characterization of the nanocomposite reveals growth of the MnO₂ intercalated PANI nanorods-like network. The electrochemical study demonstrates very interesting electrode activation phenomenon, i.e. increase in specific capacitance upto 1500 charge–discharge cycles. The activated MnO₂@PANI/graphene nanocomposite exhibits a maximum specific capacitance of 1369 F g⁻¹ at 3 A g⁻¹ current density and excellent rate capability of more than 70% by varying current density from 3 A g⁻¹ to 15 A g⁻¹. The activated electrode displays good cyclic stability by retaining SC over 83% after 5000 cycles.