In situ anchoring uniform MnO2 nanosheets on three-dimensional macroporous graphene thin-films for supercapacitor electrodes

Abstract

We present a facile and efficient fabrication of 3D macroporous rGO/MnO₂ nanosheet thin-films for supercapacitor electrodes. An amorphous-carbon-modified rGO thin-film is firstly prepared through a simple glucose and CaCO₃ particle mediated template method. Then ultrathin MnO₂ nanosheets are in situ synthesized on the rGO networks by the rapid and scalable redox reaction between KMnO₄ and amorphous carbon. The fabricated three-dimensional porous hybrid thin-film shows a high specific capacitance of 245 F g⁻¹ (based on the total mass of the film) at a scan rate of 2 mV s⁻¹, a good rate capability of 143 F g⁻¹ at 300 mV s⁻¹, and an excellent cycling stability, maintaining 81% of the initial capacitance after 2000 cycles at 2 A g⁻¹. The improved performance indicates that the lightweight and low-cost 3D porous rGO/MnO₂ nanosheet thin-films have a great potential in the area of portable energy storage devices.