Oriented Graphenes from Plasma-Reformed Coconut Oil for Supercapacitor Electrodes

Abstract

The utilization of vertical graphene nanosheet (VGN) electrodes for energy storage in supercapacitors has long been desired yet remains challenging, mostly because of insufficient control of nanosheet stacking, density, surface functionality, and reactivity. Here, we report a single-step, scalable, and environment-friendly plasma-assisted process for the fabrication of densely packed yet accessible surfaces of forested VGNs (F-VGNs) using coconut oil as precursor. The morphology of F-VGNs could be controlled from a continuous thick structure to a hierarchical, cauliflower-like structure that was accessible by the electrolyte ions. The surface of individual F-VGNs was slightly oxygenated, while their interior remained oxygen-free. The fabricated thick (>10 μm) F-VGN electrodes presented specific capacitance up to 312 F/g at a voltage scan rate of 10 mV/s and 148 F/g at 500 mV/s with >99% retention after 1000 cycles. This versatile approach suggests realistic opportunities for further improvements, potentially leading to the integration of F-VGN electrodes in next-generation energy storage devices.

Low-temperature low-power PECVD synthesis of vertically aligned graphene

“…Besides this, excellent electrical and mechanical properties of VGNs and their derivatives enabling their applicability in enormous fields, including supercapacitor, battery electrodes, power sources, field emitters, flexible electronics, gas sensors, and catalyst supporters [5][6][7][8][9][10].…”

“…Rising interest in the synthesis and application of VGNs emanates from their unique characteristics such as nonstacking morphology, high-aspect-ratio, sharp edges, and high-density reticular arrangement, etc [2][3][4]. Besides this, excellent electrical and mechanical properties of VGNs and their derivatives enabling their applicability in enormous fields, including supercapacitor, battery electrodes, power sources, field emitters, flexible electronics, gas sensors, and catalyst supporters [5][6][7][8][9][10]. An individual VGN typically consist of few stacked graphene layers having a thickness of several few nanometres with lateral and vertical dimensions of hundreds of nanometres to tens of micrometres.…”

Plasma-enabled synthesis and modification of advanced materials for electrochemical energy storage

“…Therefore, the plasma carbon electrode presented a high specific capacitance (193 F/g at 1.0 A/g), and the fabricated symmetric SC achieved an energy density of 22.0 Wh/kg at a power density of 600 W/kg. Similarly, Kumar et al [158] have successfully prepared the hierarchical cauliflower-like VGNs (F-VGNs) by plasma-assisted process using coconut oil as precursor. The effective channels connecting the top surface to the interior provide effective paths for electrolyte ions to enter and exit the electrode materials.…”

Oriented Carbon Nanostructures from Plasma Reformed Resorcinol-Formaldehyde Polymer Gels for Gas Sensor Applications

“…Inspired by the recent studies on thermal annealing of natural precursors to obtain CNs, several investigations are reported on the alternative plasma-assisted single-step synthesis of OCNs from environmentally-friendly precursors, such as coconut oil [ 30 ], honey [ 31 ], butter [ 32 ], honeycomb [ 33 ], etc. Apart from these precursors, phenol derived xerogels and aerogels are also considered as the precursor sources for the preparation of porous carbon nanoparticles and nanostructures with large surface area [ 34 , 35 ].…”