Thin sandwich graphene oxide@N-doped carbon composites for high-performance supercapacitors - Carbon4Energy

Compositing graphene oxide (GO) with controllable secondary components is of great significance to achieve high-level physico-chemical properties of carbon materials. In this study, thin sandwich composites of GO and N-doped carbon (GO@NdC) were fabricated through a controllable deposition of polyvinyl dichloride (PVDC)-dehalogenated carbon on GO, which was ensured by the high affinity between PVDC and GO. The thin deposited carbon layers on GO could achieve the thickness of 1.0 to 2.0 nm. Considering dehalogenated carbon was verified to be highly reactive for coupling alien elements, the overall N content of ~7.0 at.% was obtained with the addition of N source of melamine. Meanwhile, byproducts of EtOH and NaCl could in situ tune the composite into open 3D structure, efficiently preventing thin layered composite from re-stacking. After activation by KOH, GO@NdC further performed hierarchical pore structure and large specific surface area. Remarkably, KOH-activated GO@NdC exhibited a high specific capacitance of ~354 F g-1 and capacitance retention of >65 % (at 10.0 A g-1). Finally, GO@NdC symmetric supercapacitor also achieved a high specific energy of ~11.8 Wh Kg-1 in aqueous alkaline electrolyte.