SC-CO2-assisted process for a high energy density aerogel supercapacitor: the effect of GO loading.
Energy density, safety, and simple and environmentally friendly preparation methods are very significant aspects in the realization of a compact supercapacitor. Herein we report the use of a supercritical CO2-assisted gel drying process (SC-CO2) for the preparation of porous electrodes containing dispersed graphene in a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) binder membrane to sandwich in a new portable supercapacitor based on graphene oxide (GO). A GO loading of 60 wt.% was found to give the best combination of factors (porosity, wettability, mechanical and electrochemical properties). Cycling voltammetry and charge/discharge studies showed an excellent capacitance behaviour and stability in an ionic liquid electrolyte, suggesting SC-CO2processing as a promising platform to produce highly bulky and porous films for supercapacitors. The supercapacitor device delivers a very high energy density of 79.2 Wh kg-1at a power density of 0.23 KW kg-1(current density 0.5 A g-1, specific capacitance 36.2 F g-1) while that of steel remains at 50.3 Wh kg-1at a power density of 2.8 KW kg-1(current density 6 A g-1, specific capacitance 23.5 F g-1).
Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, I-84084, Fisciano (SA), Italy. NANO_MATES, Research Centre for Nanomaterials and Nanotechnology at the University of Salerno, University of Salerno, Via Giovanni Paolo II, 132, I-84084, Fisciano (SA), Italy.
Maria
M
Sarno
Lucia
L
Baldino
Carmela
C
Scudieri
Stefano
S
Cardea
Paolo
P
Ciambelli
Ernesto
E
Reverchon