Determinant influence of the electrical conductivity versus surface area on the performance of graphene oxide-doped carbon xerogel supercapacitors
A series of resorcinol formaldehyde based carbon xerogels were synthesized under identical conditions using different graphene oxide loads. The gelification reaction was carried out using a stable aqueous suspension of graphene oxide, yielding organic gels with graphene oxide concentrations ranging from 1.2–2.5%. After the carbonization, xerogels with medium surface area (650 m2/g) and a highly improved electrical conductivity were obtained. Specific capacitance of 120 F/g of one electrode at very high scan rate of 500 mV/s were achieved, as well as power densities above 30 kW/kg, which is a significant improvement of 180% with respect to the pristine xerogels. Carbonized xerogels were further steam activated to yield activated carbon xerogels with surface areas of up to 1800 m2/g. The use of activated xerogels improves slightly the specific capacitance at low scan rates only, and there is a sharp decrease above 20 mV/s, resulting in a worse performance than graphene oxide doped carbonized xerogels. The electrical conductivity of the graphene oxide-doped carbon xerogels decreases upon activation, which means that the influence of the electrical conductivity on a carbon xerogel is greater than its specific surface area, which it is the first time it is observed for porous carbons
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | artículo biblioteca |
| Language: | English |
| Published: |
Elsevier
2017-10-09
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| Online Access: | http://hdl.handle.net/10261/157461 http://dx.doi.org/10.13039/501100003359 http://dx.doi.org/10.13039/501100003329 |
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