@prefix dcat: . @prefix dct: . @prefix foaf: . @prefix vcard: . @prefix xsd: . a dcat:Dataset ; dct:description """ The objective of this work is to improve the energy density of carbon/carbon supercapacitors. For achieving this objective, two different strategies were followed depending on the electrolyte used: i) in aqueous electrolytes, our efforts were focused on extending the operating cell voltage by using neutral alkali sulfate solutions; ii) in organic electrolyte, the target was to improve the volumetric capacitance by setting a mild activation method able to produce a porous carbon with average pore size matching the ion size, while not enlarging the pores upon porosity development. A practical cell voltage of 1.8 V has been demonstrated by implementing aqueous alkali sulfates in symmetric carbon/carbon capacitors. It has been shown that the voltage is limited by a partial destructive electro-oxidation of the positive electrode. Such irreversible electro-oxidation could be mitigated by mild chemical oxidation of the active carbon material with hydrogen peroxide; consequently, the voltage could be further expanded up to 1.9 V. Even 2.0 V could be attained after mass balancing the electrodes in order to allow them to operate in their stability window. Finally, pouch-cells with carbon coating on stainless steel current collector were realized by using 2 mol L-1 Li2SO4 as electrolyte. An exceptional cycling stability at cell voltages up to 2.1 V was obtained during 10,000 cycles. Hence, the use of alkali sulfate electrolytes is a cost-effective alternative to organic electrolytes for producing environment friendly and safe carbon/carbon supercapacitors. Dense nanoporous carbons with pores fitting the dimension of ions of the Et4NBF4/acetonitrile organic electrolyte were obtained by high pressure oxidation of non-porous carbon at low temperature, followed by a thermal desorption to remove the surface groups and unblock pore entrances. The activation mechanism consisted in drilling the narrow pores existing initially in the char. Due to the low burn-off, the density of the electrodes was remarkably high allowing high volumetric capacitance values to be reached. This novel production method associates the advantages of environment friendly, cost-effective, high yield and low energy consumption characteristics. """ ; dct:identifier "NNT: 2013ORLE2011" ; dct:issued "2026-05-09T09:58:43.067602"^^xsd:dateTime ; dct:language "en" ; dct:modified "2026-05-09T09:58:43.067606"^^xsd:dateTime ; dct:publisher ; dct:title "Optimizing carbon/carbon supercapacitors in aqueous and organic electrolytes" ; dcat:contactPoint [ a vcard:Organization ; vcard:fn "CCSD" ] ; dcat:distribution ; dcat:keyword "chimothechemical-sciencesother", "infoeu-reposemanticsdoctoralthesis", "supercapacitors", "supercondensateurs", "theses" ; dcat:landingPage . a dcat:Distribution ; dct:format "HTML" ; dct:issued "2026-05-09T09:58:43.069395"^^xsd:dateTime ; dct:modified "2026-05-09T09:58:43.059524"^^xsd:dateTime ; dct:title "Optimizing carbon/carbon supercapacitors in aqueous and organic electrolytes" ; dcat:accessURL . a foaf:Agent ; foaf:name "test_moissonnage_selune" . a foaf:Document .