A carbonaceous composition usable to constitute a supercapacitor cell electrode, a porous electrode usable to equip such a cell, a process for manufacturing this electrode and one such cell incorporating at least one such electrode, for example in order to equip an electric vehicle. This composition is usable to be in contact with an aqueous ionic electrolyte, is based on a carbonaceous powder and comprises a hydrophilic binder-forming system. The system may include between 3% and 10% by weight a first crosslinked polymer having a number-average molecular weight Mn of greater than 1000 g/mol and having alcohol groups, and between 0.3% and 3% by weight a second polymer of at least one acid and which has a pKa of between 0 and 6 and a number-average molecular weight Mn of greater than 500 g/mol, the first polymer being crosslinked thermally in the presence of the second polymer.