The invention concerns a method for making a porous substrate-electrode complex (6) with load rate not less than 80% for a supercapacitor including at least the following steps: preparing a mixture containing at least one polymer (1), at least one liquid pore-forming plasticizer (3), and at least one active filler (2); extruding the mixture in paste form; depositing the paste on the substrate and laminating same; and treating the resulting complex to eliminate all or part of the plasticizer (3) and generate porosity in the electrode. The invention also concerns an electrode paste and a collector-electrode complex.