A method for manufacturing a hybrid binder-free electrode for electrochemical energy storage devices, said hybrid binder-free electrode comprising, preferably consisting of, a conductive metal substrate and carbon nanotubes attached to the conductive metal substrate, wherein each carbon nanotube has only one single-crystal metal nanoparticle positioned at its tip with a metal sulphide top layer, the method comprising the following subsequent steps: a) growing carbon nanotubes, preferably multi-walled carbon nanotubes, in a processing chamber using a tip-growth mechanism, wherein each carbon nanotube has only one single-crystal metal nanoparticle positioned at its tip, on a conductive metal substrate in a direction perpendicular to the surface of the conductive metal substrate, wherein the metal of the single-crystal metal nanoparticles and the metal of the conductive metal substrate are the same; b) providing the carbon nanotubes grown on the conductive metal substrate as obtained in step (a) in another processing chamber and evacuating said processing chamber to a pressure below 100 Pa, preferably to a pressure below 1 Pa, using a vacuum pump and a pressure gauge; c) supplying sulphur-containing gas to the evacuated processing chamber of step (b) to obtain a partial pressure of the sulphur-containing gas of between 1 Pa and 1·10 5 Pa; d) setting the temperature inside the processing chamber to between 25 and 300 °C, preferably to between 100 and 150 °C, with a heating element; e) allowing the single-crystal metal nanoparticles at the tips of the carbon nanotubes to interact with the sulphur-containing gas inside the processing chamber, leading to the formation of a metal sulphide top layer on the single-crystal metal nanoparticles; and f) assuring that the temperature of the processing chamber drops below a threshold value, preferably below 35 °C, and subsequently venting the processing chamber to atmospheric pressure, wherein no binder is applied during the process. a) growing carbon nanotubes, preferably multi-walled carbon nanotubes, in a processing chamber using a tip-growth mechanism, wherein each carbon nanotube has only one single-crystal metal nanoparticle positioned at its tip, on a conductive metal substrate in a direction perpendicular to the surface of the conductive metal substrate, wherein the metal of the single-crystal metal nanoparticles and the metal of the conductive metal substrate are the same; b) providing the carbon nanotubes grown on the conductive metal substrate as obtained in step (a) in another processing chamber and evacuating said processing chamber to a pressure below 100 Pa, preferably to a pressure below 1 Pa, using a vacuum pump and a pressure gauge; c) supplying sulphur-containing gas to the evacuated processing chamber of step (b) to obtain a partial pressure of the sulphur-containing gas of between 1 Pa and 1·10 5 Pa; d) setting the temperature inside the processing chamber to between 25 and 300 °C, preferably to between 100 and 150 °C, with a heating element; e) allowing the single-crystal metal nanoparticles at the tips of the carbon nanotubes to interact with the sulphur-containing gas inside the processing chamber, leading to the formation of a metal sulphide top layer on the single-crystal metal nanoparticles; and f) assuring that the temperature of the processing chamber drops below a threshold value, preferably below 35 °C, and subsequently venting the processing chamber to atmospheric pressure,