The present invention relates to microtubes made of carbon nanotubes or composites based on carbon nanotubes. The present invention also relates to the use of such microtubes made of carbon nanotubes or composites based of carbon nanotubes as stand alone electrodes electrodes or integrated with current collectors or as a part of membrane electrode assemblies applied in electrochemical systems such as primary and secondary batteries, redox flow batteries, fuel cells, electrochemical capacitors, capacitive deionization systems, electrochemical- and biosensors devices, or solar cells. Another use of the microtubes made of carbon nanotubes or composites based on carbon nanotubes relates to their application as supported or unsupported tubular membranes for water or wastewater filtration, in aqueous and organic solvent filtration, for blood filtration, for gas separation processes, in gas and liquid adsorption processes or in sensor applications.