NOVELTY - Device (100) comprises: a first sheet of a conductive material (110); a sheet of a substance (120) disposed on first sheet of conductive material, where substance is able to conduct free ions in it; and second sheet (130) of same/different conductive material disposed on the sheet of the substance, where at least one of the first and second sheet comprises metal foil layer, carbon nanotube layer directly grown on the metal foil layer, and layer of carbon nanoparticles disposed on carbon nanotube layer, and where carbon nanoparticle layer is arranged to face sheet of the substance.    USE - As a device (claimed) used in energy conversion and storage systems i.e. rechargeable batteries and supercapacitors, photovoltaic devices and fuel cells.    ADVANTAGE - The complex carbon nanostructure thus resulted can be directly used for electrodes in rechargeable batteries and supercapacitors. The process is suitable for mass productions of the nanostructured carbon material and mass production of energy conversion and storage units comprising the nanostructured carbon material. By directly growing the carbon nanotubes (CNTs) on a flexible conductive substrate, the CNTs do not have to be removed from the substrate for the applications, and the substrate can be directly used in those energy storage devices where their components must be folded or rolled for minimizing the overall volume of the devices. This not only simplifies the manufacturing procedure but also makes it more cost effective. Due to the extremely large surface area, the CNT nanostructure on a metal foils is very advantageous over traditional graphite electrodes. This process further enables the roll-to-roll fabrication of nanostructured electrodes for industrialized mass production.    DETAILED DESCRIPTION - A device (100), comprises: a first sheet of a conductive material (110); a sheet of a substance (120) disposed on the first sheet of the conductive material, the substance being able to conduct free ions in it; and a second sheet (130) of same or different conductive material disposed on the sheet of the substance, where at least one of the first sheet and second sheet comprises a metal foil layer, a carbon nanotube layer directly grown on the metal foil layer, and a layer of carbon nanoparticles disposed on the carbon nanotube layer, and where the carbon nanoparticle layer is arranged to face the sheet of the substance. The substance comprises a sheet of microperforated plastic film and an electrolyte (124) disposed on surfaces of the plastic film. The device has much larger width and length than thickness, the device is rolled up or folded and then hermetically sealed to form an energy storage unit. An INDEPENDENT CLAIM is included for forming a layer of carbon nanostructure on a flexible metal foil, involving coating a catalyst on a surface of the metal foil by low temperature evaporation of the catalyst; annealing the catalyst coated metal foil in ammonia gas at a first temperature; and growing carbon nanotubes directly on the catalyst coated surface of the metal foil in a hydrocarbon gas atmosphere at a second temperature, where the first temperature is lower than the second temperature and the second temperature is not greater than 550 degrees C.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic illustration of a thin film energy storage device structure.    Sheet of a conductive material (110)    Sheet of a substance disposed on the first sheet of the conductive material (120)    Electrolyte (124)    Separator (126)    Second sheet (130)