Dense energy storage via interacting nanostructures

An energy-storage apparatus comprising:

• a first plurality of multi-wall nanotubes, wherein each multi-wall nanotube includes an outer tube that, at a first end thereof, is bound to an underlying layer, and further includes a freely-movable inner tube;
• at least one electrode, wherein the at least one electrode is spaced apart from a second end of the outer tube of each multi-wall nanotube;
• and
• control electronics for:
• (i) applying a variable voltage across the at least one electrode and the multi-wall nanotubes;
• (ii) controlling a flow of electrical charge to the multi-wall nanotubes;
• and
• (iii) controlling a discharge of electrical charge from the multi-wall nanotubes.

A method for storing energy in a plurality of multi-wall nanotubes and releasing the energy, wherein the method comprises:

• increasing a potential energy of a van der Waals field existing between an inner tube and an outer tube of each of a plurality of multi-wall nanotubes by partially withdrawing the inner tube of each multi-wall nanotube via the application of a voltage across an electrode and each of the multi-wall nanotubes;
• electrically coupling the multi-wall nanotubes to a load;
• and
• discharging electrical energy to the load from each multi-wall nanotube by reducing a magnitude of the voltage across the electrode and the multi-wall nanotubes, thereby drawing the inner tube at least partially back into the outer tube of each multi-wall nanotube and changing the capacitance of a variable capacitor defined by the electrode and the inner tube.