This invention relates to a supercapacitor assembly having an asymmetric supercapacitor, a diode, and a switch in parallel with the diode. The asymmetric supercapacitor has at least one positive electrode, at least one negative electrode, and at least one separator impregnated with an electrolyte. The diode has an anode and a cathode, the cathode being electrically connected to the supercapacitor.