A magnetic supercapacitor has a dielectric layer positioned between magnetic layers. The magnetic layers may comprise hard, soft magnetic material or magnetic exchange coupled magnet (i.e. soft and hard magnet composite). A magnetic flux generated by the magnetic layers increases the permittivity of the dielectric layer, thereby increasing the capacitance and, hence, stored energy of the supercapacitor. When the magnetic layers comprise soft magnetic material, the capacitance of the supercapacitor can be varied. In this regard, current passing through a conductive segment within close proximity to the magnetic layers may be controlled in order to tune the capacitance as may be desired.