A capacitor includes a pair of electrodes and a metalized dielectric layer disposed between the pair of electrodes, in which the metalized dielectric layer has a plurality of metal aggregates distributed within a dielectric material. The distribution is such that a volume fraction of metal in the metalized dielectric layer is at least about 30%. Meanwhile, the plurality of metal aggregates are separated from one another by the dielectric material. A method for forming a metal-dielectric composite may include coating a plurality of dielectric particles with a metal to form a plurality of metal-coated dielectric particles and sintering the plurality of metal-coated dielectric particles at a temperature of at least about 750° C. to about 950° C. to transform the metal coatings into discrete, separated metal aggregates. Contrary to conventional techniques of separating electrodes by a dielectric tape, this inventive system and method demonstrates that a metalized dielectric layer may be formed in-situ during sintering.