Examples of the present invention include high electric energy density polymer film capacitors with high dielectric constant, low dielectric dissipation tangent, and low leakage current in a broad temperature range. More particularly, examples include a polymer film capacitor in which the dielectric layer comprise a copolymer of a first monomer (such as tetrafluoroethylene) and a second polar monomer. The second monomer component may be selected from vinylidene fluoride, trifluoroethylene or their mixtures, and optionally other monomers may be included to adjust the mechanical performance. The capacitors can be made by winding metallized films, plain films with metal foils, or hybrid construction where the films comprise the new compositions. The capacitors can be used in DC bus capacitors and energy storage capacitors in pulsed power systems.
 This invention was made with government support under Grant Nos. DE-EE0004540 and DE-SC0004191 from the United States Department of Energy. The government has certain rights in the invention.