Electrical breakdown and ultrahigh electrical energy density in poly(vinylidene fluoride-hexafluoropropylene) copolymer

This paper investigates the electrical breakdown of a polar fluoropolymer, poly(vinylidene fluoride-hexafluoropropylene) which exhibits an exceptionally high discharged electrical energy density (>25 J/cm3). It is shown that above room temperature, the breakdown strength decreases with temperature. It is further shown that such a temperature dependence of breakdown strength is consistent with the electromechanical breakdown model by taking into consideration of the plastic deformation of semicrystalline polymers.