Poly(vinylidene fluoride-co-chlorotrifluoroethylene) and polyurea composite with enhanced energy storage properties

The improvement of energy density is desired for dielectric materials in capacitors according to the developing trend of electric devices. In this article, poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-CTFE)) and polyurea (PUA) are blended in different ratios to obtain high dielectric performance composite, and the dielectric polymer composite films are fabricated and investigated. The composite films combine the advantages of both contents, showing high dielectric constant of P(VDF-CTFE) and high energy storage efficiency of PUA. The results demonstrate that the composite film contains PUA with a volume fraction of 10% exhibits the best performance, achieving a breakdown strength as high as 5020 kV/cm, which is higher than that of P(VDF-CTFE)/polythiourea (PTU) composite ever reported. Moreover, the breakdown strength and energy storage efficiency are 1.35 times and 1.65 times higher than pure P(VDF-CTFE), respectively. The article provides a new high-performance dielectric material fabricated through a simple and effective blending method, and it has a great potential in electric energy storage capacitors.