Enhancing discharged energy density and suppressing dielectric loss of poly(vinylidene fluoride-ter-trifluoroethylene-ter-chlorofluoroethylene) by a sandwiched structure

• Published in: IET Nanodielectrics Vol. 1; no. 4; pp. 127 - 131
• Main Authors: Zhu, Yingke, Jiang, Pingkai, Huang, Xingyi
• Format: Journal Article
• Language: English
• Published: Beijing The Institution of Engineering and Technology 01.12.2018; John Wiley & Sons, Inc; Wiley
• Subjects: breakdown strength; capacitors; charge barrier; D-E loops; Dielectric breakdown; dielectric constant; dielectric hysteresis; Dielectric loss; dielectric losses; Dielectric strength; dielectric thin films; Discharge; discharge efficiency; discharged energy density; Efficiency; electric breakdown; Electric devices; Electric field strength; electric strength; Energy resources; Energy storage; energy storage density; Fluorides; permittivity; poly(vinylidene fluoride‐ter‐trifluoroethylene‐ter‐chlorofluoroethylene); polymer dielectrics; Polymer films; Polymers; Polymethyl methacrylate; Polyvinylidene fluorides; Research Article; sandwich structures; sandwiched structure dielectric films; Scanning electron microscopy; Thickness; Vinylidene fluoride; permittivity; electric strength; poly(vinylidene fluoride-ter-trifluoroethylene-ter-chlorofluoroethylene); energy storage density; breakdown strength; electric breakdown; polymer films; sandwiched structure dielectric films; discharged energy density; dielectric loss; discharge efficiency; polymer dielectrics; dielectric constant; sandwich structures; polymethyl methacrylate; capacitors; dielectric hysteresis; dielectric thin films; charge barrier; dielectric losses; D-E loops
• ISSN: 2514-3255; 2514-3255
• DOI: 10.1049/iet-nde.2018.0011

Polymer dielectrics with high energy density and low dielectric loss are highly desired due to the rapid development of electric devices. Among known polymers, poly(vinylidene fluoride-ter-trifluoroethylene-ter-chlorofluoroethylene) P(VDF-TrFE-CFE) is one of the promising materials for energy storage capacitor applications because of its high dielectric constant. Nevertheless, it suffers from high dielectric loss especially at the high electric field, which suppresses its breakdown strength and energy storage density. Herein, sandwiched structure dielectric films were fabricated by employing polymethyl methacrylate (PMMA) as the outer layer and P(VDF-TrFE-CFE) as the central layer. By modulating the thickness of the central layer, an enhanced discharged energy density of 7.03 J/cm3 is achieved at a high electric field of 480 MV/m, which is 132% more than that of P(VDF-TrFE-CFE) at its maximum electric field 300 MV/m. Meanwhile, this sandwiched structure film also retains a high discharge efficiency of 78% at 480 MV/m, which is never been seen in polyvinylidene fluoride-based polymers. Results show that PMMA acts as charge barrier and simultaneously enhance the breakdown strength and suppress the dielectric loss of P(VDF-TrFE-CFE).