High field antiferroelectric-like dielectric of poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-poly(styrene-methyl methacrylate) for high pulse capacitors with high energy density and low loss
Dielectric polymer film capacitors with high energy density and low energy loss are highly desirable in compact electronic devices and high power density electric systems. To overcome the high dielectric loss of poly(vinylidene fluoride) based ferroelectric polymers, in this work, a series of antiferroelectric-like poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)-graft-poly(styrene-methyl methacrylate) (PVDF-MS) copolymers were successfully synthesized using an atom transfer radical polymerization procedure. The merits including the excellent miscibility of PMMA with both PSt and PVDF, and the promising insulating performance of PSt segments are combined in the resultant copolymers. The introduction of increased P(St-MMA) (MS) side chains leads to significantly enhanced energy density, low conduction loss and energy loss compared with the pristine P(VDF-TrFE-CTFE). The highest energy density of 17 J cm−3 and the discharge efficiency of 87% at 600 MV m−1 are achieved by the sample containing 28 wt% MS. The excellent dielectric and capacitive properties of the grafted copolymers offer a strategy for the synthesis of high dielectric polymer dielectrics with promising energy storage properties.