Highly dispersive Ba _0.6 Sr _0.4 TiO ₃ nanoparticles modified P(VDF‐HFP)/PMMA composite films with improved energy storage density and efficiency

Abstract

Polymer composite films with high energy density as well as high efficiency are promising dielectric materials in pulsed power systems. In improving the energy discharged efficiency, poly vinylidene fluoride‐hexafluoropropylene [P(VDF‐HFP)] film blended with 20 vol.% poly(methylmethacrylate) (PMMA), which has a much slimmer ferroelectric hysteresis loop, is employed as the polymer matrix. Highly dispersive Ba 0.6 Sr 0.4 TiO 3 (BST) nanoparticles with an average particle size of 12.1 nm are utilised to improve the polarisation of the blend film without sacrificing the dielectric strength. Uniform nanocomposite films with high flexibility and excellent energy‐storage performance are obtained. Especially, due to the optimisation of both polymer matrix and fillers, the BST modified P(VDF‐HFP)/PMMA blend films show improved breakdown strength and depressed energy loss, which leads to an enhanced energy density of 10.3 J/cm 3 at 378 kV/mm.