Flexible barium titanate@polydopamine/polyvinylidene fluoride/polymethyl methacrylate nanocomposite films with high performance energy storage

The introduction of high-permittivity inorganic ceramic materials into organic polymer-based dielectric materials can effectively increase the energy density of film capacitors. In this study, polydopamine (PDA) was coated on BaTiO 3 (BT) nanoparticles through a condensation reaction to form a core–shell structure of BT@PDA. Then it is introduced into the polyvinylidene fluoride/polymethyl methacrylate (PVDF/PMMA) matrix, and the BT@PDA/PVDF-PMMA nanocomposite flexible energy storage films are prepared by the solution casting method. When BT@PDA is 5%, the breakdown strength of the nanocomposite film is 378 MV/m, and the maximum energy density is 11.15 J/cm 3 . Excellent comprehensive electrical properties are due to the enhanced interface coupling between the BT nanofiller and the PVDF macromolecular chain. The introduction of PMMA can suppress the increase in residual polarization. Utilizing the respective advantages of BT@PDA nanocomposite and PVDF-PMMA blending, while improving the breakdown strength and polarization difference, this work provides feasible strategy for improving the energy density and discharge efficiency of flexible PVDF-based films capacitors. Graphical abstract The energy density of the nanomaterials with 5% BT@PDA filler was 11.15 J/cm 3 at 378 MV/m electric field intensity.