Multilayer-structured nanocomposite films with enhanced energy storage performance under intermediate electric fields via incorporation of BaTiO3/CaCu3Ti4O12@SiO2 nanofillers

The development of excellent performances polymer-based nanocomposite films with high discharge energy density and high discharge efficiency are eagerly desirable for promoting their electric energy storage applications. However, the high discharge energy density and efficiency of polymer-based nanocomposite films are usually not compatible above intermediate electric fields. To address this issue, here we propose a newly designed multilayer-structured nanocomposite film with a combination of introducing the BaTiO3/CaCu3-Ti4O12@SiO2 (BT/CCTO@SO) hybrid nanoparticles with core-shell structure in middle layer and the poly (methyl methacrylate) (PMMA) linear polymer with low loss in outer layers. These motivations of introducing the core-shell structured hybrid nanoparticles with high dielectric constant and designing the multilayered structure give rise to an enhancement of maximum electric displacement while maintaining a relatively high breakdown strength. Also importantly, bring the PMMA polymer into top and bottom layers results in the low energy loss of whole nanocomposite film. Benefiting from these merits, a larger maximum electric displacement of 11.7 mu C/cm(2) and a higher discharge energy density of 18.84 J/cm(3) accompanied with an ultrahigh discharge efficiency of 79.81% under an intermediate electric field of 418.13 MV/m are achieved in multilayer-structured nanocomposite film even at a very low filler loading of 2 wt% BT/CCTO@SO hybrid nanoparticles in middle layer, and these enhanced values are far higher than that of the monolayer nanocomposite films. This work validates the advantages of multilayered structure to integrate multiple components and presents outstanding overall performances of nanocomposite films in further applications of the dielectric capacitors with miniaturization and integration.