Enhanced energy storage performance of polymer nanocomposites using hybrid 2D ZnO@MoS₂ semiconductive nano-fillers

Polymer-based nanocomposites with hybrid fillers are expected to possess high energy storage density taking advantage of different morphologies and electric properties of the nanofillers. In this article, hybrid semi-conductive nanofillers with MoS₂ two-dimensional (2-D) nanosheets and ZnO zero-dimensional (0-D) nanoparticles in different ratios were fabricated by the wet chemical route and ultrasonic mixing. The ZnO nanoparticles have a good distribution on MoS₂ nanosheets confirmed by TEM, XRD, and XPS results. The P(VDF-CTFE-DB)/ZnO@MoS₂ composites with different weight percent of fillers were prepared by solution cast, and the influence of hybrid fillers on polymer matrix was systematically investigated. P(VDF-CTFE-DB) with hybrid filler exhibits optimized discharged energy density of 7.2 J/cm³ and efficiency of 83% at 300 MV/m, both of which are higher than those reported in polymer nanocomposites at the same electric field. Moreover, the distribution of polarization and electric field of the distribution of 2D fillers in four different models for composite P(VDF-CE-DB)/ZnO@MoS₂ with 2 mol% of fillers were investigated by the finite element simulation analysis (COMSOL). In addition, the nanocomposite also possesses high power density and excellent fatigue reliability, demonstrating it can be a good candidate for energy storage device that requires high energy density at a low electric field for safer working conditions.