Insulating SiO2 internally decorated MoS2 flowers as hybrid filler to simultaneously improve breakdown strength and dielectric performance of PVDF-based composites.

Nowadays, a great challenge in fabricating dielectric polymer composites lies in how to simultaneously achieve high dielectric constant (ε ′)and breakdown strength (E b). In this paper, silicon oxide (SiO 2) nanospheres were internally incorporated into molybdenum disulfide (MoS 2) flowers using one-step hydrothermal process. The MoS 2 @SiO 2 hybrids were utilized as fillers in dielectric polymer matrix using solution casting, and the effect of hybrids on dielectric performance was investigated systematically. An optimal composite with 1 wt% MoS 2 @SiO 2 hybrids shows an improved ε ′ of 10.8@1 kHz and high E b of 486.8 MV/m. The improved dielectric capabilities of polymer composites are ascribed to the improvement of interfacial polarization by MoS 2 flower and the suppression of carrier transportation and the charge capture by SiO 2. This work broadens the avenue to optimize performance of polymer dielectrics for capacitive energy storage applications by tailoring the interior architectures of hybrid fillers. [Display omitted] • MoS 2 @SiO 2 composite with gradient band structure was fabricated. • Several carrier traps were constructed inside the composite to inhibit the generation of leakage current. • The composites showed high breakdown strength and energy storage properties. [ABSTRACT FROM AUTHOR]