Enhanced dielectric performance of PVDF composites doped with MnO2@carbon particles

Herein, a method is proposed for preparing MnO2@carbon core–shell particles and MnO2@carbon/polyvinylidene fluoride (PVDF) composite films. The effect of MnO2@carbon core–shell particles on the dielectric properties of polymer composites was investigated. Furthermore, a comprehensive dielectric property test was conducted on the composite films. The results reveal that with the addition of MnO2@carbon core–shell particles, the dielectric properties of the composite films also improved. The dielectric constant of the 10 wt% MnO2@carbon composite is 24.2 at 100 Hz, which is 3 times that of PVDF (7.68). Currently, the energy storage density of the composite film is 4.95 J cm−3 at ∼2300 kV cm−1. The addition of MnO2@carbon core–shell particles effectively improves the energy storage density of PVDF. Based on this result, the influence of the carbon shell on the dielectric properties of the composite thin films is analysed and discussed. The significant improvement in dielectric properties is mainly due to the increased interfacial polarisation induced by the carbon shell. These characteristics of PVDF/MnO2@carbon composites indicate that the proposed method is a practical pathway to developing high-performance composites.