Dielectric properties and energy storage performance of PVDF-based composites with MoS2@MXene nanofiller

Abstract

Hybrid nanofillers designed for polymer dielectric nanocomposites are expected to obtain excellent dielectric energy storage performance by virtue of different morphologies and electrical properties. In this work, the 2D/2D heterostructures of 2D MoS2 grown on the surface of 2D transition metal carbide Ti3C2 MXene (MoS2@MXene) have been successfully obtained through hydrothermal reaction. MoS2@MXene was incorporated into poly (vinylidene fluoride) (PVDF) to form the PVDF based dielectric composites (MoS2@MXene/PVDF) through solution casting method. The composite with 3.47 wt% MoS2@MXene is very flexible with an elastic modulus of 385 MPa, which is not much different with pure PVDF (357 MPa). The maximum electric displacement at room temperature and an electric field of 400 MV/m is 10.96 μC/cm2, moreover the discharged energy density reaches 17.22 J/cm3, which is nearly 4.5 times that of pure PVDF (3.83 J/cm3 at the maximum electric field of 250 MV/m). The dielectric constant of 3.47 wt% MoS2@MXene/PVDF at room temperature and 103 Hz is 24.3, and the loss is only 0.02. Even though the filler content is increased to 12.51 wt%, the loss is only 0.06, and the dielectric constant of the composite film can reach 145.2. Compared with the blend of PVDF and MXene, the dielectric constant of MXene@MoS2/PVDF shows more excellent frequency stability and lower dielectric loss.