PVC/Ti2C MXene/Diamond-Blend Films with High Dielectric Constants and Breakdown Strength Due to Electrical Synergy Between the Filler Materials

Polymer/conductor composites are used in energy storage capacitors; however, they exhibit high interface leakage currents, causing low breakdown strength. Here, a ternary-blend strategy was used to synthesize polyvinyl chloride (PVC)/titanium carbide transition-metal carbide two-dimensional nanolayered material (Ti 2 C MXene)/diamond composites using solution casting. The PVC matrix exhibited low polarity and high insulation, while the Ti 2 C MXene and diamond fillers exhibited high conductivities and ultrahigh insulation properties, respectively. Overall, the PVC/Ti 2 C/diamond ternary composites exhibited better electrical properties than the PVC/Ti 2 C binary composites. In the ternary composites, PVC/Ti 2 C interface polarization caused high dielectric constants, while low leakage currents induced by diamond caused low dielectric losses and high breakdown strength. The optimum-composition (12 wt.% Ti 2 C and 4 wt.% diamond) ternary composite exhibited a high dielectric constant (~153 at 100 Hz), low dielectric loss (~0.14 at 100 Hz), low conductivity (~1.4 × 10 −6 S m −1 at 100 Hz), and high breakdown strength (~312 MV m −1 under a direct current field). This study indicates a synergistic effect between Ti 2 C MXene and diamond in the composite dielectrics, and could guide the fabrication of dielectric films for capacitors. Graphical Abstract