Trace BaTiO₃ Doping-Derived PVDF-Based Composite Thick Film for Dielectric Energy Storage

Ceramic-polymer nanocomposites combine the respective advantages of ceramics and polymers, boasting superior mechanical flexibility, thermal stability, optical transparency, and electrical conductivity, enabling their wide use in cutting-edge fields like medicine, aerospace, optoelectronic devices, and energy storage components. Notably, ceramic-polymer nanocomposites are a promising, widely recognized strategy for developing high-energy-density, low-dielectric-loss, and flexible capacitors, due to the ceramic phase's intrinsic high dielectric constant, which enhances dielectric capability, and the polymer phase's high breakdown strength and mechanical flexibility. Ultimately, ceramic-polymer nanocomposites can reach an optimal dielectric performance. In this study, polyvinylidene fluoride (PVDF) was used as the matrix material and barium titanate (BaTiO₃) as the reinforcing phase within the composite structure. The BaTiO₃ ceramic particles were incorporated into PVDF via spin-coating technology, with composite formulations prepared at different concentrations (0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%). A series of key parameters were measured and compared, such as the dielectric constant, breakdown strength, and energy storage density, of the BT/PVDF nanocomposite. The results indicated that the BT/PVDF nanocomposite with the optimal low BaTiO₃ content demonstrates remarkable performance, achieving a breakdown strength (E_b) of 500 MV/m and an effective energy storage density of 15.5 J/cm³. This represents an improvement over conventional uniformly high-filler films.