Preparation of Barium Titanate and Polystyrene Methyl Methacrylate Composite Dielectric Films with Energy Storage Properties

Ceramic filler/polymer matrix composites with excellent energy storage performance are important components of thin-film capacitors and basic materials in power electronics systems. In this work, composite dielectric films of barium titanate and polystyrene methyl methacrylate (BT/P(St-MMA)) were prepared by the solution casting method, and the morphological, dielectric and energy storage properties of BT/P(St-MMA) were investigated. The results showed that the dielectric constant (ε_r) of the x vol.%-BT/P(St-MMA) composite dielectric film increased by more than three times compared to that of the P(St-MMA) polymer. The 1 vol.%-BT/P(St-MMA) composite dielectric film showed the best performance at an electric field of 400 MV/m, with an energy storage density (U_d) of 15.47 J/cm³, an effective energy storage density of 14.31 J/cm³, and an energy storage efficiency (η) of 92.48%. It also exhibited high power density (12.69 MW/cm³) and a very short discharge time (τ_0.9 = 293 ns) at 200 MV/m electric field. It can be speculated that x vol.%-BT/P(St-MMA) (x = 0, 1, 3, 5) is an excellent candidate for energy storage applications.