3D-engineered BT/MF/PVDF composites: unveiling ultra-high energy storage density and superior charge discharge efficiency

In this study, we designed and engineered a novel 3D network BT/MF/PVDF (barium titanate/melamine foam/polyvinylidene fluoride) composite film using hydrothermal process and casting technology. During the engineering process, titanium oxide (HTO) nanosheets were wound onto the surface of MF to form an HTO/MF nanocomposite material. Through hydrothermal treatment of HTO/MF, petal-like BT grew on the MF network, forming a 3D BT/MF composite material. Finally, PVDF was infiltrated into the 3D BT/MF network to fabricate the BT/MF/PVDF composite film. The engineered 3D BT/MF/PVDF composite films exhibit excellent dielectric properties with dielectric constant of 46.8 at 1 kHz, very low dielectric loss (tan δ  = 0.0080), and breakdown strength increased to 196.6 MV·m −1 . In addition, the energy storage density and the charging and discharging efficiency of the composite films reach 3.685 J⋅cm −3 and 94.89%, respectively. The 3D network BT structure provides a continuous polarization path for the composite films, significantly increasing the dielectric constant and breakdown strength. The engineered composite films have a wide application prospect in the field of high-power energy storage and flexible electronic devices.