High‐Permittivity Composites Thin Films for High‐Energy Storage Capacitor Application Using the Nonvacuum Method

To investigate a new embedded capacitor material with high capacitance value, the high dielectric constant (Ba 0.8 Sr 0.2 )(Ti 0.9 Zr 0.1 )O 3 ceramic was ground into nanoscale powder (nano‐BSTZ, the average particle size was approximately 73 nm). Different nano‐BSTZ contents were mixed with polyvinylidene fluoride (PVDF) to form the PVDF/nano‐BSTZ composites. The PVDF/nano‐BSTZ composite films were formed by using the nonvacuum screen printing method on indium tin oxide (ITO) glass, and their thickness was approximately 2 μm. As the nano‐BSTZ content increased from 10 to 50 wt%, the specific capacitance of the PVDF/nano‐BSTZ composite films really increased. Three different mixing rules were used to predict the effective dielectric constants of the PVDF/nano‐BSTZ composite films, and the Bruggeman's effective medium approximation and the Lichtenecker logarithmic mixing rules fitted the measured results. For the printed PVDF/nano‐BSTZ composite films, the dielectric constants also decreased with increasing measured frequency and the loss tangents were all less than 5%.