Enhanced dielectric tunability and energy storage density of sandwich-structured Ba0.6Sr0.4TiO3/PVDF composites

The regional distribution of fillers can change the distribution of electric field in the ceramic/polymer composites and further affect the dielectric properties. Here, Ba0.6Sr0.4TiO3/PVDF (BST/PVDF) monolayer and its two kinds of sandwich structural composites, PVDF BST/PVDF PVDF (PBP) and BST/PVDF PVDF BST/PVDF (BPB), were fabricated using solution casting method combined hot pressing process. The results showed BPB structural composite possesses the best dielectric performances with a relative permittivity of 17.3, an energy density (U-e) of 10.54 J/cm(3) which is 2 times of BST/PVDF monolayer composite with the same BST content, as well as a dielectric tunability of 83.33%. Finite element simulation further proves that sandwich structure, especially BPB structure, can reduce the occurrence of electrical breakdown in the composite, and improve the energy storage characteristics and dielectric tunability. This work gives new thinking for the development of energy storage thin-film composites.

Automated summary

The regional distribution of fillers in ceramic/polymer composites can significantly impact the electric field distribution and dielectric properties. This study fabricated BST/PVDF monolayer and two sandwich structural composites, PBP and BPB, and found that the BPB structure exhibited the best dielectric performances with higher energy density and dielectric tunability. Finite element simulation further confirmed that the sandwich structure can reduce electrical breakdown and improve energy storage characteristics in the composites.