High permittivity, breakdown strength, and energy storage density of polythiophene-encapsulated BaTiO nanoparticles.

High permittivity and breakdown strength are desired to improve the energy storage density of dielectric materials based on reinforced polymer composites. This article presents the synthesis of polythiophene-encapsulated BaTiO (BTO-PTh) nanoparticles via an in situ Cu(II)-catalyzed chemical oxidative polymerization of thiophene monomer on hydrothermally obtained tetragonal BTO nanocrystals. The formed core-shell-type BTO-PTh nanoparticles exhibit excellent dielectric properties with high permittivity (25.