Tuning the microstructure of BaTiO3@SiO2 core-shell nanoparticles for high energy storage composite ceramics
Abstract Core-shell nanoparticles used as blocks to construct composite ceramics can exhibit high energy storage density, but the effects of original tunable shell thickness on the microstructures and energy storage property of finally sintered bulk ceramics has not been clarified, thus how to achieve the full potential of this technology to improve the energy storage density of ferroelectric-based ceramics remains to be solved. In this study, as precursors to fabricate bulk ceramics, BaTiO 3 @SiO 2 core-shell nanoparticles were successfully synthesized by a wet-chemical method and they were used as models to investigate the effect of the core-shell nanostructured precursors on the energy storage property of the bulk composite ceramics. The original BaTiO 3 nanoparticles coated with various homogenous SiO 2 shells were acquired by controlling the concentration of tetraethyl orthosilicate (TEOS). The surface microstructure of the bulk composite ceramics observed by scanning electron microscope (SEM) revealed that the SiO 2 outer shell of BaTiO 3 @SiO 2 nanoparticles plays an important role in constructing the microstructure of the ceramics. The remodeled microstructure has a great impact on leakage current density and dielectric property, and it makes a leading contribution to the energy storage performance of ceramics. As a result, the optimum SiO 2 loading range was confirmed and the maximum energy storage density obtained from BaTiO 3 @20 wt%SiO 2 was ∼4.799 J/cm 3 at 370 kV/cm, demonstrating that nanoscale core-shell architecture is an effective strategy to improve the energy storage performance of ferroelectric-based composite ceramics.