Realization of High Energy Storage Performance in BaTiO3-Bi(Co0.5Zr0.5)O3 Thin Film through Defect Construction in an Amorphous Structure

Amorphous engineering is becoming a competitive strategy to address the huge challenge of low energy storage density, efficiency, and breakdown strength in dielectric ceramic capacitors, owing to the low remnant polarization and high breakdown strength of the amorphous structure. Herein, BaTiO3-Bi(Co0.5Zr0.5)O3 (BT-BCZ) thin films with an amorphous structure is proposed, which is expected to obtain large ΔP (Pmax - Pr) and energy storage density. Investigations on the electric performance of these thin film materials present that Bi³⁺ ions with a special electronic structure enhance the polarization of amorphous materials; simultaneously, the defect dipole structure formed by Co²⁺ ions and oxygen vacancy will be beneficial to the increment of polarization, while maintaining low remnant polarization. As expected, an outstanding energy storage density of 109.14 J cm^-3 and efficiency of 81.17% are simultaneously realized in 0.85BT-0.15BCZ thin film. Moreover, an excellent temperature and cycle stability in wide temperature (20-150 °C) and cycle (1-10⁵) ranges are exhibited, which suggests that BaTiO3-Bi(Co0.5Zr0.5)O3 thin films with an amorphous structure possess an extensive application prospect in dielectric ceramic capacitors.