Ultra-high energy storage density BaTiO3 amorphous thin film via multi-ion synergistic optimization

Amorphous films have excellent breakdown strength and energy storage efficiency, and have broad application prospects in dielectric film capacitors. However, its low polarization greatly limits the increase of energy storage density. In this paper, (Ba0.92-xBi0.08Lax)(Ti0.96-0.5xNi0.04+0.5x)O3 (BBLTN) amorphous films were fabricated by sol-gel method. The effects of Bi, Ni and La ion doping on the electrical properties and energy storage properties of the films were studied. When x = 0.04, the film can produce an ultra-high recoverable energy storage density of 121.7 J cm−3 and an efficiency of 70.6%, and possesses outstanding stability at 20 °C–130 °C and 1-105 cycles. Combined with X-ray photoelectron spectroscopy analysis, researchers believe that the improvement of energy storage performance may be related to the dipoles formed by NiNi.. and TiTi′ defects induced by multi-ion doping. This contribution provides a feasible way for the research of high-performance dielectric film capacitors.