Energy storage in BaBi4Ti4O15 thin films with high efficiency

A ferroelectric film with slim polarization-electric (P-E) hysteresis loops, showing small remanent polarization (Pr) and large saturated polarization (Ps), is desired to obtain high recoverable energy density (Ure) and efficiency (η) in thin film capacitors. Here, small Pr and large Pm values are achieved in BaBi4Ti4O15 thin films through modulating film grain size. A large Ure of 44.3J/cm3 as well as a high η of 87.1% is obtained. In addition, the derived BaBi4Ti4O15 thin films show excellent energy storage performance in wide frequency range, thermal stability, and fatigue endurance. These results suggest that BaBi4Ti4O15 films can be considered as a candidate for dielectric energy storage capacitors, and the route through grain size optimization is a promising strategy to improve the capacitive performance of ferroelectric materials.