Improvement of fatigue endurance through modulating strain response in BaTiO3–Ca3Ti2O7 composite ceramics

Ferroelectric ceramics are highly desired for applications in energy storage devices due to their fast charge-discharge capability. However, electric field-driven gradual degradation of ferroelectric polarization (i.e., fatigue) inevitably results in a decrease in energy efficiency and energy storage density. Therefore, improving fatigue endurance is one challenge for their practical applications in energy storage devices. Here, we provide a strategy to modulate the strain response to the external electric field, and thus, increase the fatigue endurance by employing hybrid improper ferroelectricc Ca 3 Ti 2 O 7 ceramic that exhibits a negative piezoelectric effect. We synthesized [Formula: see text] BaTiO[Formula: see text] Ca 3 Ti 2 O 7 (BT-xCT) ceramics, in which the strain response of ceramics to the electric field gradually decreases with the increasing proportion of Ca 3 Ti 2 O 7 . For BT-0.3CT ceramic, the energy density storage efficiency is improved to 74.95% which is much higher than that of BT-0.1CT (48.07%). The strain response to the external electric field of BT-0.3CT is substantially lowered and almost reaches zero, leading to excellent fatigue endurance ability. This research work paves a route for designing ferroelectric ceramics with smaller strain response and enhanced fatigue endurance ability, which is expected to benefit a wide range of applications of ferroelectric ceramics in various electric capacitors and electric storage devices.