Realizing high energy storage performance under low electric fields in Bi0.5Na0.5TiO3-based ceramics by introducing rare earth elements

Relaxing ferroelectric ceramics with excellent energy storage performance are considered as the most prospective candidates applied in energy storage fields such as medical equipment, electric power transportations and military facilities, etc. However, it is difficult to achieve the high recoverable storage density (Wrec) in the unitary ceramics, especially under the low electric fields. Therefore, to achieve the outstanding Wrec, we utilize Sm3+ to substitute Bi3+ of Bi0.5Na0.5TiO3 (BNT) ceramic, which inhibits the abnormal grain growth, strengthens the breakdown field strength (EB), improves the saturation polarization (Pmax) and efficiency (7), and enlarging the RT dielectric platform. Therefore, the optimal energy storage properties (Wrec of 5.6 J/cm3, 7 of 75.4 %) are obtained in the Bi0.42Na0.5Sm0.08TiO3 (BNST) ceramic under the low EB of 305 kV/cm, companying with good temperature (20-180 degrees C) and frequence (1-220 Hz) stabilization under the electric field of 200 kV/cm. Simultaneously, the Pmax of 51.3 mu C/cm2 is achieved. All the above provide a feasible paradigm for designing dielectric materials with the outstanding energy storage performances and explore fundamental insights into the origin of the Pmax and the low residual polarization under the low electric field.