Enhanced electrocaloric response and energy storage in [(Bi0.5Na0.5)0.94Ba0.06]0.975Sr0.025TiO3 ceramic close to room temperature

Lead-free [(Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 ] 0.975 Sr 0.025 TiO 3 (BNBTS25), with morphotropic phase boundary, has attracted considerable attention due to its depolarization temperature, T d (Ferroelectric (FE)- Antiferroelectric (AFE) transition), which is in close proximity to room temperature (322K). Therefore, the research on electrocaloric and energy storage was limited to temperatures ranging from 223K to 363K. BNBTS25 presents firstly an intensive interests as promising candidate for environmental-friendly energy storage products. This material provides a good recoverable energy density up to W rec = 577 mJ/cm 3 with an energy-storage efficiency of eta = 68% in the vicinity of T d . The origin of enhanced energy storage performance is discussed from a scientific point of view. Secondly, BNBTS25 exhibits a high electrocaloric effect (ECE), including an adiabatic temperature change of A T = 1.24 K and an electrocaloric responsivity of xi = 0.301K.mm/kV was observed under an electric field of E = 40 kV/cm at a temperature near 290K. This high ECE performance exceeds that of several reported lead-free ceramics and even performs better than some lead based ceramics. The obtained results suggest that BNBTS25 ceramic is a promising candidate for both electrocaloric and energy storage applications in operating temperature such as cooling in microelectronic devices.