Enhancement of recoverable energy density and efficiency of lead-free relaxor-ferroelectric BNT-based ceramics

Electrostatic capacitors with simultaneously excellent recoverable energy density (W-rec) and efficiency (eta), and wide operate temperature range are currently the main challenge in applications of modern electronics and electrical power systems. Here, a series of lead-free relaxor-ferroelectrics 0.85[(1-x)Bi0.5Na0.5TiO3-xBi(0.1)Sr(0.85)TiO(3)]-0.15KNbO(3) ceramics with superb energy storage properties are prepared using solid-state reaction method. An excellent W-rec of 3.72 J/cm(3) accompany with high eta of 90.7% is attained concurrently with the composition of x = 0.3 under 290 kV/cm, which show remarkable advantages over recently reported lead-free ceramics. Meanwhile, superior thermal stability (20-200 degrees C) and frequency stability (1-1000 Hz) are also achieved. Moreover, by means of charge-discharge evaluations, the stored energy is released in an extremely short discharge time of 55 ns, regardless of variations in the temperature. All these characteristics demonstrate that this ceramic can be considered promising candidates for high power energy storage applications over broad temperature range.

Automated summary

Lead-free relaxor-ferroelectric ceramics with excellent energy storage properties were prepared using solid-state reaction method, achieving high recoverable energy density and efficiency, along with superior thermal and frequency stability. Charge-discharge evaluations demonstrated that the ceramics could release stored energy in an extremely short discharge time, indicating promising potential for high power energy storage applications.