Good energy storage properties of Na0.5Bi0.5TiO3 thin films

Abstract Lead-free perovskite-structured single-phase Na0.5Bi0.5TiO3 (NBT) thin films were successfully prepared by a sol-gel technology. The films exhibited a leakage current density of about 3.1 × 10-3 A/cm2 under an electric field of 500 kV/cm and their characteristic breakdown strength was 1250.49 kV/cm. At a frequency of 1 kHz, the dielectric constant and dielectric loss of the NBT films were 405 and 0.029. These films achieved good energy storage performance under an electric field of 1200 kV/cm, i.e., a recoverable energy density of 23.3 J/cm3 and an energy storage efficiency of 61.6%. Additionally, the NBT films had good fatigue resistance up to 1 × 107 charge-discharge cycles. The films may be expected to be used in capacitors with high energy storage properties.