Temperature-dependent energy storage characterization of Pb-free relaxor ferroelectrics

The energy storage properties of ( 1 − x ) Bi 0 . 5 Na 0 . 5 TiO3– x BaTiO3( 0 ≤ x ≤ 0 . 0 8 ) (BNT–BT) ceramics obtained via sol–gel method are determined from the polarization versus electric field ( P – E ) loops at various temperatures. The energy storage densities are observed to increase with increase in temperature and this may be attributed to the presence of antiferroelectric (AFE) phase at higher temperature ( ≥ 1 2 0 ∘ C). Obvious changes are observed in the saturation polarization ( P s ) and remnant polarization ( P r ) with increasing temperature. The maximum energy storage density of 0.6 J/cm3 is observed for x = 0 . 0 6 in the AFE phase at 150∘C for 90 kV/cm of applied electric field. BNT–BT can be a promising candidate for energy storage devices to be used in above-room-temperature environment.