Preparation, characterization, and improvement in the energy storage properties of Bi(Li0.5Ta0.5)O3 modified Na0.5K0.5NbO3 ceramic system

• We prepared (1-x)Na0.5K0.5NbO3-xBi (Li0.5Ta0.5) O3 ( x = 0, 0.05, 0.10, 0.15, 0.20) ceramics via solid state sintering method. • The dense microstructure is observed for all compositions. • A high energy-storage density of 1.99 J/cm3 at a breakdown electric field of 151.9 kV/cm is achieved for the composition of x = 0.15. • Good temperature stability satisfying the condition of Δεr/εr200 °C ≤±15% in a working temperature range of 30 °C to 371 is observed for x = 0.15. (1-x)K 0.5 Na 0.5 NbO 3 -xBi (Li 0.5 Ta 0.5 )O 3 ( x = 0, 0.05, 0.10, 0.15, 0.20) ceramics were processed using a solid-state sintering route. All the sintered samples were characterized in terms of phase, microstructure, dielectric, ferroelectric, and energy storage characteristics. A structural variation from orthorhombic to pseudo-cubic was observed with an increase in x from 0 to 0.20. At x ≥ 0.10, in addition to the parent phase, the formation of a secondary phase was also observed. The grain size decreased with an increase in x value to 0.15 and then increased, for example, at x = 0.20. A charged energy density (W s ) of ∼1.99 J/cm 3 along with a recoverable energy density (W rec ) of ∼1.10 J/cm 3 was obtained for the x = 0.15 composition. Moreover, the composition with x = 0.15 exhibited high stability of dielectric constant at temperatures ranging from 30 to 371 °C.