Enhanced energy storage properties of La3+ modified 0.92Bi0.5Na0.5TiO3 -0.06Ba(Zr0.2Ti0.8)O3-0.02NaNbO3 ternary ceramic system

Abstract

The development in field of hybrid vehicles, telecommunication and energy sectors require dielectric materials having high-energy storage density with optimum thermal stability to operate in certain environment. To fulfil such requirement a new set of materials along the ternary solid solutions of 0.92Bi _0.5(1-x) -La _(x) Na _0.5 TiO _3 -0.06Ba(Zr _0.2 Ti _0.8 )O _3 -0.02NaNbO _3 (NB _1-x L _x T-BZT-NN) (x = 0, 0.03, 0.05, 0.07) were fabricated through solid-state mix oxide route. The XRD patterns analysis confirmed a structural phase transformation from rhombohedral to the tetragonal-P4bm phase when x content increased from 0 to 0.07. The SEM study revealed, dense microstructure for all ceramics accompanied by a decrease in the average grain from 1.66 μ m to 1.05 μ m leading to high densities for these materials with an increase in the x content. The dielectric breakdown field increased from ∼115 to 137 kV cm ^−1 resulting in an increase in recoverable energy density from ∼0.68 to 1.14 J cm ^−3 with the increase in x content. Furthermore, excellent temperature stability (±15%) in dielectric permittivity was observed in a wide temperature range for each ceramic. In the present study, a recoverable energy density of 1.14 J cm ^−3 along with an efficiency of 70.6% was obtained for the composition of x = 0.07.

Keywords

• Bi0.5Na0.5TiO3
• energy storage
• relaxation behaviour
• thermal stability
• dielectric constant