High‐energy storage density in NaNbO3‐modified (Bi0.5Na0.5)TiO3‐BiAlO3‐based lead‐free ceramics under low electric field

Abstract Ceramic‐based dielectric capacitor are highly suitable for pulsed power applications due to their high power density and excellent reliability. However, the ultrahigh applied electric field limit their applications in integrated electronic devices. In this work, (1− x ){0.96(Bi 0.5 Na 0.5 )(Ti 0.995 Mn 0.005 )O 3 ‐0.04BiAlO 3 }‐ x NaNbO 3 (BNT‐BA‐ x NN, x = 0, 0.04, 0.08, 0.12, and 0.16) ternary ceramics were designed to achieve excellent energy storage properties. It was found that the introduction of NaNbO 3 (NN) effectively increase the difference (Δ P ) between P max and P r , resulting in an obvious enhancement of the energy storage properties. High recoverable energy storage density, responsivity, and power density, that is, W rec = 2.01 J/cm 3 , ξ = W rec / E = 130.69 J/(kV⋅m 2 ), and P D = 25.59 MW/cm 3 , accompanied with superior temperature stability were realized at x = 0.14 composition. In addition, the thermal stable dielectric properties of the sample can be prominently improved with increasing NN content. The temperature coefficient of capacitance (TCC) of x = 0.16 composition is lower than 15% over the temperature range from 49°C to 340°C, with a high dielectric permittivity of 1647 and a low dielectric loss (0.0107) at 150°C. All these features show that the BNT‐BA‐ x NN ceramics are promising materials for energy storage application.