Extreme high energy storage efficiency in perovskite structured (1-x)(Ba_0.8Sr_0.2)TiO₃-xBi(Zn_2/3Nb_1/3)O₃ (0.04 ≤ x ≤ 0.16) ceramics

Dielectric materials with high power density, fast charge and discharge rates, and high energy-storage density are urgently required due to the rapid development of hybrid vehicles and pulse power boosting technology. In this work, the novel environment-friendly (1-x)(Ba_0.8Sr_0.2)TiO₃-xBi(Zn_2/3Nb_1/3)O₃ (0.04 ≤ x ≤ 0.16) [(1-x)BST-xBZN] ceramics were designed and synthesized by traditional solid-state reaction method, exhibiting ultrahigh energy efficiency and super stability against temperature. The results show that the recoverable energy density (W_rec) and the energy efficiency (η) of the (1-x)BST-xBZN ceramics are increase sharply then decrease slightly with increasing of x value. The 0.88BST-0.12BZN ceramic demonstrated a recoverable energy density of ≈ 1.62 J/cm³ and an extreme high energy efficiency of ∼ 99.8 % at 225 kV/cm at room temperature. These extreme high efficiency and high breakdown strength would make (Ba,Sr)TiO₃-based lead-free ceramic systems might be good candidate for high power energy-storage applications pulsed power systems.