Excellent energy storage performance of (Bi_0.4Na_0.2K_0.2Ba_0.2)TiO₃-Bi(Zn_2/3Nb_1/3)O₃ high-entropy ceramics under medium electric fields

The high-entropy perovskite oxides (HEPOs) have distinctive electrical properties stemming from the high-entropy effect, rendering them as promising candidates for utilization in dielectric energy storage applications. In this work, a collection of (1-x)(Bi_0.4Na_0.2K_0.2Ba_0.2)TiO₃- xBi(Zn_2/3Nb_1/3)O₃ HEPOs was fabricated. A systematic investigation was conducted into the ferroelectric properties and dielectric performance of the resulting samples. The results demonstrate enhancing relaxor behavior and improved recoverable energy storage properties as the BZN dopants increase. It is noteworthy that the BNKBT-16BZN sample exhibits an excellent recoverable energy storage density (W_rec) of 4.86 J/cm³ and a high energy storage efficiency (η) of 83 % under a medium electric field of 280 kV/cm, respectively. Furthermore, the BNKBT-16BZN sample also shows exceptional stability under various temperatures and frequencies. The findings demonstrate that high-entropy compositional design represents an efficacious method for the fabrication of dielectric ceramics with high energy storage capabilities, thus stimulating further research into dielectric ceramic capacitors.