High energy storage performance in (Bi0.4Na0.2K0.2Ba0.2)TiO3-Bi(Zn2/3Ta1/3)O3 high-entropy ceramics with excellent temperature and frequency stability

Dielectric capacitors with high power density, cost-effectiveness, and harsh environmental working abilities have gained considerable research attention. Dielectric materials are key components of dielectric capacitors and directly influence their operational performance. Among others, high-entropy perovskites are emerging as attractive candidates for energy storage materials owing to their exceptional performance driven by the high-entropy effect. Here, a high-entropy (1- x )(Bi 0.4 Na 0.2 K 0.2 Ba 0.2 )TiO 3 - x Bi(Zn 2/3 Ta 1/3 )O 3 system for energy storage devices was designed. A systematic study was conducted to investigate the ferroelectric and dielectric properties of BNKBT-BZT high-entropy ceramics (HECs). The resultant sample exhibits strong relaxor properties and exceptional energy storage properties, with a high recoverable energy storage density ( W rec ) of 4.11 J/cm³ and an energy storage efficiency ( η ) of 84 % under an electric field of 260 kV/cm. More interestingly, the BNKBT-15BZT HECs also display outstanding thermal and frequency stability. These findings suggest that the resultant BNKBT-15BZT HECs are highly promising for applications in dielectric energy storage within low-to-moderate electric field ranges.