Superior energy storage performance of PbZrO3-based films via phase regulation and entropy engineering

Abstract

Achieving a synchronous improvement of recoverable energy storage density (W_rec) and efficiency (η) remains a critical challenge for dielectric capacitors. In this paper, a synergistic strategy combining phase regulation and entropy engineering is proposed to delay the transition from the antiferroelectric (AFE) to ferroelectric (FE) phase and enhance the relaxor behavior of the PbZrO₃ (PZO) film, optimizing both W_rec and η. Specifically, Sn⁴⁺ at the B site induces a tetragonal AFE phase within the orthorhombic AFE matrix of PZO, which reduces the domain size and facilitates the FE–AFE polarization switching upon removal of the applied electric field. La³⁺, Sr²⁺, and Ba²⁺ at the A site stabilize the AFE phase by reducing the perovskite tolerance factor and thus increase the transition field from the AFE to FE phase. Furthermore, the high-entropy design refines the microstructure and stabilizes the charge carriers through introducing chemical disorder, effectively reducing the leakage current and enhancing the breakdown field. Consequently, a large W_rec of 101.8 J cm⁻³ and an η of 71.5% are achieved in the Pb_0.895La_0.03Sr_0.03Ba_0.03Zr_0.5Sn_0.5O₃ relaxor AFE thin film, approximately 3.6- and 2-fold higher than those of pure PZO, respectively. This relaxor AFE film also exhibits excellent breakdown reliability, superior thermal stability and robust fatigue resistance.