High‐Entropy‐Induced Polarization Discontinuity Enabling Ultrahigh and Temperature‐Stable Energy Storage in Ceramic Capacitors

Abstract

ABSTRACT The development of multilayer ceramic capacitors (MLCCs) with high‐energy storage performance over a wide temperature range is critical for practical applications but remains challenging. Here, we propose a high‐entropy design to disrupt the long‐range ferroelectric order of tetragonal tungsten bronze (TTB) ceramics, inducing a polarization discontinuity composed of coexisting polar nanoregions and non‐polar regions. This unique configuration delays polarization saturation while minimizing hysteresis loss through electrostatic interactions. Consequently, the TTB‐based MLCC achieves a high recoverable energy density ( W rec ) of 15.8 J cm −3 and an ultrahigh energy efficiency ( η ) of 97.5%, yielding a record‐high figure of merit of 632 J cm −3 for TTB‐based ceramic capacitors. Furthermore, the MLCC exhibits outstanding thermal stability from 25°C to 150°C, maintaining W rec ≈ 13.04 ± 0.41 J cm −3 and η ≈ 95.43 ± 2.61%. The high‐entropy‐induced polarization discontinuity offers valuable insights into polarization modulation and provides an effective strategy for designing next‐generation high‐performance dielectrics.