High energy storage density achieved in BNT‐based ferroelectric translucent ceramics under low electric fields

Abstract The development of ceramics with superior energy storage performance and transparency holds the potential to broaden their applications in various fields, including optoelectronics, energy storage devices, and transparent displays. However, designing a material that can achieve high energy density under low electric fields remains a challenge. In this work, (1− x )Bi 0.5 Na 0.5 TiO 3 − x BaZr 0.3 Ti 0.7 O 3 :0.6mol%Er 3+ (abbreviated as (1− x )BNT− x BZT:0.6%Er 3+ ) ferroelectric translucent ceramics were prepared by the conventional solid‐state reaction method. The energy storage properties of (1− x )BNT− x BZT:0.6%Er 3+ are systematically investigated under low electric fields by modulating the coupling between coexisting phase structures of polar nano regions. Especially, 0.9BNT–0.1BZT:0.6%Er 3+ ceramic exhibits an ultra‐high maximum polarization ( P max = 66.3 µC/cm 2 ), large recoverable energy storage density ( W rec = 2.95 J/cm 3 ), total energy storage density ( W = 5.75 J/cm 3 ), and energy storage efficiency ( η = 51.3%) under 190 kV/cm. The sample also exhibits excellent thermal stability (30‐150°C) and transmittance (∼28%). This work could facilitate the advancement of energy storage systems that are more efficient and cost‐effective, and also provide opportunities for the design and manufacture of novel devices.