Na 0.5 Bi 0.5 TiO 3 (NBT) ceramic is the promising dielectric material for energy storage devices due to its high maximum polarizability and temperature stability. However, its low breakdown strength limits its application. Here, we prepared 0−3 type composite 0.45Na 0.5 Bi 0.5 TiO 3 -0.55Sr 0.7 Bi 0.2 TiO 3 /x wt % AlN (NBT-SBT/xAlN) to increase the breakdown strength. The effects of the various AlN contents on the phase composition, microstructures, dielectric, and energy storage properties of NBT-SBT were systematically discussed. The result showed that the enhanced energy storage properties were obtained by introducing AlN particles. The NBT-SBT/6AlN composite ceramics showed a high breakdown strength of 360 kV/cm, large energy density of 5.53 J/cm 3 , and energy efficiency of 90%. Meanwhile, the excellent frequency (10−500 Hz) and temperature stability (25−125 °C) were exhibited with the fluctuation of energy storage within 9% and energy efficiency more than 87%, suggesting that the 0−3 composite NBT-SBT/xAlN is a candidate dielectric material for the dielectric energy storage.

The demand for a new generation of high‐energy‐density dielectric materials in the field of capacitive energy storage is promoted by the rise of high‐power applications in electronic devices and electrical systems. Polymer‐based dielectric nanocomposites with ultrahigh charge–discharge rates and power densities play essential roles in energy storage. Recently, multilayer structure polymer‐based dielectric nanocomposites (MSPBDNs) with improved dielectric constant, breakdown constant, and discharged energy density have gained widespread interest because of their immense potential. In the present work, MSPBDNs are classified, depending on the nature of the interlayer, into those with a high insulation layer, a high dielectric layer, and a gradient structure. To further understand the breakdown process of MSPBDNs, the authors elaborate on multilayer‐structured models, analysis breakdown mechanisms, and simulations. Despite the great progress achieved, the field of developing a novel topological structure remains open to further investigation and optimization. In addition, the research prospects and directions of energy storage fields are briefly discussed and summarized.

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The field-induced-phase transition in (Na 1/2 Bi 1/2 )TiO 3 -based lead-free piezoceramics can be facilitated in the ⟨001⟩-crystallographic orientation, and the templated grain growth is an effective method to align polycrystalline ceramics along with specific directions. However, due to the low texturing degree and undesirable composite effect of the added templates, the textured ceramics using the templated grain growth (TGG) method usually require a higher driving field to trigger the phase transition instead. Here, ⟨001⟩-textured (Na 0.5 Bi 0.5 ) 0.935 Ba 0.065 Ti 0.978 (Fe 0.5 Nb 0.5 ) 0.022 O 3 ceramics are prepared through a liquid-phase-assisted TGG process at a low sintering temperature (1000 °C), in which the NaNbO 3 (NN) templates induce a strong crystallographic anisotropic structure (a high Lotgering factor of 95%) while dissolving into oriented grains. The dissolution of templates acts as a composition doping and contributes to reducing the driving electric field as proven by the phase-field simulation analysis. Furthermore, electrical and structural characterizations reveal that an increased ionic disorder occurs in the textured ceramic, causing highly dynamic polar nanoregions and a larger reversible phase transition. Thanks to the appropriate structure/composition control, the textured ceramic achieves a large d 33 * value of 907 pm/V at 40 kV/cm. The high-performance lead-free ceramic under low driving electric field benefits the development of multilayer piezoelectric actuators. KEYWORDS: (Na 1/2 Bi 1/2 )TiO 3 ceramics, templated grain growth, phase transition, large-signal piezoelectric coefficient, low driving electric field