High energy-density (Wrec) dielectric capacitors have gained a focal point in the field of power electronic systems. In this study, high energy storage density materials with near-zero loss were obtained by constructing different types of defect dipoles in linear dielectric ceramics. Mg2+and Nb5+ are strategically chosen as acceptor/donor ions, effectively replacing Ti4+ within Ca0.5Sr0.5TiO3-based ceramics. The results indicate that under an applied electric field, specific defects such as [MgTi″−VO··] and [NbTi·−Ti3+], can effectively regulate VO·· and electron movement, significantly reducing losses. Furthermore, high-density insulating grain boundaries, reduced VO·· concentrations and diminished carrier mobility contribute to enhanced resistivity, resulting in high Wrec ∼7.62 J/cm3 and η ∼92 % at 640 kV/cm, making it one of the most promising linear dielectrics to date. Notably, Wrec and η remain remarkably stable across a broad range of frequencies (1–500 Hz), temperatures (25–175 °C) and numerous cycles (up to 106). Additionally, finite element software was used to simulate the distribution of dielectric constant, electric potential, and local electric field, further verifying the correlation between microstructure and breakdown resistance. This innovative work provides a sustainable strategy to optimize the energy storage capacity of lead-free ceramics over a wide temperature range through strategic manipulation of defects.

中文翻译：

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用于近零损耗高电容储能的线性介电陶瓷


高能量密度 （Wrec） 介电电容器已成为电力电子系统领域的焦点。在本研究中，通过在线性介电陶瓷中构建不同类型的缺陷偶极子，获得了接近零损耗的高储能密度材料。Mg2+ 和 Nb5+ 被战略性地选择为受体/供体离子，有效地取代了 Ca0.5Sr0.5TiO3 基陶瓷中的 Ti4+。结果表明，在外加电场下，[MgTi“−VO··]和[NbTi·−Ti3+]等特定缺陷可以有效调节VO··和电子运动，显着减少损耗。此外，高密度绝缘晶界、降低 VO··浓度和载流子迁移率降低有助于提高电阻率，导致在 640 kV/cm 时 Wrec ∼7.62 J/cm3 和 η ∼92 %，使其成为迄今为止最有前途的线性电介质之一。值得注意的是，Wrec 和 η 在很宽的频率范围 （1–500 Hz）、温度 （25–175 °C） 和多次循环（高达 106 次）下保持非常稳定。此外，有限元软件用于模拟介电常数、电势和局部电场的分布，进一步验证了微观结构与击穿电阻之间的相关性。这项创新工作提供了一种可持续的策略，通过对缺陷的策略性操纵，在较宽的温度范围内优化无铅陶瓷的储能能力。