Dielectric capacitors are vital components in advanced electrical power systems due to their high power density. However, how to improve their comparatively low energy density is still a major challenge. In this work, we designed a dielectric capacitor with a multilayer structure by inserting different numbers of ferroelectric (NaK)BiTiO (NKBT) layers into relaxor ferroelectric BiLaTiMgO (BLTM). Through the regulation of interface engineering, that is, the joint effects of electrical field amplifying, interlayer coupling, and block layer at the interface, enhancing the energy storage density and breakdown field in (NKBT/BLTM) capacitors. A giant energy density () of 81.2 J/cm and a high breakdown electric field of 4074 kV/cm are achieved in capacitors with = 4. Consequently, interface engineering can be promoted as a universal route to optimize the energy storage performance of dielectric capacitors.

中文翻译：

---

(Na0.8K0.2)0.5Bi4.5Ti4O15/Bi4LaTi3.5Mg0.5O15多层薄膜电容器的界面工程增强储能性能

介电电容器由于其高功率密度而成为先进电力系统的重要组件。然而，如何提高其相对较低的能量密度仍然是一个重大挑战。在这项工作中，我们通过将不同数量的铁电 (NaK)BiTiO (NKBT) 层插入弛豫铁电 BiLaTiMgO (BLTM) 中，设计了一种具有多层结构的介电电容器。通过界面工程的调控，即界面电场放大、层间耦合和阻挡层的共同作用，增强（NKBT/BLTM）电容器的储能密度和击穿场。= 4的电容器实现了81.2 J/cm的巨大能量密度（）和4074 kV/cm的高击穿电场。因此，界面工程可以作为优化介电电容器储能性能的通用途径得到推广。