Grain-orientation-engineered multilayer ceramic capacitors for energy storage applications.

Abstract

Dielectric ceramics are highly desired for electronic systems owing to their fast discharge speed and excellent fatigue resistance. However, the low energy density resulting from the low breakdown electric field leads to inferior volumetric efficiency, which is the main challenge for practical applications of dielectric ceramics. Here, we propose a strategy to increase the breakdown electric field and thus enhance the energy storage density of polycrystalline ceramics by controlling grain orientation. We fabricated high-quality <111>-textured Na0.5Bi0.5TiO3-Sr0.7Bi0.2TiO3 (NBT-SBT) ceramics, in which the strain induced by the electric field is substantially lowered, leading to a reduced failure probability and improved Weibull breakdown strength, on the order of 103 MV m-1, an ~65% enhancement compared to their randomly oriented counterparts. The recoverable energy density of <111>-textured NBT-SBT multilayer ceramics is up to 21.5 J cm-3, outperforming state-of-the-art dielectric ceramics. The present research offers a route for designing dielectric ceramics with enhanced breakdown strength, which is expected to benefit a wide range of applications of dielectric ceramics for which high breakdown strength is required, such as high-voltage capacitors and electrocaloric solid-state cooling devices.