Grain engineering inducing high energy storage in CdCu3Ti4O12 ceramics

Abstract

ACu3Ti4O12-type (ACTO) perovskite ceramics with colossal permittivity always display a low energy storage density since its low breakdown field strength (Eb). In this work, we designed an effective grain engineering strategy achieving a high energy storage density in CdCu3Ti4O12(CdCTO) ceramics via a mixed oxides method based on sol-gel technique. Al2O3 was selected as grain engineering dopant enhancing Eb for achieving the high energy storage density of CdCTO ceramics. Remarkably, at an Al2O3 doping level of 3.0 wt%, a decent dielectric energy storage performance with a high nonlinear coefficient (α) ~ 4.98 and energy storage density (η) ~ 1.52 mJ/cm3 was obtained in CdCTO-3.0 wt% Al2O3 ceramic. Besides, enhanced Eb is strongly associated with the decreased grain size that induced upon Al2O3 doping. This work not only proposes an effective strategy enhancing Eb but also provides new ideas for how to simultaneously achieve a high permittivity and high energy storage density in ACTO dielectric materials.