High-entropy assisted BaTiO3-based ceramic capacitors for energy storage

Abstract

The market-dominating material BaTiO 3 is highly crucial in advanced electronics and electric power systems owing to its fast charging/discharging speed and superior cycle life. However, the low energy storage efficiency and breakdown strength hinder further device miniaturization for energy storage applications. Herein, we design a high configurational entropy (HCE) material BaTiO 3 -BiFeO 3 -CaTiO 3 with rational microstructural engineering that demonstrates an ultrahigh energy density of 7.2 J cm −3 . The HCE design leads to the increased solubility of CaTiO 3 in the matrix, which enhances the resistivity and polarization. Simultaneously, the nano-segregations around the grains can enhance the breakdown strength obviously due to strongly scattering of electron carriers and impeding of electrical breakdown pathways. Furthermore, the multilayer ceramic capacitors (MLCCs) using such dielectrics were constructed with energy density of 16.6 J cm −3 and efficiency of 83%. This work offers a route to explore new dielectric materials that are expected to benefit dielectric devices' compactness and high performance. • High-entropy relaxor-ferroelectric is designed and synthesized • Special microstructure related to the improvement of electric breakdown strength • High energy storage density of 16.6 Jcm −3 is achieved in the MLCC Qi et al. report a high-entropy relaxor-ferroelectric material BaTiO 3 -BiFeO 3 -CaTiO 3 with rational microstructural engineering. They achieve an ultrahigh energy density of 16.6 J cm −3 , and efficiency of 83% in a prototype MLCC device.