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

The market-dominating material BaTiO3 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 BaTiO3-BiFeO3- CaTiO3 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 CaTiO3 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 elec-trical breakdown pathways. Furthermore, the multilayer ceramic capacitors (MLCCs) using such dielectrics were constructed with en-ergy 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.