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 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.