Interface thickness optimization of lead-free oxide multilayer capacitors for high-performance energy storage

Abstract

The effects of interface density and total multilayer film thickness on the dielectric properties and breakdown behavior have been revealed in this work by investigating the environment-friendly energy storage multilayer films of Ba_0.7Ca_0.3TiO₃ (BCT) and BaZr_0.2Ti_0.8O₃ (BZT) dielectrics. Numerical simulations based on a finite element method have given the breakdown process vividly, which agreed well with the experimental results. Moreover, not only the ultrahigh energy storage density of 51.8 J cm⁻³ with a great efficiency of 81.2% at room temperature but also robust thermal stability has been obtained by optimizing the interface density and total thickness. High energy density above 25.1 J cm⁻³ and excellent efficiency over 63.6% from room temperature to 200 °C provide a solid basis for potential applications of the multilayer systems in harsh environments.