Significantly enhanced energy storage density with superior thermal stability by optimizing Ba(Zr0.15Ti0.85)O-3/Ba(Zr0.35Ti0.65)O-3 multilayer structure

Excellent thermal stability with high energy storage density in ultra-wide range of temperatures is the extremely important property of capacitors for applications in cold polar regions, extreme altitudes and high temperature regions. Here, we report on designing and preparing the BaZr0.15Ti0.85O3/BaZr0.35Ti0.65O3 (BZT15/BZT35) multilayer thin film capacitors. Under a given total thickness, the energy storage performances of the multilayer films can be optimized by controlling the number of interfaces. For the capacitor with an optimum period number N = 6, the markedly enhanced breakdown strength and large dielectric constant are achieved, which leads to a giant energy storage density (W-re) of similar to similar to 83.9 J/cm(3) with the efficiency (eta) of similar to 78.4% and a superior power density of 1.47 MW/cm(3) at room temperature. Moreover, the N= 6 multilayer capacitor also exhibits ultra-stable W-re of 69.1 J/cm(3) (efficiency: 84.9%) to 63.2 J/cm(3) (efficiency: 66.9%) from -100 degrees C to 200 degrees C and a good reliability in W-re and. even after 10(6) cycles at 200 degrees C. The excellent performances demonstrate that the multilayer films are a promising material system to meet the wide requirements of future applications, ranging from portable electronics to hybrid electric vehicles and aerospace power electronics.