 This study proposes a new method for improving the performance of electrostatic capacitors. It involves inserting an insulating layer between two layers of hafium oxide, HFO, followed by low temperature annealing. This process increases the polarization difference and breakdown strength of the capacitor, resulting in an ultra-high energy storage density of 87.66 J slash CM3, and a high efficiency of 68.6%. Additionally, this technique has the potential to be used in micro-electronics systems, making it highly desirable for applications such as energy storage. This article was authored by Haiyan Chen, Lei Lu, Zhong Nai Yan, and others.