Executive Summary : | Dielectric ceramic-based electrostatic capacitors are promising for advanced pulsed power energy storage applications due to their giant power density, faster charging-discharging speeds, high voltage endurance, thermal stability, and longer lifetimes. However, achieving high recoverable energy density (Ur) and energy storage efficiency (η) in a single material is difficult due to a trade-off between them. To overcome these drawbacks, a composition-gradient (CG) approach is proposed to improve energy storage performance by controlling the concentrations of a high entropy relaxor ferroelectric (HERFE) material with high ΔP and a linear dielectric (LD) material with high Eb material in the thickness direction. This approach is achieved by hierarchically depositing the LD material at the bottom and increasing the concentration of HERFE material towards the top end using pulsed laser deposition (PLD). The larger and continuous composition gradience leads to a larger ΔP without compromising Eb, achieving high energy storage performance in dielectrics. Additionally, a HERFE material with high-temperature diffusive-type transition (above150 oC) will be designed and constructed a multilayer structure based on optimized processing parameters in single-layered CG film. This approach relies on composite structure engineering in a single layer without involving complex heterolayer and expensive fabrication techniques, providing a great possibility for designing high-temperature electrostatic capacitors for use in electric vehicles and renewable energy storage grids. |