NASA requires advanced power electronic and energy storage devices that can work at various temperature (-100 degree Celsius to 400 degree Celsius) and high operating voltage with high energy and power density where traditional power and energy storage device cannot be applied. The current state-of-the-art of the capacitor suffers from temperature reliability, especially at high temperature, as well as low-energy density, making them bulky and costly. Power systems for NASA mission must be operated efficiently at high temperatures to eliminate the need for on board cooling systems. The high performance capacitor (temperature reliability and high energy density) will save space, reduce weight, and improve reliability. The proposed Phase I SBIR program will demonstrate Powdermet Inc's ability to produce an advanced nanocomposite capacitor can be applied in harsh and extreme environment as required by NASA aerospace exploration. This novel capacitor will feature as wide operating temperature (-100 degree Celsius to 400 degree Celsius), high operating voltage (>kilovolt) and high-energy density (>4 J/cc) and high powder density (>MW/cc) as well as operating in radiation environment.