Use of PVDF film in high energy density capacitors

Insulating films with high relative dielectric constants are used in capacitors when the requirements call for high energy density. Polyvinylidene Fluoride (PVDF) film is of interest in these applications because its dielectric constant is about 10 compared to usual values of 2 to 4. This paper is a summary of Maxwell's recent experience with this film. In part, this experience results from the development of capacitors which are used in pulsed plasma thrusters. Those capacitor specifications are shown in Table 1. Due to the long life requirements, life predictions are made from accelerated tests. On this basis, the recent data indicates that Maxwell has refined its manufacturing procedures to the point where the life and voltage specifications can be met. In addition to the life requirement, these spacecraft capacitors must be radiation resistant. To accomplish this, the capacitors must be paper-free because paper is known to be vulnerable to ionizing radiation.