Effect of Metal Deactivator on Breakdown and Energy Storage Properties of Polypropylene Modified by Deashing Method for Film Capacitors

In this paper, a novel deashing solution of metal deactivator/anhydrous ethanol is prepared to reduce the ash content and improve the breakdown and energy storage performances of polypropylene (PP). Meanwhile, the deashing method is optimized by adjusting the type and content of metal deactivator. The breakdown and energy storage properties of the deashed samples were tested. The results show that under the optimal concentration, the breakdown strengths of the samples deashed by different kinds of solution are improved by 29.5∼34.8% and the maximum discharge energy densities increase by 11.7∼35.6%. In addition, the total ash contents of the deashed samples decrease by 20.7∼72.1%. The chelation reaction between the metal deactivator and ash promotes the migration of ash to the deashing solution, which not only significantly reduces the ash content of PP, but also reduces the shallow trap density. Therefore, the carrier transport process is inhibited, and the breakdown and energy storage properties are significantly improved.