Methods are provided to suitably impregnate low surface energy separator materials with polar electrolyte in an electrolytic capacitor. Backfilling methods overcome the high contact angles exhibited by polar electrolytes on porous hydrophobic separators, forcing the electrolyte into the separator pores, thereby sufficiently impregnating the separator disposed between two electrodes within the capacitor assembly. Methods enable use of separators sans surfactant or surface modifications to improve wetting.
