This work presents a high voltage polymer aluminum electrolytic capacitor design without a paper separator, realized with PEDOT:PSS as electrolyte and evaluated up to 450V. Comparative testing against a conventional separator-based prototype shows significant ESR benefits at high frequencies, while maintaining high volumetric efficiency. Experimental results showed an ESR reduction by a factor of 10 at 100kHz. The improved performance originates from the electronic conduction mechanism of PEDOT:PSS. Breakdown testing confirmed stable dielectric integrity, with only a 1.6% deviation from the reference design. These findings demonstrate that a separatorless PEDOT:PSS configuration can serve as a simplified approach for compact, high-frequency DC-link and filtering applications in next-generation power electronic systems. • The new separatorless design achieved stable operation up to 450V, comparable to conventional paper-separated capacitors. • Equivalent Series Resistance (ESR) is reduced by a factor of 10 at 100kHz, significantly improving high-frequency performance. • The breakdown voltage remained nearly unchanged (1.6% deviation), confirming dielectric integrity without a separator. • The separator thickness is reduced from 80 μ m (paper) to 20 μ m (PEDOT:PSS), enhancing volumetric e!ciency.
Wittmaack et al. (Sun,) studied this question.