Abstract: Electrolytic capacitors having low equivalent series resistance and low leakage current are described. The electrolytic capacitors include a solid electrolyte layer of a conductive material in particular a conductive polymer, and an outer layer that includes binders, polymeric anions and conductive polymers (e.g., polythiophenes). Also described is a method of preparing electrolytic capacitors that involves forming the conductive polymer of the solid electrolyte layer in situ by means of chemical oxidative polymerization or electrochemical polymerization. Electronic circuits that include the electrolytic capacitors are also described.