Influence of Chemical Polymerization Conditions on the Properties of PEDT Used for the Cathodes of Tantalum Electrolytic Capacitors

This paper studied approaches to conduct preparation of poly(3, 4-ethylenedioxythiophene)(PEDT)by chemical polymerization on the surface of tantalun/tantalum pentoxide-based anode. The chemical polymerized PEDT is used for the cathodes of tantalum electrolytic capacitors. Particularly, the influence of chemical polymerization conditions, such EDT and oxidizing agent solution composition, polymerized temperature and solvent evaporated temperature, on the capacitance and dissipation factor of as made capacitor, is discussed. It is beneficial to keep the ratio of concentration of EDT and oxidizing agent between 1:3～6. The properties would be deteriorated with the increase of polymerized temperature; meanwhile, the solvent evaporated temperature should come up to 80℃ step by step.