Tantalum capacitor with increased stability

A solid electrolytic capacitor comprising a capacitor element, wherein the capacitor element comprises:

• an anode body that contains tantalum;
• a dielectric that overlies the anode body;
• a pre-coat that overlies the anode body, wherein the pre-coat is formed from a monoaminofunctional silane that is a primary amine
• a solid electrolyte that includes:
• at least one inner layer that overlies the pre-coat, is generally free of extrinsically conductive polymers, and contains an intrinsically conductive polymer containing repeating thiophene units, and
• at least one outer layer that overlies the inner layer, wherein the outer layer includes conductive polymer particles containing a complex of an extrinsically conductive thiophene polymer and a counterion;
• and
• an external polymer coating that overlies the solid electrolyte and includes conductive polymer particles containing a complex of an extrinsically conductive thiophene polymer and a counterion;
• wherein the capacitor exhibits a dielectric strength of about 0.6 volts per nanometer or more, and further wherein the capacitor exhibits a charge-discharge capacitance after being subjected to 3,000 cycles of a surge voltage and an initial capacitance prior to being subjected to the surge voltage, wherein the ratio of the charge-discharge capacitance to the initial capacitance is from about 0.75 to 1.