Solid electrolytic capacitor containing a pre-coat layer

Abstract

A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder, dielectric located over and/or within the anode body, an adhesion coating overlying the dielectric, and a solid electrolyte overlying the adhesion coating is provided. The powder has a high specific charge and in turn a relative dense packing configuration. Despite being formed from such a powder, the present inventors have discovered that the conductive polymer can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a discontinuous precoat layer in the adhesion coating that overlies the dielectric. The precoat layer contains a plurality of discrete nanoprojections of a manganese oxide (e.g., manganese dioxide).