Abstract: A wet electrolytic capacitor that includes a porous anode body containing a dielectric layer, an electrolyte, and a cathode containing a metal substrate on which is disposed a conductive coating is provided. Prior to application of the conductive coating, the metal substrate is blasted with abrasive particles to enhance the ability of the substrate to adhere to the coating. The micro-roughened metal substrate can be treated after blasting so that substantially all of the abrasive particles are removed. This is accomplished by contacting the metal substrate with an extraction solution to remove the particles, and also by selectively controlling the nature of the abrasive particles so that they are dispersible (e.g., soluble) in the solution.

Abstract: A wet electrolytic capacitor that contains an anodically oxidized porous anode body, a cathode containing a metal substrate coated with a conductive coating, and a working electrolyte that wets the dielectric on the anode. The conductive coating is formed through anodic electrochemical polymerization (“electro-polymerization”) of a precursor colloidal suspension on the surface of the substrate. The colloidal suspension includes a precursor monomer, ionic surfactant, and sulfonic acid, which when employed in combination can synergistically improve the degree of surface coverage and overall conductivity of the coating.

Abstract: A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The powder may have a high specific charge and in turn a relative dense packing configuration. Despite being formed from such a powder, a manganese precursor solution can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a “film-like” configuration and coats at least a portion of the anode in a substantially uniform manner.

Abstract: A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The present inventors have discovered a technique that is believed to substantially improve the uniformity and consistency of the manganese oxide layer. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a “film-like” configuration and coats at least a portion of the anode in a substantially uniform manner. This improves the quality of the resulting oxide as well as its surface coverage, and thereby enhances the electrical performance of the capacitor.

Abstract: A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The powder may have a high specific charge and in turn a relative dense packing configuration. Despite being formed from such a powder, a manganese precursor solution can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a “film-like” configuration and coats at least a portion of the anode in a substantially uniform manner.

Abstract: A wet electrolytic capacitor that includes a porous anode body containing a dielectric layer, an electrolyte, and a cathode containing a metal substrate on which is disposed a conductive coating is provided. Prior to application of the conductive coating, the metal substrate is blasted with abrasive particles to enhance the ability of the substrate to adhere to the coating. The micro-roughened metal substrate can be treated after blasting so that substantially all of the abrasive particles are removed. This is accomplished by contacting the metal substrate with an extraction solution to remove the particles, and also by selectively controlling the nature of the abrasive particles so that they are dispersible (e.g., soluble) in the solution.

Abstract: A wet electrolytic capacitor that contains an anodically oxidized porous anode body, a cathode containing a metal substrate coated with a conductive coating, and a working electrolyte that wets the dielectric on the anode. The conductive coating is formed through anodic electrochemical polymerization (“electro-polymerization”) of a precursor colloidal suspension on the surface of the substrate. The colloidal suspension includes a precursor monomer, ionic surfactant, and sulfonic acid, which when employed in combination can synergistically improve the degree of surface coverage and overall conductivity of the coating.

Abstract: A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body 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 a manganese precursor solution (e.g., manganese nitrate) can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a “film-like” configuration and coats at least a portion of the anode in a substantially uniform manner.

Abstract: A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body 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 a manganese precursor solution (e.g., manganese nitrate) can be readily impregnated into the pores of the anode. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a “film-like” configuration and coats at least a portion of the anode in a substantially uniform manner.

Abstract: A solid electrolytic capacitor that contains an anode body formed from an electrically conductive powder and a dielectric coating located over and/or within the anode body is provided. The present inventors have discovered a technique that is believed to substantially improve the uniformity and consistency of the manganese oxide layer. This is accomplished, in part, through the use of a dispersant in the precursor solution that helps minimize the likelihood that the manganese oxide precursor will form droplets upon contacting the surface of the dielectric. Instead, the precursor solution can be better dispersed so that the resulting manganese oxide has a “film-like” configuration and coats at least a portion of the anode in a substantially uniform manner. This improves the quality of the resulting oxide as well as its surface coverage, and thereby enhances the electrical performance of the capacitor.

Abstract: A pressed anode formed from an electrically conductive powder that contains a plurality of coarse agglomerates and fine agglomerates is provided. The fine agglomerates have an average size smaller than that of the coarse agglomerates so that the resulting powder contains two or more distinct particle sizes, i.e., a “bimodal” distribution. In this manner, the fine agglomerates can effectively occupy the pores defined between adjacent coarse agglomerates (“inter-agglomerate pores”). Through the occupation of the empty pores, the fine agglomerates can increase the apparent density of the resulting powder, which improves volumetric efficiency.