Abstract: A wet electrolytic capacitor is provided. The capacitor contains an anode comprising an anodically oxidized pellet formed from a pressed and sintered powder, a cathode that contains a metal substrate coated with a conductive polymer, and a working electrolyte in communication with the anode and the cathode. The working electrolyte is in the form of a gel and comprises an ammonium salt of an organic acid, inorganic oxide particles, an acid, and a solvent system that comprises water. The working electrolyte has a pH value of from about 5.0 to about 8.0.

Abstract: A relatively thin planar anode for use in a wet electrolytic capacitor is provided. Through a combination of specific materials and processing techniques, the present inventors have surprisingly discovered that the resulting anode may possess a high volumetric efficiency, yet still be able to operate at a high voltage and capacitance, resulting in a capacitor with a high energy density. The anode is a pressed pellet formed from an electrically conductive powder that contains a plurality of particles (including agglomerates thereof) having a flake-like morphology. The present inventors have discovered that such a morphology can optimize packing density, which reduces the thickness of the anode and improves volumetric efficiency. Such particles can provide a short transmission line between the outer surface and interior of the anode and a highly continuous and dense wire-to-anode connection with high conductivity. The particles may also increase the breakdown voltage and help lower ESR.

Abstract: A relatively thin planar anode for use in a wet electrolytic capacitor is provided. An anode leadwire is embedded within the anode and extends in a longitudinal direction therefrom. The wire may be formed from any electrically conductive material, such as tantalum, niobium, aluminum, hafnium, titanium, etc., as well as electrically conductive oxides and/or nitrides of thereof. To reduce the tendency of the leadwire to pull out of the anode due to stresses encountered during manufacturing (e.g., sintering) and/or use of the capacitor, the manner in which the wire is inserted is selectively controlled in the present invention. That is, at least a portion of the wire within the anode is bent at an angle relative to the longitudinal axis of the wire. This “bend” reduces the ease to which the wire can be pulled out in the longitudinal direction after the anode is pressed and sintered.

Abstract: A relatively thin planar anode for use in a wet electrolytic capacitor is provided. An anode leadwire is embedded within the anode and extends in a longitudinal direction therefrom. The wire may be formed from any electrically conductive material, such as tantalum, niobium, aluminum, hafnium, titanium, etc., as well as electrically conductive oxides and/or nitrides of thereof. To reduce the tendency of the leadwire to pull out of the anode due to stresses encountered during manufacturing (e.g., sintering) and/or use of the capacitor, the manner in which the wire is inserted is selectively controlled in the present invention. That is, at least a portion of the wire within the anode is bent at an angle relative to the longitudinal axis of the wire. This “bend” reduces the ease to which the wire can be pulled out in the longitudinal direction after the anode is pressed and sintered.

Abstract: A relatively thin planar anode for use in a wet electrolytic capacitor is provided. Through a combination of specific materials and processing techniques, the present inventors have surprisingly discovered that the resulting anode may possess a high volumetric efficiency, and yet still be able to operate at a high voltage and capacitance, thus resulting in a capacitor with a high energy density. More particularly, the anode is a pressed pellet formed from an electrically conductive powder that contains a plurality of particles (including agglomerates thereof). The particles may have a flake-like morphology in that they possess a relatively flat or platelet shape. The present inventors have discovered that such a particle morphology can optimize packing density, and thus reduce the thickness of the anode and improve volumetric efficiency.

Abstract: A wet electrolytic capacitor that includes an anode, cathode, and an electrolyte is provided. The cathode contains a substrate and a coating overlying the substrate. The coating comprises a sintered body containing carbonaceous particles (e.g., activated carbon) and inorganic particles (e.g., NbO2).