Abstract: A metal or metal alloy foil substrate, preferably an unetched and uncoated metal or metal alloy foil substrate, such as but not limited to titanium, palladium, lead, nickel, tin, platinum, silver, gold, zirconium, molybdenum, tantalum, palladium-silver alloy, platinum-rhodium alloy, platinum-ruthenium alloy, and/or platinum-iridium alloy, is used as the cathode in an electrolytic capacitor, preferably an aluminum electrolytic capacitor having a multiple anode flat, stacked capacitor configuration. Despite a 120 Hz bridge capacitance measurement lower than with etched aluminum, the use of an unetched and uncoated metal or metal alloy foil cathode according to the present invention will inhibit gas production and not cause the capacitor to swell. Furthermore, an electrolytic capacitor built with a 30 micron unetched and uncoated foil cathode according to the present invention can deliver a stored to discharge energy ratio sufficient for use in pulse discharge applications, such as an in an ICD.

Abstract: A method for producing battery cathodes comprises mixing a cathode active material and a conductive polymer such as polyaniline or poly(ethylenedioxythiophene). The conductive polymers are used in lieu of or in addition to conventional conductive additives and binder materials and significantly reduces or even eliminates the need for such conductive additives or binder materials. The resulting cathodes have a greater weight percentage of the active material and a larger volumetric energy density.

Abstract: Anode foil, preferably aluminum anode foil, is etched using a process of treating the foil in an electrolyte bath composition comprising a sulfate and a halide, such as sodium chloride. The anode foil is etched in the electrolyte bath composition by passing a charge through the bath. The etched anode foil is suitable for use in an electrolytic capacitor.

Abstract: Anode foil, preferably aluminum anode foil, is etched using a process of treating the foil in an electrolyte bath composition comprising a sulfate and a halide, such as sodium chloride. The anode foil is etched in the electrolyte bath composition by passing a charge through the bath. The etched anode foil is suitable for use in an electrolytic capacitor.

Abstract: The present invention provides a method for reforming a capacitor of an implantable medical device, such as an implantable cardioverter defibrillator, wherein the capacitor has a nominal voltage. The method of reforming the capacitor comprises charging the capacitor to a first voltage that is above the nominal voltage of the capacitor, partially discharging the capacitor through system leakage, charging the capacitor to a second voltage that is above the nominal voltage, and discharging the capacitor through system leakage until the charge on the capacitor dissipates. The present invention also provides an implantable medical device having a capacitor reforming circuit for reforming the capacitor. Capacitors reformed according to the present invention have reduced charge time deformation compared to capacitors conventionally reformed at the nominal voltage.

Abstract: According the present invention, anode foils are encapsulated in separator material so as to insulate them from the metal housing of an electrolytic capacitor. The present invention also provides for enclosed capacitor configurations for use in stacked capacitor configurations. Preferably, heat-sealable polymeric materials are used as separator materials to encapsulate or enclose the anode assemblies and capacitor configurations. The encapsulated anode assemblies and capacitor configurations of the present invention may be used in implantable cardioverter defibrillators.

Abstract: A method of producing a highly etched electrode for a capacitor from a foil is disclosed. The method comprises first applying a composition to the foil to form a plurality of deposits on the foil surface. The method then includes heating the deposits to form micron-sized features and etching the foil. Preferably, the micron-sized features facilitate etching of the foil surface at the location of the micron-sized features. After etching, the foil is optionally further processed in a combination of optional steps such as widening, forming and finishing steps. The controlled application and heating of deposits on the foil surface allows for positional control of tunnel initiation during etching. Thus, the present invention relates to a method of controlling the etching of a foil, such that tunnel initiation density and the location of tunnel initiation is controlled.

Abstract: A method of producing a highly etched electrode for a capacitor from a foil is disclosed. The method comprises first applying a laser beam to the foil to form a plurality of marks on the foil surface and then etching the foil. Preferably, the laser marks facilitate etching of foil surface in areas near the marks and retard etching of foil surface inside the marks. After etching, the foil is further processed in a combination of optional steps such as forming and finishing steps. The laser marking of the foil allows for positional control of tunnel initiation, such that tunnel initiation density and the location of tunnel initiation is controlled. By controlling the position of tunnel initiation, foils are etched more uniformly and have optimum tunnel distributions, thus allows for the production of highly etched foils that maintain high strength and have high capacitance.

Abstract: A micro-denier fiber of less than approximately 2.0 microns is coated in a valve metal to a metal thickness of approximately 0.2 to 2.0 microns. In one embodiment, a long filament of coated fiber is wound on a spool in such a way that the maximum arrangement of fiber density is achieved For example, the spool may have a cross section exhibiting a hexagonal close-packed arrangement of the fibers. In another embodiment, a plurality of fibers may be grown or formed into a particular arrangement prior to coating. Once coated and arranged, the fiber mass is compressed and constrained so that shapes can be cut out in various thicknesses, such as, for example, approximately 50 microns to 5000 microns. Each sheet is sintered to bind the metal and remove the fiber, leaving a porous anode that can be oxidized and formed in the usual manner for a capacitor.

Abstract: According the present invention, anode foils are encapsulated in separator material so as to insulate them from the metal housing of an electrolytic capacitor. The present invention also provides for enclosed capacitor configurations for use in stacked capacitor configurations. Preferably, heat-sealable polymeric materials are used as separator materials to encapsulate or enclose the anode assemblies and capacitor configurations. The encapsulated anode assemblies and capacitor configurations of the present invention may be used in implantable cardioverter defibrillators.

Abstract: A process for producing high stability crystalline anodic aluminum oxide includes anodizing an anodic foil, hydrating the foil, and forming a barrier oxide layer on the foil. Anodizing the anodic foil produces nano-porous amorphous oxides which can then be converted to a crystalline precursor material by hydrating the foil. Next, an oxide layer formation step is utilized to form a barrier oxide layer on the surface of the anodized and hydrated foil. The resulting anodic oxides have very low levels of defects, voids and tensile stresses and have rise times as low as about 1 second to about 3 seconds after exposure of the formed samples to boiling water for 2 hours.

Abstract: The present invention is directed to a conductive polyethylenedioxythiophene (PEDOT) polymer coated electrode adapted for use as a cathode electrode of an electrolytic capacitor and a method of manufacturing the same. According to the present invention, a metal foil substrate is placed in an aqueous solution of a doped 3,4-ethylenedioxythiophene (EDOT) monomer and a co-solvent, to dissolve the EDOT monomer, and a current is applied until the desired thickness of the polymer coating is electrochemically deposited. Additionally, an organic acid is added to the aqueous solution to act as an oxidizer. In order to improve the uniformity and adherence of the coating a surfactant may also be added. In a preferred embodiment, the EDOT monomer and cosolvent are first mixed, and then added to a water solution of oxidizer and dopant. The polymer film is deposited electrochemically onto the substrate by applying a DC current between 0.05 mA/cm2 and 5.0 mA/cm2 for 1 to 60 minutes, more preferably between about 0.

Abstract: A method of producing an electrode for use in the manufacture of electrolytic capacitors for implantable cardioverter defibrillators comprises first coating the foil with a photoresist, second, applying a holographic image to the photoresist, third, removing a portion of the photoresist to expose a portion of the foil and create a pattern of photoresist on the foil and etching the foil. Alternatively, the method comprises applying an oxide or metal layer to the exposed foil surface, removing the pattern of photoresist to create a pattern of oxide or metal and etching the foil. The patterns of photoresist, oxide or metal all retard or prevent etching of the foil where the foil surface is covered. This results in a pattern of unetched foil with the remaining area being heavily etched. The resulting patterns stop crack propagation through the etched portions to yield foils with high gain and improved strength.

Abstract: The present invention relates to electrolytic capacitors and, more particularly, to the reduction of water content within an electrolytic capacitor. Aluminum electrolytic capacitors tend to degrade with time. This is due, in part, to water in the electrolyte attacking the thin film of aluminum oxide (Al2O3) formed on the anode surface. Deformation of the aluminum oxide increases the leakage current of the capacitor, such that when one or more capacitors are used for shock delivery in an ICD, the first shock (after a hiatus) will have a significantly longer charge time. Unfortunately, one cannot remove all of the water from the electrolyte, as it is needed for conduction, as well as for the formation of the cut edges of the aluminum foil after assembly. According to the present invention, a desiccant material is used within an electrolytic capacitor casing to reduce the water content of a finished capacitor to below 1% by weight of the electrolyte.

Abstract: The present invention is directed to an electrolytic capacitor having a novel floating anode between the cathode and the powered anode of the capacitor, resulting in a single capacitor having a working voltage double that of the formation voltage of the powered anode. The floating anode acts as cathode to the powered anode and as an anode to the cathode, such that the capacitor according to the present invention supports half the working voltage between the cathode and the floating anode and half the working voltage between the floating anode and the powered anode. The arrangement of the cathode, floating anode and powered anode according to the present invention results in a single capacitor with half the capacitance and twice the voltage of a single anode device.

Abstract: The present invention is directed to a method of creating porous anode foil for use in multiple anode stack configuration electrolytic capacitors, producing a pore structure that is microscopic in pore diameter and spacing, allowing for increased energy density with a minimal increase in ESR. Initially, an anode metal foil is etched, according to a conventional etch process, to produce an enlargement of surface area. The etched foil is then placed into the electrochemical drilling solution of the present invention. Alternatively, the etched foil may be masked, so that only small areas of the etched foil are exposed, prior to being placed in the electrochemical drilling solution. A DC power supply is used to electrochemically etch the masked or unmasked foil in the electrochemical drilling solution of the present invention such that pores on the order of a few microns diameter are produced through the foil.

Abstract: The present invention is directed toward an enhanced very high volt electrolyte for use in electrolytic capacitors. In particular, by the inclusion of a polymer matrix of a hydrogel, preferably of the family of poly(hydroxy alkyl methacrylate) but also including polyvinylalcohol (PVA), polyacrylonitrile (PAN), into a standard fill electrolyte, the breakdown voltage of the enhanced very high volt electrolyte of the present invention is raised to as much as 800 V. An electrolytic capacitor impregnated with the enhanced very high volt electrolyte of the present invention, is capable of operating at a voltage of 700 to 800 volts. The production of a very high volt capacitor capable of operating at a voltage of 700 to 800 volts allows a single high volt electrolytic capacitor to replace the conventional two capacitors-in-series arrangement of an Implantable Cardioverter Defibrillator (ICD).

Abstract: The present invention relates to an improved method of impregnating electrolytic capacitor stacks or wound rolls with a polymer based electrolyte, such as a hydroxyethylmethacrylate (HEMA) or hydroxyethylacrylate (HEA) based electrolyte, to render them suitable for use in electrolytic capacitors, and to such electrolytic capacitors. The initiator to promote the polymerization of the polymer based electrolyte and a surface active wetting agent are deposited on the foil or in the stack or wound roll prior to impregnation of the stack or wound roll with a polymer based electrolyte, allowing the polymer based electrolyte solution to be warmed prior to impregnation to a temperature suitable for easy impregnation into the anode and cathode foil and paper. Polymerization does not begin until impregnation of the capacitor with the polymer based electrolyte and the surfactant allows the polymer based electrolyte to more fully incorporate itself into the microscopic features of the anode foil.

Abstract: The present invention is directed toward a very high volt capacitor for use in an implantable cardioverter defibrillator. In particular, by the inclusion of a polymer matrix of a hydrogel, preferably of the family of poly(hydroxyalkylmethacrylate)but also including polyvinyl alcohol (PVA), polyacrylnitrile (PAN), into a standard fill electrolyte, the breakdown voltage of the enhanced very high volt electrolyte of the present invention is raised to as much as 800 V. A very high volt electrolytic capacitor according to the present invention, impregnated with the enhanced very high volt electrolyte of the present invention, is able to support voltages of 700 to 800 volts, while maintaining the described desired properties, and is therefore superior to other known electrolytic capacitors for use in implantable cardioverter defibrillators.

Abstract: The present invention is directed toward a very high volt capacitor for use in an implantable cardioverter defibrillator. In particular, by the inclusion of a polymer matrix of a hydrogel, preferably of the family of polyhydroxyalkylmethacrylate) but also including polyvinyl alcohol (PVA), polyacrylnitrile (PAN), into a standard fill electrolyte, the breakdown voltage of the enhanced very high volt electrolyte of the present invention is raised to as much as 800 V. A very high volt electrolytic capacitor according to the present invention, impregnated with the enhanced very high volt electrolyte of the present invention, is able to support voltages of 700 to 800 volts, while maintaining the described desired properties, and is therefore superior to other known electrolytic capacitors for use in implantable cardioverter defibrillators.