Pacesetter, Inc.

Clemson University

Christopher R Feger

Thomas Flavian Strange

Timothy R Marshall

James L Stevens

Roland Francis Dapo

Melissa A Moore

Joseph William Kolis

Naixiong Jiang

Jesse S Shaffer

Terry M Tritt

W Joseph Beauvais

Roy L Littleton

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.

Electrolytic capacitors with alternate cathode materials for use in pulse discharge applications

A method for manufacturing an electrolytic capacitor with improved deformation qualities includes impregnating an electrolytic capacitor with a first electrolyte, aging the electrolytic capacitor after impregnating and reimpregnating the electrolytic capacitor with a second electrolyte. The water content of the second electrolyte is lower than the water content of the first electrolyte. The second electrolyte may also have a lower viscosity and a higher conductivity than the first electrolyte.

Method for manufacturing an electrolytic capacitor with improved deformation qualities

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.

Method for producing highly conductive battery electrodes

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.

Design for capacitor anode assembly

An electrolyte including &#x3b3;-butyrolactone, a cosolvent and an alcohol is disclosed, which may be used in an electrolytic capacitor with very high operating voltage. Optional additional additives are added to the electrolyte to enhance its conductivity and reliability.

Electrolyte for high voltage electrolytic capacitors

This disclosure provides methods for assembling multiple anode stacked capacitor configurations with a temporary adhesive to aide in the alignment of separator materials and electrodes without sacrificing energy density, and electrolytic capacitors comprising such configurations. The temporary adhesive for use in the electrode assemblies will preferably comprise a polymer that is substantially soluble in a solvent-based electrolyte for use in an electrolytic capacitor.

Electrode-separator combination for improved assembly of layered electrolytic capacitors

The present invention is directed to an electrolyte for use in very high voltage electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a mixture of an alkoxy-substituted alcohol, such as 2-methoxyethanol, 2-ethoxyethanol, or 2-butoxyethanol, and a long chain dicarboxylic acid, where the acid functional groups are separated by 34 carbons (referred to as 'dimer acid') or 54 carbons (referred to as 'trimer acid'). The solution is then neutralized with ammonium hydroxide or other amine, such as ammonia, dimethylamine, trimethylamine, diethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, diisopropylethylamine and N-methylimidazole. Additional cosolvents, such as ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, di(ethylene glycol), tri(ethylene glycol), tetra(ethylene glycol), propyl alcohol, isopropyl alcohol, n-butanol, and di(ethylene glycol) butyl ether, may be added. Also, a cathode depolarizer, or degassing agent, from the group of nitro-substituted aromatic compounds (nitroaromatics) can be added to reduce the amount of gas produced during capacitor life.

Electrolyte for very high voltage electrolytic capacitors

Capacitor anode assembly

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/cmand 5.0 mA/cmfor 1 to 60 minutes, more preferably between about 0.13 mA/cmto about 0.26 mA/cmfor between 9 and 18 minutes, such that a conductive polyethylenedioxythiophene (PEDOT) coating is formed on the electrode surface. According to the present invention, the increased surface area of the coated cathode results in lower gas generation and, therefore, reduced capacitor swelling, reduced oxide buildup on the cathode and prevention of electrolysis. The present invention results in electrodes with a minimum capacitance of 1 mF/cm. The present invention also makes it possible to use thinner electrodes than conventional aluminum electrodes, thereby reducing the physical dimensions of the capacitor.

High surface area cathode for electrolytic capacitors using conductive polymer

The present invention is directed to a conductive electrolyte for use in high voltage electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a two solvent mixture of ethylene glycol and a polar organic cosolvent from the group of 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, hexyl alcohol, or di(ethylene glycol). Dissolved in this mixture is a combination of boric acid with either an aliphatic dicarboxylic acid of carbon chain length from eight to thirteen (C to C ) or a very long chain dicarboxylic acid, where the acid functional groups are separated by 34 carbons (referred to as &ldquo;dimer acid&rdquo;). The solution is then neutralized with an amine. A cathode depolarizer, or degassing agent, from the group of nitro-substituted aromatic compounds (nitroaromatics) can be added to reduce the amount of gas produced during capacitor life. Hypophosphorous acid and/or a colloidal suspension of silica in ethylene glycol may be added to enhance the life characteristics of the electrolyte, resulting in lower leakage currents and better voltage droop characteristics. The water content may be adjusted with deionized water to achieve a Karl Fischer titration (water content) measurement of 1.0-8.0% to achieve proper age characteristics.

Conductive electrolyte for high voltage capacitors

The present invention is directed to a conductive electrolyte for use in high voltage electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a two solvent mixture of ethylene glycol and a polar organic cosolvent. Dissolved in this mixture is a combination of: a high dielectric cosolvent, a long chain monocarboxylic acid and an aliphatic dicarboxylic acid of carbon chain length from eight to thirteen (C to C ). The solution is then neutralized with an amine. A cathode depolarizer, or degassing agent may be added to reduce the amount of gas produced during capacitor life. Hypophosphorous acid may be added to enhance the life characteristics of the electrolyte. The water content may be adjusted with deionized water to achieve a Karl Fischer titration (water content) measurement of about 1.0% to about 8.0% to achieve proper age characteristics.

Conductive electrolyte system with viscosity reducing co-solvents

The present invention is directed to a high voltage, highly conductive electrolyte for use in electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a two solvent mixture of ethylene glycol and N-methylformamide; a combination of hypophosphorous acid, boric acid and an aliphatic dicarboxylic acid of carbon chain length from eight to twelve, such as azelaic, sebacic, or brassylic acid; an amine including ammonia, ammonium hydroxide, diethylamine, dimethylamine, triethylamine, or triethanolamine; and a nitro-substituted aromatic compound as a degassing agent, such as 3&prime;-nitroacetophenone. Anhydrous ammonia may also be added to neutralize the solution. In an alternative embodiment of the electrolyte of the present invention, the ethylene glycol/NMF two solvent mixture can be substituted with 1,2-propanediol, using &ggr;-butyrolactone as a cosolvent with or without NMF. The electrolyte of the present invention will allow the construction of multi-anode capacitors with low equivalent series resistance (ESR), which will have superior energy density and delivery, while being thinner due to fewer spacer and cathode layers with the same number of anodes. This resultant capacitor, when incorporated into an ICD, will reduce the size and thickness of the overall device.

High voltage, highly conductive electrolyte for electrolytic capacitors

The present invention is directed to a conductive electrolyte for use in high voltage electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a two solvent mixture of ethylene glycol and an alkoxy-substituted alcohol, such as 2-methoxyethanol, 2-ethoxyethanol, or 2-butoxyethanol. Dissolved in this mixture is a combination of acids including at least one straight chain aliphatic dicarboxylic acid of carbon chain length from eight to thirteen (C to C ) and a longer chain dicarboxylic acid, where the acid functional groups are separated by 34 carbons (referred to as &ldquo;dimer acid&rdquo;). As further additives, boric acid and hypophosphorous acid can be added, with the former providing corrosion inhibition in the finished capacitor, and the latter resulting in lower leakage currents and better voltage droop characteristics. Also, a cathode depolarizer, or degassing agent, from the group of nitro-substituted aromatic compounds (nitroaromatics) can be added to reduce the amount of gas produced during capacitor life. The solution is neutralized with an amine.

The present invention is directed to a conductive electrolyte for use in high voltage electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a two solvent mixture of ethylene glycol and di(ethylene glycol); a combination of boric acid with an aliphatic dicarboxylic acid of carbon chain length from eight to thirteen, such as suberic, azelaic, sebacic, undecanedioic, dodecanedioic, or brassylic acid; a very long chain dicarboxylic acid, where the acid moieties are separated by 34 carbons; and a nitro-substituted aromatic compound as a degassing agent, such as 3-nitroacetophenone or 2-nitroanisole. This electrolyte is then titrated with a light amine such as ammonia, diethylamine, dimethylamine, trimethylamine, or triethylamine. The electrolyte according to the present invention, when impregnated in an electrolytic capacitor, provides an acceptable breakdown voltage while having a reasonable bulk conductivity. This electrolyte, when impregnated within a capacitor constructed of appropriate foils and paper spacers, should provide a part with a working voltage of at least 500 volts, while having a bulk conductivity of approximately 3 mS/cm.

The thermoelectric properties (resistivity, thermopower and thermal conductivity) of single crystals of the low-dimensional pentatelluride materials are disclosed. The pentatellurides are well suited for use in thermoelectric devices. In general, the pentatellurides include hafnium pentatelluride and zirconium pentatelluride, which can both be substituted with selective amounts of various metals, including titanium, selenium, and antimony.

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Easley, SC, United States of America

Christopher R Feger