Abstract: A wet tantalum electrolytic capacitor containing a cathode, fluidic working electrolyte, and anode formed from an anodically oxidized sintered porous tantalum pellet is described. The pellet is formed from a pressed tantalum powder. The tantalum powder is formed by reacting a tantalum oxide compound, for example, tantalum pentoxide, with a reducing agent that contains a metal having an oxidation state of 2 or more, for example, magnesium. The resulting tantalum powder is nodular or angular and has a specific charge that ranges from about 9,000 ?F*V/g to about 11,000 ?F*V/g. Using this powder, wet tantalum electrolytic capacitors have breakdown voltages that ranges from about 340 volts to about 450 volts. This makes the electrolytic capacitors ideal for use in an implantable medical device.

Abstract: A wet tantalum electrolytic capacitor containing a cathode, fluidic working electrolyte, and anode formed from an anodically oxidized sintered porous tantalum pellet is provided. The pellet is formed from a pressed tantalum powder. The tantalum powder is formed by reacting a tantalum oxide compound, for example, tantalum pentoxide, with a reducing agent that contains a metal having an oxidation state of 2 or more, for example, magnesium. The resulting tantalum powder is nodular or angular and has a specific charge that ranges from about 11,000 ?F*V/g to about 14,000 ?F*V/g. Using this powder, wet tantalum electrolytic capacitors have breakdown voltages that ranges from about 250 volts to about 400 volts. This makes the electrolytic capacitors ideal for use in an implantable medical device.

Abstract: A capacitor for powering an implantable medical device is described. The capacitor includes a casing having contoured surfaces to more closely conform to body contours. This means that the anode housed in the casing must also have a contoured shape substantially matching that of the casing. Accordingly, the anode is comprised of a pressed pellet having a surrounding peripheral edge extending to spaced-apart first and second major face walls. An anode lead wire comprises an embedded portion extending into the anode pellet. First and second channel-shaped recesses aligned with each other extend into the anode pellet from the first and second major face walls to intersect with the embedded lead wire portion. The first and second channel-shaped recesses also extend to opposed locations at the surrounding peripheral edge of the anode pellet.

Abstract: A wet tantalum electrolytic capacitor containing a cathode, fluidic working electrolyte, and anode formed from an anodically oxidized sintered porous tantalum pellet is provided. The pellet is formed from a pressed tantalum powder. The tantalum powder is formed by reacting a tantalum oxide compound, for example, tantalum pentoxide, with a reducing agent that contains a metal having an oxidation state of 2 or more, for example, magnesium. The resulting tantalum powder is nodular or angular and has a specific charge that ranges from about 11,000 ?F*V/g to about 14,000 ?F*V/g. Using this powder, wet tantalum electrolytic capacitors have breakdown voltages that ranges from about 250 volts to about 400 volts. This makes the electrolytic capacitors ideal for use in an implantable medical device.

Abstract: A capacitor for powering an implantable medical device is described. The capacitor includes a casing having contoured surfaces to more closely conform to body contours. This means that the anode housed in the casing must also have a contoured shape substantially matching that of the casing. Accordingly, the anode is comprised of a pressed pellet having a surrounding peripheral edge extending to spaced-apart first and second major face walls. An anode lead wire comprises an embedded portion extending into the anode pellet. First and second channel-shaped recesses aligned with each other extend into the anode pellet from the first and second major face walls to intersect with the embedded lead wire portion. The first and second channel-shaped recesses also extend to opposed locations at the surrounding peripheral edge of the anode pellet.

Abstract: A capacitor having at least two side-by-side anodes with a cathode current collector disposed between the anodes and housed inside a casing is described. Cathode active material is supported on the opposed major faces of the current collector and the current collector/cathode active material subassembly is housed in a first separator envelope. The first separator envelope is positioned between the side-by-side anodes and this electrode assembly is then contained in a second separator envelope. The two anodes can be connected in parallel inside or outside casing, or they can be unconnected to each other. There is also cathode active material supported on inner surfaces of the casing in a face-to-face alignment with an adjacent one of the anodes. That way, the second separator envelope also prevents direct physical contact between the anode pellets and the cathode active material supported on the casing sidewalls.

Abstract: A wet tantalum capacitor of either a single anode design or of multiple anode configurations having cathode active material supported on the casing and sealed in its own separator material is described. The separator “covers’ the cathode active material and is adhered directly to the casing. For a multiple anode design, an inner cathode foil positioned between opposed anode pellets is sealed in its own separator bag. Preferably, a polymeric restraining device prevents the anode from contacting the casing. The completed anode/cathode electrode assembly is sealed in the casing, which is filled with electrolyte thru a port. The fill port is hermetically sealed to complete the capacitor.

Abstract: A capacitor is described. A casing for the capacitor comprises a container having a face wall joined to a surrounding sidewall extending to a annular edge defining an open end of the container. An inwardly extending protrusion is located intermediate the face wall and the annular edge at the container open end. A partition plate is supported on the protrusion to thereby provide a first capacitor enclosure bounded by the face wall, the surrounding sidewall and the partition plate. A cover plate is secured to the annular edge to close the open end of the container and provide a second capacitor enclosure bounded by the partition plate, the surrounding sidewall and the cover plate. An anode, for example of tantalum, and a cathode active material, for example of ruthenium oxide, reside in capacitive association with each other inside each of the first and second capacitor enclosures. A working electrolyte is also contained in the capacitor enclosures.

Abstract: A capacitor is described. The capacitor comprises a first casing member having a first face wall extending to a first surrounding sidewall in turn extending to a first annular edge defining a first open end. A second casing member has a second face wall extending to a second surrounding sidewall in turn extending to a second annular edge defining a second open end. The second casing member is supported on the first annular edge to thereby close the first open end of the first casing member and provide a first capacitor enclosure comprising the first and second casing members in a stacked relationship. A cover is secured to the second annular edge to close the second casing member and provide a second capacitor enclosure. An anode, for example of tantalum, and a cathode active material, for example of ruthenium oxide, reside in capacitive association with each other inside each of the first and second capacitor enclosures. A working electrolyte is also contained in the capacitor enclosures.

Abstract: A capacitor having at least two side-by-side anodes with a cathode current collector disposed between the anodes and housed inside a casing is described. Cathode active material is supported on the opposed major faces of the current collector and the current collector/cathode active material subassembly is housed in a first separator envelope. The first separator envelope is positioned between the side-by-side anodes and this electrode assembly is then contained in a second separator envelope. The two anodes can be connected in parallel inside or outside casing, or they can be unconnected to each other. There is also cathode active material supported on inner surfaces of the casing in a face-to-face alignment with an adjacent one of the anodes. That way, the second separator envelope also prevents direct physical contact between the anode pellets and the cathode active material supported on the casing sidewalls.

Abstract: A wet tantalum capacitor of either a single anode design or of multiple anode configurations having cathode active material supported on the casing and sealed in its own separator material is described. The separator “covers' the cathode active material and is adhered directly to the casing. For a multiple anode design, an inner cathode foil positioned between opposed anode pellets is sealed in its own separator bag. Preferably, a polymeric restraining device prevents the anode from contacting the casing. The completed anode/cathode electrode assembly is sealed in the casing, which is filled with electrolyte thru a port. The fill port is hermetically sealed to complete the capacitor.

Abstract: Tantalum powders produced using a tantalum fiber precursor are described. The tantalum fiber precursor is chopped or cut into short lengths having a uniform fiber thickness and favorable aspect ratio. The chopped fibers are formed into a primary powder having a controlled size and shape, narrow/tight particle size distribution, and low impurity level. The primary powder is then agglomerated into an agglomerated powder displaying suitable flowability and pressability such that pellets with good structural integrity and uniform pellet porosity are manufacturable. The pellet is sintered and anodized to a desired formation voltage. The thusly created capacitor anode has a dual morphology or dual porosity provided by a primary porosity of the individual tantalum fibers making up the primary powder and a larger secondary porosity formed between the primary powders agglomerated into the agglomerated powder.

Abstract: An implantable cardioverter defibrillator (ICD) includes a communication interface operable to receive a communication signal from an external programmer. With the ICD not being in the presence of an MRI field generated by an MRI scanner, a communication signal is sent precharging a high energy storage capacitor before the patient undergoes the MRI scan. The signal also switches the ICD into an MRI mode which turns off the ICD's sensing functions detecting a dangerous ventricular arrhythmia. An operator monitors the patient's vital signs with sensors connected to the patient. If the patient does require the defibrillation shock, the operator sends a second communication signal delivering the defibrillation shock from the precharged high energy storage capacitor of the ICD. The patient can then be removed from the MRI scanner and the RF and gradient fields of the MRI scanner turned off.

Abstract: Tantalum powders produced using a tantalum fiber precursor are described. The tantalum fiber precursor is chopped or cut into short lengths having a uniform fiber thickness and favorable aspect ratio. The chopped fibers are formed into a primary powder having a controlled size and shape, narrow/tight particle size distribution, and low impurity level. The primary powder is then agglomerated into an agglomerated powder displaying suitable flowability and pressability such that pellets with good structural integrity and uniform pellet porosity are manufacturable. The pellet is sintered and anodized to a desired formation voltage. The thusly created capacitor anode has a dual morphology or dual porosity provided by a primary porosity of the individual tantalum fibers making up the primary powder and a larger secondary porosity formed between the primary powders agglomerated into the agglomerated powder.

Abstract: An economical method for manufacturing an electrode assembly of virtually any shape to fit into a similarly shaped casing without compromising volumetric efficiency is described. This is accomplished by providing an electrode assembly of multiplate anode and cathode plates that substantially match the internal shape of the casing. A layer of adhesive membrane is provided between the plates to keep them together and provide adequate alignment and spacing between electrodes. That way, no matter what shape the device being powered by the cell dictates the electrode assembly assumes, as little internal volume as possible is left unoccupied by electrode active materials.

Abstract: Tantalum powders produced using a tantalum fiber precursor are described. The tantalum fiber precursor is chopped or cut into short lengths having a uniform fiber thickness and favorable aspect ratio. The chopped fibers are formed into a primary powder having a controlled size and shape, narrow/tight particle size distribution, and low impurity level. The primary powder is then agglomerated into an agglomerated powder displaying suitable flowability and pressability such that pellets with good structural integrity and unifrom pellet porosity are manufacturable. The pellet is sintered and anodized to a desired formation voltage. The thusly created capacitor anode has a dual morphology or dual porosity provided by a primary porosity of the individual tantalum fibers making up the primary powder and a larger secondary porosity formed between the primary powders agglomerated into the agglomerated powder.

Abstract: An implantable cardioverter defibrillator (ICD) includes a communication interface operable to receive a communication signal from an external programmer. With the ICD not being in the presence of an MRI field generated by an MRI scanner, a communication signal is sent precharging a high energy storage capacitor before the patient undergoes the MRI scan. The signal also switches the ICD into an MRI mode which turns off the ICD's sensing functions detecting a dangerous ventricular arrhythmia. An operator monitors the patient's vital signs with sensors connected to the patient. If the patient does require the defibrillation shock, the operator sends a second communication signal delivering the defibrillation shock from the precharged high energy storage capacitor of the ICD. The patient can then be removed from the MRI scanner and the RF and gradient fields of the MRI scanner turned off.

Abstract: An electrolyte for activating an electrolytic or electrochemical capacitor is described. The electrolyte preferably includes a mixed solvent of water and ethylene glycol having an ammonium salt dissolved therein. An acid such as phosphoric or acetic acid is used to provide a pH of about 3 to 6. The electrolyte is particularly useful for activating a ruthenium oxide/tantalum capacitor having an anode breakdown voltage in the range of 175 to 300 volts.

Abstract: Tantalum powders produced using a tantalum fiber precursor are described. The tantalum fiber precursor is chopped or cut into short lengths having a uniform fiber thickness and favorable aspect ratio. The chopped fibers are formed into a primary powder having a controlled size and shape, narrow/tight particle size distribution, and low impurity level. The primary powder is then agglomerated into an agglomerated powder displaying suitable flowability and pressability such that pellets with good structural integrity and unifrom pellet porosity are manufacturable. The pellet is sintered and anodized to a desired formation voltage. The thusly created capacitor anode has a dual morphology or dual porosity provided by a primary porosity of the individual tantalum fibers making up the primary powder and a larger secondary porosity formed between the primary powders agglomerated into the agglomerated powder.

Abstract: Tantalum powders produced using a tantalum fiber precursor are described. The tantalum fiber precursor is chopped or cut into short lengths having a uniform fiber thickness and favorable aspect ratio. The chopped fibers are formed into a primary powder having a controlled size and shape, narrow/tight particle size distribution, and low impurity level. The primary powder is then agglomerated into an agglomerated powder displaying suitable flowability and pressability such that pellets with good structural integrity and uniform pellet porosity are manufacturable. The pellet is sintered and anodized to a desired formation voltage. The thusly created capacitor anode has a dual morphology or dual porosity provided by a primary porosity of the individual tantalum fibers making up the primary powder and a larger secondary porosity formed between the primary powders agglomerated into the agglomerated powder.