Wilson Greatbatch Ltd.

Greatbatch Ltd.

Wilson Greatbatch Technologies, Inc.

Sally Ann Smesko

Esther S Takeuchi

W Richard Brown

Christine A Frysz

Peter A Kreidler

Hong Gan

Mark J Roy

Steven J Ebel

Bruce Platt

Eric Ziarniak

William M Paulot

Joseph M Probst

Steven Davis

Karen Nuwer

William B Paulot

Steven M Davis

A lithium/fluorinated carbon electrochemical cell having the CFmaterial supported on a titanium current collector screen sputter coated with a noble metal is described. The gold, iridium, palladium, platinum, rhodium and ruthenium-coated titanium current collector provides the cell with higher rate capability, even after exposure to high temperatures, in comparison to cells of a similar chemistry having the CFcontacted to a titanium current collector painted with a carbon coating.

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Nickel-based alloys are provided for use as a positive electrode current collector in a solid cathode, nonaqueous liquid electrolyte, alkali metal anode active electrochemical cell. The nickel-based alloys are characterized by chemical compatibility with aggressive cell environments, high corrosion resistance and resistance to fluorination and passivation at elevated temperatures, thus improving the longevity and performance of the electrochemical cell. The cell can be of either a primary or a secondary configuration.

Nickel-based alloys as positive electrode support materials in electrochemical cells containing nonaqueous electrolytes

A titanium substrate having a thickened outer oxidation layer provided thereon by a treatment process performed either in an air atmosphere at elevated temperatures or through electrolytic oxidation (anodization), is discribed. The thusly conditioned titanium substrate serving as a cathode current collector for an electrode incorporated into an electrochemical cell exhibits improved electrical performance in comparison to the prior art techniques, i.e., electrically conducted carbon coated titanium screen and use of highly corrosion resistant materials, upon subsequent elevated temperature exposure.

Oxidized titanium as a cathodic current collector

The minimization or elimination of swelling in lithium cells containing CF as part of the cathode electrode and discharged under high rate applications is described. When CF materials are synthesized from fibrous carbonaceous materials, in comparison to petroleum coke, cell swelling is greatly reduced, and in some cases eliminated. Preferred precursors are carbon fibers and MCMB.

Control of cell swelling by the proper choice of carbon monofluoride (CFx) cathode materials in high rate defibrillator cells

An electrode having the configuration: first active material/current collector/second active material is described. One of the electrode active materials in a cohesive form of active particles being firmly held together as part of the same mass is incapable of moving through the current collector to the other side thereof. However, in an un-cohesive form of active particles not being firmly held together as part of a mass, the one electrode active material is capable of communication through the current collector. The other or second active material is in a form in-capable of communication through the current collector, whether it is in a cohesive or un-cohesive powder form. Then, the assembly of first active material/current collector/second active material is pressed from either the direction of the first electrode active material to the second electrode active material, or visa versa.

Pellet process for double current collector screen cathode preparation

Cobalt-based alloys are provided for use as a positive electrode current collector in a solid cathode, nonaqueous liquid electrolyte, alkali metal anode active electrochemical cell. The cobalt-based alloys are characterized by chemical compatibility with aggressive cell environments, high corrosion resistance and resistance to fluorination and passivation at elevated temperatures, thus improving the longevity and performance of the electrochemical cell. The cell can be of either a primary or a secondary configuration.

Cobalt-based alloys as positive electrode current collectors in nonaqueous electrochemical cells

An alkali metal/solid cathode electrochemical cell, particularly a Li/CF cell, having an electrolyte-to-cathode (E/C) weight ratio of about 0.938 to about 0.73, and an anode-to-cathode (A/C) capacity ratio of about 1.03, is described. This provides the cell with an improvement in terms of delivered capacity of about 6% to about 15% under a 1 kohm discharge load, and of about 2% to about 5% under a 2 kohm load in comparison to prior art Li/CF cells. Fabricating the cathode electrode at such high pressures was not previously thought possible.

Enhanced capacity Li/CFx electrochemical cell

The present invention is directed to a novel electrode edge having a full radius shape used in combination with a novel terminal lead/current collector connection to increase both the gravimetric and volumetric energy densities of the cell by occupying previously unused space within the casing.

Electrode edge design

A combination separator comprising a single layer of a non-woven, polyolefinic cloth superposed with a single layer of a polyolefinic, microporous film for use in an electrochemical cell, is described. A preferred polyolefinic material for both the non-woven cloth and the microporous film is polypropylene. The redundancy of using two layers of separator is an enhanced safety characteristic of the cell; however, the use of the polypropylene web/film combination adds another dimension to the cell's safety characteristics by imparting the benefits of each type of material.

Separator for nonaqueous electrochemical cells

An alkali metal/solid cathode electrochemical cell, particularly a Li/CF.sub.x cell, having an electrolyte-to-cathode (E/C) weight ratio of about 0.94 to 0.96, and an anode-to-cathode (A/C) capacity ratio of about 1.03, is described. These ratios provide the cell with an improvement of about 6.7% in terms of volumetric energy density and about 11.9% in terms of gravimetric energy density over prior art Li/CF.sub.x cells.

Alkali metal electrochemical cell with improved energy density

An alkali metal electrochemical cell having the cathode comprising at least two distinct active mixtures having differing formulations of a discharge promoter component mixed with electrode active material, is described. The active mixture contacting the current collector has a greater percentage of the discharge promoter component than the remainder of the cathode, and a preferred electrode active material is fluorinated carbon.

Electrochemical cell having a cathode comprising differing active

Battery-powered implantable medical devices require a suitable method for indicating end-of-service of the power source so that there is ample time for elective replacement of the device and/or power source. The present invention utilizes mixed cathode materials preferably comprising a major portion of a fluorinated carbon and a minor portion of a metal-containing material. This mixed cathode formulation is characterized by two, discretely different operating voltages, the second of which may be used as an end-of-life indicator.

Mixed cathode formulation for achieving end-of-life indication

Heat treating the inner, contact surface of an electrochemical cell casing in an oxidizing atmosphere such as air to render the inner surface thereof essentially contamination free and suitable as a current collector, is described. The casing is preferably of stainless steel and houses the alkali metal-halogen couple in a case-positive configuration. The oxidized cases are ready for cell assembly upon cooling and cell electrical performance is maintained without the need for wet chemical treatment of any kind.

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North Tonawanda, NY, United States of America

Sally Ann Smesko