Greatbatch Ltd.

Marcus J Palazzo

Robert S Rubino

Joseph M Lehnes

Ho-Chul Yun

William C Thiebolt

Mark J Roy

Ashish Shah

David M Spillman

David Dianetti

Daniel Baumer

Esther S Takeuchi

Randolph A Leising

Lasantha Viyannalage

David Wutz

Paul W Krehl

Ho Chul Yun

Joshua C Ulrich

Jared Arellano

Daniel M Baumer

A miniature electrochemical cell of a primary or secondary chemistry with a total volume that is less than 0.5 cc is described. The cell casing comprises an annular sidewall connected to a base plate opposite an upper lid. A sealing glass forms a hermetic glass-to-ceramic seal with a dielectric material contacting a lower portion of the annular sidewall and a glass-to-metal seal with the base plate. Since the glass seals against three surfaces of the annular sidewall, which are the inner and outer sidewall surfaces adjacent to the lower edge, the glass seal is robust enough to withstand the heat generated when the lid is welded to the upper edge of the annular sidewall. The lid has a sealed electrolyte fill port that is axially aligned with an annulus residing between the inner surface of the annular sidewall and the electrode assembly.

Electrochemical cell casing having an annular sidewall secured to a base plate by a ceramic-to-glass-to-metal seal

A miniature electrochemical cell of a primary or a secondary chemistry with a total volume that is less than 0.5 cc is described. The cell has a casing comprising an annular sidewall supported on a lower plate opposite an upper closure plate. The upper plate has a sealed electrolyte fill port. A current collector having an opening aligned with the fill port contacts an inner surface of the upper plate. An anode active material contacts the lower plate, and a cathode active material contacts the upper closure plate. A dielectric material coats the lower open end of the annular sidewall and a portion of the inner surface of the sidewall. A glass seals the dielectric material to the lower plate. An electrolyte contacts the electrode assembly. The cathode active material contacting the current collector has an opening aligned with the current collector opening and the electrolyte fill port.

Electrochemical cell activated with a liquid electrolyte wetting the electrode assembly through an opening in one of the electrodes

A miniature electrochemical cell of a primary or secondary chemistry with a total volume that is less than 0.5 cc is described. The cell has a casing comprising an annular sidewall supported on a lower plate opposite an upper lid. The lid has a sealed electrolyte fill port. At least one electrolyte channel in the inner surface of the lid extends radially from the fill port and outwardly beyond an outer peripheral edge of the current collector. A current collector contacts an inner surface of the lid with a first electrode active material contacting the current collector. An opposite polarity active material contacts the lower plate. A dielectric material coats the lower open end of the annular sidewall and a portion of the inner surface of the sidewall. A glass seals the dielectric material to the lower plate. An electrolyte activates the electrode assembly.

Electrochemical cell activated with a liquid electrolyte wetting the electrode assembly through a channel system in the casing lid

An electrochemical cell having a casing housing an electrode assembly of a separator residing between a lithium anode and a cathode comprising silver vanadium oxide and fluorinated carbon is described. The electrode assembly is activated with a nonaqueous electrolyte comprising a lithium salt dissolved in a solvent system of propylene carbonate mixed with 1,2-dimethoxyethane, dibenzyl carbonate (DBC), lithium bis(oxalato)borate (LiBOB), and fluoroethylene carbonate (FEC). Preferably DBC is present in an amount ranging from about 0.005 moles (M) to about 0.25M, LiBOB is present in an amount ranging from about 0.005 wt. 5 to about 5 wt. %, and FEC is present in an amount ranging from about 0.01 wt. % to about 10 wt. %. This electrolyte formulation is more conductive than the conventional or prior art binary and ternary solvent system electrolytes while being chemically and electrochemically stable toward Li/SVO cells, Li-SVO/CFmixture cells, and Li-SVO/CFsandwich cathode primary electrochemical cells.

Lithium electrochemical cell activated with an electrolyte containing DBC, LiBOB and FEC additives

An electrochemical cell having a casing housing an electrode assembly of a separator residing between a lithium anode and a cathode comprising silver vanadium oxide and fluorinated carbon is described. The electrode assembly is activated with a nonaqueous electrolyte comprising a lithium salt dissolved in a solvent system of propylene carbonate mixed with 1,2-dimethoxyethane, lithium bis(oxalato)borate (LiBOB), and fluoroethylene carbonate (FEC). Preferably LiBOB is present in an amount ranging from about 0.005 wt. 5 to about 5 wt. %, and FEC is present in an amount ranging from about 0.01 wt. % to about 10 wt. %. This electrolyte formulation is more conductive than the conventional or prior art binary and ternary solvent system electrolytes while being chemically and electrochemically stable toward Li/SVO cells, Li-SVO/CFmixture cells, and Li-SVO/CFsandwich cathode primary electrochemical cells.

Lithium electrochemical cell activated with an electrolyte containing LiBOB and FEC additives

A current collector for an electrochemical cell is described. Unlike conventional current collector designs, the current collector does not have an unperforated perimeter frame completely bordering or surrounding a perforated interior region. Instead, only that portion of the current collector adjacent to the connector tab is unperforated. Otherwise, perforations extend directly to the perimeter edge.

Foil-type current collector having an unperforated strip at the connector tab

A lithium electrochemical cell with increased energy density is described. The electrochemical cell comprises an improved sandwich cathode design with a second cathode active material of a relatively high energy density but of a relatively low rate capability sandwiched between two current collectors and with a first cathode active material having a relatively low energy density but of a relatively high rate capability in contact with the opposite sides of the two current collectors. In addition, a cathode fabrication process is described that increases manufacturing efficiency. The cathode fabrication process comprises a process in which first and second cathode active materials are directly applied to opposite surfaces of a perforated current collector and laminated together. The present cathode design is useful for powering an implantable medical device requiring a high rate discharge application.

Sandwich cathode lithium battery with high energy density

The present invention related to an electrochemical cell comprising an anode of a Group IA metal and a cathode of a composite material prepared from an aqueous mixture of iron sulfate, cobalt sulfate and sulfur. The cathode material of the present invention provides an increased rate pulse performance compared to iron disulfide cathode material. This makes the cathode material of the present invention particularly useful for implantable medical applications.

Method for providing a high capacity cathode material with improved rate capability performance

The present invention relates to an electrochemical cell comprising an anode of a Group IA metal and a cathode of a composite material prepared from an aqueous mixture of iron sulfate, nickel sulfate, and sulfur. The cathode material of the present invention provides for a lithium electrochemical cell having an increased operating voltage and power performance with high discharge capacity as compared to a lithium cell comprising nickel disulfide cathode material. In addition, the cathode material of the present invention exhibits a smaller initial irreversible voltage loss as compared to iron disulfide. This makes the cathode material of the present invention particularly useful for implantable medical applications.

High capacity cathode material with improved operating voltage

The prevention of lithium clusters from bridging between the negative and positive portions of a cell during discharge is described. This is done by providing a glass wool material at an intermediate location between the casing and anode current collector of a negative polarity and the cathode current collector and the terminal pin being of a positive polarity. Typically, a lithium ion concentration gradient sufficient to cause lithium cluster formation is induced by the high rate, intermittent discharge of a lithium/silver vanadium oxide (Li/SVO) cell. However, sufficient free electrolyte necessary for normal cell function is held in the relatively large pore volume throughout the extent of the glass wool material. Moreover, permeability within the glass wool material is tortuous, which effectively increases the distance between the negative and positive surfaces of the anode and cathode. This tortuosity effectively stops 'straight line' dendrite growth of lithium clusters between opposite polarity structures inside the casing.

Internal insulation design using porous material for an electrochemical cell

The invention is directed to an SVO electrochemical cell having high rate capability. The cathode is produced by coating a mixture of an active material, conductive additives, a mixed binder, and an aluminum foil current collector. The mixed binder consists of a mixture of styrene butadiene with PVDF. The use of the styrene butadiene maintains adhesion to the conductive current collector while the PVDF portion of the binder gives flexibility. A particularly preferred couple is of a lithium/silver vanadium oxide (Li/SVO) chemistry and the binder mixture enables an active slurry of SVO to be coated onto a current collector without delamination.

Development of mixed binder system for primary cell cathodes

The prevention of lithium clusters from bridging between the negative and positive portions of a cell during discharge is described. This is done by limiting the amount of electrolyte in the cell, thereby eliminating excess electrolyte pooling above the cell stack. It is in this excess electrolyte that a relatively higher Liion concentration can occur, creating an anodically polarized region resulting in the reduction of lithium ions on the negative and positive surfaces as the concentration gradient is relaxed. Typically, a lithium ion concentration gradient sufficient to cause lithium cluster formation is induced by the high rate, intermittent discharge of a lithium/silver vanadium oxide (Li/SVO) cell.

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Wheatfield, NY, United States of America

Marcus J Palazzo