Wilson Greatbatch Ltd.

Wilson Greatbatch Technologies, Inc.

Marcus J Palazzo

Esther S Takeuchi

Hong Gan

Randolph A Leising

It is known that reforming implantable defibrillator capacitors at least partially restores and preserves their charging efficiency. An industry-recognized standard is to reform implantable capacitors by pulse discharging the connected electrochemical cell about once every three months throughout the useful life of the medical device. A Li/SVO cell typically powers such devices. The present invention relates to methodologies for significantly minimizing, if not entirely eliminating, the occurrence of voltage delay and irreversible Rdc growth in the about 35% to 70% DOD region by subjecting Li/SVO cells to novel discharge regimes. At the same time, the connected capacitors in the cardiac defibrillator are reformed to maintain them at their rated breakdown voltages.

Electrochemical treatment method to reduce voltage delay and cell resistance in lithium/silver vanadium oxide cells

The current invention relates to the preparation of an improved cathode active material for non-aqueous lithium electrochemical cell. In particular, the cathode active material comprises &egr;-phase silver vanadium oxide prepared by using a &ggr;-phase silver vanadium oxide starting material. The reaction of &ggr;-phase SVO with a silver salt produces the novel &egr;-phase SVO possessing a lower surface area than &egr;-phase SVO produced from vanadium oxide (V O ) and a similar silver salt as starting materials. Consequently, the low surface area &egr;-phase SVO material provides an advantage in greater long term stability in pulse dischargeable cells.

Silver vanadium oxide having low internal resistance and method of manufacture

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 heat treated polyamic acid with PVDF. The use of heat treated polyamic acid 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.

Electrochemical cell having an electrode of silver vanadium oxide coated to a current collector

A mixture of polymeric binders that is insoluble in nonaqueous organic electrolytes activating alkali metal or alkali metal ion electrochemical cells, is described. The mixed binder formulation provides electrodes that are flexible and non-brittle, and cells incorporating the electrodes are dischargeable at elevated temperatures. A preferred binder formulation is a mixture of polyvinylidene and polyimide binders.

Use of heat-treated electrodes containing a polyamic acid-PVDF binder mixture

The present invention relates to an improved method for synthesizing unsymmetric linear organic carbonates comprising the reaction of two symmetric dialkyl carbonates, R.sup.1 and R.sup.2, in the presence of a nucleophilic reagent or an election donating reductant as a catalyst, wherein R.sup.1 and R.sup.2 can be either saturated or unsaturated alkyl or aryl groups, is described. The presence invention further provides a preparation method for a nonaqueous organic electrolyte having an unsymmetric linear organic carbonate as a co-solvent.

Method for preparing nonaqueous electrolytes for alkali ion

The present invention relates to an improved method of synthesizing unsymmetric linear organic carbonates comprising the reaction of two symmetric dialkyl carbonates, R.sup.1 and R.sup.2, in the presence of a nucleophilic reagent or an election donating reductant as a catalyst, wherein R.sup.1 and R.sup.2 can be either saturated or unsaturated alkyl or aryl groups, is described. The present invention further provides a preparation method for a nonaqueous organic electrolyte having an unsymmetric linear organic carbonate as a co-solvent.

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Niagara Falls, NY, United States of America

Marcus J Palazzo