Abstract: 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.

Abstract: The use of an increased cathode weight and thickness or basis weight in a primary electrochemical cell for the purpose of reducing DC resistance (Rdc) is described. This is particularly important when the cell is subjected to high rate discharge conditions of the type typically required for medical device applications, such as activating a cardiac defibrillator. A preferred couple is of a lithium/silver vanadium oxide (Li/SVO) cell or a lithium/copper silver vanadium oxide (Li/CSVO) cell. Reducing cell Rdc by increasing basis weight has the added benefit of increasing the cell's energy density through comparatively greater amounts of active cathode material in a give casing volume.

Abstract: 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 Li+ ion 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.

Abstract: 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.

Abstract: 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 (V2O5) 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 (V2O5) 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.

Abstract: 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.

Abstract: 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.