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 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 battery pack having a first secondary cell and a second secondary cell, preferably of a non-aqueous chemistry, is described. Each secondary cell has a discharge capacity and an internal resistance to a direct charge current. To diminish and alleviate problems associated with extended cycling of battery packs, the internal resistance to the direct charge current and the discharge capacity of each secondary cell is substantially matched. Thereby, the battery packs have longer running voltages and increased energy density.

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 new cathode design having a second cathode active material of a relatively high energy density but of a relatively low rate capability sandwiched between two current collectors with a first cathode active material having a relatively low energy density but of a relatively high rate capability in contract with the opposite sides of the two current collectors, is described. At least the first cathode active material is of particles having an average diameter less than about 1&mgr;. The present cathode design is useful for powering an implantable medical device requiring a high rate discharge application.

Abstract: The invention is directed to an electrochemical cell having at least one of its electrodes produced by coating a slurry mixture of an active material, possibly a conductive additive, and a binder dispersed in a solvent and contacted to a perforated current collector foil. It is particularly important that the active slurry does not move through the perforations of the current collector. For this reason, a barrier is placed against the opposite side of the current collector to block the perforations as the current collector is being coated with the slurry. After volatilizing the solvent, a second, different active material is coated to the opposite side of the current collector, either as a slurry, a pressed powder, a pellet or a free standing sheet. An example of this is a cathode having a configuration of: SVO/current collector CFx. The opposed active materials on the current collector can also be of the same chemistry.

Abstract: The minimization or elimination of swelling in lithium cells containing CFx as part of the cathode electrode and discharged under high rate applications is described. When CFx 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.

Abstract: The present invention is directed to providing a lithium carbonate passivation layer on lithium through exposure of the active material to gaseous carbon dioxide prior to cell assembly. This results in an electrochemical cell which possesses improved safety and voltage delay characteristics in comparison to prior art cells comprising unexposed lithium. The preferred cell is of a lithium oxyhalide chemistry.

Abstract: An autoclavable elctrochemical cell which may be used in an implantable medical device. The anode active material is lithium or other material from groups IA and IIA of the Periodic Table and having a melting point greater than about 150 degrees C. The cathode active material is silver vanadium oxide or other metal oxide or carbon monoflouride. The solvent for the electrolyte has a boiling point greater than about 100 degrees C. and a dielectric constant greater than about 5 so that the cell. may be dimensionally and chemically stable during repeated exposures of about one hour each to the autoclaving temperatures.

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 accurately determining the precise boundaries of voltage delay and irreversible Rdc growth region in the about 25% to 70% DOD region so that more frequent pulse discharging for the purpose of cell reform is confined to the limits of the region. At the same time, the connected capacitors in the cardiac defibrillator are reformed to maintain them at their rated breakdown voltages.

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 hermetically sealed coin cell is described. The coin cell has the opposite polarity terminals isolated from one another by a glass-to-metal seal. Glassing a conductive disc inside a ring of greater diameter and height forms this seal. The height of the ring is equivalent to the desired height of the cell. The disc acts as one cell terminal, which can be positive or negative, and the ring serves as the other terminal. In plan view, both terminals are on the same side of the cell. This allows for easy mounting and connection to an electric circuit board, and the like.

Abstract: An alkali metal/solid cathode electrochemical cell, such as of a Li/SVO couple, having the cathode material supported on a titanium current collector screen coated with a carbonaceous material is described. The thusly-coated titanium current collector provides the cell with higher rate capability in comparison to cells of a similar chemistry having the cathode active material contacted to an uncoated titanium current collector.

Abstract: 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.

Abstract: A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one carbonate additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture including ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate. The preferred additive is either a linear or cyclic carbonate containing covalent O—X and O—Y bonds on opposite sides of a carbonyl group wherein at least one of the O—X and the O—Y bonds has a dissociation energy less than about 80 kcal/mole.

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: An alkali metal secondary electrochemical cell, and preferably a lithium ion cell, activated with an equilibrated quaternary solvent system, is described. The solvent system comprises a mixture of dialkyl carbonates and cyclic carbonates, and preferably a quaternary mixture of dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate and ethylene carbonate with dimethyl carbonate, diethyl carbonate and ethylmethyl carbonate in an equilibrated molar mixture. Lithium ion cells activated with this electrolyte have good room temperature cycling characteristics and excellent low temperature discharge behavior.

Abstract: The invention includes a method of using a cell, such as a battery. In a method according to the invention, the cell is charged, discharged, and a voltage of the cell is measured after the discharge period. The measured voltage is compared to a standard voltage, and then the cell is charged again.

Abstract: 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.