Abstract: The present invention relates to a new sandwich cathode design having two cathode active materials provided on opposite sides of a current collector. The respective active materials are similar in terms of, for example, their rate capability, their energy density, or some other parameter. However, one material may have an advantage over the other in one characteristic, but is disadvantageous in another. The cathode is built in a sandwich configuration having a first one of the active materials sandwiched between two current collectors. Then, the second active material is provided in contact with at least the other side of one of the current collectors, and preferably facing the anode. An exemplary cathode has the following configuration: MnO2/current collector/SVO/current collector/MnO2.

Abstract: A new sandwich negative electrode design for a secondary cell is provided comprising a “sacrificial” alkali metal along with a carbonaceous anode material. In the case of a hard carbon anode material, the sacrificial alkali metal is preferably lithium and is sized to compensate for the initial irreversible capacity of this anode material. Upon activating the cells, the lithium metal automatically intercalates into the hard carbon anode material. That way, the sacrificial lithium is consumed and compensates for the generally unacceptable irreversible capacity of hard carbon. The superior cycling longevity of hard carbon now provides a secondary cell of extended use beyond that know for conventional secondary cells having only graphitic anode materials.

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: The negative electrode or anode for a secondary electrochemical cell comprising a mixture of graphite or “hairy carbon” and a lithiated metal oxide, a lithiated mixed metal oxide or a lithiated metal sulfide, and preferably a lithiated metal vanadium oxide, is described. A most preferred formulation is graphite mixed with lithiated silver vanadium oxide or lithiated copper silver vanadium oxide.

Abstract: The present comprises an electrode having the configuration: first active material/current collector screen/second active material. When one of the active materials is in a powder form, it is possible for that material to move through openings in the current collector screen to “contaminate” the interface between the other active material and the current collector. The present invention consists of having the other electrode active materials in a form incapable of moving through the current collector to the other side thereof. Then, the assembly is pressed from the direction of the other electrode active material. This seals off the current collector as the pressing force moves the current collector against the powdered electrode active material.

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 25% 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: 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: An electrochemical cell comprising an anode of a Group IA metal and a cathode of a mixed phase metal oxide prepared from a combination of starting materials comprising vanadium oxide and a mixture of at least one of a decomposable silver-containing constituent and a decomposable copper-containing constituent is described. The starting materials are mixed together to form a homogeneous admixture that is not further mixed once decomposition heating begins. The resulting cathode material is particularly useful for implantable medical applications.

Abstract: A new sandwich cathode design having a first cathode active material of a relatively low energy density but of a relatively high rate capability sandwiched between two current collectors and with a second cathode active material having a relatively high energy density but of a relatively low rate capability in contact with the opposite sides of the two current collectors, is described. The present cathode design is relatively safer under short circuit and abuse conditions than cells having a cathode active material of a relatively high rate density but a relatively low energy capability alone. A preferred cathode is: CFx/current collector/SVO/current collector/CFx. The SVO provides the discharge end of life indication since CFx and SVO cathode cells discharge under different voltage profiles. This is useful as an end-of-replacement indicator (ERI) for an implantable medical device, such as a cardiac pacemaker.

Abstract: A new sandwich cathode design is provided having a first cathode structure of a first cathode active material of a relatively low energy density but of a relatively high rate capability, for example SVO, mixed with a second cathode active material having a relatively high energy density but a relatively low rate capability, for example CFx, with the percentage of SVO being less than that of CFx and sandwiched between two current collectors. Then, a second cathode mixture of SVO and CFx active materials is contacted to the outside of the current collectors. However, the percentage of SVO to CFx is greater in the second structure than in the first. Such an exemplary cathode design might look like: (100−y)% SVO+y% CFx, wherein 0≦y≦100/current collector/(100−x)% SVO+x% CFx, wherein 0≦x≦100/current collector/(100−y)% SVO+y% CFx, wherein 0≦y≦100, and wherein the ratio of x to y is selected from the group consisting of y<x, x<y and x=y.

Abstract: An improved cathode material for nonaqueous electrolyte lithium electrochemical cell is described. The preferred active material is &egr;-phase silver vanadium oxide (Ag2V4O11) coated with a protective layer of a metal oxide, preferably &ggr;-phase SVO (Ag1.2V3O1.8). The SVO core provides high capacity and rate capability while the protective coating reduces reactivity of the active particles with electrolyte to improve the long-term stability of the cathode.

Abstract: An electrochernical cell comprising an anode of a Group IA metal and a cathode of a mixed phase metal oxide prepared from a combination of starting materials comprising vanadium oxide and a mixture of at least one of a decomposable silver-containing constituent and a decomposable copper-containing constituent is described. The starting materials are mixed together to form a homogeneous admixture that is not further mixed once decomposition heating begins. The resulting cathode material is particularly useful for implantable medical applications.

Abstract: An electrochemical cell comprising a medium rate electrode region intended to be discharged under a substantially constant drain and a high rate electrode region intended to be pulse discharged, is described. Both electrode regions share a common anode and are activated with the same electrolyte.

Abstract: A new sandwich cathode design is provided comprising a cathode active material mixed with a binder and a conductive diluent in at least two differing formulations. The formulations are then individually pressed on opposite sides of a current collector, so that both are in direct contact with the current collector. Preferably, the active formulation on the side of the current collector facing the anode is of a lesser percentage of the active material than that on the opposite side of the current collector. Such an exemplary cathode design might look like: SVO (100-x % active)/current collector/SVO (100-y % active)/current collector/SVO (100-x % active), wherein x is greater than y.

Abstract: A new sandwich cathode design is provided comprising a cathode active material provided in at least two different thicknesses. The different thickness cathode structures are then individually pressed on opposite sides of a current collector so that both are in direct contact with the substrate. Preferably, the cathode structure on the side facing the anode is of a lesser thickness than that on the opposite side of the current collector. Such an exemplary cathode design might look like: SVO(x)/current collector/SVO(y)/current collector/SVO(z), wherein x, y and z represent thicknesses and wherein x and z are lesser than y.

Abstract: A method for powering an implantable medical device with a lithium electrochemical cell having a sandwich cathode electrode of SVO/CFx/SVO active materials is described. A preferred cathode is of a &ggr;-SVO/CFx/&ggr;-SVO or (&ggr;+&egr;)-SVO/CFx/(&ggr;+&egr;)-SVO sandwich configuration.

Abstract: A rechargeable lithium-ion cell capable of being discharged to deliver high power pulses sufficient for implantable defibrillation applications and the like, is described. The cell is housed in a casing having an external volume of 5 cm3, or less. Both the negative and positive electrodes are less than about 0.15 mm in total thickness. Negative and positive electrodes of a reduced thickness provide the cell with high electrode surface area relative to its volume. As such, the present cell is capable of providing pulses in excess of 30C with minimal voltage drop.

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: A lithium ion secondary battery having an irregular shape with a unitary anode and unitary cathode that are spirally wound and that provide a high energy density for an implantable biomedical device.

Abstract: An electrode configuration for use in a defibrillator battery to improve the battery capacity and its utilization efficiency by using a combination SVO cell and a CFx cell discharged in parallel, is described. In other words, the anode of the SVO cell is connected to the anode of the CFx cell and the cathode of the SVO cell is connected to the cathode of the CFx cell. The SVO cell provides a relatively high discharge rate while the CFx cell results in long service life. This results in 100% of the usable capacity from both cells being utilized.