Abstract: An electrochemical cell comprising a lithium anode, a cathode comprising a blank cut from a free-standing sheet of a silver vanadium oxide mixture contacted to a current collector. The active material has having a relatively lower surface area and an electrolyte activating the anode and the cathode is described. By optimizing the cathode active material surface area in a SVO-containing cell, the magnitude of the passivating film growth at the solid-electrolyte interphase (SEI) and its relative impermeability to lithium ion diffusion is reduced. Therefore, by using a cathode of an active material, in a range of from about 0.2 m2/gram to about 2.6 m2/gram, and preferably from about 1.6 m2/gram to about 2.4 m2/gram, it is possible to eliminate or significantly reduce undesirable irreversible Rdc growth and voltage delay in the cell and to extend its useful life in an implantable medical device.

Abstract: A new design for a cathode having a configuration of: SVO/first current collector/CFx/second current collector/SVO is described. The two cathode current collectors are vertically aligned one on top of the other in a middle region or zone of the cathode. This coincides to where a winding mandrel will be positioned to form a wound electrode assembly with an anode. The overlapping region of the two current collectors helps balance the expansion forces of the exemplary SVO and CFx active material layers. This, in turn, helps maintain a planar cathode that is more amenable to downstream processing. The use of two current collectors on opposite sides of an intermediate cathode active material also provides for enhanced reliability when cathodes are wound from the center as they lend structural integrity to outer portions of the wind.

Abstract: An electrochemical cell comprising a lithium anode, a cathode comprising a blank cut from a free-standing sheet of a silver vanadium oxide mixture contacted to a current collector. The active material has having a relatively lower surface area and an electrolyte activating the anode and the cathode is described. By optimizing the cathode active material surface area in a SVO-containing cell, the magnitude of the passivating film growth at the solid-electrolyte interphase (SEI) and its relative impermeability to lithium ion diffusion is reduced. Therefore, by using a cathode of an active material in a range of from about 0.2 m2/gram to about 2.6 m2/gram, and preferably from about 1.6 m2/gram to about 2.4 m2/gram, it is possible to eliminate or significantly reduce undesirable irreversible Rdc growth and voltage delay in the cell and to extend its useful life in an implantable medical device.

Abstract: An electrochemical cell comprising an anode, and a cathode of a first cathode active material contacted to a first side of a current collector and a second cathode active material contacted to a second side of the current collector thereby forming an elongated cathode sheet. The first cathode active material has a first energy density and first rate capability, and the second cathode active material has a second energy density and a second rate capability. The first energy density of the first material is less than the second energy density of the second material, while the first rate capability of the first material is greater than the second rate capability of the second material. The elongated cathode sheet is folded onto itself to form a sandwich cathode having the configuration of: first cathode active material/current collector/second cathode active material/second cathode active material/current collector/first cathode active material.

Abstract: A new cathode design is provided comprising a cathode active material mixed with a binder and a conductive diluent in at least two differing formulations. Each of the formulations exists as a distinct cathode layer. After each layer is pressed or sheeted individually, a first one of the layers is contacted to a current collector. The other layer is then contacted to the opposite side of the layer contacting the current collector. Therefore, by using electrodes comprised of layers, where each layer is optimized for a desired characteristic (i.e. high capacity, high power, high stability), the resulting battery will display improved function over a wide range of applications. Such an exemplary cathode is comprised of: SVO (100?x %)/SVO (100?y %)/current collector/SVO (100?y %)/SVO (100?x %), wherein x and y are different and represent percentages of non-active materials.

Abstract: An electrochemical cell comprising a lithium anode, a silver vanadium oxide cathode having a relatively lower basis weight, and an electrolyte activating the anode and the cathode is described. By limiting the amount of cathode active material per unit area (i.e. basis weight) facing the anode in the Li/SVO cell, the magnitude of the passivating film growth at the solid-electrolyte interphase (SEI) and its relative impermeability to lithium ion diffusion is reduced. Therefore, by using a cathode of a relatively low basis weight active material, it is possible to eliminate or significantly reduce undesirable irreversible Rdc growth and voltage delay in the cell and to extend its useful life in an implantable medical device.

Abstract: A new design for a cathode having a configuration of: SVO/first current collector/CFx/second current collector/SVO is described. The two cathode current collectors are vertically aligned one on top of the other in a middle region or zone of the cathode. This coincides to where a winding mandrel will be positioned to form a wound electrode assembly with an anode. The overlapping region of the two current collectors helps balance the expansion forces of the exemplary SVO and CFx active material layers. This, in turn, helps maintain a planar cathode that is more amenable to downstream processing. The use of two current collectors on opposite sides of an intermediate cathode active material also provides for enhanced reliability when cathodes are wound from the center as they lend structural integrity to outer portions of the wind.

Abstract: A new design for a cathode having a configuration of: SVO/first current collector/CFx/second current collector/SVO is described. The two cathode current collectors are vertically aligned one on top of the other in a middle region or zone of the cathode. This coincides to where a winding mandrel will be positioned to form a wound electrode assembly with an anode. The overlapping region of the two current collectors helps balance the expansion forces of the exemplary SVO and CFx active material layers. This, in turn, helps maintain a planar cathode that is more amenable to downstream processing. The use of two current collectors on opposite sides of an intermediate cathode active material also provides for enhanced reliability when cathodes are wound from the center as they lend structural integrity to outer portions of the wind.

Abstract: An electrochemical cell comprising an electrode, whether it is the cathode of a primary cell or an anode or a cathode of a secondary cell, comprised of a mixture of a robust, high temperature binder along with a sacrificial decomposable polymer is described. The robust binder remains in the electrode throughout formation and processing, and maintains adhesion and cohesion of the cathode during utilization. The sacrificial decomposable polymer is present during the electrode formation stage. However, it is decomposed via a controlled treatment prior to electrode utilization. Upon subsequent high pressure pressing, the void spaces formerly occupied by the sacrificial polymer provides sites where the electrode active material collapses into a tightly compressed mass with enhanced particle-to-particle contact between the active material particles. For a cathode in a primary cell, for example a Li/SVO cell, the result is believed to be improved rate capability, capacity and stability throughout discharge.

Abstract: Improvements in the performance of lithium electrochemical cells comprising a first cathode active material of a relatively high energy density but of a relatively low rate capability, for example CFx, contacted to one side of a current collector and with a second cathode active material having a relatively low energy density but of a relatively high rate capability, for example SVO, contacted to the opposite current collector side are described. An exemplary cathode has the configuration: SVO/first current collector/CFx/second current collector/SVO, and wherein the anodic coulombic capacity does not exceed the total coulombic capacities of the SVO and CFx by greater than 25%. Manganese oxide (MnO2) is another typically used cathode active material in lieu of SVO, and the present invention is applicable to lithium cells of that system as well.

Abstract: An improved cathode material for nonaqueous electrolyte lithium electrochemical cell is described. The preferred active material is silver vanadium oxide (SVO) coated with a protective layer of an inert metal oxide (MxOy) or lithiated metal oxide (LixMyOz). A preferred coating method is by a sol-gel process. 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 electrochemical cell comprising a lithium anode and a fluorinated silver vanadium oxide cathode activated with a nonaqueous electrolyte is described. The fluorinated silver vanadium oxide is of the formula Ag4V2O11-xFx, wherein x ranges from about 0.02 to about 0.3.

Abstract: Heat generation is an important concern of electrochemical cell design. The invention is directed toward a cell design that efficiently and responsively dissipates heat by transfer from the cell to the casing through multiple parallel connections. This invention relates to battery designs having cell stacks in which both the anode and cathode are of a plate structure and the anode plates are independently connected to the cell casing or connected thereto via a bridge or bus. They may also consist of cell assemblies of wound electrode configurations or plate-serpentine configurations having multiple parallel connections to the cell casing.

Abstract: An electrochemical cell comprising a casing, an anode comprising anode active material, a cathode, and an electrolyte solution activating the cathode and the anode is described. In one embodiment, the cathode is comprised of a first current collector, first and second sheets of a first cathode active material in contact with the first current collector, a second current collector, third and forth sheets of the first cathode active material in contact with the second current collector, and a first sheet of a second cathode active material in non-adherent and congruent contact with the second and third sheets of the first cathode active material.

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: A single step, in situ curing method for making gel polymer lithium ion rechargeable cells and batteries is described. This method used a precursor solution consisting of monomers with multiple functionalities such as multiple acryloyl functionalities, a free-radical generating activator, nonaqueous solvents such as ethylene carbonate and propylene carbonate, and a lithium salt such as LiPF6. The electrodes are prepared by slurry-coating a carbonaceous material such as graphite onto an anode current collector and a lithium transition metal oxide such as LiCoO2 onto a cathode current collector, respectively. The electrodes, together with a highly porous separator, are then soaked with the polymer electrolyte precursor solution and sealed in a cell package under vacuum. The whole cell package is heated to in situ cure the polymer electrolyte precursor.

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 comprised ?-phase silver vanadium oxide prepared by using silver- and vanadium-containing starting materials in a stoichiometric molar proportion to give a Ag:V ratio of about 1:2. The reactants are homogenized and then added to an aqueous solution followed by heating in a pressurized vessel. The resulting ?-phase SVO possesses a higher surface area than ?-phase SVO produced by other prior art techniques. Consequently, the ?-phase SVO material provides an advantage in greater discharge capacity in pulse dischargeable cells.

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: Increased Rdc in electrochemical cells is detrimental because under high rate discharge regimes, such as used in powering an implantable cardiac defibrillator (ICD), the amount of energy delivered by the cell over a given period of time is lower as Rdc increases. This reduction in delivered energy results in a longer period of time needed to fully charge the ICD capacitors so that it takes longer to deliver the necessary therapy. Further, an industry recognized standard is to pulse discharge cell about every 90 days to charge the capacitors in the ICD to or near their maximum energy breakdown voltage to heal microfractures that can occur in the capacitor dielectric oxide. However, the present invention requires initiation of more frequent current pulsing upon the detection of an increase in Rdc or charge time. This is even though the Rdc measurement may be below some threshold reading.

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.