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 nitrate additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture that includes ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate. The preferred additive is an organic alkyl nitrate compound.

Abstract: A solid cathode liquid organic electrolyte alkali metal high rate cell wherein a combination of an elongated alkali metal anode and elongated solid cathode with separator therebetween is wound to form an anode-cathode subassembly having a jellyroll type configuration and wherein the combination is shaped so that the resulting sub-assembly has a substantially rectangular cross-section, the shaping of the combination being done either simultaneously with or subsequent to the winding thereof. The anode-cathode sub-assembly is placed in a conductive cell casing of prismatic shape having opposed flat faces, a lead of either the anode or cathode is attached to the cell casing depending upon whether case positive or case negative electrical configuration is desired and a lead of the other of the anode or cathode is connected to an electrical connector means extending through the casing in an insulated manner.

Abstract: A method of making a multi-plate wound cell assembly constructed similar to a conventional jellyroll electrode assembly except that each electrode comprises a series of plates spaced along a continuous current collector, and the plates are flat-folded rather than wound into a cylinder, is described. The length of the current collector between adjacent plates of the anode and cathode electrodes increases as the folding progresses to allow for the increase as the electrode assembly is flat-folded.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of hydrogen fluoride to the nonaqueous electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and hydrogen fluoride having LiAsF.sub.6 or LiPF.sub.6 dissolved therein.

Abstract: A final closure sealing member and a method for hermetically sealing an opening, such as an electrolyte fill opening in an electrochemical cell or a battery, are disclosed. After a cell is fully assembled and filled with electrolyte, the present sealing member is force-fit into sealing registry with the electrolyte fill opening to form a secondary seal for the cell. PreferablY, an outwardly facing portion of the sealing member is flush or slightly recessed with the side wall surrounding the fill opening. Then, the outwardly facing portion is welded to the opening side wall to form a primary hermetic seal.

Abstract: A current collector in the form of a conductive substrate subjected to a special chemical etch on both major surfaces to provide a "basket weave" structure, is described. The basket weave structures has a lattice construction surrounded by a frame and comprising first strand structures intersecting second strand structures to provide a plurality of diamond-shaped openings or interstices bordered by the strands. The strand structures intersect or join with each other at junctions thereby forming the current collector as an integral unit.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one phosphonate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl phosphonate additive.

Abstract: A method for improving the electrical conductivity of a substrate of metal, metal alloy or metal oxide comprising depositing a small or minor amount of metal or metals from Group VIIIA metals (Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt) or from Group IA metals (Cu, Ag, Au) on a substrate of metal, metal alloys and/or metal oxide from Group IVA metals (Ti, Zr, Hf), Group VA metals (V, Nb, Ta), Group VIA metals (Cr, Mo, W) and Al, Mn, Ni and Cu. The native oxide layer of the substrate is changed from electrically insulating to electrically conductive. The step of depositing is carried out by a low temperature arc vapor deposition process. The deposition may be performed on either treated or untreated substrate. The substrate with native oxide layer made electrically conductive is useable in the manufacture of electrodes for devices such as capacitors and batteries.

Abstract: A power source including two alkali metal/transition metal oxide cells discharged in parallel to power an implantable medical device is described. The first cell powers the medical device in both a device monitoring mode, for example in a cardiac defibrillator for monitoring the heart beat, and a device actuation mode for charging capacitors requiring high rate electrical pulse discharging. At such time as the first cell is discharged to a predetermined voltage limit, the first cell is disconnected from pulse discharge duty and only used for the device monitoring function. At that time, the second cell is utilized for the high rate electrical pulse discharging function. When the first cell reaches 100% efficiency or a present voltage limit, the second cell then takes over both device monitoring and device actuation functions. In that manner, a greater average discharge efficiency is realized from the two cells than is capable of being delivered from a single cell of similar chemistry.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one phosphate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl phosphate additive.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one dicarbonate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl dicarbonate additive.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one nitrate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkali metal nitrate, alkaline earth metal nitrate and/or an organic alkyl nitrate additive.

Abstract: 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.

Abstract: A flat-folded, multi-plate electrode assembly is described. The electrode assembly consists of anode and cathode electrodes in the form of continuous strips having extension plates which are first folded against their connection electrode portions to provide anode and cathode plate pairs. The anode and the cathode are then operatively associated with each other such that at least a portion of the anode strip is interleaved between corresponding ones of the cathode plate pairs and at least a portion of the cathode strip is interleaved between corresponding ones of the anode plate pairs. The assembly is then "Z" folded into the desired electrode stack. The extension plates of both electrodes insure electrode overlap in each and every fold, thereby optimizing electrode output. This design has the advantage of permitting the electrodes to be enlarged due to the electrode configuration and header connection, eliminates multiple components and insures matched electrode overlap.

Abstract: An electrode assembly constructed of continuous anode and cathode electrode that are overlaid in overlapping fashion and folded several times rather than wound into a cylinder in the conventional "jelly roll" electrode assembly. The electrode assembly has a first side that is curved substantially along a single arc and a second side opposite the first side that is curved substantially along a plurality of arcs. The electrode assembly is designed for casings for electrochemical cells or batteries having profiles that are not well suited for the jelly roll configuration.

Abstract: A perforated fabric for modifying the effective electrochemical surface area of a cell is described. The size and pattern of perforations in the fabric determine the effective electrochemical surface area of the cell. In practice, the modified cell comprises a layer of perforated fabric placed between the anode and the cathode along with a suitable electrolyte absorbent separator material. Electrodes are then assembled into a cell using typical techniques with a spirally-wound configuration being preferred. The present perforated fabric provides for the production of cells with variable effective electrochemical surface areas while using a single manufacturing line. A preferred cell chemistry comprises a fluorinated carbon electrode present in an alkali metal system with the preferred perforated fabric comprising a Fluorpeel fabric, which is a woven fiberglass cloth impregnated with PTFE polymer.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one nitrite additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and an alkyl nitrite additive.

Abstract: An alkali metal, solid cathode, nonaqueous electrochemical cell capable of delivering high current pulses, rapidly recovering its open circuit voltage and having high current capacity, is described. The stated benefits are realized by the addition of at least one organic sulfate additive to an electrolyte comprising an alkali metal salt dissolved in a mixture of a low viscosity solvent and a high permittivity solvent. A preferred solvent mixture includes propylene carbonate, dimethoxyethane and a dialkyl sulfate additive.

Abstract: In fabrication of conventional spirally wound cells, a length of separator is provided at least twice as long as one of the electrodes, for example, the cathode, and then folded to cover both sides of the electrode. The separator is also somewhat wider than the covered electrode to extend beyond the upper and lower edges thereof. The cathode assembly is then placed along side a strip of anode material and rolled into a jellyroll configuration. The separator sheet is not sealed at the opposed upper and lower edges of the cathode, and during high shock and vibration conditions the edges tend to mushroom which can lead to short circuit conditions. The insulator of the present invention is a slotted member that covers the upper and lower edges of the other electrode not covered by the separator, for example the anode with the anode leads extending through the slots to shield them from short circuit conditions with the cell casing or other leads if the cell should be subjected to severe shock forces and the like.

Abstract: A power source including two alkali metal/transition metal oxide cells discharged in parallel to power an implantable medical device is described. The first cell powers the medical device in both a device monitoring mode, for example in a cardiac defibrillator for monitoring the heart beat, and a device actuation mode for charging capacitors requiring high rate electrical pulse discharging. At such time as the first cell is discharged to a predetermined voltage limit, the first cell is disconnected from pulse discharge duty and only used for the device monitoring function. At that time, the second cell is utilized for the high rate electrical pulse discharging function. When the first cell reaches 100% efficiency or a present voltage limit, the second cell then takes over both device monitoring and device actuation functions. In that manner, a greater average discharge efficiency is realized from the two cells than is capable of being delivered from a single cell of similar chemistry.