Abstract: Provided are alternative fabrication methods and compositions for an electrochemical cell. The methods of the present invention are applicable to the manufacture of polymer-cased lithium-ion secondary battery cells. Briefly, electrochemical cell fabrication techniques and articles that enhance the adhesion of polymer-metal laminate packaging materials and components to conductive leads (tabs) to thereby provide a reliable hermetic seal are provided. The tab surface treatments include chromate conversion coatings, phosphate conversion coatings, anodization, and surface cleaning.

Abstract: Provided are alternative fabrication methods and compositions for an electrochemical cell. The methods of the present invention are applicable to the manufacture of polymer-cased lithium-ion secondary battery cells. They are particularly, but not exclusively, applicable to manufacturing scale processes of fabricating polymer-cased lithium-ion secondary battery cells. Briefly, the present invention provides an electrochemical cell fabrication process wherein a binder is applied to a porous battery separator material. Binder solutions in accordance with the present invention, are formulated with a low boiling/high solubility (“good”) solvent and a higher boiling/no or low solubility (“bad”) solvent to dissolve the binder and coat it on the separator. When the separator is subsequently dried by evaporation of the solvents, a porous coating of binder is formed on the separator material.

Abstract: Provided are alternative fabrication methods and compositions for an electrochemical cell. The methods and compositions of the present invention are particularly, though not exclusively, applicable to the manufacture of polymer-cased lithium-ion secondary battery cells. Briefly, the present invention provides an electrochemical cell fabrication process wherein a PVDF-based binder specifically selected for its physical and chemical properties, in particular, it's high crystallinity, is coated on a porous separator material to form a porous separator. The high crystallinity PVDF of the binder results in improved cell structure and performance.

Abstract: Provided are alternative fabrication methods and compositions for an electrochemical cell. The methods and compositions of the present invention are particularly, though not exclusively, applicable to the manufacture of polymer-cased lithium-ion secondary battery cells. Briefly, the present invention provides an electrochemical cell fabrication process wherein a PVDF-based binder specifically selected for its physical and chemical properties, in particular, its high crystallinity, is coated on a porous separator material to form a porous separator. The high crystallinity PVDF of the binder results in improved cell structure and performance.

Abstract: Positive electrodes including a lithium nickel cobalt metal oxide are disclosed. The lithium nickel cobalt metal oxides have the general formula LixNiyCOzMnO2, where M is selected from the group consisting of aluminum, titanium, tungsten, chromium, molybdenum, magnesium, tantalum, silicon, and combinations thereof, x is between about 0 and about 1 and can be varied within this range by electrochemical insertion and extraction, the sum of y+z+n is about 1, n ranges between above 0 to about 0.25, y and z are both greater than 0, and the ratio z/y ranges from above 0 to about 1/3. Also disclosed are composite positive electrodes including the above-described lithium nickel cobalt metal oxides together with a lithium manganese metal oxide of the formula LixMn2−rM1rO4, where r is a value between 0 and 1 and M1 is chromium, titanium, tungsten, nickel, cobalt, iron, tin, zinc, zirconium, silicon, or a combination thereof.

Abstract: Disclosed are safe, easy to manufacture prismatic cells having scored regions strategically located on portions of the prismatic cell can or cell header. When they are located on the cell can, the scored regions are provided on the side of the can, rather than on the bottom of the can as in other designs. The scored region may be located on a corner of one side of the side of the cell can. Scored regions so located tend to release excess pressure over a relatively narrow and easier to control pressure range. Similar benefits can be obtained by placing the scored region on a "dished" header of a prismatic cell. Such dished header designs have a vertical lip around the perimeter of a substantially flat horizontal portion. The scoring may be provided near one of the ends of the header's substantially flat portion.

Abstract: Positive electrodes including a lithium nickel cobalt metal oxide are disclosed. The lithium nickel cobalt metal oxides have the general formula Li.sub.x Ni.sub.y Co.sub.z M.sub.n O.sub.2, where M is selected from the group consisting of aluminum, titanium, tungsten, chromium, molybdenum, magnesium, tantalum, silicon, and combinations thereof, x is between about 0 and about 1 and can be varied within this range by electrochemical insertion and extraction, the sum of y+z+n is about 1, n ranges between above 0 to about 0.25, y and z are both greater than 0, and the ratio z/y ranges from above 0 to about 1/3. Also disclosed are composite positive electrodes including the above-described lithium nickel cobalt metal oxides together with a lithium manganese metal oxide of the formula Li.sub.x Mn.sub.2-r M1.sub.r O.sub.4, where r is a value between 0 and 1 and M1 is chromium, titanium, tungsten, nickel, cobalt, iron, tin, zinc, zirconium, silicon, or a combination thereof.

Abstract: Control circuitry is described for regulating charging current from a current source to a battery. The control circuitry includes a switch for transmitting the charging current from the current source to the positive terminal of the battery. A charge pump drives the gate terminal of the switch above the positive terminal voltage. A comparator stage with hysteresis gates the charge pump. A filtering stage senses the battery voltage and drives the comparator stage. The control circuitry controls the average value of the battery voltage by pulse width modulating the charging current.

Abstract: Positive electrodes including a lithium nickel cobalt metal oxide are disclosed. The lithium nickel cobalt metal oxides have the general formula Li.sub.x Ni.sub.y CO.sub.z M.sub.n O.sub.2, where M is selected from the group consisting of aluminum, titanium, tungsten, chromium, molybdenum, magnesium, tantalum, silicon, and combinations thereof, x is between about 0 and about 1 and can be varied within this range by electrochemical insertion and extraction, the sum of y+z+n is about 1, n ranges between above 0 to about 0.25, y and z are both greater than 0, and the ratio z/y ranges from above 0 to about 1/3. Also disclosed are composite positive electrodes including the abovedescribed lithium nickel cobalt metal oxides together with a lithium manganese metal oxide of the formula Li.sub.x Mn.sub.2-r M1.sub.r O.sub.4, where r is a value between 0 and 1 and M1 is chromium, titanium, tungsten, nickel, cobalt, iron, tin, zinc, zirconium, silicon, or a combination thereof.

Abstract: A cell pressure control system is disclosed which has a two stage control mechanism. In the first stage, increased cell pressure causes a conductive deflection member to bend to a position where it opens an electrical contact and places the cell in open circuit. This prevents current from flowing through the cell and thereby possibly slowing or preventing further increases in cell pressure. The electrical contact relies only upon the pressure of two members (one of which is the deflection member) pushing against one another. If the cell's internal pressure continues to increase even after the pressure contact is broken, the second stage of the pressure control mechanism is activated. Specifically, a pressure rupturable region in the above-mentioned deflection member ruptures to relieve the cell's internal pressure. The pressure rupturable region is a circularity scored region on the conductive deflection member.

Abstract: A cell pressure control system is disclosed which includes a conductive frangible tab which tears in response to a defined pressure. The frangible tab is affixed at one position to a stationary member and at another position to a deflection member which deflects in response to increasing internal cell pressure. When the cell pressure increases to a dangerous level, the deflection member exerts sufficient pressure on the frangible tab to cause it to break. When the tab breaks, the cell goes to open circuit, thus reducing the danger of continued pressure build up. If the cell's internal pressure continues to increase even after the pressure contact is opened, a second stage of the pressure control mechanism may be activated. Specifically, a pressure rupturable region in the above-mentioned deflection member will rupture and release the cell's internal pressure.

Abstract: The present invention provides a method of preparing carbon electrodes for use in electrochemical energy storage cells such as lithium ion batteries. The process involves a step of precipitating a polymer from a concentrated solution to yield a structure having at least a partially fractious morphology. The solvent from which the polymer has been precipitated (the "primary solvent") is then exchanged with another solvent (the "secondary solvent") in which the polymer is relatively insoluble. Thereafter, the secondary solvent is removed from the precipitated polymer and the dry polymer is contacted with a dopant such as phosphorous. Subsequently, the polymer with dopant is pyrolyzed to yield a carbon material which is assembled into an electrode.