Abstract: A battery pack for a portable electronic device includes a case for carrying a battery. The case supports a charge sensing circuit carried by the case, the charge sensing circuit producing a discharge signal corresponding to a measurement of an amount of charge removed from a battery. The case also supports a processor responsive to the discharge signal from the charge sensor circuit to produce a signal corresponding to an amount of time prior to discharge of the battery based on a current rate of discharge and a display responsive to the signal to display a time period corresponding to the amount of time to discharge the battery based upon the current rate of discharge of the battery.

Abstract: Electrolytic solutions containing a malonate ester having no alpha-carbon hydrogen atoms are disclosed. The electrolytic solutions can be used in lithium ion batteries.

Abstract: An end cap assembly is disclosed for sealing the open end of a cylindrical alkaline cell housing preferably having a diameter less than the diameter of AAA size cells. The end cap assembly is preferably intended for sealing AAAA (LR61) size cylindrical alkaline cells. The end cap assembly comprises a terminal end cap, an insulating sealing disk underlying said end cap, and an elongated current collector penetrating through an aperture in said insulating sealing disk. At least a portion of the insulating sealing disk lies within the cell housing to seal the open end thereof. The terminal end cap has a peripheral edge, preferably formed from a curved rib, which is locked within the peripheral edge of the insulating sealing disk. The end cap assembly does not require other metal disks held within the sealing and insulating disk. The insulating disk comprises a discontinuous skirt comprising a plurality of integral legs emanating downwardly into the cell interior from the peripheral edge of said insulating disk.

Abstract: A current interrupt mechanism for electrochemical cells is disclosed. A thermally activated current interrupt mechanism is integrated into an end cap assembly for an electrochemical cell. The thermally responsive mechanism preferably includes a free floating bimetallic disk or shape memory alloy member which deforms when exposed to elevated temperature causing a break in an electrical pathway within the end cap assembly. This prevents current from flowing through the cell and effectively shuts down an operating cell. The thermally responsive mechanism may include a heat producing electrical resistance means, preferably a Zener diode, to enhance thermal sensitivity. The end cap assembly may include a pressure responsive mechanism which ruptures when there is extreme gas pressure buildup. Gas is allowed to escape from the cell interior to the external environment through a series of vent apertures within the end cap assembly.

Abstract: An end cap assembly is disclosed for sealing the open end of a cylindrical alkaline cell housing preferably having a diameter less than the diameter of AAA size cells. The end cap assembly is preferably intended for sealing AAAA (LR61) size cylindrical alkaline cells. The end cap assembly comprises a terminal end cap, an insulating sealing disk underlying said end cap, and an elongated current collector penetrating through an aperture in said insulating sealing disk. At least a portion of the insulating sealing disk lies within the cell housing to seal the open end thereof. The terminal end cap is located outside of said housing. The end cap assembly may include an insulating washer between the terminal end cap and the cell housing. The terminal end cap and the insulating washer are stacked over the peripheral edge of the cell housing at the open end of the cell housing. The insulating washer electrically insulates the terminal end cap from the cell housing.

Abstract: The invention features a prismatic battery with an electrically conductive housing comprising an elongated, prismatic can with an open end, and a housing cover pressed into the open end of the can and welded in place. The novel cover has an outer flange about its periphery, extending generally in the direction of extension of the sides of the can, which elastically deflects as the cover is pressed into the can to provide good contact for welding. The cover has two raised bumps forming internal pockets that are part of the internal volume of the cell. The bumps are also arranged to prevent rotation of the seal/vent assembly. One embodiment includes a plugged fill hole in one of the bumps. Corresponding methods of manufacture are also disclosed.

Abstract: A current interrupt assembly for electrochemical cells is disclosed. The current interrupter assembly may be a self-contained, sealed unit which may be separately inserted into the cell during cell construction. Several current interrupt assemblies may be inserted in the cell. The current interrupter assembly has particular utility for thin rechargeable cells and when inserted in the cell forms a portion of the electrical pathway between a cell electrode and corresponding terminal. The current interrupt mechanism comprises a thin thermally responsive member preferably comprising a disk of a shape memory metal alloy having a curved surface. The current interrupt mechanism may include a heat producing electrical resistance means, preferably a Zener diode in proximity to the thermally responsive member. When cell temperature exceeds a predetermined value the disk deflects to cause a break in the electrical pathway within the assembly.

Abstract: A method of manufacturing conductive cobalt oxyhydroxide, including providing a positive electrode, a negative electrode, a CoOOH precursor, and a basic solution to form a combination; applying a current to the positive electrode to form conductive CoOOH on the positive electrode; then removing the conductive CoOOH from the combination, is disclosed.

Abstract: An end cap assembly for an electrochemical cell, for example an alkaline cell, is disclosed comprising an exposed terminal end cap of single piece construction having a convoluted surface, an electrically insulating member and a metal support disk between the insulating member and the terminal end cap. The end cap assembly is inserted into the open end of the cell housing after the cell contents have been supplied. A portion of the end cap surface is a flat annular step which improves contact between the end cap and the electrically conductive portion of a condition tester for the cell which may be integrated into the cell label. The annular step is advantageously located at about right angle to the cell's longitudinal axis. The surface step is integral with the end cap and preferably located at about the same level as the shoulder of the cell housing at the end of the cell containing the end cap. The end cap assembly as a whole provides a tight seal for the cell.

Abstract: An electrochemical cell is disclosed, having a sealed prismatic housing with two opposing, internal side surfaces defining therebetween an internal cavity having width and length. One of the side surfaces defines a convex arc, and the other of the side surfaces has a center portion opposing the convex arc of the one side surface, and features extending toward the one side surface and straddling the convex arc. An electrode stack is contained within the internal cavity of the housing, having positive and negative electrode sheets arranged in face-to-face relation. The electrode stack is arranged between the side surfaces of the housing such that the stack is retained between the one side surface and the extending features of the other side surface, and deflected to follow the convex arc to maintain contact pressure between the positive and negative electrode sheets. The stack is thus stretched across an inwardly crowned surface of the housing.

Abstract: A lithium ion cell having an amount of a Group 1 element between the positive electrode and the negative electrode is described. The Group 1 element can be on an surface of an electrode separator as a deposit. The Group 1 element can increase the charging capacity of the cell, eliminate the irreversible capacity of the cell, improve the rechargeable cell cyclability, or increase the charging reversibility of the cell.

Abstract: A light transparent moisture barrier useful for preventing moisture from destroying the effectiveness of a moisture sensitive cell condition tester on an electrochemical cell, comprises a plurality of very thin layers of amorphous silicon nitride and a hydrophobic fluorocarbon polymer on a flexible, polymeric substrate. The layers are formed on the substrate by a deposition process such as sputtering. The thickness of any individual layer is less than one micron.

Abstract: A current interrupt mechanism for electrochemical cells is disclosed. A thermally activated current interrupt mechanism is integrated into an end cap assembly for an electrochemical cell. The thermally responsive mechanism preferably includes a free floating bimetallic disk or shape memory alloy member which deforms when exposed to elevated temperature causing a break in an electrical pathway within the end cap assembly. This prevents current from flowing through the cell and effectively shuts down an operating cell. The end cap assembly may include a pressure responsive mechanism which ruptures when there is extreme gas pressure buildup. Gas is allowed to escape from the cell interior to the external environment through a series of vent apertures within the end cap assembly.

Abstract: The surface of material containing a hydrogen storage alloy are treated with an organometallic compound to provide the alloy with corrosion resistance.

Abstract: Disclosed is a process for treating manganese dioxide containing ion-exchangeable cations by replacing the ion-exchangeable cations present in the manganese dioxide with lithium by a process comprising first replacing ion-exchangeable cations present in the manganese dioxide with hydrogen. This readily is accomplished by slurrying the manganese dioxide in an aqueous acid solution. The resulting acidic manganese dioxide then is neutralized with a basic solution of a lithium containing compound, such as lithium hydroxide. This neutralization step serves to accomplish replacement of the previously introduced hydrogen, by ion-exchange, with lithium. The manganese dioxide then is washed with water, dried, and heat-treated at an elevated temperature, in conventional manner, to convert the gamma manganese dioxide to a mixture of the gamma and beta forms, which then is used as the active cathodic component in an electrochemical cell.

Abstract: An improved high rate alkaline cell is obtained by employing an anode current collector comprising a foraminous metal.

Abstract: A method of treating lithium manganese oxide of spinel structure is disclosed. The method involves heating the lithium manganese oxide spinel in an atmosphere of an inert gas, e.g, argon, helium, nitrogen or carbon dioxide, which does not react with the spinel. Alternatively, the spinel may be first coated with an alkali metal hydroxide, preferably lithium, sodium or potassium hydroxide and then heated in an atmosphere preferably containing carbon dioxide. Such treatment of lithium manganese oxide spinel improves the performance of the spinel when employed as an electrode in rechargeable cells such as lithium-ion cells. Alternatively, the spinel may be first treated in an aqueous solution of a soluble metal salt of a carboxylic acid prior to treatment with heated carbon dioxide or inert gas. In such latter case the spinel may optionally also be treated with an alkali metal hydroxide prior to treatment with carbon dioxide or inert gas.