Abstract: The present invention provides a module for retaining and cooling a group of primary or secondary electrochemical cells for use in powered devices. To provide more effective cooling and reduce thermal gradients, cells are aligned in a side-by-side configuration within a multi-pass cooling passage. The multi-pass cooling in each module results in potentially longer useful life for the entire array. Large array batteries are formed of multiple modules, the shape and configuration of the modules allowing a variety of compact combinations having high energy density. In one configuration of an array battery according to the invention, two decks of modules are stacked vertically within a rigid enclosure. Air as a cooling medium is induced through each module to reduce cell temperatures. Temperature monitoring of each cell in a module and array allow for maintenance and identification of thermal events effecting continued long term operation.

Abstract: The present invention provides a positive electrode for a rechargeable cell including a two dimensional electrically conductive substrate supporting a coating comprising nickel hydroxide and a binder, preferably a styrene-ethylene/butylene-styrene triblock copolymer binder. The coating is formed by applying a paste to the two-dimensional substrate surface. The present invention also includes the cell made therefrom. The present invention further provides a method of producing this electrode including the steps of forming the paste and coating the paste onto the two-dimensional substrate. The capacity, midpoint voltage and power delivery of the coated electrode are comparable to or exceed those of traditional sintered and foam positive electrodes.

Abstract: A modularized power supply is presented employing individual electrochemical cells which are rendered inert when separated from a specified unlocking circuit. The cells are enclosed in a cell module having a disabling circuit which isolates the cell terminals and prevents release of significant cell energy. A switch in the disabling circuit is activated when the cell module is connected to the specified unlocking circuit in an external frame. The frame includes receptacles for receiving multiple modules, all of which must be connected before power is delivered to a host interface. The frame may include circuits and devices for monitoring the performance of the modules, for controlling cell charging and discharging, and protective elements to protect the modules and tray from aberrant conditions such as high temperatures, overcurrent, and similar events. By including these in the frame, fewer elements are required in the individual modules, reducing their complexity, weight and cost.

Abstract: The subject invention pertains to a method and apparatus for recalibrating and/or estimating a battery's state of charge (SOC). The subject invention is advantageous in situations where the battery infrequently, if ever, reaches a full charge and/or a full discharge. In a specific embodiment, the subject method and apparatus can utilize a battery's voltage and/or current, and/or changes in a battery's voltage and/or current with time, to recalibrate and/or estimate the battery's SOC. The method and apparatus of the subject invention can monitor various parameters relating to the condition of the battery in order to determine where on the open circuit voltage (OCV) versus SOC curve, the dOCV/dSOC versus SOC curve, and/or d2OCV/dSOC2 versus SOC curve the curve the battery is and, in a specific embodiment, when the battery reaches inflection point of the OCV versus SOC curve.

Abstract: An electrode having a notch along one edge is provided. The notch prevents unintentional internal shorting between the electrode and internal cell structures having an opposing polarity. In a preferred embodiment, the electrode is used in jellyroll electrochemical cells to avoid contact between the most exterior electrode wrap of the jellyroll and the can. A method of making such an electrode from a continuous strip of electrode material is also provided.

Abstract: A connector assembly connects a plurality of battery cells in a serial/parallel arrangement. Each battery cell includes a cover and a canister having a side and a bottom. Each battery cell is constructed such that a segment of the side of the canister forms a top crimped portion that retains the cover and is electrically isolated from the cover. The connector assembly includes a conductive weld cup. The conductive weld cup includes a bordered portion and recessed portion. The bordered portion includes a first side wall and a ledge that is substantially planar. The recessed portion is recessed within the ledge. The recessed portion includes a recessed portion and a floor that is substantially planar. The first side wall includes an integrated tab projecting from it. An inner surface of the bordered portion engages an outer surface of the side and the bottom of the canister of an upper adjacent battery cell. An outer surface of the floor engages a cover of a lower adjacent battery cell.

Abstract: A seal and method of sealing for use in electrochemical cells and similar devices. A preformed seal assembly is produced by insert-molding a seal element about a cell cover plate. By preforming the seal element, a more effective seal geometry is produced. In particular, the seal element is formed with a low profile seal flange on the outer face of the cover plate. One benefit of this lower profile is to assist in increasing the effective capacity of the associated cell. Another benefit of the preformed seal element is that it is not necessary to grossly deform the seal element during cell assembly in order to capture the cover plate. This enables use of more desired seal materials such as amorphous polymers, particularly polysulfone. To improve the effectiveness of the seal, a seal flange and shoulder portions, between which the cover plate is captured, are each axially compressed to increase the leakage path and reduce cold flow of the seal element.

Abstract: A formation procedure for a NiMH electrochemical cell is disclosed that significantly shortens the time required to fully form such a cell. The formation procedure includes a first step during which the cell is charged at a constant voltage of preferably 1.0 volt for approximately three hours. A second charging step is performed by applying either a constant charge current at a predetermined rate of C/3 for five hours or applying a constant voltage of 1.45 to 1.5 volts for five to nine hours. A third step may optionally be used whereby the cell is charged at a constant current of C/10 for about two hours. NiMH cells subjected to this formation procedure have a much greater percentage of the starting cobalt material in the positive electrode converted to CoOOH thereby improving the conductive matrix formed about the Ni(OH)2/NiOOH particles, which constitute the active material of the positive electrode.

Abstract: A cell grading test fixture includes an array of cell sockets electrically interconnected in series so that current through the entire array of cells flows through each of the cells once inserted into the fixture. Associated with each socket is an indicator which indicates to the operator when a cell voltage has fallen to a predetermined level. Each socket of the test fixture includes a spring-loaded switch contact such that upon removal of a cell which has dropped below a threshold voltage, the movable contact engages the contact of an adjacent socket, shorting out the cell location such that the series circuit of cells continues to provide a current path for the remaining cells.

Abstract: A safety vent is provided for incorporation into sealed electrochemical cells. The vent is particularly applicable to cells experiencing transient conditions producing pressures above 250 psi (17.6 kg/cm.sup.2). By configuring a cover plate to plastically deform at elevated pressures, an increased venting area can be produced. The increased venting area allows for venting of solid matter which may be forced into vent holes during high temperatures and pressures. Effective plastic deformation is obtained by proper selection of a ductile material and cover plate thickness. By ensuring that vent clogging does not occur, pressures are limited and the integrity of the cell is maintained. By incorporating this vent into a cell, methods of successfully passing industry standard test procedures for secondary cells are provided. The vent also includes an elastomeric sealing element which is captured between the cover plate and a rigid upper plate.

Abstract: This invention relates to methods for producing nickel-based battery electrodes which comprise, when charged, stably cyclable gamma-nickel oxyhydroxide and to electrodes and electrode materials produced by these processes which do not require the addition of expensive stabilizing materials extraneous to the traditional electrode formation process.