An integral low profile cell closure equipped with resealable safety valve means is disclosed having a cover, an apertured seat centrally enclosed within the cover, elongated resilient sealing means bearing on the seat, and a top cover bearing on the resilient means at a position outwardly spaced from the bearing positions formed with the seat. The cover and top cover are secured together at their respective marginal portions, effected by crimping the cover around the top cover, for instance, to provide a large cross-sectional escape path for gas released through the valve.
A vent structure intended for use in venting gas from the interior of a battery housing can be constructed so as to use a generally cup-shaped, resilient valve element. The element is positioned within a cavity at the top of the housing with the bottom of the element spaced from an opening in the bottom of the cavity and with the peripheral wall of the element resiliently engaging the interior of the cavity. A retainer extends across the open top of the cavity and engages the bottom of the valve element so as to hold it in place. The retainer holds the valve element so that the peripheral wall of the valve element can flex inwardly to permit the escape of gas. The vent structure is utilized with a gas-liquid separator placing the opening in the bottom of the cavity in communication with the interior of the housing. The cavity and the gas liquid separator are shaped so as to permit liquid to drain back into the interior of the housing from within the interiors of the cavity and the gas-liquid separator.
High energy composition which is meant for propellants, pyrotechnical and technical compositions, explosives or corresponding items, and production method.
A current interrupt device for rechargeable, electrochemical cells having a safety valve, insulating spacer and a thin metal plate for coupling to an electrode assembly is provided. The thin metal plate electrically couples to the safety valve by way of a conductive polymer, preferably having a positive temperature coefficient characteristic. The positive temperature coefficient characteristic is such that the impedance of the polymer increases with increasing temperature. In normal operation, the polymer conducts current. In high current situations, where internal components heat due to parasitic resistances, the polymer becomes an insulator and disconnects the cell from the exterior can. When gasses build within the cell, the safety valve deforms, thereby causing the safety valve to separate from the thin metal plate. Once the safety valve and thin metal plate have separated, the electrode assembly is electrically isolated from the exterior can.
In the current path cut-off mechanism in a cell according to the present invention, a current path is formed between a cell lid and a power generating element through a diaphragm portion D and an internal terminal, and a base portion of the internal terminal is embedded in an insulating member by insert molding so that a bonding portion of the internal terminal becomes flush with the diaphragm portion D-side surface of the insulating member. Therefore, it is possible to eliminate variations in the position of the bonding portion of the internal terminal and hence possible to eliminate variations in the bonding strength between the internal terminal and the diaphragm portion.
A battery construction includes a casing which defines a cavity in which the electro-chemical contents of the battery is confined. A cover is disposed across an open end of the casing, and an aluminum interconnecting member is welded to the top of the cover. A cap, preferably made of steel, is fitted over an outwardly projecting portion of the cover to provide a terminal. A seam in the cover, closed by cold welding and epoxy is disposed beneath the outwardly projecting portion and the cap.
