Electrochemical cell with circuit disconnect device
AssigneeEveready Battery Company, Inc.
InventorPhilip Georgopoulos
Life of this patent
Estimating the term…
Abstract
The invention relates to an electrochemical cell employing a resettable safety disconnect device operable by a nonresettable shape memory alloy element. The shape memory alloy element is preferably in the form of a twisted wire that is restrained in the normal operation of the cell and expands when the internal temperature exceeds a preselected value whereupon the shape memory alloy wire will exert force on a moveable element in the electrical circuit of the cell to break contact in the electrical circuit thereby rendering the cell inoperative. This device could also include an opposing spring member to restore the shape memory alloy element to its original shape upon cooling and thus restore electrical contact.
Claims20
An electrochemical cell comprising an electrode assembly containing at least one positive electrode and at least one negative electrode;
- a housing containing the electrode assembly and containing first means for providing a terminal on the housing for one of the said positive and negative electrodes;
- a cover for the housing and an insulating member for insulating the cover from the housing;
- second means within the housing for providing a terminal on the cover for the opposite electrode;
- one of said first and second means comprising a current collector assembly containing a movable member adapted for movement from a first position in which the current collector assembly is in electronic contact with one of the terminals to a second position in which the moveable member breaks the electronic contact between the current collector assembly and the terminal;
- and a shape memory alloy member disposed adjacent the moveable member and adapted to move the moveable member to the second position when the temperature within the cell exceeds a predetermined temperature thereby breaking the electronic contact between the current collector assembly and the terminal.
Dependencies are inferred from the claim text.