Housing for a sealed electrochemical cell
View Patent ↗An electrochemical cell with a collector assembly for sealing the open end of a cell container. The collector assembly includes a retainer and a contact spring with a peripheral flange, each having a central opening therein. A pressure release vent member disposed between the retainer and the peripheral flange of the contact spring seals the openings in the retainer and contact spring under normal conditions and ruptures to release pressure from within the cell when the internal pressure exceeds a predetermined limit.
1. An electrochemical cell, comprising:
a cylindrical container having: a closed bottom, an open top end and a bead that separates top and bottom portions of the container;
a spirally wound electrode assembly disposed in the bottom portion of the container with an electrolyte, the spirally wound electrode assembly including a negative electrode consisting essentially of lithium or a lithium alloy, a positive electrode including particulate iron disulfide, and a separator disposed between the positive and negative electrodes;
a collector assembly seated on the bead so that, when an outermost edge of the top end is crimped around the collector assembly, the container is axially sealed;
wherein the collector assembly includes an insulating gasket, a terminal cover, a PTC member, a conductive member defining a vent release channel, a vent member, a retainer and a contact tab forming a direct electrical connection between the electrode assembly and the collector assembly;
wherein the terminal cover is seated on a top-facing portion of the PTC member; and
wherein the retainer is coupled to the vent member, disposed beneath a bottom-facing portion of the PTC member and crimped around the conductive member.
2. The electrochemical cell according to claim 1 , wherein the vent member is bonded to the retainer.
3. The electrochemical cell according to claim 1 , wherein the electrolyte includes less than 500 ppm of water.
4. The electrochemical cell according to claim 1 , wherein the vent member comprises a layer of aluminum.
5. The electrochemical cell according to claim 1 , wherein the conductive member is welded to the contact tab.