Apparatus for releasing gases from rechargeable lithium electrochemical cells during the formation stage of manufacturing

A system for providing an electrochemical cell, which comprises:

• a) a tank having selective access into its interior from a position outside the tank, the tank being of a sufficient size to house at least one electrochemical cell moved into its interior from outside the tank;
• b) an electrochemical cell comprising:
• i) a casing comprising a container having a container opening closed by a lid secured to the container, wherein the container and lid provide the casing having a casing side wall enclosing a casing interior accessable through a casing opening;
• ii) a negative electrode of a negative electrode active material which intercalates and deintercalates with an alkali metal;
• iii) a positive electrode comprising a positive electrode active material which intercalates and deintercalates with the alkali metal;
• and
• v) an electrolyte solution activating the negative and positive electrodes housed inside the casing;
• c) an inert gas provided inside the tank;
• d) wherein the electrochemical cell is positionable inside the tank with the casing opening supporting a removable vent providing fluid flow communication between the casing interior and the inert gas in the tank;
• e) wherein the cell is cyclable between a discharged condition and a charged condition while inside the tank;
• f) a filter inside the tank for separating the inert gas from gaseous by-products produced by cycling the cell;
• and
• g) a seal for closing the casing opening after the vent has been removed therefrom.

An electrochemical cell, which comprises:

• a) a container having a container opening;
• b) a negative electrode;
• c) a positive electrode;
• d) an electrolyte solution activating the negative and positive electrodes housed inside the container through the container opening;
• e) a lid closing the container opening, wherein the lid has a thickness defined by opposed inner and outer sides extending to and meeting with an intermediate lid side wall surrounding a lid opening;
• g) a removable gas release valve received in a gas tight, sealed relationship with the surrounding side wall of the lid opening, wherein the gas release valve selectively provides for gas inside the casing to vent to outside the casing;
• and
• g) wherein the gas release valve is removable from the lid opening with the lid opening being closable by a seal.

An electrochemical cell, which comprises:

• a) a container having a container opening;
• b) a negative electrode of a carbonaceous material which intercalates and deintercalates with lithium;
• c) a positive electrode comprising lithium cobalt oxide which intercalates and deintercalates with lithium;
• d) an electrolyte solution activating the negative electrode and the positive electrode housed inside the container through the container opening;
• e) a lid closing the container opening, wherein the lid has a thickness defined by opposed inner and outer sides extending to and meeting with an intermediate side wall surrounding a lid opening;
• f) a removable gas release valve received in a gas tight, sealed relationship with the surrounding side wall of the lid opening, wherein the gas release valve selectively provides for gas inside the casing to vent to outside the casing;
• and
• g) wherein the gas release valve is removable from the lid opening with the lid opening being closable by a seal.

A gas release valve for temporarily mounting in an opening provided in a surrounding side wall of a container, the gas release valve comprising:

• a) a vent stack having a surrounding side wall providing an internal bore communicating between a first open end and a second open end of the vent stack;
• b) a frusto-conically shaped seat formed by the inner side wall of the vent stack;
• c) a ball seated in the frusto-conically shaped seat to block fluid flow communication through the internal bore;
• d) a coil spring comprising first and second ends, wherein a first end of the coil spring surrounds a chimney providing a portion of the internal bore of the vent stack and the second end of the coil spring surrounds a guide having an opposed frusto-conical surface contacting the ball seated in the seat by the spring biasing against the chimney and the guide;
• e) a surrounding channel provided in an outer surface of the side wall of the vent stack spaced intermediate the first open end and the second open end;
• and
• f) an O-ring received in the surrounding channel.

A method for providing an electrochemical cell, comprising the steps of:

• a) providing a casing having a side wall with a casing opening;
• b) providing a negative electrode comprising a negative electrode active material which intercalates and deintercalates with an alkali metal;
• c) providing a positive electrode comprising a positive electrode active material which intercalates and deintercalates with the alkali metal;
• d) activating the negative electrode and the positive electrode housed inside the casing with an electrolyte;
• and
• e) positioning a gas release device in fluid flow communication with the casing opening for selectively providing for cell gas inside the casing to vent to outside the casing.

A method for providing an electrochemical cell, comprising the steps of:

• a) a casing having a side wall with a casing opening;
• b) providing a negative electrode comprising a negative electrode active material which intercalates and deintercalates with lithium;
• c) providing a positive electrode comprising a lithiated electrode active material which intercalates and deintercalates with lithium;
• and
• d) activating the negative electrode and the positive electrode housed in the casing with an electrolyte including an alkali metal salt dissolved in a quaternary, nonaqueous carbonate solvent mixture of ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate;
• e) closing the casing opening with a lid, wherein the lid has a thickness defined by opposed inner and outer side walls extending to and meeting with an intermediate side wall surrounding a lid opening;
• f) mounting a gas release valve in a removable gas tight sealed relationship with the surrounding side wall of the lid opening, wherein the gas release valve selectively provides for gas inside the casing to vent to outside the casing;
• g) removing the gas release valve from the lid opening in an environment which does not permit gas to enter the casing;
• and
• h) hermetically sealing the casing opening.