Method and apparatus for regulating charging of electrochemical cells

An axially extending rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal cavity with an open end, a positive and negative electrode disposed in the internal cavity, and a terminal end cap enclosing the open end;
• and
• (b) an end cap assembly including:
• i. a flexible member extending radially inwardly from the can, wherein the flexible member flexes from a first position towards a second position in response to internal cell pressure;
• ii. a first conductive element in electrical communication with the terminal end cap;
• iii. a second conductive element in electrical communication with the positive electrode, and in removable electrical communication with the first conductive element, wherein the second conductive element is in mechanical communication with the flexible member, the second conductive element including:
• a) a first contact having one end extending from the positive electrode, and a second end opposite the first end;
• b) a second contact extending through the flexible member having a first end in contact with the second end of the first contact, and a second end opposite the first end;
• and
• c) a third contact having a first end in contact with the second end of the second contact, and a second end opposite the first end and in removable contact with the first conductive element
• wherein the first and second conductive elements are removed from electrical communication when the flexible member flexes towards the second position in response to an internal pressure exceeding a predetermined threshold during charging.

A rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal cavity that is closed by a terminal end cap;
• and
• (b) an electrode disposed in the cavity;
• and
• (c) end cap assembly including:
• i. first and second contacts in removable electrical communication with each other, wherein an electrical path is formed between the terminal end cap and the electrode when the contacts are in communication, and wherein the electrical path is broken when the contacts are removed from communication;
• and
• ii. a pressure-responsive flexible member in addition to the contacts that, in response to an elevated internal cell pressure, flexes and directly biases one of the contacts away from the other to break the electrical path.

A rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal cavity that is closed by a terminal end cap;
• and
• (b) an electrode disposed in the cavity;
• and
• (c) an end cap assembly including:
• i. a nonconductive flexible member extending radially inwardly from the outer can, wherein the flexible member flexes from a first position to a second position in response to internal cell pressure;
• ii. first and second contacts in removable electrical communication with each other to form an electrical path extending through the flexible member between the terminal end cap and the electrode, wherein the path is broken when the flexible member flexes to the second position.

A rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal cavity that is closed by a terminal end cap;
• and
• (b) an electrode disposed in the cavity;
• and
• (c) an end cap assembly including:
• i. first and second contacts in removable electrical communication with each other to form an electrical path between the terminal end cap and the electrode;
• and
• ii. a flexible grommet extending radially inwardly from the can, wherein the grommet flexes from a first position to a second position in response to an elevated internal cell pressure to break the electrical path.

A rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal chamber that is closed by a terminal end cap;
• and
• (b) an electrode;
• and
• (c) an end cap assembly including a flexible member extending radially inwardly from an axially extending portion of the outer can to divide the internal chamber into an active cell cavity housing the electrode, and a switching cavity that houses a first and second contact that connect to close an electrical path extending between the terminal end cap and the electrode, wherein the flexible member flexes and breaks the electrical path in response to an elevated internal cell pressure.

A rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal cavity that is closed by a terminal end cap;
• and
• (b) an electrode disposed in the cavity;
• and
• (c) end cap assembly including:
• i. first and second contacts in removable electrical communication with each other, wherein an electrical path is formed between the terminal end cap and the electrode when the contacts are in communication, and wherein the electrical path is broken when the contacts are removed from communication;
• and
• ii. a pressure-responsive flexible member in addition to the contacts that becomes displaced in response to an elevated internal cell pressure and, in turn, displaces one of the contacts a distance substantially equal to the displacement of the flexible member to break the electrical path.

A rechargeable electrochemical cell comprising:

• (a) an outer can defining an internal chamber having an open end that is closed by a terminal end cap;
• and
• (b) an electrode disposed in the chamber;
• and
• (c) an end cap assembly including:
• i. first and second contacts in removable electrical communication with each other to form an electrical path between the terminal end cap and the electrode;
• and
• ii. a flexible member in addition to the contacts, wherein the flexible member includes an outer portion proximal the can and an inner portion extending radially inwardly from the outer portion, wherein the flexible member flexes from a first position to a second position in response to an elevated internal cell pressure to break the electrical path,
• wherein the outer can is crimped about an outer portion of the flexible member to provide a seal at the open end.

A rechargeable electrochemical cell comprising:

• (a) an outer can extending along a centrally disposed axis, the can defining an internal chamber having an open end that is closed by a terminal end cap;
• and
• (b) an electrode disposed in the chamber;
• and
• (c) an end cap assembly including:
• i. first and second contacts in removable electrical communication with each other to form an electrical path between the terminal end cap and the electrode;
• and
• ii. a flexible member extending from the can and symmetrically disposed about the axis, wherein the flexible member flexes from a first position to a second position in response to an elevated internal cell pressure to urge one of the contacts away from the other and break the electrical path.