Cell having current cutoff valve

• US 4,943,497 A
• Filed: 10/20/1989
• Issued: 07/24/1990
• Est. Priority Date: 10/21/1988
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Watanabe, Mochiyuki, Abe, Takao, Nagaura, Toru, Oishi, Shigeru
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US07/424,696
• Time in Patent Office: 277 Days
• Field of Search: 429/53, 429/54, 429/55, 429/56, 429/72, 429/61, 429/82
• US Class Current: 429/53
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 50/574 Devices or arrangements for the interruption of current
• CPC Class Codes: H01M 50/578 in response to pressure

Abstract

A cell having an explosion proof valve is disclosed, in which the valve is deformable upon increase of inner pressure of the cell to cut a connection lead which connects the valve with a generator unit contained in the cell. The supply of charging current is cut off when the inner pressure of the cell has abnormally increased. The gradual increase of the inner pressure can be effected by selecting suitable cathode active material.

Claims

1. A cell comprising:

a container having therein a generator unit formed of an anode, a cathode, a separator interposed between said anode and said cathode, and electrolyte;

an explosion proof valve sealing said container;

an electrical lead connected at one end to one of said anode or cathode and at the other end to said explosion proof valve; and

a stripper element provided between said generator unit andd said explosion proof valve;

said explosion proof valve being deformable upon increase of inner pressure of said container and said stripper element holding said electrical lead at a side of said generator unit to remove said electrical lead from said explosion proof valve upon deformation of said explosion proof valve.

2. A cell according to claim 1, wherein said stripper element has a through hole, through which said electrical lead is led out from said generator unit to said explosion proof valve.

3. A cell according to claim 1, wherein said stripper element and said explosion proof valve are unitized at peripheral portions thereof.

4. A cell according to claim 1, 2, or 3, wherein said stripper element is sealed with said container through an insulating gasket.

5. A cell comprising:

a container having therein a generator unit formed of an anode, a cathode, a separator interposed between said anode and said cathode, and electrolyte; and

an explosion proof valve deformable upon increase of inner pressure of the cell to cut current supply to said generator unit;

said anode being formed of a material which can be doped and un-doped of lithium upon charging and discharging the cell, and said cathode being formed of a first cathode active material expressed by the first formula Li_x Ni_y Co_1-y O₂ (wherein 0<

x≦

l, and 0≦

y ≦

0.50) and a second cathode active material expressed by the second formula Li_x'"'"' Ni_y'"'"' Co_1-y'"'"'O2 (wherein 0<

x'"'"'≦

1, and 0.50≦

y'"'"'≦

0.90).