CURRENT INTERRUPTION DEVICE AND ELECTRIC STORAGE DEVICE USING SAME

• US 20150079432A1
• Filed: 04/11/2013
• Published: 03/19/2015
• Est. Priority Date: 04/12/2012
• Status: Active Grant

• Current Assignee: Eagle Industry Company Limited
• Original Assignee: Eagle Industry Company Limited, Kabushiki Kaisha Toyota Jidoshokki
• Inventors: Okuda, Motoaki, Umemura, Satoshi, Kato, Takayuki, Minagata, Atsushi, Akiyama, Hirokuni, Hirose, Takayuki, Ogawa, Yoshihiro, Iwa, Toshiaki, Nishihara, Hiroyasu, Odagiri, Toshio
• Granted Patent: US 10,020,146 B2
• Time in Patent Office: Days
• US Class Current: 429/61
• CPC Class Codes: H01G 11/16 against electric overloads, e.g. including fuses
• CPC Class Codes: H01G 2/14 Protection against electric or thermal overload by cooling H01G2/08
• CPC Class Codes: H01G 9/0003 Protection against electric or thermal overload; cooling arrangements; means for avoiding the formation of cathode films H01G9/12 takes precedence
• CPC Class Codes: H01G 9/12 Vents or other means allowing expansion
• CPC Class Codes: H01H 35/26 Details
• CPC Class Codes: H01H 35/346 in which the movable contact is formed or directly supported by the diaphragm
• CPC Class Codes: H01M 2200/20 Pressure-sensitive devices
• CPC Class Codes: H01M 50/55 on the same side of the cell
• CPC Class Codes: H01M 50/578 in response to pressure
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A current interruption device includes: a deforming plate configured to deform when the internal pressure of the casing rises above the predetermined level; a conducting plate which configures the current path; and a contact plate. The conducting plate includes a first contact portion configured to contact the contact plate. The contact plate includes a second contact portion configured to contact the first contact portion. The deforming plate includes a pressure receiving portion configured to receive the internal pressure of the casing and a contacting portion configured to contact the first contact portion. The second contact portion is configured to be separated from the conducting plate by deformation causing the contacting portion to move toward the contact plate. The deforming plate is insulated from the conducting plate and the contact plate. The conducting plate is disposed to be interleaved between the deforming plate and the contact plate.

Claims

1. A current interruption device configured to electrically connect a positive electrode external terminal and an electrode assembly comprising a positive electrode and a negative electrode or to connect a negative electrode external terminal and the electrode assembly, and to interrupt a current path of the positive electrode external terminal and the electrode assembly or a current path of the negative electrode external terminal and the electrode assembly when an internal pressure of a casing accommodating the electrode assembly rises above a predetermined level, the current interruption device comprising:

a deforming plate configured to deform when the internal pressure of the casing rises above the predetermined level;

a conducting plate which configures the current path; and

a contact plate,

wherein

the conducting plate includes a first contact portion configured to contact the contact plate,

the contact plate includes a second contact portion configured to contact the first contact portion,

the first contact portion and the second contact portion are disposed on the current path,

the deforming plate includes a pressure receiving portion configured to receive the internal pressure of the casing and a contacting portion configured to contact at least one of the first contact portion and the second contact portion,

at least the second contact portion, among the first contact portion and the second contact portion, is configured to be separated from the conducting plate by deformation of the deforming plate causing the contacting portion to move toward the contact plate,

the deforming plate is insulated from at least one of the conducting plate and the contact plate and disposed such that the deforming plate configures an outer face of the current interruption device, and

the conducting plate is disposed to be interleaved between the deforming plate and the contact plate.

2. The current interruption device according to claim 1, wherein

the first contact portion is disposed at a center portion of the conducting plate and the second contact portion is disposed at a center portion of the contact plate.

3. The current interruption device according to claim 1, wherein

a projection projecting toward the contact plate is disposed at a center portion of the deforming plate, and

the contacting portion is included in the projection.

4. The current interruption device according to claim 1, wherein

a groove is disposed around a center portion of the conducting plate around a portion with which the contacting portion is to make contact.

5. The current interruption device according to claim 3, wherein

the current interruption device is configured to shift among a first condition, a second condition and a third condition,

in the first condition a gap is provided between the deforming plate and the conducting plate during when the internal pressure of the casing is below the predetermined level,

in the second condition the contact plate is separated from the conducting plate by the projection of the deforming plate moving toward the conducting plate and adding an impact to the contact plate when the internal pressure of the casing rises above the predetermined level,

in the third condition a force of the contact plate moving toward the conducting plate and a force of the deforming plate separating the contact plate from the conducting plate are balanced, and

in the third condition the contact plate is separated from the conducting plate so as not to conduct with the conducting plate.

6. The current interruption device according to claim 4, wherein

the deforming plate is an inverting plate, and

an elastic force that inverts the deforming plate is larger than a force that breaks the groove of the conducting plate.

7. The current interruption device according to claim 1, further comprising:

an insulating member having an insulation property disposed between the deforming plate and the conducting plate.

8. The current interruption device according to claim 1, wherein

a recess is disposed at a center portion of the conducting plate on a deforming plate side.

9. The current interruption device according to claim 4, wherein

an area surrounded by the groove of the conducting plate is recessed toward an opposite side of the deforming plate than a surface positioned at an outer side of the groove of the conducting plate.

10. The current interruption device according claim 1, wherein

a fragile portion is disposed around the second contact portion of the contact plate, the fragile portion being more fragile than other portions of the contact plate.

11. The current interruption device according to claim 10, wherein

an interspacing portion is disposed between an outer circumference portion of the contact plate and the second contact portion, a distance from the interspacing portion to the conducting plate being increased from the outer circumference portion toward a center portion of the contact plate, and

the fragile portion is disposed on the interspacing portion.

12. The current interruption device according to claim 1, wherein

a periphery of the first contact portion on a surface of the conducting plate on a contact plate side is recessed.

13. The current interruption device according to claim 1, wherein

the deforming plate and the contact plate are configured by thin plates.

14. The current interruption device according to claim 13, wherein

the deforming plate is configured by a thin plate having an arc-shaped wavy portion, and

the contact plate is configured by a flat thin plate.

15. The current interruption device according to claim 13, wherein

the deforming plate is configured by a flat thin plate, and

the contact plate is configured by a thin plate having an arc-shaped wavy portion.

16. The current interruption device according to claim 1, wherein

a through-hole configured to allow the contacting portion to pass through is disposed at a center portion of the conducting plate.

17. The current interruption device according to claim 1, wherein

a pressure hole configured to exert a pressure change caused by the deformation of the deforming plate on the contact plate is disposed on the conducting plate.

18. The current interruption device according to claim 3, further comprising:

an insulating cap covering the a projection.

19. The current interruption device according to claim 18, wherein

the cap including a guide portion that is supported with an outer circumference portion of the conducting plate.

20. The current interruption device according to claim 18, wherein

a groove surrounds an entire periphery of a portion with which the contacting portion makes contact, and

an area surrounded by the groove is recessed relative to a surface of the conducting plate on an outer side of the groove.

21. The current interruption device according to claim 1, further comprising:

a conductive sealing cover body provided so as to cover an outer side of the contact plate,

wherein the sealing cover body is screw-fixed to the external terminal.

22. The current interruption device according to claim 1, further comprising:

a conductive sealing cover body provided so as to cover an outer side of the contact plate,

wherein the sealing cover body is connected to the external terminal via a connecting member.

23. The current interruption device according to claim 1, wherein

the current interruption device is disposed on the current path formed between the negative electrode external terminal and the electrode assembly.

24. The current interruption device according to claim 1, wherein

the deforming plate is made of a same material as the negative electrode.

25. An electric storage device comprising:

the current interruption device according to claim 1.

26. The electric storage device according to claim 25, wherein

the electric storage device is a secondary battery.