Battery pack of improved safety

Patent metadata

Field	Value
Publication number	US-9455436-B2
Application number	US-201414154828-A
Country	US
Kind code	B2
Filing date	Jan 14, 2014
Priority date	Jul 25, 2011
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

Disclosed herein is a battery pack configured such that battery modules, each of which includes a plurality of battery cells or unit modules connected to each other in series, are connected to each other in series in a state in which the battery modules are in tight contact with each other or stacked adjacent to each other, the battery pack including a fuse connected in series in an electrical connection circuit between the battery modules and a circuit breaker mounted at an outside of at least one of the battery modules to perform electric conduction when the battery cells swell, the circuit breaker being electrically connected to the electrical connection circuit to break the fuse when electric conduction is performed due to swelling of the battery cells.

First claim

The invention claimed is:

1. A battery pack configured such that battery modules, each of which comprises a plurality of battery cells or unit modules connected to each other in series, are connected to each other in series in a state in which the battery modules are in tight contact with each other or stacked adjacent to each other, the battery pack comprising:
a fuse connected in series in an electrical connection circuit between the battery modules;
a circuit breaker mounted at an outside of at least one of the battery modules to perform electric conduction when the battery cells swell, the circuit breaker being electrically connected to the electrical connection circuit to break the fuse when electric conduction is performed due to swelling of the battery cells, and
wherein the circuit breaker comprises:
a first conductive member contacting a side of one of the battery modules;
a second non-conductive member coupled to the first conductive member via an elastic guide in a state in which the second member is fixed in position to the battery module; and
a conduction member comprising a cathode conduction part and an anode conduction part mounted to the second non-conductive member such that the cathode conduction part and the anode conduction part come into contact with the first conductive member according to the increase in volume of the battery modules at the time of swelling of the battery cells, the cathode conduction part and the anode conduction part being electrically connected to the electrical connection circuit between the battery modules.

2. The battery pack according to claim 1 , wherein electrode terminal portions of the battery pack are fixed such that a stacked state of the battery modules is maintained even when volume of the battery cells is changed, and the circuit breaker is located at a portion corresponding to a side of one of the battery modules on which expansion stress due to swelling of the battery cells concentrates.

3. The battery pack according to claim 1 , wherein the circuit breaker is located at a portion corresponding to a side of an outermost battery module.

4. The battery pack according to claim 1 , wherein a cathode terminal of one outermost battery module and an anode terminal of the other outermost battery module are electrically connected to the cathode conduction part and the anode conduction part of the circuit breaker via wires, respectively.

5. The battery pack according to claim 1 , wherein the first conductive member and the conduction member are electrically spaced apart from each other in a state in which the battery modules normally operate.

6. The battery pack according to claim 1 , wherein, when the battery cells swell in a state in which the battery modules abnormally operate, the first conductive member is pushed outward by the battery module, the volume of which expands, with the result that opposite ends of the first conductive member come into contact with the cathode conduction part and the anode conduction part, whereby high current flows between the cathode conduction part and the anode conduction part and thus the fuse is broken.

7. The battery pack according to claim 1 , wherein the first conductive member comprises:
a first contact part, formed in a bracket shape when viewed in horizontal section, contacting a central portion of the outside of the battery module; and
second contact parts extending from opposite sides of the first contact part to portions corresponding to the cathode conduction part and the anode conduction part of the conduction member.

8. The battery pack according to claim 1 , wherein the elastic guide comprises a combination of a bolt and a nut coupled to the first conductive member and the second non-conductive member in a state in which a compression spring is interposed between the first conductive member and the second non-conductive member.

9. The battery pack according to claim 1 , wherein each of the unit modules comprises:
two or more battery cells configured to have a stacked structure in which electrode terminals are connected to each other in series and an electrode terminal connection portion of the electrode terminals is bent; and
a pair of sheathing members coupled to fully cover an outside of a battery cell stack excluding the electrode terminals.

10. The battery pack according to claim 9 , wherein each of the sheathing members has an inner structure corresponding to an external shape of the battery cell stack, and the sheathing members are coupled to each other by assembly and fastening.

11. The battery pack according to claim 9 , wherein the electrode terminals are coupled to each other by welding.

12. The battery pack according to claim 1 , wherein each of the battery cells is a plate-shaped battery cell configured to have a structure in which an edge of a battery case formed of a laminate sheet comprising a resin layer and a metal layer is sealed in a state in which an electrode assembly is mounted in the battery case.

13. The battery pack according to claim 12 , wherein the battery case is a pouch-shaped case formed of an aluminum laminate sheet.

14. The battery pack according to claim 9 , wherein the sheathing members are high-strength cell covers.

15. The battery pack according to claim 9 , wherein the electrode terminals are formed at an upper end or a lower end of each of the battery cells or respectively formed at the upper and the lower end of each of the battery cells.

16. The battery pack according to claim 1 , wherein, when swelling of the battery cells causes the increase in volume of the battery cells equivalent to two to five times a thickness of each of the battery cell, the circuit breaker senses the change in volume of the battery cells to break the circuit of the battery pack.

17. The battery pack according to claim 1 , wherein the battery pack is used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Assignees

• Lg Chemical Ltd

Inventors

• Roh Taehwan
• Lee Jin Kyu
• Choi Junseok
• Jang Min Chul
• Shin In Cur
• Kang Dalmo
• Kim Seongtae
• Kim Taehyuck

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2200/00

  Safety devices for primary or secondary batteries · CPC title

• H01M50/516

  by welding, soldering or brazing · CPC title

• H01M50/548

  on opposite sides of the cell · CPC title

• H01M50/583

  in response to current, e.g. fuses · CPC title