Battery pack of improved safety

Patent metadata

Field	Value
Publication number	US-9768473-B2
Application number	US-201414276539-A
Country	US
Kind code	B2
Filing date	May 13, 2014
Priority date	Jan 26, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Disclosed is a battery pack configured such that a plurality of battery modules is connected to each other in series in a state in which the modules are in contact with each other or stacked adjacent to each other, the pack being fixed such that a stacked state of the modules is maintained even when volume of the modules is changed during charge and discharge, the pack including a cut-off portion connected in series to an electrical connection circuit between modules, a fixing member to fix a circuit breaker to at least one outer surface of the pack, and the breaker configured to be electrically conducted when an outer surface of at least one module expands by a reference volume value or more, the breaker being connected in series to the electrical connection circuit to short-circuit the cut-off portion when electric conduction is performed due to swelling of the modules.

First claim

The invention claimed is:

1. A battery pack configured such that a plurality of battery modules 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 being fixed such that a stacked state of the battery modules is maintained even when volume of the battery modules is changed during charge and discharge of the battery modules, the battery pack comprising:
a cut-off portion connected in series to an electrical connection circuit between the battery modules;
a fixing member to fix a circuit breaker to at least one outer surface of the battery pack; and
the circuit breaker configured to be electrically conducted when an outer surface of at least one battery module expands by a reference volume value or more, the circuit breaker being connected in series to the electrical connection circuit to short-circuit the cut-off portion when electric conduction is performed due to swelling of the battery modules,
wherein the circuit breaker comprises:
an electrically insulative housing fixed to the fixing member in position, the housing having a receiving part open at a top thereof;
an electrically insulative cap mounted in the receiving part while being in contact with a side of one of the battery modules such that the cap can elastically move in response to the change in volume of the battery modules;
an electrically conductive electric conduction connection member interlocked with the cap; and
a conduction member comprising a cathode conduction part and an anode conduction part, each of which has one end located inside the receiving part such that one end comes into contact with the electric conduction connection member when the volume of the battery modules increases and the other end located outside the receiving part such that the other end is connected in series to the electrical connection circuit between the battery modules.

2. The battery pack according to claim 1 , wherein each of the battery modules comprises one or more battery cells.

3. The battery pack according to claim 2 , wherein each of the battery cells is a pouch-shaped battery cell having an electrode assembly mounted in a case formed of a laminate sheet comprising a resin layer and a metal layer.

4. The battery pack according to claim 1 , wherein electrode terminal portions of the battery pack are fixed such that the stacked state of the battery modules is maintained even when the volume of the battery modules is changed.

5. The battery pack according to claim 1 , wherein the cut-off portion comprises a fuse.

6. The battery pack according to claim 1 , wherein the fixing member comprises a frame open at a middle thereof such that the circuit breaker contacts the battery modules, the frame being fastened to the battery modules in an assembling manner.

7. The battery pack according to claim 6 , wherein the fixing member is provided with one or more brackets to fix the circuit breaker in position, the one or more brackets extending from the frame toward the open middle of the frame.

8. The battery pack according to claim 1 , wherein the circuit breaker further comprises at least one guide bolt, by which the cap is elastically mounted to the housing, a through hole formed through the cap and the electric conduction connection member such that the guide bolt can be inserted through the through hole, at least one compression spring mounted at a lower end of the electric conduction connection member, and a nut coupled to the guide bolt at an opposite side of the receiving part of the housing.

9. The battery pack according to claim 8 , wherein the at least one guide bolt comprises two or more guide bolts, and the at least one compression spring comprises two or more compression springs.

10. The battery pack according to claim 8 , wherein the circuit breaker further comprises a bushing mounted between the compression spring and a bottom of the receiving part of the housing.

11. The battery pack according to claim 1 , wherein the cap and the housing each have an upwardly tapered structure in which one side or opposite sides of the cap and one side or opposite sides of the housing are tapered upward.

12. The battery pack according to claim 1 , wherein the housing is provided at a side wall thereof defining the receiving part with a slit, through which a spacing distance between the electric conduction connection member and the conduction member can be observed or measured.

13. 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 conductive wires, respectively.

14. The battery pack according to claim 1 , wherein the electric conduction connection member is electrically spaced apart from the conduction member in a state in which the battery modules normally operate.

15. The battery pack according to claim 1 , wherein, when the battery modules swell in a state in which the battery modules abnormally operate, the cap of the circuit breaker is pushed outward by the battery modules, the volume of which expands, with the result that opposite ends of the electric conduction connection member mounted in the cap come into contact with the cathode conduction part and the anode conduction part, whereby high electric current flows between the cathode conduction part and the anode conduction part and thus the cut-off portion short-circuits.

16. A device comprising a battery pack according to claim 1 as a power source.

17. The device according to claim 16 , wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Assignees

• Lg Chemical Ltd

Inventors

• Roh Tae Hwan
• Lee Jin Kyu
• Choi Jun Seok
• Kim Seong Tae
• Kim Tae Hyuck
• Kim Dongyeon

Classifications

• H01M50/583

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

• H01M50/262

  with fastening means, e.g. locks · CPC title

• H01M50/211 Primary

  adapted for pouch cells · CPC title

• H01M50/572

  Means for preventing undesired use or discharge · CPC title

• H01M50/20 Primary

  Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders (structural combination of accumulators with charging apparatus H01M10/46) · CPC title