Battery module with swelling sensing means

Abstract

The present invention relates to a battery module including a plurality of battery cells having electrode leads for early detection of swelling, a module case for accommodating the plurality of battery cells, an interconnect board (ICB) assembly having bus bars electrically connected to the electrode leads, and a swelling detection means for detecting swelling of the battery cells.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2021-0138260 dated October 18, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module including a swelling detection means, which is capable of detecting swelling of a battery cell at an early stage. [Background technology]

[0003] As technological development and demand for mobile devices such as smartphones, notebook PCs, and digital cameras increases, research into rechargeable secondary battery technology is being actively conducted. Secondary batteries are an alternative energy source to fossil fuels that generate air pollutants, and are used in electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and energy storage devices (ESSs).

[0004] Currently, the types of secondary batteries that are widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such unit secondary battery cells, i.e., unit battery cells, is about 2.0V to 5.0V. Therefore, if a higher output voltage is required, a cell module assembly can be constructed by connecting a plurality of battery cells in series, or a battery module can be constructed by connecting cell module assemblies in series or parallel depending on the required output voltage or charge / discharge capacity. In this way, it is common to manufacture a battery pack by adding additional components using at least one battery module.

[0005] If such a battery cell is overcharged, overheated, impacted, or short-circuited, gas may be generated inside the battery cell, causing the battery cell to swell, resulting in a swelling phenomenon.

[0006] Such swelling phenomenon generally occurs prior to a battery cell fire or explosion.

[0007] Therefore, various methods have been devised for detecting the swelling phenomenon in order to detect the swelling phenomenon before a fire or explosion occurs in a battery cell.

[0008] Patent Document 1 relates to a battery pack 200, in which battery cells 10 are housed and stacked in a module case 50, and which includes a horizontal detection sensor 70 capable of determining whether a wall surface of the module case 50 is distorted.

[0009] The horizontal detection sensor 70 can detect that the module case 50 is distorted by the side of the expanded battery cell 10 when swelling of the battery cell 10 occurs, and based on this, transmits a signal from the control unit 80 to the injector 62 to inject the extinguishing agent 60, thereby discharging the extinguishing agent.

[0010] However, unlike the battery pack of Patent Document 1, in the case of a battery pack / module that does not have a module case capable of detecting horizontality between battery cells to increase energy density or is densely stacked without any space, there is a problem that it is difficult for the horizontality detection sensor to detect swelling.

[0011] In particular, in the case of a battery pack or module in which battery cells are densely stacked with no space between them, even if gas is generated in a particular battery cell, the side portion that is in close contact with the adjacent battery cell cannot easily expand due to pressure. Instead, a phenomenon occurs in which the sealing portion side from which the electrode lead protrudes in the battery cell swells first.

[0012] Therefore, in order to detect swelling of a battery pack or module in which the side portions of battery cells are in close contact with each other at an early stage, a detection means that utilizes this phenomenon is needed. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Korean Patent Publication No. 2017-0061582 Summary of the Invention [Problem to be solved by the invention]

[0014] In order to solve the above problems, an object of the present invention is to provide a battery module that can detect swelling at an early stage by including a swelling detection means having a detection pocket in a space between a battery cell and an ICB. [Means for solving the problem]

[0015] To achieve the above object, a battery module according to the present invention includes a plurality of battery cells each having an electrode lead, a module case for accommodating the plurality of battery cells, an interconnect board (ICB) assembly including a bus bar electrically connected to the electrode lead, and a swelling detection means for detecting swelling of the battery cell.

[0016] In the battery module according to the present invention, the battery cells are pouch-type battery cells.

[0017] In the battery module according to the present invention, the swelling detection means is filled with gas or liquid.

[0018] In addition, the battery module according to the present invention is characterized in that the swelling sensing means includes a plurality of sensing pockets, a connection part connecting the plurality of sensing pockets, and an injection part for injecting gas or liquid therein.

[0019] In the battery module according to the present invention, the plurality of sensing pockets are located in a space between the ICB assembly and the battery cells.

[0020] In the battery module according to the present invention, the plurality of sensing pockets, the connection portion, and the injection portion are integrally formed.

[0021] In the battery module according to the present invention, the swelling sensing means is made of an elastic polymer material.

[0022] In addition, the battery module according to the present invention is characterized in that the polymer material is any one selected from the group consisting of natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (H-NBR), chloroprene rubber (CR), ethylene propylene rubber (EPDM), butyl rubber (IIR), acrylic rubber (ANM / ACM), silicone rubber, fluoro rubber (FKM / FPM), and urethane rubber (AU / EU).

[0023] In the battery module according to the present invention, the swelling detection means detects swelling of the battery cell by monitoring a change in an internal pressure.

[0024] A battery pack according to the present invention includes the battery module according to the present invention.

[0025] A device according to the present invention is also characterized in that it comprises the battery pack according to the present invention. Effect of the Invention

[0026] The battery module of the present invention has an advantage that, by including the swelling detection means, a swelling phenomenon can be detected early even when the battery cells are closely stacked.

[0027] In addition, the battery module of the present invention has an advantage that the swelling phenomenon can be detected and dealt with early, thereby reducing the risk of fire or explosion of the battery cell. [Brief description of the drawings]

[0028] [Figure 1] 1 is a cross-sectional view illustrating a schematic structure of a conventional battery pack. [Diagram 2] 1 is a cross-sectional view illustrating a battery module before being provided with a swelling sensing means according to an embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view illustrating a battery module having a swelling sensing means according to an embodiment of the present invention; [Figure 4] FIG. 2 is a cross-sectional view illustrating a swelling sensing means according to an embodiment of the present invention. [Diagram 5] 1 is a cross-sectional view illustrating a battery module including a battery cell in which a swelling phenomenon occurs according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] In this application, the terms "including," "having," or "comprising" are intended to specify the presence of features, numbers, steps, components, parts, or combinations thereof described in the specification, but should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0030] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0031] Hereinafter, a battery module according to the present invention will be described with reference to the accompanying drawings.

[0032] Hereinafter, a battery module according to the present invention will be described with reference to the accompanying drawings.

[0033] FIG. 2 is a cross-sectional view illustrating a battery module before being equipped with a swelling sensing means according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating a battery module equipped with a swelling sensing means according to an embodiment of the present invention.

[0034] The battery module 1000 of the present invention will be described with reference to FIGS. 2 and 3. The battery module 1000 includes a plurality of stacked battery cells 100, a module case 200, an ICB assembly 300, and a swelling sensing means 400.

[0035] First, the battery cell 100 can be classified into a cylindrical battery cell, a prismatic battery cell, and a pouch-type battery cell according to the shape of the case, and the battery cell 100 of the present invention is preferably a pouch-type battery cell 100.

[0036] The pouch-type battery cell 100 generally refers to a battery cell 100 in which a battery case for accommodating an electrode assembly is a pouch case.

[0037] Here, the pouch case 120 generally has an inner layer / metal layer / outer layer laminate sheet structure. The inner layer is in direct contact with the electrode assembly, so it must have insulating properties and electrolyte resistance, and the inner layers must have excellent sealing properties, i.e., excellent thermal adhesion strength at the sealing portion where the inner layers are thermally bonded to each other, in order to seal against the outside.

[0038] The material of such an inner layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, polyurethane resins, and polyimide resins, which have excellent chemical resistance and sealing properties, but are not limited thereto.

[0039] The metal layer in contact with the internal layer corresponds to a barrier layer that prevents moisture and various gases from penetrating into the interior of the battery from the outside. A preferred material for such a metal layer is a thin aluminum film, which is lightweight yet has excellent formability.

[0040] An outer layer is provided on the other side of the metal layer, and the outer layer may be made of a heat-resistant polymer having excellent tensile strength, moisture permeability, and air permeability so as to protect the electrode assembly and ensure heat resistance and chemical resistance, such as, but not limited to, nylon or polyethylene terephthalate.

[0041] In addition, the battery cell 100 generally has positive and negative electrode leads 110 protruding / extending outside the pouch case, and the directions in which the positive and negative electrode leads 110 protrude may be the same or different from each other.

[0042] Such a pouch-type battery cell 100 is manufactured by a process of housing an electrode assembly inside a pouch case, injecting an electrolyte, and then sealing the pouch case. Such a pouch-type battery cell 100 typically has a sealing part 120 formed on the outer periphery of three or four sides including the part where the electrode lead 110 protrudes.

[0043] The module case 200 houses a plurality of battery cells 100 and serves to protect them from external impacts, and various known module cases 200 may be used.

[0044] Next, the ICB (Interconnect Board) assembly 300 generally includes a bus bar 310 and serves to electrically connect the electrode lead 110 of the battery cell 100 to the bus bar 310 .

[0045] In addition, the battery charge / discharge circuit 104 may also transmit various electrical signals corresponding to the temperature or voltage of the battery cell 100 to a battery management system (BMS) during charging / discharging of the battery cell 100.

[0046] FIG. 4 is a cross-sectional view showing a schematic diagram of a swelling sensing means according to an embodiment of the present invention.

[0047] The swelling sensing means 400 of the present invention will be described with reference to FIGS. 2 to 4. The swelling sensing means 400 includes a sensing pocket 410, a connecting portion 420, and an injection portion 430.

[0048] The swelling sensing means 400 is used by injecting gas or liquid into the inside after being mounted on the battery module 1000.

[0049] The sensing pocket 410 is located in the space between the battery cell 100 and an adjacent battery cell 100, specifically, in the space between the electrode lead 110 of one battery cell 100 and the sealing portion 120 surrounding the electrode lead 110 and the electrode lead 110 of the adjacent battery cell 100 and the sealing portion 120 surrounding the electrode lead 110, and multiple sensing pockets 410 may be provided depending on the number of stacked battery cells 100.

[0050] From another perspective, the sensing pocket 410 is located in the space between the ICB assembly 300 and the battery cell 100 of FIG. 2, which is omitted in FIG.

[0051] The connection portion 420 connects the plurality of sensing pockets 410 and is used as a passage for injecting gas or liquid into the sensing pockets 410 .

[0052] Next, the injection part 430 serves as an inlet / outlet for injecting gas or liquid into the sensing pocket 410 and the connection part 420, and is located outside the module case 200, and serves to inject gas or liquid from the outside after the swelling sensing means 400 is attached and the battery module 1000 is formed.

[0053] In addition, the injector 430 may be connected to a sensor for monitoring a pressure change inside the swelling sensing means 400 .

[0054] The sensing pocket 410, the connecting portion 420, and the injection portion 430 are preferably formed integrally so that gas or liquid is injected therein, and further, are preferably formed from an elastic polymer material in order to effectively sense the pressure of the battery cell 100 that has expanded due to swelling.

[0055] Such a polymer material may be a composite material including one or more selected from the group consisting of natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (H-NBR), chloroprene rubber (CR), ethylene propylene rubber (EPDM), isobutylene isoprene rubber (IIR), acrylic rubber (ANM / ACM), silicone rubber, fluoro rubber (FKM / FPM), and urethane rubber (AU / EU).

[0056] The swelling sensing means 400 can be manufactured by integrally forming such a polymer material using various known molding methods.

[0057] As the gas or liquid injected into the swelling sensing means 400, various known gases or liquids capable of sensing the battery cell 100 expanded due to swelling can be used.

[0058] For example, air or water are the most readily available and cheapest to use fluids, and the swelling detection means 400 does not only simply function to detect swelling, but can also inject a fire extinguishing liquid therein so that the internal gas or liquid can be used to extinguish a fire in the event of a fire.

[0059] Injecting such a fire extinguishing liquid has the effect of suppressing the spread of the fire to the adjacent battery cells 100.

[0060] FIG. 5 is a cross-sectional view illustrating a battery module including a battery cell in which a swelling phenomenon occurs according to an embodiment of the present invention.

[0061] Referring to FIG. 5, the process of detecting the occurrence of swelling in a battery module 1000 including a swelling detection means 400 will be described. First, when swelling occurs in a particular battery cell 100, as shown in FIG. 5, expansion S occurs first in the sealing portion 120 where the electrode lead 110 protrudes rather than in the side portion that is in close contact with the adjacent battery cell 100.

[0062] The expansion of the sealing part 120 presses the sensing pocket 410 of the swelling sensing means 400 located between the electrode leads 110, causing a flow of gas or liquid inside. By sensing this with a sensor connected to the injection part 430, it is possible to detect the occurrence of swelling inside the battery module.

[0063] Therefore, it is possible to quickly perform follow-up measures such as stopping the operation of the battery module 1000 and removing the battery cell 100 in which swelling has occurred.

[0064] In addition, compared to the manufacturing process of the existing battery module 1000, the battery module 1000 of the present invention can be manufactured by installing the swelling sensing means 400 formed integrally in advance in space, which has the advantage that most of the design and manufacturing processes of the existing battery module 1000 can be shared, thereby minimizing increases in manufacturing costs.

[0065] In addition, a battery pack can be manufactured by including one or more battery modules 1000 of the present invention and adding various devices such as a BMS, and such a battery pack or battery module 1000 can be used as a power supply source for various devices.

[0066] Although certain parts of the contents of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific techniques are merely preferred embodiments and do not limit the scope of the present invention. Various changes and modifications are possible within the scope of the scope and technical ideas of the present invention, and it goes without saying that such changes and modifications are also included in the scope of the attached claims. [Explanation of symbols]

[0067] 1000 Battery Module 100 Battery Cells 110 Electrode Lead 120 Sealing part 200 module case 300 ICB assembly 310 Busbar 400 Swelling detection means 410 Sensing Pocket 420 Connection section 430 Injection part

Claims

1. A plurality of battery cells each having an electrode lead; a module case that houses the plurality of battery cells; an ICB (Interconnect Board) assembly including a bus bar electrically connected to the electrode lead; A swelling detection means for detecting swelling of the battery cell; Including, The swelling sensing means has a gas or liquid injected therein, The swelling sensing means includes a plurality of sensing pockets, a connecting portion that connects the plurality of sensing pockets, and an injection portion for injecting gas or liquid into the interior of the battery module.

2. The battery module according to claim 1 , wherein the battery cells are pouch-type battery cells.

3. The battery module of claim 1 , wherein the plurality of sensing pockets are located in a space between the ICB assembly and the battery cells.

4. The battery module according to claim 1 , wherein the plurality of sensing pockets, the coupling portion, and the injection portion are integrally formed.

5. The battery module according to claim 1 , wherein the swelling sensing means is made of an elastic polymer material.

6. The polymer materials include natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (H-NBR), chloroprene rubber (CR), ethylene propylene rubber (EPDM), butyl rubber (Isobutylene Isoprene), and ethylene propylene rubber (EPDM).

6. The battery module according to claim 5, wherein the rubber material is any one selected from the group consisting of IIR rubber, ANM / ACM acrylic rubber, silicone rubber, FKM / FPM fluoro rubber, and AU / EU urethane rubber.

7. The battery module according to claim 1 , wherein the swelling detection means detects swelling of the battery cell by monitoring a change in the internal pressure.

8. A battery pack comprising the battery module according to any one of claims 1 to 7.

9. A device comprising the battery pack of claim 8.

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