Battery module

Abstract

The present application provides a battery module configured to block heat propagation in response to an event occurring in a battery cell. The battery module includes a plurality of battery cells arranged in one direction and at least one insulating spacer between the plurality of battery cells. The insulating spacer includes a pocket defining a space therein and a phase change material configured to fill at least a portion of the space.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2024 - 0012236, filed with the Korean Intellectual Property Office on January 26, 2024, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] Embodiments relate to a battery module. Background art

[0004] A secondary battery is an energy storage system that converts electrical energy into chemical energy, stores the chemical energy, and provides a high energy density. Compared with a primary battery that cannot be recharged, a secondary battery is rechargeable and is widely used in IT devices such as smart phones, cellular phones, laptop computers, and tablet computers. Recently, due to the prevention of environmental pollution, there has been increasing interest in electric vehicles, and high - capacity secondary batteries are being adopted in electric vehicles. Secondary batteries require characteristics such as high energy density, high output, and stability.

[0005] The information disclosed in this section is provided only for enhancing the understanding of the background of the present disclosure, so it may contain information that does not constitute the prior art. Summary of the invention

[0006] Embodiments provide a battery module configured to block heat propagation in response to an event occurring in a battery cell.

[0007] It should be noted that the objectives of the present invention are not limited to the above - mentioned objectives, and other objectives not mentioned in the present disclosure will be clearly understood by those skilled in the art from the following description and the accompanying drawings.

[0008] A battery module according to an embodiment of the present disclosure includes a plurality of battery cells arranged in one direction and at least one insulating gasket between the plurality of battery cells. The insulating gasket includes a pocket region in which a space is defined and a phase - change material configured to fill at least a part of the space.

[0009] The phase - change material may be configured to be in a liquid state in response to the temperature of the phase - change material being lower than a predetermined temperature.

[0010] The phase - change material may be configured to evaporate from a liquid state to a gas state in the space of the pocket region in response to the temperature of the phase - change material being equal to or higher than the predetermined temperature.

[0011] The phase - change material may fill half or less of the space.

[0012] The insulating gasket may include a front sheet and a rear sheet that are coupled to each other and define the pocket region. The edge of the pocket region may be ultrasonically fused or bonded.

[0013] The pouch area may include polyethylene or polypropylene.

[0014] The shape of the pouch area may be configured to change in response to pressure in the pouch area.

[0015] The front and rear sheets of the pouch area may contact battery cells among a plurality of battery cells that are adjacent to the front and rear sheets.

[0016] The phase change material may include a material having a boiling point of about 60 °C to about 150 °C.

[0017] The phase change material may include nonafluorobutyl methyl ether (C4F9OCH3).

[0018] The pouch area may seal the phase change material by ultrasonic fusion or adhesion.

[0019] The volume of the phase change material may be configured to increase in response to evaporation, and the volume increases sequentially from the upper part of the pouch area.

[0020] The insulating gasket may further include a front sheet, a rear sheet, and an adhesive area that adhesively bonds the front and rear sheets at substantially the middle of the pouch area.

[0021] The adhesive area may divide the pouch area into an upper part and a lower part.

[0022] The adhesive area may include a plurality of adhesive areas arranged in at least one row.

[0023] The adhesive area may be configured to maintain the adhesion between the front and rear sheets even in response to an increase in the volume of the pouch area.

[0024] The insulating gasket may further include a boundary area along the edge of the pouch area.

[0025] The boundary area may include mica. Description of the Drawings

[0026] The accompanying drawings incorporated in this specification illustrate example embodiments and are used to further illustrate the technical idea of the present disclosure in combination with the detailed description of the following example embodiments, and the present disclosure is not construed as being limited to the content shown in these drawings. In the drawings:

[0027] Figure 1A is a side cross-sectional view showing a battery module according to an embodiment of the present disclosure;

[0028] Figure 1B is a plan view showing a battery module according to an embodiment of the present disclosure;

[0029] Figure 2A is a front view showing the structure of an insulating gasket used in a battery module according to an embodiment of the present disclosure;

[0030] Figure 2BA side cross-sectional view showing the structure of an insulating gasket used in a battery module according to an embodiment of the present disclosure;

[0031] Figure 3A A side cross-sectional view showing the operation of the insulating gasket when an event occurs in a battery module according to an embodiment of the present disclosure;

[0032] Figure 3B A plan view showing the operation of the insulating gasket when an event occurs in a battery module according to an embodiment of the present disclosure;

[0033] Figure 4 A cross-sectional view showing the operation of the insulating gasket when an event occurs in a battery module according to an embodiment of the present disclosure;

[0034] Figure 5A A front view showing the structure of an insulating gasket used in a battery module according to another embodiment of the present disclosure; and

[0035] Figure 5B For showing when an event occurs in a battery module according to another embodiment of the present disclosure Figure 5A A cross-sectional view of the operation of the insulating gasket. Detailed Embodiments

[0036] Embodiments are provided to more fully explain the present disclosure to those of ordinary skill in the art. The following embodiments can be modified in various other forms, and the scope of the present disclosure is not limited to the following embodiments. The embodiments are provided to make the present disclosure more credible and complete, and to fully convey the concept of the present disclosure to those skilled in the art.

[0037] In the following drawings, for convenience and clear description, the dimensions (e.g., thickness) of each layer are enlarged, and the same reference numerals in the drawings refer to the same elements. As used herein, the term "and / or" includes any one of the listed items and any combination of multiple thereof. As used herein, the term "connection" refers not only to the direct connection between member A and member B, but also to the indirect connection between member A and member B with member C interposed therebetween.

[0038] The terms used in the specification are intended to describe particular embodiments and are not intended to limit the disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms may include the plural forms. As used herein, the terms "comprise" (or "include") and / or "comprising" (or "including") are intended to indicate the presence of the specified figures, numbers, steps, operations, components, elements, and / or groups thereof, without excluding the presence or addition of one or more other figures, numbers, steps, operations, components, elements, and / or groups thereof.

[0039] Although terms such as first and second are used herein to describe various components, parts, regions, layers, and / or portions, the components, parts, regions, layers, and / or portions are not limited by these terms. These terms are only used to distinguish one component, one part, one region, one layer, or one portion from another component, another part, another region, another layer, or another portion. Thus, without departing from the teachings of the disclosure, the first component, the first part, the first region, the first layer, or the first portion described below may refer to the second component, the second part, the second region, the second layer, or the second portion.

[0040] Spatial - related terms, such as "beneath", "below", "lower", "above", and "upper", may be used to facilitate understanding of the difference between one element or feature shown in the drawings and another element or feature. The spatial - related terms are intended to facilitate understanding of the disclosure in various processes or usage states and are not intended to limit the disclosure. For example, if the element or feature in the drawing is inverted, the element or feature described as "beneath" or "below" will become "above" or "upper". Thus, "beneath" encompasses the concepts of "above" or "below".

[0041] Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.

[0042] Figure 1A It is a side - sectional view showing a battery module according to an embodiment of the disclosure. Figure 1B It is a plan view showing a battery module according to an embodiment of the disclosure. Figure 2A It is a front view showing the structure of an insulating gasket used in a battery module according to an embodiment of the disclosure. Figure 2B It is a side - sectional view showing the structure of an insulating gasket used in a battery module according to an embodiment of the disclosure.

[0043] See Figures 1A to 2B , a battery module 100 according to an embodiment of the disclosure may include a plurality of battery cells 110 and a plurality of insulating gaskets 120 located between adjacent battery cells 110.

[0044] Multiple battery cells 110 may be arranged in one direction. Each of the battery cells 110 may include an electrode assembly, in which a positive electrode plate, a separator, and a negative electrode plate are stacked or wound and are received or contained together with an electrolytic solution in a case. A cover plate configured to seal the case may be coupled to one surface of the case, and two electrode terminals 111 may be at the cover plate. A vent 112 may be formed in a part of the cover plate that has a thickness smaller than that of the remaining part of the cover plate, and the vent 112 may be configured to open first in response to a pressure caused by a gas at or above a reference pressure.

[0045] Multiple battery cells 110 may be arranged in one direction such that wide side surfaces of the cases of the battery cells 110 are adjacent to each other. The multiple battery cells 110 may be coupled to each other via insulating gaskets 120 therebetween. Each of the insulating gaskets 120 may have an area corresponding to a side surface of each of the battery cells 110, and the insulating gaskets 120 may prevent (or at least slow down) the cases of the battery cells 110 from directly contacting each other. The multiple battery cells 110 may be electrically isolated and thermally isolated from each other by the insulating gaskets 120. The multiple battery cells 110 may be connected in series, in parallel, or in series-parallel via bus bars coupled to the electrode terminals 111 at the tops of the battery cells 110.

[0046] The insulating gaskets 120 may be between the multiple battery cells 110, and adjacent battery cells 110 may be spaced apart from each other by a distance corresponding to the thickness of the insulating gaskets 120. The insulating gaskets 120 may be made of an electrically insulating material and may have thermal insulation properties. Each insulating gasket 120 may isolate adjacent battery cells among the battery cells 110 to prevent (or at least slow down) heat transfer from a specific battery cell 110 in which an event has occurred to an adjacent battery cell 110 thereto.

[0047] See Figures 2A to 2B , each of the insulating gaskets 120 may include a boundary region 121 and a pocket region 122 inside the boundary region 121.

[0048] The boundary region 121 of the insulating gasket 120 may include a rigid material capable of maintaining the spacing between the battery cells 110. In one or more embodiments, the boundary region 121 of the insulating gasket 120 may be made of mica. The size (e.g., thickness) of the boundary region 121 may remain constant regardless of the temperature of the insulating gasket 120.

[0049] The pocket region 122 of the insulating gasket 120 may include a liquid received therein and may include a material configured to be deformed by the pressure of internal gas. In one or more embodiments, the pocket region 122 of the insulating gasket 120 may include polypropylene (PP) or polyethylene (PE).

[0050] The pocket area 122 may include two sheets, such as a front sheet and a rear sheet. The front sheet and the rear sheet may be joined to each other at the boundary of the adjacent boundary area 121 by ultrasonic fusion or adhesion. The inner surface 123 of the pocket area 122 may create a space S (e.g., a small internal area or cavity).

[0051] The liquid phase change material l may be at the lower part of the space S of the pocket area 122. The phase change material l may fill a part of the lower part of the pocket area 122 to a certain height due to gravity, and the upper part of the space S may be empty. The phase change material l is sealed in the space S of the pocket area 122 and may be kept sealed by ultrasonic fusion or adhesion of the pocket area 122.

[0052] The phase change material l may be configured to be in a liquid state in response to the temperature of the phase change material l being lower than a predetermined temperature (including the temperature under normal conditions). However, in response to the temperature of the phase change material l in the insulating gasket 120 being equal to or higher than the predetermined temperature, the phase change material l may be configured to evaporate, and the phase of the phase change material l may change from a liquid state to a gas state. The phase change material l in the gas state may have a volume larger than the volume of the phase change material l in the liquid state, and thus the evaporation of the phase change material l may increase the volume of the pocket area 122 surrounding the phase change material l. As a result, the volume of the insulating gasket 120 including the pocket area 122 may increase, and the distance between the battery cells 110 spaced apart from each other by the insulating gasket 120 may increase. Accordingly, in response to an event occurring in one battery cell 110 in which the temperature increases to or above the predetermined temperature, the distance from the battery cell 110 to the adjacent battery cell 110 may increase, thereby preventing the heat generated by the event from spreading to the surroundings.

[0053] Hereinafter, the operation of the insulating gasket 120 when an event occurs in an example of a battery module according to an embodiment of the present disclosure will be described in more detail.

[0054] Figure 3A A side cross-sectional view showing the operation of the insulating gasket 120 when an event occurs in the battery module 100 according to an embodiment of the present disclosure. Figure 3B A plan view showing the operation of the insulating gasket 120 when an event occurs in the battery module 100 according to an embodiment of the present disclosure. Figure 4 A cross-sectional view showing the operation of the insulating gasket 120 when an event occurs in the battery module 100 according to an embodiment of the present disclosure.

[0055] As Figure 3A and Figure 3BAs shown, in response to an event occurring in one cell 110a that generates heat, the thickness of each of the insulating gaskets 120a located on the opposite side of the cell 110a can be changed from the thickness d1 in the normal state to d2 that is greater than d1. This change can cause an increase in the distance between the cell 110a in which the event has occurred and the adjacent cell 110b to the cell 110a, and is configured to prevent or reduce the heat generated by the event from being transferred to the adjacent cell 110b.

[0056] As Figure 4 shown, the phase change material l' can receive the heat generated by the event in the cell 110a and can evaporate in the pocket region 122. As a result, the phase change material l' can have a height h' that is less than the height of the phase change material l in the normal state. The phase change material l' can optionally be configured such that all (or substantially all) of the liquid evaporates into a gas. As a result, the volume of the space S' in the pocket region 122 can increase when the phase change material l' evaporates, thereby increasing the distance between the cell 110a in which the event has occurred and the adjacent cell 110b to the cell 110a as described above.

[0057] In one or more embodiments, the phase change material l can be a non-conductive liquid and can have a boiling point of about 60 °C to about 150 °C. The phase change material l can include nonafluorobutyl methyl ether (C4F9OCH3). In one or more embodiments, where the volume of the space S of the pocket region 122 of the insulating gasket 120 is set to about 0.00004 m 3 , the degree of volume expansion can be set by filling the phase change material l to a volume of about 0.00002 m 3 , which is half (or about half) of the volume of the space S. In one or more embodiments, where nonafluorobutyl methyl ether is the phase change material l, the mass of the phase change material l can be about 0.03228 kg because the density of nonafluorobutyl methyl ether is about 1,614 kg / m 3 . In one or more embodiments, where the yield stress of the housing of the cell 110 at the time of the event is about 5 MPa, if all of the phase change material l evaporates, a specific volume of 0.0049 m 3 / kg can be considered under the conditions of 5 MPa and 200 °C. Therefore, the volume increased by evaporation can be about 0.00016 m 3 . In this embodiment, the volume of the space S of the pocket region 122 can become about 0.0002 m 3 , which is greater than about 0.00004 m 3The initial volume, so the distance between the battery cells 110 can be increased to about (approximately) 10 mm. Accordingly, in response to an event occurring in one battery cell 110, the distance between the battery cell 110 and the adjacent battery cell 110 can be increased, thereby preventing (or at least slowing down) the heat generated by the event from spreading to the surroundings.

[0058] Hereinafter, a battery module according to another embodiment of the present disclosure will be described.

[0059] Figure 5A A front view showing the structure of the insulating gasket 220 used in a battery module according to another embodiment of the present disclosure. Figure 5B To show when an event occurs in a battery module according to another embodiment of the present disclosure Figure 5A A cross-sectional view of the operation of the insulating gasket 220.

[0060] First, refer to Figure 5A , the insulating gasket 220 of a battery module according to another embodiment of the present disclosure may include an adhesion zone 224, which is formed by, for example, ultrasonic fusion or bonding of a front sheet and a rear sheet at approximately its middle. As shown, the adhesion zone 224 may include a plurality of adhesion zones arranged in a single row, but in one or more embodiments, two or more rows of adhesion zones may be provided. The plurality of adhesion zones 224 may be formed as a single long zone, as long as the adhesion zone is configured to provide a flow path for gas to move (e.g., flow) in the middle of the bag zone 122.

[0061] Since the front sheet and the rear sheet of the bag zone 122 of the insulating gasket 220 are held coupled to each other at approximately the middle portion thereof by the adhesion zone 224, in response to the evaporation of the phase change material l, volume expansion of the upper portion of the bag zone 122 above the adhesion zone 224 may occur. Therefore, even if Figure 5A in the embodiment depicted in Figure 4 and the embodiment depicted in

[0062] the same phase change material l is used, the volume of the upper portion of the bag zone 122 can be mainly increased, whereby the insulating gasket 220 can experience more volume expansion in the horizontal direction than in the previous embodiments. Figure 5B As a result, compared with Figure 4Compared with the embodiments depicted, the insulating gasket 220 may experience a relatively large volume expansion in the horizontal direction, which may ultimately increase the distance between the battery cell 110b (see Figure 3A ) adjacent to the battery cell 110a in which an event has occurred and the battery cell 110a (see Figure 3A ) and the battery cell 110a (see Figure 3A ) by a relatively large distance.

[0063] As is apparent from the above description, the battery module according to the embodiments of the present disclosure may include a phase change material in the insulating gasket such that in response to an event occurring in a particular battery cell, the phase change material evaporates and the volume of the insulating gasket increases, so that the distance between the battery cell in which the event has occurred and the adjacent battery cells may increase, thereby preventing (or at least slowing down) the heat generated by an event in one battery cell from spreading to the surroundings.

[0064] The effects of the present disclosure are not limited to those described above, and from the description of the above exemplary embodiments, other technical effects not mentioned will be apparent to those skilled in the art.

[0065] The description of the embodiments is merely illustrative, and those of ordinary skill in the art to which the present disclosure pertains will understand that various modifications and other equivalent solutions can be made from the embodiments. Therefore, the true scope of protection of the present invention is determined by the appended claims, and all scope differences equivalent to the scope set forth in the claims should be construed as falling within the scope of protection defined by the claims.

Claims

1. A battery module, comprising: a plurality of battery cells arranged in one direction; and at least one insulating gasket between the plurality of battery cells, wherein the insulating gasket includes: a bag area defining a space therein; and a phase change material configured to fill at least a part of the space.

2. The battery module according to claim 1, wherein the phase change material is configured to be in a liquid state in response to the temperature of the phase change material being lower than a predetermined temperature.

3. The battery module according to claim 1, wherein the phase change material is configured to evaporate from a liquid state to a gas state in the space of the bag area in response to the temperature of the phase change material being equal to or higher than a predetermined temperature.

4. The battery module according to claim 1, wherein the phase change material fills half or less of the space.

5. The battery module according to claim 1, wherein the insulating gasket includes a front sheet and a rear sheet coupled to each other and defining the bag area, and wherein an edge of the bag area is ultrasonically fused or bonded.

6. The battery module according to claim 5, wherein the bag area includes polyethylene or polypropylene.

7. The battery module according to claim 5, wherein a shape of the bag area is configured to change in response to pressure in the bag area.

8. The battery module according to claim 5, wherein the front sheet and the rear sheet of the bag area contact battery cells among the plurality of battery cells adjacent to the front sheet and the rear sheet.

9. The battery module according to claim 1, wherein the phase change material includes a material having a boiling point of 60°C to 150°C.

10. The battery module according to claim 1, wherein the phase change material includes nonafluorobutyl methyl ether.

11. The battery module according to claim 1, wherein the bag area seals the phase change material by ultrasonic fusion or bonding.

12. The battery module according to claim 1, wherein a volume of the phase change material is configured to increase in response to evaporation, and the volume sequentially increases from an upper portion of the bag area.

13. The battery module according to claim 1, wherein the insulating gasket further includes a front sheet, a rear sheet, and a bonding area bonding the front sheet to the rear sheet at a middle of the bag area.

14. The battery module according to claim 13, wherein the bonding area divides the bag area into an upper portion and a lower portion.

15. The battery module according to claim 14, wherein the bonding area includes a plurality of bonding areas arranged in at least one row.

16. The battery module according to claim 14, wherein the bonding area is configured to maintain bonding between the front sheet and the rear sheet even in response to an increase in volume of the bag area.

17. The battery module according to claim 5, wherein the insulating gasket further includes a boundary area along an edge of the bag area.

18. The battery module according to claim 17, wherein the boundary area includes mica.

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