Battery module and battery pack including the same

Abstract

A battery module and a battery pack including the battery module are provided. The battery module according to an embodiment of the present disclosure includes: a battery cell stack formed by stacking a plurality of battery cells; and a barrier layer interposed between adjacent battery cells among the plurality of battery cells, wherein the barrier layer includes a main body portion disposed parallel to the battery cells, and an extension portion bent at one end of the main body portion and covering an upper end portion of the battery cells. The barrier layer formed between a pair of adjacent battery cells in the battery cell stack functions as a flame retardant member, so that when a battery cell catches fire, the heat propagation speed between adjacent battery cells can be delayed.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of Korean Patent Application Nos. 10-2020-0169334, filed on December 7, 2020, and 10-2021-0150561, filed on November 4, 2021, the entire disclosures of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a battery module and a battery pack including the battery module, and more particularly, to a battery module that effectively delays the heat propagation speed between battery cells and a battery pack including the battery module. Background Art

[0004] With the development of technology and the increasing demand for mobile devices, the demand for batteries as an energy source has increased rapidly. In particular, secondary batteries have received considerable attention as an energy source for power-driven devices such as electric bicycles, electric vehicles, and hybrid electric vehicles, as well as for mobile devices such as mobile phones, digital cameras, laptop computers, and wearable devices.

[0005] Medium or large-sized battery modules are preferably manufactured to have as small a size and weight as possible. For this reason, prismatic batteries, pouch-type batteries, etc. that can be stacked with high integration and have a small weight-to-capacity ratio are generally used as battery cells of medium or large-sized battery modules. In addition, in order to protect the battery cell stack from external shocks, heat, or vibrations, the battery module may include a module frame with an open front surface and rear surface to accommodate the battery cell stack in an internal space.

[0006] Figure 1 is a perspective view of a conventional battery module. Figure 2 is a top view of a battery cell stack included in a conventional battery module. Figure 3 (a) of Figure 2 is a plan view of region A when viewed from above Figure 3 and (b) of

[0007] Refer to Figure 1 and Figure 2, A conventional battery module includes: a battery cell stack 12 in which a plurality of battery cells 11 are stacked in one direction, a module frame for accommodating the battery cell stack 12, and end plates 15 for covering the front and rear surfaces of the battery cell stack 12. The module frame includes a lower frame 30 for covering the lower surface and two side surfaces of the battery cell stack 12, and an upper plate 40 for covering the upper surface of the battery cell stack 12.

[0008] In addition, the battery cell stack 12 includes a fixing member 17 for fixing the plurality of battery cells to each other, and the fixing member 17 is located at the central portion and / or ends of the battery cell stack 12. In addition, a compression pad 20 is located between a pair of adjacent battery cells in the battery cell stack 12.

[0009] Referring to Figure 2 and Figure 3 , the compression pad 20 located in the conventional battery cell stack contacts the upper or lower surface of the battery cell 11. The compression pad 20 can absorb the impact transmitted to the adjacent battery cells 11. In addition, when a battery cell 11 catches fire, due to the thickness of the compression pad 20, the heat propagation speed can be delayed. However, when a battery cell 11 catches fire, secondary cell fires may occur due to heat conduction between adjacent battery cells 11 caused by the flame generated in the battery cell 11 and external heat conduction.

[0010] Therefore, it is difficult to sufficiently delay the heat propagation speed only by using the conventional compression pad 20. Accordingly, there is a need to develop a battery module that is different from the conventional battery module and effectively delays the heat propagation speed between battery cells. SUMMARY OF THE INVENTION

[0011] TECHNICAL PROBLEM

[0012] An object of the present disclosure is to provide a battery module that effectively delays the heat propagation speed between battery cells and a battery pack including the battery module.

[0013] However, the technical problems to be solved by the embodiments of the present disclosure are not limited to the above problems, and various extensions can be made within the scope of the technical concept included in the present disclosure.

[0014] TECHNICAL SOLUTION

[0015] According to an embodiment of the present disclosure, there is provided a battery module including: a battery cell stack formed by stacking a plurality of battery cells; and a barrier layer interposed between adjacent battery cells among the plurality of battery cells, wherein the barrier layer includes a main body portion disposed parallel to the battery cells and an extension portion bent at one end of the main body portion and covering the upper end portion of the battery cells.

[0016] The extension part may be formed of a flexible material and cover the upper ends of at least two battery cells.

[0017] The barrier layer may include a first barrier layer arranged parallel to the battery cell and a second barrier layer arranged between the first barrier layer and the battery cell. The second barrier layer may include a main body portion arranged parallel to the first barrier layer and an extension portion that bends at one end of the main body portion and covers the upper end of the battery cell.

[0018] The first barrier layer is located between a first battery cell and a second battery cell adjacent to each other. The second barrier layer includes a 2-1 barrier layer located between the first barrier layer and the first battery cell and a 2-2 barrier layer located between the first barrier layer and the second battery cell. The 2-1 barrier layer includes a main body portion arranged parallel to the first barrier layer and a first extension portion that bends at one end of the main body portion and covers the upper end of the battery cell. The 2-2 barrier layer includes a main body portion arranged parallel to the first barrier layer and a second extension portion that bends at one end of the main body portion and covers the upper end of the battery cell. And the first extension portion of the 2-1 barrier layer and the second extension portion of the 2-2 barrier layer may bend in the same direction.

[0019] The first extension portion and the second extension portion may overlap each other.

[0020] The main body portion includes an additional extension portion that covers the end of the battery cell where the electrode lead is located.

[0021] An opening for the lead to pass through may be formed in the additional extension portion of the main body portion.

[0022] The barrier layer may be formed of a flame-retardant member.

[0023] The first barrier layer may be formed of a silicon material, a mica material, or a mixed material thereof, and the second barrier layer may be formed of a mica material.

[0024] At least two barrier layers may be provided, and at least two battery cells may be placed between two adjacent barrier layers among the barrier layers.

[0025] The extension portions of adjacent barrier layers may bend in mutually different directions.

[0026] According to another embodiment of the present disclosure, a battery pack including the above battery module is provided.

[0027] Beneficial effects

[0028] According to an embodiment of the present disclosure, a barrier layer formed between a pair of adjacent battery cells in a battery cell stack acts as a flame retardant member, thereby delaying the heat propagation speed between adjacent battery cells when a battery cell catches fire.

[0029] In addition, the barrier layer is applied not only to the main body portion of the battery cell but also to the top portion and the lead portion of the battery cell extending from the main body portion, thereby delaying the heat propagation speed of external flames entering a battery cell that has not generated flames.

[0030] The effects of the present disclosure are not limited to the above effects, and those skilled in the art will clearly understand other additional effects not described above from the description of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a perspective view of a conventional battery module;

[0032] Figure 2 is a top view of a battery cell stack included in a conventional battery module.

[0033] Figure 3 (a) of is a plan view of region A when viewed from above Figure 2 of, Figure 3 and (b) of is a cross-sectional view taken along cutting plane B-B of (a);

[0034] Figure 4 is a diagram showing a method of forming a battery cell stack according to a comparative example;

[0035] Figure 5 is a diagram showing a method of forming a battery cell stack included in a battery module according to an embodiment of the present disclosure;

[0036] Figure 6 is a diagram showing Figure 5 a perspective view of a single battery cell included in the battery cell stack of ;

[0037] Figure 7 is a diagram showing a state in which a barrier layer extends in a direction in which an electrode lead protrudes from a battery cell included in a battery module according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0039] Portions not relevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals denote like elements throughout the application.

[0040] In addition, in the drawings, for ease of description, the dimensions and thicknesses of each element are arbitrarily shown, and the present disclosure is not necessarily limited to those shown in the drawings. In the drawings, the thicknesses of layers, regions, etc. are exaggerated for clarity. In the drawings, for ease of description, the thicknesses of some layers and regions are shown exaggeratedly.

[0041] In addition, it will be understood that when an element such as a layer, film, region, or plate is referred to as being “on” or “above” another element, the element may be directly on the other element or there may also be intervening elements. In contrast, when an element is referred to as being “directly on” another element, this means that there are no other intervening elements. In addition, the terms “on...” or “above...” mean being disposed above or below a reference portion, and do not necessarily mean being disposed at the upper end in the direction opposite to gravity of the reference portion.

[0042] In addition, throughout the application, when a portion is referred to as “including” a certain component, this means that the portion may further include other components without excluding other components, unless otherwise specified.

[0043] In addition, throughout the application, when referring to a “plane,” it means when viewing the target portion from the upper side, and when referring to a “cross-section,” it means when viewing the target portion from one side of a vertically cut cross-section.

[0044] Figure 4 is a diagram showing a method of forming a battery cell stack according to a comparative example

[0045] Referring to Figure 4 , in the step of stacking battery cells 11, stacking can be performed by inserting compression pads 20 between adjacent battery cells 11 and battery cells 11. After stacking the compression pads 20, stacking of the battery cells 11 can be continued again. At this time, the compression pads 20 can have a constant thickness. The compression pads 20 can serve to prevent cell curling and can delay heat propagation to a certain extent when the cell catches fire. The battery cells 11 and the compression pads 20 can be stacked to form a battery cell stack, and then through a lead welding process and a module frame process, a battery module is formed.

[0046] Figure 5 is a diagram showing a method of forming a battery cell stack included in a battery module according to an embodiment of the present disclosure. Figure 6 is a diagram showing Figure 5 a perspective view of one battery cell included in the battery cell stack of

[0047] Referring toFigure 5 , a battery cell stack included in a battery module according to the present embodiment is formed by stacking a plurality of battery cells 110, and the battery cell stack includes a barrier layer 200 interposed between adjacent battery cells 110 among the plurality of battery cells 110. The barrier layer 200 according to the present embodiment includes: main body portions 200b11 and 200b21 arranged in parallel with the battery cell 110, and extension portions 200b12 and 200b22 that are bent at one end of the main body portions 200b11 and 200b21 and cover the upper end portions of the battery cells 110.

[0048] Specifically, the barrier layer 200 according to the present embodiment includes: a first barrier layer 200a arranged in parallel with the battery cell 110, and a second barrier layer 200b arranged between the first barrier layer 200a and the battery cell 110. The second barrier layer 200b includes: main body portions 200b11 and 200b21 arranged in parallel with the first barrier layer 200a, and extension portions 200b12 and 200b22 that are bent at one end of the main body portions 200b11 and 200b21 and cover the upper end portions of the battery cells 110. The extension portions 200b12 and 200b22 can be formed of a flexible material and cover the upper end portions of at least two battery cells 110.

[0049] More specifically, the first barrier layer 200a is located between a first battery cell 110a and a second battery cell 110b that are adjacent to each other. The second barrier layer 200b may include: a 2-1 barrier layer 200b1 located between the first barrier layer 200a and the first battery cell 110a, and a 2-2 barrier layer 200b2 located between the first barrier layer 200a and the second battery cell 110b. The 2-1 barrier layer 200b1 includes: a main body portion 200b11 arranged in parallel with the first barrier layer 200a, and a first extension portion 200b12 that is bent at one end of the main body portion 200b11 and covers the upper end portion of the battery cell 110. The 2-2 barrier layer 200b2 includes: a main body portion 200b21 arranged in parallel with the first barrier layer 200a, and a second extension portion 200b22 that is bent at one end of the main body portion 200b21 and covers the upper end portion of the battery cell 110. At this time, the first extension portion 200b12 of the 2-1 barrier layer 200b1 and the second extension portion 200b22 of the 2-2 barrier layer 200b2 can be bent in the same direction. At this time, the first extension portion 200b12 and the second extension portion 200b22 can overlap each other, and their overlapping portion can be on the upper end portion of at least one battery cell 110.

[0050] According to the present embodiment, the first extension part 200b12 and the second extension part 200b22 cover the upper end part of the battery cell 110 while overlapping each other, thereby being able to cut off external propagation caused by an inter-cell flame.

[0051] The barrier layer 200 according to this embodiment is made of a flame retardant member. At this time, the first barrier layer 200a may be formed of a silicon material, a mica material, or a mixed material thereof, and the second barrier layer 200b may be formed of a mica material. The first barrier layer 200a may be formed in the form of a mica sheet, and the second barrier layer 200b may be formed of a thin mica material having a thickness of about 1 mm or less and having a good bending form.

[0052] In the battery module according to the present embodiment, at least two barrier layers 200 may be provided, and at least two battery cells 110 may be placed between two adjacent barrier layers 200 among the barrier layers 200.

[0053] In addition, according to the present embodiment, the extension parts of the adjacent barrier layers 200 may be bent in mutually different directions. For example, as Figure 5 shown, the extension part included in the barrier layer 200 located on the right side based on the two central battery cells 110 may be bent in the rightward direction, and the extension part included in the barrier layer 200 located on the left side based on the two central battery cells 110 may be bent in the leftward direction.

[0054] The battery cell 110 according to an embodiment of the present disclosure is preferably a pouch-type battery cell. For example, referring to Figure 6 , the battery cell 110 according to the present embodiment has a structure in which two electrode leads 111 and 112 face each other and protrude from one end 114a and the other end 114b of the battery body 113, respectively. The battery cell 110 can be manufactured by bonding two ends 114a and 114b of the battery case 114 and one side 114c connecting the two ends in a state where an electrode assembly (not shown) is accommodated in the battery case 114. In other words, the battery cell 110 according to the present embodiment has a total of three sealing parts 114sa, 114sb, and 114sc, and the sealing parts 114sa, 114sb, and 114sc have a structure sealed by a method such as heat fusion, and the other end can be formed by a connecting part 115. The length direction of the battery cell 110 may be defined between the two ends 114a and 114b of the battery case 114, and the width direction of the battery cell 110 may be defined between one side 114c connecting the two ends 114a and 114b of the battery case 114 and the connecting part 115.

[0055] The connecting portion 115 is a region extending longitudinally along one edge of the battery cell 110, and a protruding portion 110p of the battery cell 110 may be formed at an end of the connecting portion 115. The protruding portion 110p may protrude in a direction perpendicular to the direction in which the connecting portion 115 extends. The protruding portion 110p may be located between one of the sealing portions 114sa and 114sb at the two end portions 114a and 114b of the battery case 114 and the connecting portion 115.

[0056] The battery case 114 generally has a laminated structure of a resin layer / a metal thin film layer / a resin layer. For example, when the surface of the battery case is formed of an O (oriented) nylon layer, when a plurality of battery cells are stacked to form a medium or large battery module, it is likely to slide due to an external impact. Therefore, in order to prevent this problem and maintain a stable stacked structure of the battery cells, a battery cell stack may be formed by attaching an adhesive member to the surface of the battery case. The adhesive member is, for example, a sticky type adhesive (such as a double-sided tape) or a chemical adhesive that is bonded by a chemical reaction during adhesion. In the present embodiment, the battery cells 110 may be stacked in the y-axis direction.

[0057] Figure 7 is a view showing a state in which a barrier layer extends in a direction in which an electrode lead protrudes from a battery cell included in a battery module according to another embodiment of the present disclosure.

[0058] On the other hand, in Figure 7 and the following description, in order to explain the main body portion and the extending portion of the second barrier layer 200b, the reference numerals of the main body portion 200b21 and the second extending portion 200b22 of the above-described 2-2 barrier layer 200b2 are used together. However, this is only for convenience of explanation, and the content described below may also be applicable to the main body portion 200b11 and the first extending portion 200b12 of the 2-1 barrier layer 200b1. In addition, in the above-mentioned content, the reference numeral "200b22" has been described as the second extending portion 200b22, but this is for convenience of explanation, and in Figure 7 the description will be represented by "extending portion".

[0059] Referring to Figure 7 , the barrier layer 200 according to the present embodiment includes a second barrier layer 200b for covering Figure 6 the surface 110C of the main body of the battery cell 110, and as described above, the second barrier layer 200b includes: a main body portion 200b21 disposed in parallel with the first barrier layer 200a, and an extending portion 200b22 that is bent at one end of the main body portion 200b21 and covers the upper end portion 110T of the battery cell 110.

[0060] The surface 110C of the main body of the battery cell 110 refers to one surface of the battery cell 110 facing the y-axis direction (the stacking direction of the battery cells 110). The upper end portion 100T of the battery cell 110 may be a portion corresponding to Figure 6 one side portion 114c that connects the two end portions 114a and 114b of the battery case 114. In other words, the upper end portion 100T of the battery cell 110 may refer to the upper end portion of the battery cell 110 based on the width direction.

[0061] At this time, the thickness of the main body portion 200b21 of the second barrier layer 200b may be greater than the thickness of the extension portion 200b22 of the second barrier layer 200b. The main body portion 200b21 of the second barrier layer 200b may be formed to be relatively thick, thereby improving the flame retardant performance of interrupting heat transfer between adjacent battery cells 110. Since the extension portion 200b22 of the second barrier layer 200b is formed to be relatively thin, the gap between the module frame for accommodating the battery cell stack and the upper end portion of the battery cell 110 can be minimized. In addition, the extension portion 200b22 of the second barrier layer 200b is formed of a flexible material, so that the double-sided folding structure of the upper end portion of the battery cell 110 can be tightly covered.

[0062] Referring to Figure 7 , according to the present embodiment, the barrier layer 200 may further include a third barrier layer 200c. The third barrier layer 200c is used to cover the end portion of the battery cell 110 around the electrode leads 111 and 112 protruding from the battery cell 110. Openings 200D through which the electrode leads 111 and 112 pass may be formed in the third barrier layer 200c. The third barrier layer 200c may be formed by extending the second barrier layer 200b, or the third barrier layer 200c may be formed by extending the first barrier layer 200a, or the third barrier layer 200c may be formed by a separate barrier layer, and thus is referred to as an "additional extension portion".

[0063] In addition, one or more of the battery modules according to the embodiments of the present disclosure may be packaged in a group case to form a battery pack.

[0064] The above battery module and the battery pack including the battery module can be applied to various devices. These devices can be applied to transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present disclosure is not limited thereto, and can be applied to various devices that can use the battery module and the battery pack including the battery module, which also belongs to the scope of the present disclosure.

[0065] Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto. Various modifications and improvements made by those skilled in the art using the basic concept of the present disclosure defined in the following claims also fall within the scope of the present disclosure.

Claims

1. A battery module, comprising: a battery cell stack formed by stacking a plurality of battery cells; and a barrier layer interposed between adjacent battery cells among the plurality of battery cells, wherein the barrier layer includes a main body portion disposed parallel to the battery cells, and an extension portion bent at one end of the main body portion and covering the upper end portion of the battery cells, and wherein: the barrier layer includes a first barrier layer disposed parallel to the battery cells, and a second barrier layer disposed between the first barrier layer and the battery cells, and the second barrier layer includes a main body portion disposed parallel to the first barrier layer, and an extension portion bent at one end of the main body portion and covering the upper end portion of the battery cells, and the barrier layer is formed of a flame retardant member.

2. The battery module according to claim 1, wherein: the extension portion is formed of a flexible material and covers the upper end portions of at least two battery cells.

3. The battery module according to claim 1, wherein: the first barrier layer is located between a first battery cell and a second battery cell adjacent to each other, the second barrier layer includes a 2-1 barrier layer located between the first barrier layer and the first battery cell, and a 2-2 barrier layer located between the first barrier layer and the second battery cell, the 2-1 barrier layer includes a main body portion disposed parallel to the first barrier layer, and a first extension portion bent at one end of the main body portion and covering the upper end portion of the battery cells, the 2-2 barrier layer includes a main body portion disposed parallel to the first barrier layer, and a second extension portion bent at one end of the main body portion and covering the upper end portion of the battery cells, and the first extension portion of the 2-1 barrier layer and the second extension portion of the 2-2 barrier layer are bent in the same direction.

4. The battery module according to claim 3, wherein: the first extension portion and the second extension portion overlap each other.

5. The battery module according to claim 1, wherein: the main body portion includes an additional extension portion that covers an end portion of the battery cell where the electrode lead is located.

6. The battery module according to claim 5, wherein: an opening for passing the lead is formed in the additional extension portion of the main body portion.

7. The battery module according to claim 1, wherein: the first barrier layer is formed of a silicon material, a mica material, or a mixed material thereof, and the second barrier layer is formed of a mica material.

8. The battery module according to claim 1, wherein: at least two barrier layers are provided, and at least two battery cells are placed between two adjacent barrier layers among the barrier layers.

9. The battery module according to claim 8, wherein: the extension portions of adjacent barrier layers are bent in mutually different directions.

10. A battery pack comprising the battery module according to any one of claims 1 to 9.

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