Battery module and battery pack including same

Abstract

A battery module and a battery pack including the same are provided. A battery module according to one embodiment of the present disclosure comprises: a battery cell stack formed by stacking a plurality of battery cells; and a barrier layer interposed between battery cells adjacent to each other among the plurality of battery cells, wherein the barrier layer includes a main body portion disposed in parallel with 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. A barrier layer formed between a pair of battery cells adjacent to each other in the battery cell stack functions as a flame-retardant member, thereby being able to delay a heat propagation velocity between adjacent battery cells when a battery cell is on fire.

Description

[0001] This application is a divisional application of the invention patent application with the application date of December 3, 2021, application number 202111468036.9, and invention name “Battery module and battery pack including the battery module”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of Korean Patent Application No. 10-2020-0169334, filed on December 7, 2020, and Korean Patent Application No. 10-2021-0150561, filed on November 4, 2021, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0004] The present disclosure relates to a battery module and a battery pack including the same, and more particularly, to a battery module that effectively delays heat propagation speed between battery cells and a battery pack including the same. Background Art

[0005] With the development of technology and the increasing demand for mobile devices, the demand for batteries as energy sources is rapidly increasing. In particular, secondary batteries have attracted considerable attention as energy sources for electric drive devices such as electric bicycles, electric vehicles, and hybrid electric vehicles, as well as for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices.

[0006] Medium- and large-sized battery modules are preferably manufactured to be as small and light as possible. For this reason, prismatic cells, pouch-type cells, and the like, which can be stacked with high integration and have a low weight-to-capacity ratio, are often used as battery cells in medium- and large-sized battery modules. Furthermore, to protect the battery cell stack from external impact, heat, or vibration, the battery module may include a module frame with open front and rear surfaces to house the battery cell stack within its interior space.

[0007] 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) is when viewed from above Figure 2 The plan view of area A, Figure 3 (b) is a cross-sectional view taken along the cutting plane BB of (a).

[0008] Reference Figure 1 and Figure 2A 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 both side surfaces of the battery cell stack 12, and an upper plate 40 for covering the upper surface of the battery cell stack 12.

[0009] Furthermore, the battery cell stack 12 includes fixing members 17 for fixing the plurality of battery cells to each other, and the fixing members 17 are located at a central portion and / or ends of the battery cell stack 12. Furthermore, a compression pad 20 is located between a pair of battery cells adjacent to each other in the battery cell stack 12.

[0010] Reference Figure 2 and Figure 3 In a conventional battery cell stack, the compression pad 20 contacts the upper or lower surface of the battery cell 11. The compression pad 20 absorbs shock that propagates to adjacent battery cells 11. Furthermore, the thickness of the compression pad 20 can slow the rate of heat propagation in the event of a battery cell 11 fire. However, in the event of a battery cell 11 fire, secondary cell fires may occur due to heat conduction between adjacent battery cells 11 caused by the flames in the battery cell 11 and external heat conduction.

[0011] Therefore, it is difficult to sufficiently delay the heat propagation speed by only using the conventional compression pad 20. Therefore, it is necessary to develop a battery module that effectively delays the heat propagation speed between battery cells, unlike conventional battery modules. Summary of the Invention

[0012] Technical issues

[0013] An object of the present disclosure is to provide a battery module that effectively delays the speed of heat propagation between battery cells and a battery pack including the battery module.

[0014] 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.

[0015] Technical Solution

[0016] According to one embodiment of the present disclosure, a battery module is provided, 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 comprises a main body portion arranged 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 cell.

[0017] The extension portion may be formed of a flexible material and cover upper end portions of at least two battery cells.

[0018] 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 bent at one end of the main body portion and covering the upper end portion of the battery cell.

[0019] The first barrier layer is located between a first battery cell and a second battery cell adjacent to each other, and 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 bent at one end of the main body portion and covering the upper end portion 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 bent at one end of the main body portion and covering the upper end portion 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 can be bent in the same direction.

[0020] The first extension portion and the second extension portion may overlap each other.

[0021] The main body portion includes an additional extension portion that covers an end portion of the battery cell where an electrode lead is located.

[0022] An opening for passing the lead wire may be formed in the additional extension portion of the main body portion.

[0023] The barrier layer may be formed of a flame retardant member.

[0024] 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.

[0025] At least two barrier layers may be provided, and at least two battery cells may be placed between two barrier layers adjacent to each other among the barrier layers.

[0026] The extension portions of the barrier layers adjacent to each other may be bent in directions different from each other.

[0027] According to another embodiment of the present disclosure, there is provided a battery pack including the above-mentioned battery module.

[0028] Beneficial effects

[0029] According to an embodiment of the present disclosure, a barrier layer formed between a pair of battery cells adjacent to each other in a battery cell stack functions as a flame retardant member, thereby being able to delay a heat propagation speed between adjacent battery cells when the battery cells catch fire.

[0030] Furthermore, the barrier layer is applied not only to the main body portion of the battery cell but also to the top and lead portions of the battery cell extending from the main body portion, thereby delaying the heat propagation speed of the flame outside the cell into the battery cell where no flame is generated.

[0031] The effects of the present disclosure are not limited to the above-described effects, and further other effects that are not described above will be clearly understood by those skilled in the art from the description of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a perspective view of a conventional battery module;

[0033] Figure 2 is a top view of a battery cell stack included in a conventional battery module.

[0034] Figure 3 (a) is when viewed from above Figure 2 The plan view of area A, Figure 3 (b) is a cross-sectional view taken along the cutting plane BB of (a);

[0035] Figure 4 is a diagram illustrating a method of forming a battery cell stack according to a comparative example;

[0036] Figure 5 is a diagram illustrating a method of forming a battery cell stack included in a battery module according to an embodiment of the present disclosure;

[0037] Figure 6 It shows Figure 5 a perspective view of a battery cell included in a battery cell stack;

[0038] Figure 7 is a diagram illustrating 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

[0039] Hereinafter, various 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 ways and is not limited to the embodiments set forth herein.

[0040] Parts irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals denote like elements throughout the application.

[0041] In addition, in the drawings, for the convenience of description, the size and thickness of each element are arbitrarily shown, and the present disclosure is not necessarily limited to those shown in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for the convenience of description.

[0042] Furthermore, it will be understood that when an element, such as a layer, film, region, or plate, is referred to as being "on" or "over" another element, the element can be directly on the other element or intervening elements may be present. Conversely, when an element is referred to as being "directly on" another element, this means that no intervening elements are present. Furthermore, the terms "on" or "over" refer to being positioned above or below a reference portion, and do not necessarily mean being positioned at the upper end of the reference portion facing opposite to the force of gravity.

[0043] In addition, throughout the application, when a part is referred to as “comprising” a certain component, it means that the part may further include other components, but does not exclude the other components, unless otherwise stated.

[0044] Furthermore, throughout the application, when "plane" is referred to, it means when the target portion is viewed from the upper side, and when "cross section" is referred to, it means when the target portion is viewed from one side of the cross section cut vertically.

[0045] Figure 4 is a diagram illustrating a method of forming a battery cell stack according to a comparative example

[0046] Reference Figure 4 In the step of stacking the battery cells 11, the stacking can be performed by inserting a compression mat 20 between the adjacent battery cells 11. After stacking the compression mat 20, the stacking of the battery cells 11 can be continued. At this time, the compression mat 20 can have a constant thickness. The compression mat 20 can prevent the cells from curling and can delay heat propagation to a certain extent when the cells catch fire. The battery cells 11 and the compression mat 20 can be stacked to form a battery cell stack, which is then subjected to a wire welding process and a module frame process to form a battery module.

[0047] Figure 5 is a diagram illustrating a method of forming a battery cell stack included in a battery module according to an embodiment of the present disclosure. Figure 6 It shows Figure 5 A perspective view of one battery cell included in a battery cell stack.

[0048] Reference Figure 5 The battery cell stack included in the 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 disposed parallel to the battery cells 110, and extension portions 200b12 and 200b22 bent at one end of the main body portions 200b11 and 200b21 and covering the upper end portions of the battery cells 110.

[0049] Specifically, the barrier layer 200 according to this embodiment includes a first barrier layer 200a disposed parallel to the battery cells 110, and a second barrier layer 200b disposed between the first barrier layer 200a and the battery cells 110. The second barrier layer 200b includes main portions 200b11 and 200b21 disposed parallel to the first barrier layer 200a, and extension portions 200b12 and 200b22 bent at one end of the main portions 200b11 and 200b21 and covering the upper ends of the battery cells 110. The extension portions 200b12 and 200b22 may be formed of a flexible material and cover the upper ends of at least two battery cells 110.

[0050] More specifically, the first barrier layer 200a is located between the first and second battery cells 110a and 110b, which 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 200b11 arranged parallel to the first barrier layer 200a, and a first extension 200b12 bent at one end of the main body 200b11 and covering the upper end of the battery cell 110. The 2-2 barrier layer 200b2 includes a main body 200b21 arranged parallel to the first barrier layer 200a, and a second extension 200b22 bent at one end of the main body 200b21 and covering the upper end 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 may be bent in the same direction. At this time, the first extension portion 200b12 and the second extension portion 200b22 may overlap each other, and their overlapping portion may be on the upper end portion of at least one battery cell 110.

[0051] According to the present embodiment, the first extension portion 200b12 and the second extension portion 200b22 cover the upper end portion of the battery cell 110 while overlapping each other, thereby being able to cut off external propagation due to inter-cell flame.

[0052] The barrier layer 200 according to this embodiment is made of a flame-retardant member. In this case, the first barrier layer 200a can be formed of a silicon material, a mica material, or a mixed material thereof, and the second barrier layer 200b can be formed of a mica material. The first barrier layer 200a can be formed in the form of a mica sheet, and the second barrier layer 200b can be formed of a thin mica material having a thickness of about 1 mm or less and having a good bending form.

[0053] 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 barrier layers 200 adjacent to each other among the barrier layers 200 .

[0054] In addition, according to this embodiment, the extension portions of the adjacent barrier layers 200 may be bent in different directions. Figure 5 As shown in , the extension included in the barrier layer 200 located on the right side with respect to the two central battery cells 110 may be bent in the right direction, while the extension included in the barrier layer 200 located on the left side with respect to the two central battery cells 110 may be bent in the left direction.

[0055] The battery cell 110 according to the embodiment of the present disclosure is preferably a pouch-type battery cell. Figure 6 According to the present embodiment, the battery cell 110 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 the two end portions 114a and 114b of the battery case 114 and one side portion 114c connecting the two end portions in a state where the 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 portions 114sa, 114sb, and 114sc, and the sealing portions 114sa, 114sb, and 114sc have a structure sealed by a method such as heat fusion, and the other side end portion can be formed by the connecting portion 115. The length direction of the battery cell 110 may be defined between both ends 114a and 114b of the battery case 114 , and the width direction of the battery cell 110 may be defined between one side portion 114c of the battery case 114 connecting the both ends 114a and 114b and the connection portion 115 .

[0056] The connection portion 115 is a region extending elongated along one edge of the battery cell 110, and a protrusion 110p of the battery cell 110 may be formed at an end of the connection portion 115. The protrusion 110p may protrude in a direction perpendicular to the direction in which the connection portion 115 extends. The protrusion 110p may be located between one of the sealing portions 114sa and 114sb of the two end portions 114a and 114b of the battery case 114 and the connection portion 115.

[0057] The battery case 114 generally has a laminated structure of a resin layer / metal film layer / resin layer. For example, in the case where 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, they are prone to sliding due to external impact. Therefore, in order to prevent this problem and maintain a stable stacking structure of the battery cells, a battery cell stack can be formed by attaching an adhesive member to the surface of the battery case, the adhesive member being, for example, a viscous adhesive (such as a double-sided tape) or a chemical adhesive that is bonded by a chemical reaction during adhesion. In this embodiment, the battery cells 110 can be stacked along the y-axis direction.

[0058] Figure 7 is a diagram illustrating 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.

[0059] On the other hand, Figure 7 In the following description, in order to explain the main body and extension of the second barrier layer 200b, the reference numerals of the main body 200b21 and the second extension 200b22 of the 2-2 barrier layer 200b2 are used together. However, this is only for the convenience of explanation, and the following description is also applicable to the main body 200b11 and the first extension 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 extension 200b22, but this is for the convenience of explanation. Figure 7 The description will be represented by "extension".

[0060] Reference Figure 7 According to this embodiment, the barrier layer 200 includes a Figure 6 The second barrier layer 200b is formed on the main body surface 110C of the battery cell 110, and as described above, the second barrier layer 200b includes: a main body 200b21 arranged parallel to the first barrier layer 200a, and an extension portion 200b22 bent at one end of the main body 200b21 and covering the upper end portion 110T of the battery cell 110.

[0061] The main body surface 110C of the battery cell 110 refers to a 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 Figure 6 The upper end portion 100T of the battery cell 110 corresponds to a portion of the battery case 114 that connects the two end portions 114a and 114b. 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.

[0062] In this case, the thickness of the main portion 200b21 of the second barrier layer 200b can be greater than the thickness of the extension portion 200b22 of the second barrier layer 200b. The main portion 200b21 of the second barrier layer 200b can be formed relatively thick, thereby improving the flame retardant performance of interrupting the heat transfer between adjacent battery cells 110. Since the extension portion 200b22 of the second barrier layer 200b is formed relatively thin, the gap between the module frame for accommodating the battery cell stack and the upper end 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 folded structure of the upper end of the battery cell 110 can be tightly covered.

[0063] Reference Figure 7 The barrier layer 200 according to this embodiment may further include a third barrier layer 200c for covering the end portion of the battery cell 110 around the electrode leads 111 and 112 protruding from the battery cell 110. Openings 200D may be formed in the third barrier layer 200c for allowing the electrode leads 111 and 112 to pass through. The third barrier layer 200c may be formed by extending the second barrier layer 200b, or by extending the first barrier layer 200a, or by forming a separate barrier layer, which is referred to as an "additional extension portion."

[0064] In addition, one or more of the battery modules according to the embodiments of the present disclosure may be packaged in a pack case to form a battery pack.

[0065] The battery modules and battery packs including the battery modules can be applied to various devices. These devices can be applied to vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, but the present disclosure is not limited thereto. The battery modules and battery packs including the battery modules can be applied to various devices that can use the battery modules, which also fall within the scope of the present disclosure.

[0066] Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and 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 blocking portion interposed between battery cells adjacent to each other among the plurality of battery cells, The blocking portion includes a first blocking portion disposed in parallel with the battery cell and a second blocking portion disposed between the first blocking portion and the battery cell, and The second blocking portion includes a main body portion arranged parallel to the first blocking portion, and an extension portion bent at one end of the main body portion and covering an upper end portion of the battery cell.

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

3. The battery module according to claim 1, wherein: The first barrier portion is located between a first battery cell and a second battery cell adjacent to each other, and the second barrier portion includes a 2-1 barrier portion located between the first barrier portion and the first battery cell, and a 2-2 barrier portion located between the first barrier portion and the second battery cell. The first extending portion of the 2-1 blocking portion and the second extending portion of the 2-2 blocking portion are bent in the same direction.

4. The battery module according to claim 1, wherein: The extension portions of the adjacent blocking portions are bent in directions different from each other. 5 . A battery pack comprising the battery module according to claim 1 .

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