Battery module and battery pack including the same

Abstract

A battery module according to one embodiment of the present invention comprises: a battery cell stack including a plurality of battery cells stacked along a first direction; and an outer member that surrounds the outer surface of the battery cell stack, wherein the center of the lower surface of the battery cell stack is open, and one end of the outer member is attached to one side of the lower surface of the battery cell stack, and the other end of the outer member is attached to the other side of the lower surface of the battery cell stack.

Description

Technology Field

[0001] The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module and a battery pack including the same that improve cooling performance while improving the swelling phenomenon of the battery cell. Background Technology

[0002] With the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting significant interest as an energy source not only for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0003] While small mobile devices use one or two or three battery cells per device, medium-to-large devices such as automobiles require high output and large capacity. Therefore, medium-to-large battery modules consisting of multiple battery cells electrically connected are used.

[0004] Since it is desirable for medium-to-large battery modules to be manufactured with the smallest possible size and weight, prismatic batteries and pouch-type batteries, which can be stacked with high integration density and have a low weight-to-capacity ratio, are mainly used as battery cells for medium-to-large battery modules. Meanwhile, the battery module may include a module frame that houses the battery cell stack in an internal space, with the front and rear sides open, to protect the battery cell stack from external shock, heat, or vibration.

[0005] FIG. 1 is a perspective view of a conventional battery module. FIG. 2 is an exploded perspective view of the battery module of FIG. 1. FIG. 3 is a drawing showing a part of a cross-section cut along the cutting line AA of FIG. 1.

[0006] Referring to FIGS. 1 and 2, a conventional battery module (10) includes a battery cell stack (12) in which a plurality of battery cells (11) are stacked in one direction, and an outer member (30) that accommodates the battery cell stack (12). Here, the outer member (30) has an open front and rear surface, so that the front and rear surfaces of the battery cell stack (12) accommodated in the outer member (30) are open.

[0007] Here, the battery module (10) is mounted on a thermally conductive resin layer (14) formed on a pack frame member (not shown). Accordingly, in the conventional battery module (10), an outer member (30) is positioned between the battery cell stack (12) and the thermally conductive resin layer (14).

[0008] Referring to FIG. 3, a compression pad (50) is positioned between the battery cell stack (12) and the lower frame (30), but there is a problem that the compression pad (50) is generally limited in its ability to absorb deformation in the width direction of the battery module (10).

[0009] Referring to FIG. 3, the conventional battery module (10) has a structure that indirectly cools the lower part of the battery cell stack (12) through a thermally conductive resin layer (14), and the heat generated from the battery cell (11) flows through the outer member (30) to the thermally conductive resin layer (14). Here, the conventional battery module (10) has a problem in that heat transfer is hindered due to an air layer formed between the outer member (30) and the battery cell stack (12) or between the outer member (30) and the thermally conductive resin layer (14). Considering that the temperature of the battery cell (11) is one of the factors limiting the output of the battery, a localized temperature rise occurring within the battery cell (11) is highly likely to limit the output of the battery prematurely, so there is a need to improve this. In addition, as the battery module (10) has recently become larger, the number of battery cells (11) stacked within the module has increased, and the cooling disparity between the battery cells (11) is becoming more severe.

[0010] Accordingly, there is a need to develop a battery module and a battery pack including the same that improves cooling performance for heat generated within the battery cell stack (12) while preventing swelling within the battery cell stack (12). The problem to be solved

[0011] The problem to be solved by the present invention is to provide a battery module with improved cooling performance and a battery pack including the same, while improving the swelling phenomenon of the battery cell.

[0012] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art from this specification and the attached drawings. means of solving the problem

[0013] A battery module according to one embodiment of the present invention comprises: a battery cell stack including a plurality of battery cells stacked along a first direction; and an outer member that surrounds the outer surface of the battery cell stack, wherein the center of the lower surface of the battery cell stack is open, and one end of the outer member is attached to one side of the lower surface of the battery cell stack, and the other end of the outer member is attached to the other side of the lower surface of the battery cell stack.

[0014] The outer surface of the outer casing member of the battery module is exposed to the outside, and the center of the lower surface of the battery cell stack located between one end of the outer casing member and the other end of the outer casing member may be exposed to the outside.

[0015] The above exterior member may be made of an elastic material.

[0016] The above exterior member may be formed by wrapping the outer surface of the battery cell stack from one side of the lower surface of the battery cell stack to the other side of the lower surface of the battery cell stack.

[0017] The battery cell stack includes compression pads located on both sides thereof, wherein the compression pads are located between the outer surface of the battery cell stack and the outer surface thereof, and the outer surface of the battery cell stack can press the battery cell stack in the first direction.

[0018] The above-mentioned outer member presses the upper surface of the battery cell stack in a second direction, and the second direction may be perpendicular to the first direction.

[0019] The second direction above may be the width direction of the plurality of battery cells.

[0020] The above compression pad may extend along the side of the battery cell stack.

[0021] A battery pack according to another embodiment of the present invention includes the battery module described above.

[0022] The above battery pack comprises a lower pack frame on which at least two battery modules are mounted, an upper pack frame covering the upper portion of the at least two battery modules, and a thermally conductive resin layer formed on the lower pack frame, wherein the center of the lower surface of the battery cell stack can come into contact with the thermally conductive resin layer.

[0023] The lower pack frame includes a plurality of module areas, and the battery module can be mounted in the module areas.

[0024] The above thermally conductive resin layers may each be formed on the module area.

[0025] The above thermally conductive resin layer may have the same size as the center of the lower surface of the battery cell laminate.

[0026] The side of one end of the above-mentioned exterior member and one side of the above-mentioned thermal conductive resin layer may be in contact, and the side of the other end of the above-mentioned exterior member may be in contact with the other side of the above-mentioned thermal conductive resin layer. Effects of the invention

[0027] According to the embodiments, the present invention can provide a battery module and a battery pack including the same, which includes an outer member that surrounds the outer surface of a battery cell stack, wherein the center of the lower surface of the battery cell stack is open, thereby improving the swelling phenomenon of the battery cell and improving cooling performance.

[0028] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the accompanying drawings. Brief explanation of the drawing

[0029] Figure 1 is a perspective view of a conventional battery module. Figure 2 is an exploded perspective view of the battery module of Figure 1. Figure 3 is a drawing showing a part of a cross-section cut along the cutting line AA of Figure 1. FIG. 4 is a perspective view of a battery module according to one embodiment of the present invention. Fig. 5 is an exploded perspective view of the battery module of Fig. 4. Figure 6 is a cross-sectional view taken along the cutting line BB of Figure 4. FIG. 7 is an exploded perspective view of a battery cell stack included in the battery module of FIG. 4. FIG. 8 is a perspective view of a battery pack according to one embodiment of the present invention. Fig. 9 is an exploded perspective view of the battery pack of Fig. 8. Figure 10 is a cross-sectional view taken along the cutting line CC of Figure 8. Figure 11 is a drawing showing an enlarged portion of the cross-sectional view of Figure 10. Specific details for implementing the invention

[0030] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0031] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0032] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0033] Furthermore, throughout the specification, when a part is described as “comprising” a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0034] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0035] Hereinafter, a battery module according to an embodiment of the present invention will be described. However, the description herein will be based on the front side of the battery module, but is not necessarily limited thereto, and the description may be identical or similar in the case of the rear side.

[0037] FIG. 4 is a perspective view of a battery module according to one embodiment of the present invention. FIG. 5 is an exploded perspective view of the battery module of FIG. 4.

[0038] Referring to FIGS. 4 and 5, the battery module (100) includes a battery cell stack (120) in which a plurality of battery cells (110) are stacked in a first direction, an outer member (300) that surrounds the battery cell stack (120), and a sensing member (not shown) that covers the front and rear surfaces of the battery cell stack.

[0039] The battery cell stack (120) wrapped in an outer member (300) comprises a plurality of battery cells (110) stacked therein, and preferably, the battery cells (110) are pouch-type battery cells. The battery cells (110) can be manufactured by housing an electrode assembly in a pouch case made of a laminate sheet including a resin layer and a metal layer, and then heat-fusing the sealing portion of the pouch case. Such battery cells (110) may be composed of a plurality of such cells, and the plurality of battery cells (110) form a stacked battery cell stack (120) so that they can be electrically connected to each other.

[0041] Below, the exterior member (300) will be described in more detail.

[0042] Figure 6 is a cross-sectional view taken along the cutting line BB of Figure 4.

[0043] Referring to FIGS. 4 to 6, the outer member (300) can wrap around the outer surface of the battery cell stack (120). The outer member (300) can wrap around the outer surface of the battery cell stack (120) while the center of the lower surface of the battery cell stack (120) is open. That is, the outer member (300) can wrap around both sides and the upper surface of the battery cell stack (120), and the front and rear surfaces of the battery cell stack (120) are open, while the center of the lower surface is open.

[0044] More specifically, in the battery module (100) of the present embodiment, one end (300a) of the outer member (300) is attached to one side of the lower surface of the battery cell stack (120), and the other end (300b) of the outer member (300) is attached to the other side of the lower surface of the battery cell stack (120). That is, the outer member extends from one end (300a) of the outer member (300) to the other end (300b) of the outer member (300) so as to wrap both sides, the upper surface, and both sides of the lower surface of the battery cell stack (120).

[0045] Additionally, the outer surface of the outer member (300) may be exposed while the outer member (300) is wrapped around the battery cell stack (120). That is, when the battery module (100) is mounted on the lower pack frame (1200) of the battery pack in a process to be described later, the outer member (300) may come into contact with the lower pack frame (1200). Additionally, the center of the lower surface of the battery cell stack (120) located between the one end (300a) of the outer member (300) and the other end (300b) of the outer member (300) may be exposed to the outside. That is, when the battery module (100) is mounted on the lower pack frame (1200) of the battery pack in a process to be described later, the outer member (300) may come into direct contact with the thermally conductive resin layer (1400) formed on the lower pack frame (1200).

[0046] Accordingly, in this embodiment, the outer member (300) has the center of the lower surface of the battery cell stack (120) open to the outside, and the thermally conductive resin layer (1400), to be described later, is in direct contact with the center of the lower surface of the battery cell stack (120), so that heat generated within the battery cell stack (120) can be directly cooled. That is, the cooling performance of the outer member (300) according to this embodiment can be further improved.

[0047] Additionally, the two sides and the upper and lower surfaces of the exterior member (300) may each have a size corresponding to the size of the outer surface of the battery cell stack. For example, the two sides of the exterior member (300) may have the same size as the side of the battery cell stack (120) or a smaller size. Additionally, the upper surface of the exterior member (300) may have the same size as the upper surface of the battery cell stack (120) or a smaller size. Furthermore, the one end (300a) and the other end (300b) of the exterior member (300) extend along the length direction of the lower surface of the battery cell stack (120), and may have a length equal to or smaller than the length of the lower surface of the battery cell stack (120).

[0048] Accordingly, in this embodiment, the outer member (300) can press the battery cell stack (120) in a certain direction and wrap the battery cell stack (120). That is, the outer member (300) presses the battery cell (110) included in the battery cell stack (120) in a certain direction, thereby preventing swelling of the battery cell and improving the dimensional stability of the battery module. In addition, through the process of wrapping the battery cell stack (120) with the outer member (300), the battery cell stack (120) is simultaneously pressed, so a separate process of pressing the battery cell stack (120) is not required, and thus the process and production line can be simplified.

[0049] For example, the outer member (300) may be made of an elastic material. The elastic material may be made of at least one of materials such as polyethylene (PE) and polytetrafluoroethylene (PTFE). Here, the outer member (300) may be formed by wrapping the outer surface of the battery cell stack (120) from one side of the lower surface of the battery cell stack (120) to the other side of the lower surface of the battery cell stack (120) with a film or heat shrink tube of the elastic material. For example, the outer member (300) may be formed by wrapping the upper and lower surfaces and both sides of the outer surface of the battery cell stack (120) with the film or heat shrink tube of the elastic material, and then removing a portion of the film or heat shrink tube of the elastic material that covers the lower surface of the battery cell stack (120). However, it is not limited to this, and any material having elasticity capable of effectively absorbing external shocks while sufficiently pressing the battery cell (110) included in the battery cell stack (120) can be applied without limitation.

[0050] Accordingly, in this embodiment, the outer member (300) can prevent swelling of the battery cell and improve the dimensional stability of the battery module. In addition, the outer member (300) has elasticity of its own, so there is an advantage that deformation due to volume changes of the battery cell (110) can be minimized.

[0051] Additionally, the outer surface of the battery cell stack (120) may be attached to the inner surface of the outer member (300). Here, the elastic material included in the outer member (300) may have adhesive properties of its own. Furthermore, the outer member (300) and the battery cell stack (120) may be fixed through frictional force between the inner surface of the outer member (300) and the outer surface of the battery cell stack (120). Additionally, a separate adhesive layer may be formed between the outer member (300) and the battery cell stack (120).

[0052] For example, the adhesive layer may be formed by being made of tape or coated with an adhesive binder. More preferably, the adhesive layer may be coated with an adhesive binder or made of double-sided tape so that the battery cell laminate (120) and the outer member (300) can be easily fixed. However, it is not limited thereto, and any material having adhesive performance capable of fixing the battery cells (110) to each other or between the battery cells (110) and the outer member (300) may be applied without limitation.

[0053] Accordingly, the battery cell stack (120) can be stably accommodated within the outer member (300).

[0055] Additionally, referring to FIG. 6, the outer member (300) presses the battery cell stack (120) in the first direction. More specifically, the first direction may be the width direction of the battery module (100), and this may be the same as the stacking direction of the plurality of battery cells (110) in the battery cell stack (120).

[0056] Accordingly, the outer member (300) presses the battery cell stack (120) in the same direction as the width direction of the battery module (100) or the stacking direction of the battery cell (110), thereby effectively preventing swelling of the battery module. In addition, a compression pad (500) is positioned between the outer member (300) and the battery cell stack (120) to effectively absorb deformation occurring in the width direction of the battery module (100). Furthermore, the lifespan of the battery module (100) can also be improved.

[0057] Additionally, the outer member (300) presses the upper and lower surfaces of the battery cell stack in a second direction, and the second direction may be perpendicular to the first direction. More specifically, the second direction may be the width direction of the plurality of battery cells (110).

[0058] Accordingly, the outer member (300) can apply a predetermined pressure to the width direction of the battery cell (110) which is perpendicular to the width direction of the battery module (100), thereby effectively preventing swelling in the width direction of the battery cell (110). In addition, the lifespan of the battery module (100) can be further improved.

[0059] FIG. 7 is an exploded perspective view of a battery cell stack included in the battery module of FIG. 4.

[0060] Referring to FIGS. 6 and 7, in the battery module (100) according to the present embodiment, a compression pad (500) may be positioned between the outer surface of the outer member (300) and the battery cell stack (120). Here, the compression pad (500) may extend along the outer surface of the battery cell stack (120). Additionally, the compression pad (500) may have a size equal to or smaller than the outer surface of the battery cell stack (120). Furthermore, both ends of the compression pad (500) may be in contact with the outer member (300) or wrapped by the outer member (300).

[0061] Additionally, referring to FIGS. 6 and 7, according to another embodiment of the present invention, a battery cell stack (120) comprises a first battery cell stack and a second battery cell stack, and a compression pad (500) may be positioned between the first battery cell stack and the second battery cell stack. Additionally, the compression pad (500) may extend along the sides of the first battery cell stack and the second battery cell stack.

[0062] For example, the compression pad (500) may be a pad made of polyurethane material. However, it is not limited to this, and any material capable of absorbing volume changes when the battery cell (110) expands may be applied.

[0063] Accordingly, the compression pad (500) can easily absorb the expansion generated in the battery cell (110) included in the battery cell stack (120), thereby assisting the outer member (300) in pressing the outer surface of the battery cell stack (120).

[0065] FIG. 8 is a perspective view of a battery pack according to one embodiment of the present invention. FIG. 9 is an exploded perspective view of the battery pack of FIG. 8.

[0066] Referring to FIGS. 8 and 9, a battery pack (1000) according to another embodiment of the present invention includes the battery module (100) described above. Meanwhile, one or more of the battery modules (100) may be packaged within a pack case (1200, 1300) to form a battery pack (1000).

[0067] More specifically, the battery pack (1000) of the present embodiment includes a lower pack frame (1200) on which at least two battery modules (100) are mounted, an upper pack frame (1300) covering the upper portion of at least two battery modules (100), and a thermally conductive resin layer (1400) formed on the lower surface of the lower pack frame (1200). Here, at least two battery modules (100) are arranged in a unidirectional manner to form a battery module array (1100). Additionally, the lower pack frame (1200) includes a plurality of module regions, and battery modules (100) may be mounted in the module regions. Here, as the battery modules (100) are mounted in the module regions, the center of the lower surface of the battery cell stack (120) and the thermally conductive resin layer (1400) may come into contact.

[0068] Accordingly, heat generated in the battery cell (110) is transferred to a thermally conductive resin layer (1400) that is in direct contact with the center of the lower surface of the battery cell stack (120), thereby improving the cooling performance of the battery module (100) and reducing the cooling variation between the battery cells (110). In addition, the lifespan of the battery module (100) can also be further improved.

[0069] For example, a thermally conductive resin layer (1400) may be formed by applying a thermally conductive resin to each module area of ​​the lower pack frame (1200) before the battery module (100) is mounted on the module area of ​​the lower pack frame (1200). Subsequently, the thermally conductive resin layer (1400) may be formed as the thermally conductive resin hardens.

[0070] Accordingly, as the thermally conductive resin hardens, the lower surface of the battery module (100) can be stably fixed to the thermally conductive resin layer (1400).

[0071] FIG. 10 is a cross-sectional view taken along the cutting line CC of FIG. 8. FIG. 11 is an enlarged view of a portion of the cross-sectional view of FIG. 10.

[0072] More specifically, referring to FIGS. 10 and 11, the thermally conductive resin layer (1400) may be formed in the module area formed in the lower pack frame (1200). Additionally, the thermally conductive resin layer (1400) may have the same size as the center of the lower surface of the battery cell stack (120).

[0073] Accordingly, heat generated from the battery cell (110) in each battery module (100) mounted on the lower pack frame (1200) can be transferred to the thermally conductive resin layer (1400) that is in direct contact with the center of the lower surface of the battery cell stack (120). That is, while heat propagation between the battery modules (100) does not occur, the cooling performance of each battery module (100) is improved, and the cooling variation between the battery cells (110) within each battery module (100) can also be reduced. In addition, the lifespan of the battery module (100) can be further improved.

[0074] Additionally, the side of one end (300a) of the exterior member (300) may come into contact with one side of the thermally conductive resin layer (1400), and the side of the other end (300b) of the exterior member (300) may come into contact with the other side of the thermally conductive resin layer (1400).

[0075] Accordingly, as the thermally conductive resin hardens, one end (300a) and the other end (300b) of the outer member (300) located on the lower surface of the battery module (100) can be stably fixed to the thermally conductive resin layer (1400).

[0077] The battery module and the battery pack containing the same described above can be applied to various devices. Such devices may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and can be applied to various devices capable of using the battery module and the battery pack containing the same, and this also falls within the scope of the rights of the present invention.

[0078] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0079] 100: Battery module 110: Battery cell 120: Battery cell laminate 300: Exterior parts 500: Compression pad

Claims

Claim 1 A battery cell stack comprising a plurality of battery cells stacked along a first direction; an outer member covering the outer surface of the battery cell stack, wherein the center of the lower surface of the battery cell stack is open; and a thermally conductive resin extending between one end of the outer member and the other end of the outer member, wherein one end of the outer member is attached to one side of the lower surface of the battery cell stack and the other end of the outer member is attached to the other side of the lower surface of the battery cell stack, and the center of the lower surface of the battery cell stack located between the one end of the outer member and the other end of the outer member is exposed to the outside, and the exposed center of the lower surface of the battery cell stack comes into direct contact with the thermally conductive resin to directly cool the heat generated in the battery cell stack. Claim 2 A battery module according to claim 1, wherein the outer surface of the outer casing member of the battery module is exposed to the outside. Claim 3 In paragraph 2, the above-mentioned exterior member is a battery module made of an elastic material. Claim 4 In paragraph 3, the outer member is a battery module formed by wrapping the outer surface of the battery cell stack from one side of the lower surface of the battery cell stack to the other side of the lower surface of the battery cell stack. Claim 5 A battery module according to claim 1, comprising compression pads located on both sides of the battery cell stack, wherein the compression pads are located between the outer surface of the battery cell stack and the outer surface of the battery cell stack, and the outer surface of the battery cell stack presses the battery cell stack in the first direction. Claim 6 In paragraph 5, the outer member presses the upper surface of the battery cell stack in a second direction, and the second direction is perpendicular to the first direction, forming a battery module. Claim 7 In paragraph 6, the battery module, wherein the second direction is the width direction of the plurality of battery cells. Claim 8 In paragraph 5, the compression pad is a battery module extending along the side of the battery cell stack. Claim 9 A battery pack comprising a battery module according to paragraph 1. Claim 10 In claim 9, the battery pack comprises a lower pack frame on which at least two battery modules are mounted, and an upper pack frame covering the upper portion of the at least two battery modules. Claim 11 In claim 10, the lower pack frame comprises a plurality of module regions, and the battery pack is configured such that the battery module is mounted in the module regions. Claim 12 In claim 11, the above thermally conductive resin layer is formed on each of the module regions of the battery pack. Claim 13 In claim 12, the above thermally conductive resin layer is a battery pack having the same size as the center of the lower surface of the battery cell laminate. Claim 14 A battery pack according to claim 13, wherein the side of one end of the outer casing member contacts one side of the thermally conductive resin layer, and the side of the other end of the outer casing member contacts the other side of the thermally conductive resin layer.

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