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 having a plurality of battery cells stacked thereon; a module frame accommodating the battery cell stack; and a sliding plate disposed between adjacent battery cells among the plurality of battery cells.

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 with enhanced safety and a battery pack including the same. Background Technology

[0002] As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are receiving a lot of attention 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 an exploded perspective view of a conventional battery module. FIG. 2 is a perspective view showing the combined state of the components constituting the battery module of FIG. 1. FIG. 3 is a cross-sectional view taken along the cutting line A-A' of FIG. 2.

[0006] Referring to FIGS. 1 to 3, a conventional battery module (10) comprises a battery cell stack (12) in which a plurality of battery cells (11) are stacked in one direction, a module frame (25) that accommodates the battery cell stack (12), and an end plate (15) that covers the front and rear surfaces of the battery cell stack (12). At this time, the module frame (25) includes a lower frame (30) that covers the lower and both sides of the battery cell stack (12) and an upper plate (40) that covers the upper surface of the battery cell stack (12). Additionally, a busbar assembly (13) may be formed between the battery cell stack (12) and the end plate (15).

[0007] Additionally, as illustrated in FIG. 3, a compression pad (20) is positioned between a pair of adjacent battery cells in a battery cell stack (12). Referring to FIG. 2 and FIG. 3, the compression pad (20) included in the conventional battery module (10) can be in contact with one side of the battery cell (11).

[0008] When the battery cell (11) swells, the battery cell stack (12) may apply stress to the lower frame (30) and the upper plate (40), which can reduce the module rigidity, making it difficult to ensure the stability of the battery module. At this time, the compression pad (20) can absorb some of the swelling phenomenon, but there are limitations in controlling the large amount of swelling that occurs during the charging and discharging process using only the compression pad (20). In addition, there is a possibility of thickness differences and tolerances in the battery cell (11) or unpressurized parts, so in the case of a battery module that requires securing initial pressure, it is difficult to maintain the initial pressure using only the compression pad (20). In particular, in the case of a battery cell made of pure silicon (Si) or an all-solid-state battery cell, a certain pressure needs to be maintained even initially, and since a large amount of swelling occurs during the charging and discharging process compared to conventional battery cells, a structure capable of appropriately controlling this is required, and it is necessary to secure module rigidity by forming an additional structure to minimize the occurrence of swelling.

[0009] Accordingly, there is a need to develop battery modules and battery packs that, unlike conventional ones, possess initial pressurization and can control internal pressure by absorbing a large amount of swelling that occurs during charging and discharging. The problem to be solved

[0010] The problem to be solved by the present invention is to provide a battery module capable of maintaining initial pressure and absorbing a large amount of cell swelling, and a battery pack including the same.

[0011] 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

[0012] A battery module according to one embodiment of the present invention comprises: a battery cell stack having a plurality of battery cells stacked thereon; a module frame accommodating the battery cell stack; and a sliding plate disposed between adjacent battery cells among the plurality of battery cells.

[0013] The above sliding plate includes a first sliding plate and a second sliding plate, and the first sliding plate and the second sliding plate may be formed to be spaced apart from each other between the adjacent battery cells.

[0014] The battery module includes a connecting member formed between the first sliding plate and the second sliding plate, and the connecting member can connect the first sliding plate and the second sliding plate.

[0015] The above connecting member may include a spring member.

[0016] The above connecting members may be formed in multiple numbers between the first sliding plate and the second sliding plate.

[0017] The above battery module includes shaft members formed on the upper and lower portions of the battery cell stack, and the shaft members can be connected to the end portion of the sliding plate.

[0018] The above module frame includes a frame member covering the lower and both sides of the battery cell stack and an upper plate covering the upper part of the battery cell stack, and the shaft member may be formed parallel to the upper plate.

[0019] The shaft members are formed in multiple numbers, and each shaft member is fixedly installed on each side of the frame member, and each shaft member can be connected to the first sliding plate and the second sliding plate, respectively.

[0020] The shaft member may include a first shaft member connected to the first sliding plate and a second shaft member connected to the second sliding plate.

[0021] The first shaft member may include a first-1 shaft member connected to the upper end of the first sliding plate and a first-2 shaft member connected to the lower end of the first sliding plate, and the second shaft member may include a second-1 shaft member connected to the upper end of the second sliding plate and a second-2 shaft member connected to the lower end of the second sliding plate.

[0022] A battery module according to another embodiment of the present invention may include a mounting portion formed on the side portion of the module frame.

[0023] The above mounting portion may be formed along the longitudinal direction of the battery cell.

[0024] A battery pack according to another embodiment of the present invention includes the battery module described above. Effects of the invention

[0025] According to an embodiment of the present invention, an initial pressure can be maintained through a sliding plate and a connecting member structure interposed between a pair of adjacent battery cells, and a swelling phenomenon occurring during charging and discharging can be controlled.

[0026] In particular, pressure changes caused by cell swelling can be controlled through the sliding plate, connecting member, and shaft member.

[0027] In addition, swelling can be suppressed through the mounting portion formed on the module frame.

[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 an exploded perspective view of a conventional battery module. FIG. 2 is a perspective view showing the combined state of the components constituting the battery module of FIG. 1. Figure 3 is a cross-sectional view taken along the cutting line A-A' of Figure 2. FIG. 4 is a perspective view of the battery module of the present invention. FIG. 5 is a cross-sectional view of a battery module according to one embodiment of the present invention, taken by cutting parallel to the xz plane along the cutting line B-B' of FIG. 4. FIG. 6 is a cross-sectional view of a battery module according to another embodiment of the present invention. FIG. 7 is a perspective view showing one battery cell included in the battery cell stack of FIG. 5 and FIG. 6. FIG. 8 is an exploded perspective view of a battery pack according to another embodiment of the present invention. Specific details for implementing the invention

[0030] Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, 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, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0034] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0035] 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.

[0037] Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS. 4, 5, and 7.

[0038] FIG. 4 is a perspective view of a battery module of the present invention. FIG. 5 is a cross-sectional view of a battery module according to one embodiment of the present invention, taken by cutting along the cutting line B-B' of FIG. 4 parallel to the xz plane. FIG. 7 is a perspective view showing one battery cell included in the battery cell stack of FIG. 5.

[0039] Referring to FIGS. 4 and 5, the battery module (100) according to the present embodiment includes a battery cell stack (120) in which a plurality of battery cells (110) are stacked, a module frame (200) that accommodates the battery cell stack (120), and an end plate (150) that covers the front and rear surfaces of the battery cell stack (120).

[0040] It is preferable that the battery cell (110) be a pouch-type battery cell. For example, referring to FIG. 7, the battery cell (110) according to the present embodiment has a structure in which two electrode leads (111, 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 ends (114a, 114b) of the case (114) and the two sides (114c) connecting them, while housing an electrode assembly (not shown) 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, 114sc), and the sealing portions (114sa, 114sb, 114sc) are sealed by a method such as heat fusion, and the other side portion may be formed as a connecting portion (115). The distance between the two ends (114a, 114b) of the battery case (114) can be defined in the length direction of the battery cell (110), and the distance between the side portion (114c) connecting the two ends (114a, 114b) of the battery case (114) and the connecting portion (115) can be defined in the width direction of the battery cell (110).

[0041] The connecting portion (115) is an area that extends along one edge of the battery cell (110), and a protrusion (110p) of the battery cell (110) may be formed at the end of the connecting portion (115). The protrusion (110p) may be formed at least one of the two ends of the connecting portion (115) and may protrude in a direction perpendicular to the direction in which the connecting portion (115) extends. The protrusion (110p) may be located between the connecting portion (115) and one of the sealing portions (114sa, 114sb) of the two ends (114a, 114b) of the battery case (114).

[0042] The battery case (114) is generally composed of a laminate structure of a resin layer / metal thin film layer / resin layer. For example, when the surface of the battery case is composed of an O(oriented)-nylon layer, there is a tendency for multiple battery cells to slide easily due to external impact when stacking them to form a medium-to-large battery module. Therefore, to prevent this and maintain a stable stacked structure of the battery cells, an adhesive member such as a double-sided tape or a chemical adhesive that bonds through a chemical reaction upon adhesion can be attached to the surface of the battery case to form a battery cell stack (120).

[0043] The module frame (200) includes a frame member (300) that covers the lower and side portions of the battery cell stack (120) with the upper surface, front and rear surfaces open, and an upper plate (400) that covers the upper portion of the battery cell stack (120). However, the module frame (200) is not limited thereto and may be replaced with a frame of other shapes, such as an L-shaped frame or a mono frame that surrounds the battery cell stack (120) excluding the front and rear surfaces. The battery cell stack (120) housed inside the module frame (200) can be physically protected through the module frame (200). At this time, the frame member (300) may include a bottom portion (300a) that supports the lower portion of the battery cell stack (120) and side portions (300b) that extend upward from each end of the bottom portion (300a).

[0044] The upper plate (400) can cover the open upper side of the module frame (200). The end plate (150) can cover the front and rear sides of the battery cell stack (120) that is open in the module frame (200). The end plate (150) can be joined to the front and rear end corners of the upper plate (400) and the front and rear end corners of the module frame (200) through welding.

[0045] Conventional battery modules attempted to absorb cell swelling by including compression pads interposed between battery cells. However, in the case of battery cells containing pure silicon (Si) and all-solid-state cells, which exhibit a very high degree of swelling, conventional compression pads alone had limitations in absorbing cell swelling. In particular, while the battery cells also require the maintenance of a constant initial pressure, conventional compression pads alone had limitations in generating this initial pressure.

[0046] Accordingly, referring to FIG. 5, the battery module (100) according to the present embodiment includes a sliding plate (500) disposed between adjacent battery cells (110) among a plurality of battery cells (110). At this time, the sliding plate (500) may include a first sliding plate (510) and a second sliding plate (520), and the first sliding plate (510) and the second sliding plate (520) may be formed to be spaced apart from each other between adjacent battery cells (110).

[0047] The battery module according to the present embodiment may include a connecting member (600) formed between a first sliding plate (510) and a second sliding plate (520). At this time, the connecting member (600) may be selected without restriction within a range that does not restrict the movement of the sliding plate (500), and specifically, the connecting member (600) may include a spring member. The connecting member (600) may connect the first sliding plate (510) and the second sliding plate (520).

[0048] At this time, the connecting member (600) can form an initial pressure by being formed between the first sliding plate (510) and the second sliding plate (520). In particular, the connecting member (600) is compressed when cell swelling occurs, thereby enabling movement of the first sliding plate (510) and the second sliding plate (520), and thus achieving the effect of enabling pressure control due to cell swelling.

[0049] Accordingly, at least one connecting member (600) may be formed between the first sliding plate (510) and the second sliding plate (520), and more specifically, by forming multiple members, the effect of maintaining the initial pressure and absorbing cell swelling due to the elastic force of the connecting member (600) can be achieved.

[0050] Meanwhile, in order to maintain the initial pressure, a fixed member may be formed together with the connecting member (600), and the fixed member may be removed after fixing the position of the connecting member (600) to form the initial pressure.

[0052] Meanwhile, the battery module (100) according to the present embodiment may include a shaft member (700) formed on the upper and lower portions of the battery cell stack (120). In particular, the shaft member (700) may be connected to the end portion of the sliding plate (500). At this time, for the connection, a hole may be formed in the sliding plate (500) to insert and fix the shaft member (700) through the hole, or an adhesive member may be further formed between the sliding plate (500) and the shaft member (700). In addition, the sliding plate (500) and the shaft member (700) may be connected in various ways, not limited to the above methods.

[0053] Meanwhile, when a shaft member (700) is formed within the battery module (100) according to the present embodiment, the shaft member (700) may be formed parallel to the upper plate (400). Specifically, referring to FIGS. 4 and 5, the shaft member (700) may be formed along the x-axis and -x-axis directions, which are the stacking directions of the battery cells, and may be formed parallel to the upper plate (400) while being formed along said directions.

[0054] Additionally, a plurality of shaft members (700) may be formed, and the shaft members (700) are fixedly installed on each side portion (300b) of the frame member, and the shaft members (700) may be connected to the first sliding plate (510) and the second sliding plate (520), respectively.

[0055] That is, referring to FIG. 5, the shaft member (700) may include a first shaft member (710) connected to a first sliding plate (510) and a second shaft member (720) connected to a second sliding plate (520). At this time, the first shaft member (710) may include a first-1 shaft member (711) connected to an upper end portion of the first sliding plate (510) and a first-2 shaft member (712) connected to a lower end portion of the first sliding plate (510). Additionally, the second shaft member (720) may include a second-1 shaft member (721) connected to an upper end portion of the second sliding plate (520) and a second-2 shaft member (722) connected to a lower end portion of the second sliding plate (520). Accordingly, shaft members (700) may be formed at both ends of the sliding plate (500), and the sliding plate (500) may move smoothly without shifting in one direction during cell swelling.

[0057] When swelling of a battery cell (110) occurs on a battery module (100) according to the present embodiment, the battery cells (110) adjacent to the sliding plate (500) may apply pressure to the sliding plate (500). At this time, a connecting member (600) located between the sliding plates (500) may be compressed by the pressure, and the sliding plate (500) may move in the direction of the connecting member (600) due to the compression, and at the same time, a shaft member (700) connected to the sliding plate (500) may be extended according to the movement of the sliding plate (500).

[0058] Therefore, cell swelling can be absorbed by compressing the connecting member (600) by the pressure applied to the sliding plate (500), and at the same time, the pressure caused by swelling can be controlled by moving the sliding plate (500) and extending the shaft member (700). In addition, the stability of the battery module can be improved by minimizing the cell swelling phenomenon and increasing the effect of absorbing the swelling.

[0060] Hereinafter, a battery module according to another embodiment of the present invention will be described with reference to FIG. 6. Since there is overlap with the content described above, only the parts that differ from the content described above will be described.

[0061] FIG. 6 is a cross-sectional view of a battery module according to another embodiment of the present invention.

[0062] Referring to FIG. 6, the battery module according to the present embodiment may include a mounting portion (800) formed on the side portion of the module frame (200). Specifically, the mounting portion (800) may be formed on the side portion (300b) of the frame member (300).

[0063] At this time, referring to FIG. 5, the mounting portion (800) may be formed on the side portion (300b) along the y-axis and -y-axis directions, which are the longitudinal directions of the battery cell (110). That is, the mounting portion (800) may be formed in the direction of the cell swelling phenomenon occurring along the longitudinal direction of the battery cell (110). In addition, the mounting portion (800) may be formed to have a shape that repeatedly protrudes and indents from the side portion (300b).

[0064] By forming the mounting portion (800) as described above, the effect of minimizing the possibility of deformation of the module frame (200) due to cell swelling can be achieved. In particular, the mounting portion (800) formed along the direction of cell swelling can achieve the effect of suppressing cell swelling.

[0066] Hereinafter, a battery pack according to another embodiment of the present invention will be described with reference to FIG. 8.

[0067] FIG. 8 is an exploded perspective view of a battery pack according to another embodiment of the present invention.

[0068] Referring to FIG. 8, the battery pack (1000) according to the present embodiment may be formed by packaging one or more of the battery modules described above within a pack case. In particular, the battery pack (1000) may be formed by packaging an upper pack case (1100) and a lower pack case (1200), and may have a structure in which a Battery Management System (BMS) that manages the temperature or voltage of the battery and a cooling device are added to the pack. At this time, the stability of the battery pack according to the present embodiment may be improved by including a structure capable of absorbing and minimizing cell swelling.

[0069] Furthermore, the battery module and 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 battery pack containing the same, and this also falls within the scope of the present invention.

[0070] 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

[0072] 110: Battery cell 120: Battery cell stack 200: Module Frame 300: Frame missing 400: Upper plate 500: Sliding plate 600: Connecting member 700: Shaft member 800: Mounting part 1000: Battery pack

Claims

Claim 1 A battery cell stack having a plurality of battery cells stacked therein; a module frame accommodating the battery cell stack; and a sliding plate disposed between adjacent battery cells among the plurality of battery cells and including a first sliding plate and a second sliding plate, wherein the first sliding plate and the second sliding plate are formed to be spaced apart from each other between the adjacent battery cells, and a connecting member including a spring member is formed between the first sliding plate and the second sliding plate, wherein the connecting member connects the first sliding plate and the second sliding plate, and a shaft member formed on the upper and lower portions of the battery cell stack, wherein the shaft member is connected to the end portion of the sliding plate, and an adhesive member formed between the sliding plate and the shaft member connects the end portion of the shaft member and the sliding plate. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 In claim 1, the connecting member is a battery module formed in plurality between the first sliding plate and the second sliding plate. Claim 6 delete Claim 7 In claim 1, the module frame comprises a frame member covering the lower and both sides of the battery cell stack, and an upper plate covering the upper part of the battery cell stack, and the shaft member is formed parallel to the upper plate, forming a battery module. Claim 8 In claim 7, the shaft members are formed in plurality, and the shaft members are fixedly installed on each side of the frame member, and the shaft members are connected to the first sliding plate and the second sliding plate, respectively, in a battery module. Claim 9 In claim 8, the above-mentioned shaft member comprises a first shaft member connected to the first sliding plate and a second shaft member connected to the second sliding plate, forming a battery module. Claim 10 A battery module according to claim 9, wherein the first shaft member comprises a first-1 shaft member connected to the upper end portion of the first sliding plate and a first-2 shaft member connected to the lower end portion of the first sliding plate, and the second shaft member comprises a second-1 shaft member connected to the upper end portion of the second sliding plate and a second-2 shaft member connected to the lower end portion of the second sliding plate. Claim 11 A battery module comprising a mounting portion formed on the side portion of the module frame in claim 1. Claim 12 In claim 11, the mounting portion is a battery module formed along the longitudinal direction of the battery cell. Claim 13 A battery pack comprising a battery module according to paragraph 1.

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