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 therein, a module frame housing the battery cell stack, and at least one flame separation structure interposed between adjacent battery cells among the plurality of battery cells and between the battery cell stack and the module frame, wherein the flame separation structure comprises a first extension portion extending to the space between the battery cell stack and the module frame.

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] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0004] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0005] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0006] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, battery modules in which multiple battery cells are electrically connected are used. In such battery modules, capacity and output are improved by connecting multiple battery cells in series or parallel to form a stack of battery cells. One or more battery modules can be mounted together with various control and protection systems, such as a Battery Disconnect Unit (BDU), a Battery Management System (BMS), and a cooling system, to form a battery pack.

[0007] FIG. 1 is a perspective view showing a conventional battery module.

[0008] Referring to FIG. 1, a conventional battery module (10) can be manufactured by housing a battery cell stack (not shown) in a module frame (20) and then attaching an end plate (40) to an open part of the module frame (20). At this time, since the battery cell stack housed inside the module frame (20) has a structure in which multiple battery cells are stacked, there is a problem that if a problem such as thermal runaway occurs in any of the battery cells, the heat and flame generated from that cell can easily spread to adjacent battery cells. In addition, as the risk of explosion increases when heat accumulates inside, there is an increasing need for a structure that can properly release heat and flame to the outside without spreading them to adjacent cells. The problem to be solved

[0009] The problem that the present invention aims to solve is to provide a battery module and a battery pack including the same that can block the transmission of flames to adjacent battery cells and easily discharge the flames to the outside even if a fire occurs inside the battery module.

[0010] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention. means of solving the problem

[0011] A battery module according to one embodiment of the present invention comprises a battery cell stack having a plurality of battery cells stacked therein, a module frame housing the battery cell stack, and at least one flame separation structure interposed between adjacent battery cells among the plurality of battery cells and between the battery cell stack and the module frame, wherein the flame separation structure comprises a first extension portion extending to the space between the battery cell stack and the module frame.

[0012] The flame separation structure described above includes at least two or more flame separation structures, and one or more battery cells may be located between two adjacent flame separation structures.

[0013] Among the flame separation structures above, between two adjacent flame separation structures, an isolated space surrounded by the first extension, the module frame, and the battery cell stack may be formed.

[0014] Each of the above plurality of battery cells includes an electrode lead, and the flame separation structure may include a second extension portion extended in correspondence with the area where the electrode lead protrudes.

[0015] The flame separation structure may include an opening formed in at least a portion of the remaining part excluding the first extension and the second extension.

[0016] The flame separation structure above may include at least one of a flame-retardant pad and a flame separation sheet.

[0017] The flame-retardant pad mentioned above may include a silicone foam pad.

[0018] The flame separation structure described above includes the flame-retardant pad and may include a flame separation sheet formed on at least a portion of at least one surface of the flame-retardant pad.

[0019] The flame separation sheet above can be formed in a portion corresponding to the first extension.

[0020] The flame separation sheet above may be formed in a portion corresponding to the second extension.

[0021] The flame separation sheet may include at least one of calcium carbonate (CaCO3), mica, glass fiber, and mineral fiber composite.

[0022] The battery cell stack further includes an end plate covering the front and rear surfaces of the battery cell stack, and an insulating cover disposed between the battery cell stack and the end plate, and the inner surface of the insulating cover facing the battery cell stack may include a plurality of partitions protruding toward the battery cell stack.

[0023] One of the plurality of bulkheads may include a pair of sub-bulkheads formed on both sides of the location where the flame separation structure is formed.

[0024] The insulating cover may include at least one first vent hole formed between adjacent partitions among the plurality of partitions.

[0025] The above end plate may include at least one second vent hole formed corresponding to at least one first vent hole.

[0026] A battery pack according to another embodiment of the present invention includes the battery module described above. Effects of the invention

[0027] According to embodiments of the present invention, by configuring to form a space capable of blocking a flame generated in any one cell within a battery module and providing a path for the flame to be discharged from said space, the transmission of flame to an adjacent battery cell from the point of ignition is blocked, and the flame can be easily discharged to the outside.

[0028] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0029] FIG. 1 is a perspective view showing a conventional battery module. FIG. 2 is a perspective view showing a battery module according to one embodiment of the present invention. Figure 3 is an exploded perspective view of the battery module of Figure 2. Figure 4 is a drawing showing a part of the cross-section along a-a' of Figure 3. FIGS. 5A and FIGS. 5B are drawings illustrating modified examples of a flame separation structure in one embodiment of the present invention. FIG. 6 is an exploded perspective view showing a battery cell stack in a battery module according to another embodiment of the present invention. FIG. 7 is a perspective view showing a battery module according to another embodiment of the present invention. FIG. 8 is a perspective view showing the end plate and insulating cover of the battery module of FIG. 7 as viewed from the inside. Figure 9 is a drawing showing part B of the cross-section along b-b' in Figure 7. 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, 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 on" another part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" 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.

[0036] Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS. 2 to 4.

[0037] FIG. 2 is a perspective view showing a battery module according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of the battery module of FIG. 2. FIG. 4 is a drawing showing a part of a cross-section along a-a' of FIG. 3.

[0038] Referring to FIGS. 2 to 4, a battery module (100) according to one embodiment of the present invention includes a battery cell stack (120) in which a plurality of battery cells (110) are stacked, a module frame (200) that houses the battery cell stack (120), and end plates (410, 420) that cover the front and rear of the battery cell stack (120).

[0039] First, it is preferable that the battery cell (110) be a pouch-type battery cell. For example, the battery cell (110) according to the present embodiment has a structure in which two electrode leads (111, 112) protrude from each end of the cell body facing each other. More specifically, the electrode leads (111, 112) are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell (110).

[0040] A plurality of battery cells (110) may be configured, and a plurality of battery cells (110) may be stacked so as to be electrically connected to each other to form a battery cell stack (120). Referring to FIG. 3, battery cells (110) may be stacked along the y-axis direction to form a battery cell stack (120). A first busbar frame (310) may be located on one side of the battery cell stack (120) in the direction in which the electrode lead (111) protrudes (x-axis direction). Although not specifically illustrated, a second busbar frame may be located on the other side of the battery cell stack (120) in the direction in which the electrode lead (112) protrudes (-x-axis direction). The battery cell stack (120) and the first busbar frame (310) may be accommodated together in a module frame (200). The module frame (200) can protect the battery cell stack (120) housed inside the module frame (200) and the electrical components connected thereto from external physical impact. As shown in FIG. 3, the module frame (200) may be a module frame (200) in the form of a metal plate with an integrated top surface, bottom surface, and both sides. That is, in the case of a module frame (200) in the form of a square tube, a space is formed inside in which the battery cell stack (120) can be housed, and end plates (410, 420) are attached to both ends of the square tube shape. However, it is not limited thereto, and various types of module frames (200) may be applied. As a possible variation, a module frame (200) in the form where an upper cover is combined with a U-shaped frame or a module frame (200) in the form where a lower plate is combined with an inverse U-shaped frame is also possible, and is not particularly limited.

[0041] Meanwhile, the module frame (200) may be opened in the direction in which the electrode leads (111, 112) protrude (x-axis direction, -x-axis direction), and end plates (410, 420) may be positioned on each of the open sides of the module frame (200). The two end plates (410, 420) shall be referred to as the first end plate (410) and the second end plate (420), respectively. The first end plate (410) may be joined to the module frame (200) while covering the first busbar frame (310), and the second end plate (420) may be joined to the module frame (200) while covering the second busbar frame (not shown). That is, a first busbar frame (310) may be positioned between the first end plate (410) and the battery cell stack (120), and a second busbar frame (not shown) may be positioned between the second end plate (420) and the battery cell stack (120). Additionally, an insulating cover (800) for electrical insulation may be positioned between the first end plate (410) and the first busbar frame (310).

[0042] The first end plate (410) and the second end plate (420) are positioned to cover the one side and the other side, respectively, of the battery cell stack (120). The first end plate (410) and the second end plate (420) can protect the first busbar frame (310) and various electrical components connected thereto from external impacts, and for this purpose, they must have a certain strength and may include a metal such as aluminum. Additionally, the first end plate (410) and the second end plate (420) can each be joined to the corresponding corner of the module frame (200) by means such as welding.

[0043] The first busbar frame (310) is positioned on one side of the battery cell stack (120) to cover the battery cell stack (120) and simultaneously guide the connection between the battery cell stack (120) and an external device. Specifically, at least one of a busbar, a terminal busbar, and a module connector may be mounted on the first busbar frame (310). In particular, at least one of a busbar, a terminal busbar, and a module connector may be mounted on the side opposite to the side of the first busbar frame (310) facing the battery cell stack. For example, FIG. 3 shows a busbar (510) and a terminal busbar (520) mounted on the first busbar frame (310).

[0044] The electrode lead (111) of the battery cell (110) can be bent and joined to the bus bar (510) or terminal bus bar (520) after passing through a slit formed in the first bus bar frame (310). The battery cells (110) constituting the battery cell stack (120) can be connected in series or in parallel by the bus bar (510) or terminal bus bar (520). Additionally, the battery cells (110) can be electrically connected to an external device or circuit through the terminal bus bar (520) exposed to the outside of the battery module (100).

[0045] The first busbar frame (310) may include an electrically insulating material. The first busbar frame (310) can prevent a short circuit by restricting the busbar (510) or terminal busbar (520) from contacting the battery cells (110), except for the portion where the busbar (510) or terminal busbar (520) is joined to the electrode lead (111).

[0046] Meanwhile, as described above, a second busbar frame may be positioned on the other side of the battery cell stack (120), and at least one of a busbar, a terminal busbar, and a module connector may be mounted on the second busbar frame. An electrode lead (112) may be bonded to such a busbar.

[0047] In the battery cell stack (120) according to the present embodiment, at least one flame separation structure (130) disposed between the battery cells (110) may be included. That is, the flame separation structure (130) may be interposed at least one of the following: between adjacent battery cells (110) among the plurality of battery cells (110), and between the battery cell stack (120) and the module frame (120).

[0048] At this time, the flame separation structure (130) may include a first extension (131) that extends to the space between the upper surface of the battery cell stack (120) and the upper plate of the module frame (220). That is, referring to FIG. 4, one or more battery cells (110) are disposed between the two flame separation structures (130), and each first extension (131) that extends to the upper part of the two flame separation structures (130) (i.e., the z-axis upward direction in the drawing) may be formed to contact the module frame (200). By doing so, an isolated space (SP) surrounded by the two first extensions (131), the battery cells (110), and the module frame (200) may be formed.

[0049] Additionally, the flame separation structure (130) may further include a second extension (132) that is extended in correspondence with the area where the electrode lead of the battery cell (110) protrudes.

[0050] Accordingly, even if ignition occurs in any of the battery cells (110), the gas and flames caused by it can remain within the isolation space (SP) while blocking as much as possible the spread of such gas and flames to neighboring battery cells (110). In addition, since the isolation space (SP) is not connected to adjacent cells but extends in the direction in which the second extension (132) of the flame separation structure (130) is formed, it can serve as a passage for the flames to move and guide the gas and flames to be discharged to the outside along this path. That is, safety can be improved because the movement of flames can be guided along a certain path while blocking as much as possible the transfer of flames and heat between cells.

[0051] The specific configuration of such a flame separation structure (130) is explained with reference to FIGS. 5a and FIGS. 5b.

[0052] FIGS. 5A and FIGS. 5B are drawings illustrating modified examples of a flame separation structure in one embodiment of the present invention.

[0053] The flame separation structure (130) may include at least one of a flame-retardant pad (130a) and a flame separation sheet (130b) to prevent the transfer of heat and flame generated in the battery cell (110). At this time, as shown in FIGS. 5A and 5B, it may include a flame-retardant pad (130a) and a flame separation sheet (130b) formed on one side thereof, or it may include a single layer of a flame-retardant pad (130a) or a single layer of a flame separation sheet (130b). In addition, it may have a multi-layer structure by further including a flame-retardant pad (130a) and a flame separation sheet (130b) instead of two layers. Furthermore, it may include the same flame separation structure (130) within a single battery module (100), or it may include flame separation structures (130) configured differently depending on the location.

[0054] The flame separation sheet (130b) may be formed over the entire surface of one side of the flame-retardant pad (130a) (Fig. 5b), or may be formed only in correspondence with the first extension (131) and the second extension (132) of the flame separation structure (130), which are the parts where the need for flame separation is directly required (Fig. 5a).

[0055] Here, the flame-retardant pad (130a) can be formed from a silicone foam pad. A silicone foam pad is a foamed pad with pores formed inside, possessing high thermal and chemical stability and excellent flame-retardant and thermal insulation properties. In particular, even better flame-retardant properties can be secured by applying a silicone foam pad made of thermosetting foamed silicone. However, it is not limited to this, and any material having excellent thermal properties can be appropriately used as the flame-retardant pad (130a).

[0056] As the flame separation sheet (130b), a sheet-shaped material comprising at least one of calcium carbonate (CaCO3), mica, glass fiber, or mineral fiber composite may be used. In particular, a mica sheet may be appropriately used, but is not limited thereto, and any material having excellent thermal properties may be appropriately used as the flame separation sheet (130b).

[0057] Next, another embodiment of the present invention will be described with reference to FIG. 6.

[0058] FIG. 6 is an exploded perspective view showing a battery cell stack in a battery module according to another embodiment of the present invention.

[0059] Referring to FIG. 6, in another embodiment of the present invention, the flame separation structure (130) is configured to further include an opening (133) corresponding to the main body of the battery cell (110). That is, the opening (133) may be formed in at least a portion of the remaining parts excluding the first extension (131) and the second extension (132) of the flame separation structure (130). According to this, while maintaining the effect of preventing heat and flame transfer between cells and inducing flame movement by the flame separation structure (130) as described above, the amount of the flame separation structure (130) required can be reduced, thereby reducing material costs and reducing the overall weight of the battery module (100).

[0060] Next, another embodiment of the present invention will be described with reference to FIGS. 7 and 8.

[0061] FIG. 7 is a perspective view showing a battery module (101) according to another embodiment of the present invention. FIG. 8 is a perspective view showing the end plate and the insulating cover of the battery module of FIG. 7 viewed from the inside. FIG. 9 is a drawing showing part B of the cross-section along b-b' in FIG. 7.

[0062] Referring to FIGS. 7 through 9, in another embodiment of the present invention, a plurality of partitions (810) are included on the inner side of an insulating cover (800). That is, the plurality of partitions (810) are formed on the inner surface of the insulating cover (800) where the insulating cover (800) and the battery cell stack (120) face each other. One of the plurality of partitions (810) is composed of a pair of sub-partitions (811), and these sub-partitions (811) are spaced apart from each other with the portion where the second extension (132) of the flame separation structure (130) is formed in between. Accordingly, the flame and heat induced between the flame separation structures (130) can still be separated and induced between the partitions (810).

[0063] In the area corresponding to the partition walls (810), the insulating cover (800) may be provided with at least one first vent hole (820). That is, flames guided into the passage between the partition walls (810) can be discharged to the outside of the insulating cover (800) through this first vent hole (820).

[0064] Additionally, in the area corresponding to the first vent hole (820), the end plate (410) may include a second vent hole (411). That is, flames guided through the passage between the partitions (810) and passing through the first vent hole (820) can be completely discharged to the outside through the second vent hole (411).

[0065] According to this structure, even if a thermal runaway occurs in some of the battery cells (110) and flames and gases are generated, the transfer to neighboring cells can be blocked as much as possible. Additionally, the generated flames and gases can be guided along a passage formed by the first and second extensions (131, 132) of the flame separation structure (130) and discharged to the outside through the first and second vent holes (820, 411) formed in the insulating cover (800) and the end plate (410), respectively. Thus, by effectively blocking the transfer of flames and gases generated in one cell to another cell and rapidly inducing discharge to the outside, the accumulation of thermal energy inside the battery module (100) can be suppressed.

[0066] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the observer.

[0067] One or more battery modules according to the embodiment described above can be mounted together with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack.

[0068] The above-mentioned battery module or battery pack can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0069] 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

[0070] 100, 101: Battery module 120: Battery cell laminate 200: Module Frame 410: First end plate 420: Second end plate 800: Insulation cover 130: Flame separation structure 131: First extension 132: Second extension 130a: Flame-retardant pad 130b: Flame separation sheet 810: Bulkhead 820: 1st vent hole 411: Second Vent Hall

Claims

Claim 1 A battery cell stack having multiple battery cells stacked thereon; a module frame housing the battery cell stack; A battery module comprising: at least one flame separation structure interposed between adjacent battery cells among the plurality of battery cells and between the battery cell stack and the module frame; an end plate covering the front and rear surfaces of the battery cell stack; and an insulating cover disposed between the battery cell stack and the end plate, wherein each of the plurality of battery cells includes an electrode lead, and the flame separation structure includes a first extension extending to the space between the battery cell stack and the module frame, and a second extension extending in correspondence with the area where the electrode lead protrudes, and the inner surface of the insulating cover facing the battery cell stack includes a plurality of partitions protruding toward the battery cell stack, and one of the plurality of partitions includes a pair of sub-partitions formed on both sides of the location where the second extension is formed, the insulating cover includes at least one first vent hole formed between adjacent partitions among the plurality of partitions, and the end plate includes at least one second vent hole formed in correspondence with the at least one first vent hole. Claim 2 A battery module according to claim 1, wherein the flame separation structure comprises at least two or more flame separation structures, and one or more battery cells are located between two adjacent flame separation structures. Claim 3 A battery module according to paragraph 2, wherein an isolated space surrounded by the first extension, the module frame, and the battery cell stack is formed between two adjacent flame separation structures among the flame separation structures. Claim 4 delete Claim 5 In claim 1, the flame separation structure comprises a battery module including an opening formed in at least a portion of the remaining part excluding the first extension and the second extension. Claim 6 In claim 1, the flame separation structure comprises a battery module including at least one of a flame-retardant pad and a flame separation sheet. Claim 7 In paragraph 6, the flame-retardant pad is a battery module comprising a silicone foam pad. Claim 8 In claim 6, the flame separation structure comprises the flame-retardant pad and a battery module comprising a flame separation sheet formed on at least a portion of at least one surface of the flame-retardant pad. Claim 9 In paragraph 8, the flame separation sheet is a battery module formed in a portion corresponding to the first extension. Claim 10 In paragraph 8, the flame separation sheet is a battery module formed in a portion corresponding to the second extension. Claim 11 In claim 8, the flame separation sheet comprises at least one of calcium carbonate (CaCO3), mica, glass fiber, and mineral fiber composite, in a battery module. Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 A battery pack including a battery module according to paragraph 1.

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