Battery module and battery pack including the same

Abstract

A battery module is provided, including: a battery cell stack in which a plurality of battery cells are stacked; a module frame that accommodates the battery cell stack; and at least one flame isolation structure that is interposed between adjacent battery cells among the plurality of battery cells or between the battery cell stack and the module frame, wherein the flame isolation structure includes a first extension that extends to a space between the battery cell stack and the module frame.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2021-0024696, filed on February 24, 2021, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a battery module and a battery pack including the battery module, and more specifically, to a battery module with enhanced safety and a battery pack including the battery module. Background Technology

[0004] In modern society, mobile devices such as mobile phones, laptops, portable video cameras, and digital cameras are used daily, leading to active development of technologies related to these devices. Furthermore, rechargeable batteries can be a solution to air pollution caused by conventional gasoline vehicles using fossil fuels, and can be used as a power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs). Therefore, the demand for rechargeable batteries is growing.

[0005] Currently, commercially available rechargeable batteries include nickel-cadmium (NiCd), nickel-metal hydride (NiMH), nickel-zinc (NiZn), and lithium-ion batteries. Among these, lithium-ion batteries are likely to attract significant attention due to their smaller memory effect compared to nickel-based batteries, resulting in free charge / discharge, extremely low self-discharge rate, and high energy density.

[0006] Lithium-ion secondary batteries can primarily use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively. A lithium-ion secondary battery may include: an electrode assembly having a positive electrode plate and a negative electrode plate respectively coated with positive and negative electrode active materials, and a separator inserted between the positive and negative electrode plates; and a battery casing that houses and seals the electrode assembly and electrolyte.

[0007] Generally, lithium secondary batteries can be classified into can-type secondary batteries with electrode components embedded in a metal can and pouch-type secondary batteries with electrode components embedded in an aluminum laminate, based on the shape of their external materials.

[0008] Secondary batteries used in small devices may contain two or three individual cells. However, secondary batteries used in medium to large devices such as automobiles may use battery modules in which multiple individual cells are electrically connected to each other. Such battery modules (where multiple individual cells are connected in series or parallel to form a battery cell stack) can have increased capacity and output. One or more battery modules may be installed together with various control and protection systems such as battery disconnect units (BDUs), battery management systems (BMSs), cooling systems, etc., to form a battery pack.

[0009] Figure 1 This is a perspective view of a conventional battery module.

[0010] Reference Figure 1 A conventional battery module 10 can be manufactured by housing a stack of battery cells (not shown) within a module frame 20 and then attaching end plates 40 to openings in the module frame 20. Here, the stack of battery cells housed in the module frame 20 can have a structure with several battery cells stacked together. Therefore, when thermal runaway occurs in any battery cell, the heat and flame generated from that cell can easily propagate to adjacent battery cells. Furthermore, the risk of explosion may increase when heat accumulates within the battery module, thus increasing the need for structures that properly dissipate heat and flame to the outside without propagating to adjacent cells. Summary of the Invention

[0011] Technical issues

[0012] An exemplary embodiment of the present invention provides a battery module that can prevent the flame from spreading to adjacent battery cells even when a fire occurs in the battery module and can easily vent the flame to the outside, as well as a battery pack including the battery module.

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

[0014] Technical solution

[0015] According to an exemplary embodiment of the present invention, a battery module includes: a battery cell stack, wherein a plurality of battery cells are stacked in the battery cell stack; a module frame for accommodating the battery cell stack; and at least one flame isolation structure inserted between adjacent battery cells in the plurality of battery cells, or inserted between the battery cell stack and the module frame, wherein the flame isolation structure includes a first extension that extends into the space between the battery cell stack and the module frame.

[0016] It can be provided with at least two flame isolation structures, and one or more battery cells can be located between two adjacent flame isolation structures.

[0017] An isolation space, surrounded by a first extension, a module frame, and a battery cell stack, can be provided between two adjacent flame isolation structures in the flame isolation structure.

[0018] Each of the plurality of battery cells may include an electrode lead, and the flame isolation structure may include a second extension extending corresponding to the area where the electrode lead protrudes.

[0019] The flame isolation structure may include an opening located in at least a portion of the remaining portion other than the first extension and the second extension.

[0020] Flame isolation structures may include at least one of flame-retardant pads and flame isolation panels.

[0021] Flame retardant pads may include silicone foam pads.

[0022] The flame isolation structure may include a flame-retardant pad and a flame isolation plate located on at least a portion of at least one surface of the flame-retardant pad.

[0023] The flame isolation plate is configured to correspond to the first extension.

[0024] The flame shield is configured to correspond to the second extension.

[0025] Flame shielding panels may include at least one of calcium carbonate (CaCO3), mica, glass fiber, and mineral fiber composite materials.

[0026] The battery module may also include: 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 multiple partition walls protrude from the inner surface of the insulating cover facing the battery cell stack toward the battery cell stack.

[0027] One of the multiple partition walls may include a pair of sub-partition walls located on either side of the flame isolation structure.

[0028] The insulating cover may include at least one first vent hole located between adjacent partition walls in a plurality of partition walls.

[0029] The end plate may include at least one second vent hole configured to correspond to at least one first vent hole.

[0030] A battery pack according to another exemplary embodiment of the present invention may include a battery module.

[0031] Beneficial effects

[0032] According to an exemplary embodiment of the present invention, by including a space for preventing flames from being generated from any of the battery cells in the battery module and a path for the flames to be discharged from the space, it is possible to prevent the flames from spreading from the ignition point to adjacent battery cells and to allow the flames to be easily discharged to the outside.

[0033] The effects of the present invention are not limited to those described above, and those skilled in the art can clearly understand other effects not mentioned in the claims. Attached Figure Description

[0034] Figure 1 This is a perspective view of a conventional battery module.

[0035] Figure 2 This is a perspective view showing a battery module according to an exemplary embodiment of the present invention.

[0036] Figure 3 yes Figure 2 An exploded perspective view of the battery module.

[0037] Figure 4 It shows along Figure 2 A diagram of a portion of the cross section cut from aa′.

[0038] Figure 5a and Figure 5b These are figures illustrating modified examples of the flame isolation structure in exemplary embodiments of the present invention.

[0039] Figure 6 This is an exploded perspective view showing a stack of battery cells in a battery module according to another exemplary embodiment of the present invention.

[0040] Figure 7 This is a perspective view showing a battery module according to yet another exemplary embodiment of the present invention.

[0041] Figure 8 It shows the view from its interior. Figure 7 A perspective view of the end plate and insulating cover of the battery module.

[0042] Figure 9 It shows along Figure 7 The diagram shows part B of the cross section bb′ cut off. Detailed Implementation

[0043] In the following, exemplary embodiments of the invention will be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily practice the invention. The invention can be implemented in many different forms and is not limited to the embodiments provided herein.

[0044] For the sake of clear description of the invention, parts that are not relevant to the description have been omitted, and the same or similar parts are indicated by the same reference numerals throughout this specification.

[0045] Furthermore, for ease of description, the dimensions and thicknesses of various components are shown arbitrarily in the accompanying drawings; therefore, the present invention is not necessarily limited to the contents shown in the drawings. The thicknesses of several layers and regions are exaggerated in the drawings for clarity. Additionally, the thicknesses of certain layers and regions are exaggerated in the accompanying drawings for ease of description.

[0046] Furthermore, when an element such as a layer, film, region, or plate is referred to as being "on" or "above" another element, the element may be directly on the other element or may have a third element inserted therein. Conversely, when an element is referred to as being "directly on" another element, no third element is inserted therein. Additionally, when an element is referred to as being "on" or "above" a reference element, the element may be located above or below the reference element, and may not necessarily be "on" or "above" the reference element in the opposite direction of gravity.

[0047] Furthermore, throughout this specification, unless explicitly stated otherwise, when an element “includes” another component, it should be understood that the element may further include a third component rather than exclude a third component.

[0048] In addition, throughout the instruction manual, the phrase "on a plane" can refer to the view of the target from the top, while the phrase "on a cross section" can refer to the view of the target from the side as a cross section taken in the vertical direction.

[0049] In the following text, refer to Figures 2 to 4 A battery module according to an exemplary embodiment of the present invention is described.

[0050] Figure 2 This is a perspective view showing a battery module according to an exemplary embodiment of the present invention. Figure 3 yes Figure 2 An exploded perspective view of the battery module. Figure 4 It shows along Figure 2 A diagram of a portion of the cross section cut from aa′.

[0051] Reference Figures 2 to 4 According to an exemplary embodiment of the present invention, the battery module 100 may include a battery cell stack 120 in which a plurality of battery cells 110 are stacked, a module frame 200 for accommodating the battery cell stack 120, and end plates 410 and 420 respectively covering the front and rear surfaces of the battery cell stack 120.

[0052] First, preferably, the battery cell 110 can be a pouch cell. For example, the battery cell 110 according to this exemplary embodiment can have a structure in which two electrode leads 111 and 112 face each other and protrude from both ends of the cell body. More specifically, the electrode leads 111 and 112 can be connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell 110.

[0053] Multiple battery cells 110 can be configured, and these cells 110 can be stacked and electrically connected to each other to form a battery cell stack 120. (See reference...) Figure 3 Battery cells 110 can be stacked along the y-axis to form a battery cell stack 120. A first busbar frame 310 can be located on one surface of the battery cell stack 120 along the direction in which the electrode leads 111 protrude (i.e., the x-axis direction). Although not specifically shown, a second busbar frame can be located on another surface of the battery cell stack 120 along the direction in which the electrode leads 112 protrude (i.e., the -x-axis direction). The battery cell stack 120 and the first busbar frame 310 can be housed together in a module frame 200. The module frame 200 can protect the battery cell stack 120 and the electronic components connected to it within the module frame 200 from external physical impacts. Figure 3 As shown, the module frame 200 can be a metal plate-shaped module frame 200, wherein the upper surface, lower surface, and both sides of the metal plate are integrally formed with each other. That is, the square tube-shaped module frame 200 can have space therein to accommodate the battery cell stack 120, and has end plates 410 and 420 respectively connected to the two ends of the square tube-shaped module frame. However, the invention is not limited to this, and any various types of module frame 200 can be used. As a possible modification, the module frame 200 can also have an upper cover and a U-shaped frame joined together, or a lower plate and a reverse U-shaped frame joined together. However, the module frame is not limited to any particular shape.

[0054] Simultaneously, the module frame 200 can have openings in the directions in which the electrode leads 111 and 112 protrude (i.e., the x-axis direction and the -x-axis direction), and end plates 410 and 420 can be located on both sides of the opening of the module frame 200, respectively. The two end plates 410 and 420 can be referred to as the first end plate 410 and the second end plate 420, respectively. The first end plate 410 can cover the first busbar frame 310 and engage with the module frame 200, and the second end plate 420 can cover the second busbar frame (not shown) and engage with the module frame 200. That is, the first busbar frame 310 can be located between the first end plate 410 and the battery cell stack 120, and the second busbar frame (not shown) can be located between the second end plate 420 and the battery cell stack 120. In addition, an insulating cover 800 for electrical insulation can be located between the first end plate 410 and the first busbar frame 310.

[0055] The first end plate 410 and the second end plate 420 can be configured to cover one surface and the other surface of the battery cell stack 120, respectively. The first end plate 410 and the second end plate 420 can protect the first busbar frame 310 and various electronic components connected thereto from external impacts, and for this purpose may require a predetermined strength and may contain metals such as aluminum. Furthermore, the first end plate 410 and the second end plate 420 can be joined to the edges of their corresponding module frames 200, respectively, using methods such as welding.

[0056] The first busbar frame 310 can be located on one surface 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 the busbar, terminal busbar, and module connector can be mounted on the first busbar frame 310. More specifically, at least one of the busbar, terminal busbar, and module connector can be mounted on the surface of the first busbar frame 310 opposite its surface facing the battery cell stack. For example, Figure 3 Busbar 510 and terminal busbar 520 are shown mounted on the first busbar frame 310.

[0057] The electrode leads 111 of the battery cell 110 can be bent after passing through a slit located in the first busbar frame 310 and engage with the busbar 510 or the terminal busbar 520. The battery cells 110 included in the battery cell stack 120 can be connected in series or in parallel with each other via the busbar 510 or the terminal busbar 520. In addition, external devices or circuits can be electrically connected to the battery cells 110 via the terminal busbar 520 exposed to the outside of the battery module 100.

[0058] The first busbar frame 310 may include an electrically insulating material. Except for the portion of the first busbar frame 310 that connects the busbar 510 or terminal busbar 520 to the electrode lead 111, the first busbar frame 310 can prevent short circuits by limiting the contact between the busbar 510 or terminal busbar 520 and the battery cell 110.

[0059] Meanwhile, as described above, the second busbar frame can be located on another surface of the cell stack 120, and at least one of the busbar, terminal busbar, and module connector can be mounted on the second busbar frame. The electrode lead 112 can engage with this busbar.

[0060] The battery cell stack 120 according to this exemplary embodiment may include at least one flame isolation structure 130 disposed between the battery cells 110. That is, the flame isolation structure 130 may be inserted between adjacent battery cells 110 in a plurality of battery cells 110, or between the battery cell stack 120 and the module frame 200.

[0061] Here, the flame isolation structure 130 may include a first extension 131 that extends into the space between the upper surface of the battery cell stack 120 and the upper plate of the module frame 200. That is, referring to... Figure 4 One or more battery cells 110 can be disposed between two flame isolation structures 130, wherein a first extension 131 extending to the upper part of the two flame isolation structures 130 (i.e., in the upward direction of the z-axis in the figure) can contact the module frame 200 respectively. Thus, an isolation space SP is provided surrounded by the two first extensions 131, the battery cells 110 and the module frame 200.

[0062] Additionally, the flame isolation structure 130 may also include a second extension 132 that extends corresponding to the region where the electrode leads of the battery cell 110 protrude.

[0063] Therefore, even if any battery cell 110 catches fire, the propagation of gas and flame to adjacent battery cells 110 can be prevented as much as possible, and the gas and flame can be kept within the isolation space SP. Furthermore, the isolation space SP can extend in the direction forming the second extension 132 of the flame isolation structure 130 without connecting to adjacent cells, and the isolation space SP serves as a path for flame movement, thereby guiding gas and flame to the outside. In other words, safety is improved by guiding the flame along a fixed path and preventing the transfer of flame and heat between cells as much as possible.

[0064] Reference Figure 5a and Figure 5b To describe the detailed structure of the flame isolation structure 130.

[0065] Figure 5a and Figure 5b These are figures illustrating modified examples of the flame isolation structure in exemplary embodiments of the present invention.

[0066] The flame isolation structure 130 may include at least one of a flame-retardant pad 130a and a flame isolation plate 130b to prevent the transfer of heat and flame within the battery cell 110. Here, as... Figure 5a and 5b As shown, the flame isolation structure 130 may include a flame-retardant pad 130a and a flame isolation plate 130b located on one surface of the flame-retardant pad. Alternatively, the flame isolation structure 130 may include a single layer of flame-retardant pad 130a or a single layer of flame isolation plate 130b. Furthermore, the flame isolation structure 130 may have a multi-layer structure by further including a flame-retardant pad 130a and a flame isolation plate 130b without including two layers of flame-retardant pad 130a and flame isolation plate 130b. Additionally, a battery module 100 may include all identical flame isolation structures 130 disposed therein or flame isolation structures 130 configured differently based on their locations.

[0067] Flame shield 130b can be entirely positioned on the surface of flame retardant pad 130a (see...). Figure 5b Alternatively, it can be configured as either the first extension 131 or the second extension 132 corresponding to the flame isolation structure 130 (see...). Figure 5a This refers to the part that directly needs to be isolated from the flame.

[0068] Here, the flame-retardant pad 130a may include a silicone foam pad. As a foam pad with pores formed therein, the silicone foam pad can possess high thermal and chemical stability, as well as excellent flame-retardant and heat-insulating properties. In particular, by using a silicone foam pad made of thermosetting silicone foam, better flame-retardant performance can be ensured. However, the invention is not limited thereto, and any material with excellent thermal properties can be suitably used as the flame-retardant pad 130a.

[0069] The flame shield 130b can be made of a sheet material comprising at least one of calcium carbonate (CaCO3), mica, glass fiber, and mineral fiber composites. Specifically, mica sheets can be suitably used in the flame shield 130b. However, the invention is not limited thereto, and any material with excellent thermal properties can be suitably used as the flame shield 130b.

[0070] Next, refer to Figure 6 Another exemplary embodiment of the present invention is described below.

[0071] Figure 6This is an exploded perspective view showing a stack of battery cells in a battery module according to another exemplary embodiment of the present invention.

[0072] Reference Figure 6 In another exemplary embodiment of the present invention, the flame isolation structure 130 may further include an opening 133 corresponding to the main body of the battery cell 110. That is, the opening 133 may be located in at least a portion of the remaining portion of the flame isolation structure 130, excluding the first extension 131 and the second extension 132. Therefore, the amount of flame isolation structure 130 required can be reduced, and the aforementioned effects of preventing heat and flame transfer between cells and guiding flame movement can be maintained by using the flame isolation structure 130. Therefore, the material cost and overall weight of the battery module 100 can be reduced.

[0073] Next, refer to Figure 7 and Figure 8 Another exemplary embodiment of the present invention is described below.

[0074] Figure 7 This is a perspective view showing a battery module 101 according to yet another exemplary embodiment of the present invention. Figure 8 It shows the view from its interior. Figure 7 A perspective view of the end plate and insulating cover of the battery module. Figure 9 It shows along Figure 7 The diagram of part B in the cross section cut by bb′

[0075] Reference Figures 7 to 9 According to another exemplary embodiment of the present invention, the insulating cover 800 may include a plurality of partition walls 810 located on its inner side. That is, the plurality of partition walls 810 may be located on the inner surface of the insulating cover 800, with the insulating cover 800 and the battery cell stack 120 facing each other on the inner surface. One of the partition walls 810 may include a pair of sub-partition walls 811, and the sub-partition walls 811 may be spaced apart from each other while the second extension 132 of the flame isolation structure 130 is inserted therebetween. Therefore, flames and heat guided between the flame isolation structures 130 can still be isolated and guided between the partition walls 810.

[0076] The insulating cover 800 may include at least one first vent 820 located in the region between the partition walls 810. That is, flames introduced into the path between the partition walls 810 can be discharged to the outside of the insulating cover 800 through the first vent 820.

[0077] Additionally, end plate 410 may include a second vent 411 located in the region corresponding to the first vent 820. That is, flames introduced into the path between partition walls 810 and passing through the first vent 820 can be completely discharged to the outside through the second vent 411.

[0078] Even in the event of thermal runaway in some of the battery cells 110, resulting in flames and gases, this structure can minimize the transmission of flames and gases to adjacent cells. Furthermore, the generated flames and gases can be guided along a path formed by the first extension 131 and the second extension 132 of the flame isolation structure 130, and discharged to the outside through the first vent 820 and the second vent 411 formed in the insulating cover 800 and the end plate 410, respectively. Therefore, by effectively preventing the transmission of flames and gases generated in one cell to another and rapidly guiding the flames and gases to the outside, the accumulation of heat energy in the battery module 100 can be suppressed.

[0079] In this exemplary embodiment, terms such as front, back, left, right, up, and down are used to indicate directions, and these terms are for convenience only and may vary depending on the position of the target object or the observer's position.

[0080] One or more battery modules according to the exemplary embodiments described above can be installed together with various control and protection systems such as a battery management system (BMS), a cooling system, etc., to form a battery pack.

[0081] Battery modules or battery packs can be applied to a variety of devices. Specifically, battery modules or battery packs can be applied to vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, but are not limited to these, and can be applied to a variety of devices that can use rechargeable batteries.

[0082] Although exemplary embodiments of the present invention have been described in detail above, the scope of the invention is not limited thereto. That is, various modifications and substitutions made by those skilled in the art using the basic concepts of the invention as defined in the appended claims fall within the scope of the invention.

[0083] <Explanation of Figure Markers>

[0084] 100, 101: Battery Module

[0085] 120: Battery cell stack

[0086] 200: Module Framework

[0087] 410: First end plate

[0088] 420: Second end plate

[0089] 800: Insulating cover

[0090] 130: Flame isolation structure

[0091] 131: First Extension

[0092] 132: Second Extension

[0093] 130a: Flame retardant pad

[0094] 130b: Flame isolation plate

[0095] 810: Partition wall

[0096] 820: First exhaust port

[0097] 411: Second exhaust port

Claims

1. A battery module comprising: a cell stack in which a plurality of battery cells are stacked; a module frame accommodating the cell stack; and at least one flame isolation structure interposed between adjacent battery cells among the plurality of battery cells or between the cell stack and the module frame, wherein the flame isolation structure includes a first extension portion extending to a space between the cell stack and the module frame, wherein the battery module further comprises: an end plate covering front and rear surfaces of the cell stack; and an insulation cover disposed between the cell stack and the end plate, wherein a plurality of partition walls protrude from an inner surface of the insulation cover facing the cell stack toward the cell stack, wherein one partition wall among the plurality of partition walls includes a pair of sub-partition walls located on both sides of the flame isolation structure, wherein the insulation cover includes at least one first exhaust hole between adjacent partition walls among the plurality of partition walls, and wherein the end plate includes at least one second exhaust hole disposed to correspond to the at least one first exhaust hole. At least two flame isolation structures are provided, and one or more battery cells are located between adjacent two flame isolation structures among the flame isolation structures.

2. The battery module of claim 1, wherein, An isolation space surrounded by the first extension portion, the module frame, and the cell stack is provided between the adjacent two flame isolation structures among the flame isolation structures.

3. The battery module of claim 2, wherein, 4.The battery module of claim 1, wherein: each of the plurality of battery cells includes an electrode lead, and the flame isolation structure includes a second extension portion extending in correspondence with an area in which the electrode lead protrudes. The flame isolation structure includes an opening in at least a portion of a remaining portion other than the first extension portion and the second extension portion.

5. The battery module of claim 4, wherein, The flame isolation structure includes at least one of a fire retardant pad and a flame isolation plate.

6. The battery module of claim 4, wherein, The fire retardant pad includes a silica gel foam pad.

7. The battery module of claim 6, wherein, The flame isolation structure includes the fire retardant pad and the flame isolation plate on at least a portion of at least one surface of the fire retardant pad.

8. The battery module of claim 6, wherein, The flame isolation plate is disposed to correspond to the first extension portion.

9. The battery module of claim 8, wherein, The flame isolation plate is disposed to correspond to the second extension portion.

10. The battery module of claim 8, wherein, The flame isolation plate includes at least one of calcium carbonate (CaCO3), mica, glass fiber, and a mineral fiber composite.

11. The battery module of claim 8, wherein, 12.A battery pack comprising the battery module of claim 1. ​

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