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 surrounding the battery cell stack; and a fire suppression member interposed between the battery cells, wherein the battery cells include a first battery cell and a second battery cell adjacent to each other, and the fire suppression member surrounds the upper surface of the first battery cell, the space between the first battery cell and the second battery cell, and the lower surface of the second battery cell in a zigzag shape.

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 with improved safety. 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. Additionally, one or more battery modules 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.

[0007] If the temperature of a secondary battery exceeds the optimal level, its performance may degrade, and in severe cases, there is a risk of explosion or ignition. In particular, if thermal runaway occurs in a specific cell of a secondary battery, it propagates to adjacent cells very rapidly. Furthermore, since the propagation of thermal runaway between cells poses a high risk of large-scale fires and explosions, it is crucial to prevent thermal runaway and to suppress and delay its propagation.

[0008] Figure 1 is a drawing showing a battery cell and an adhesive member included in a conventional battery module.

[0009] Referring to FIG. 1, the battery cell stack includes an adhesive member (50a, 50b) interposed between a battery cell (11) and adjacent battery cells (11). In this case, the adhesive member (50a, 50b) includes a separable adhesive member (50a) or a whole adhesive member (50b) depending on its shape.

[0010] That is, in a conventional battery module, the battery cells (11) are attached to each other through an adhesive member (50a, 50b), such as double-sided tape, between the battery cells (11) to form a battery cell stack. However, in this case, there was a problem in that it was difficult to delay the transfer of the ignition phenomenon from some battery cells (11) to other battery cells (11) when a fire occurred in the battery module.

[0011] In addition, in the case of the adhesive members (50a, 50b), the upper and lower parts of the battery cell (11) are not covered, so in particular, when a thermal runaway phenomenon occurs, heat and flames are easily transferred to adjacent battery cells (11).

[0012] Therefore, it is necessary to develop a battery module with improved safety that can not only cover the upper and lower parts of the battery cell (11), but also suppress thermal runaway and prevent and delay the propagation of thermal runaway between the battery cells (11). The problem to be solved

[0013] The problem to be solved by the present invention is to provide a battery module that prevents the propagation of thermal runaway between battery cells or effectively delays the propagation of thermal runaway when thermal runaway occurs, and a battery pack including the same.

[0014] However, 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

[0015] 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 surrounding the battery cell stack; and a fire suppression member interposed between the battery cells, wherein the battery cells include a first battery cell and a second battery cell adjacent to each other, and the fire suppression member surrounds the upper surface of the first battery cell, the space between the first battery cell and the second battery cell, and the lower surface of the second battery cell in a zigzag shape.

[0016] The above-mentioned extinguishing member may include a extinguishing agent; and a case for accommodating the extinguishing agent.

[0017] The above case melts when a high temperature is generated inside the battery module, and the fire extinguishing agent contained in the case can be released outside the case.

[0018] The above-mentioned extinguishing member may have double-sided adhesive properties.

[0019] The above case may have double-sided adhesive properties.

[0020] The above-mentioned fire extinguishing member may come into contact with the upper part of the module frame and the lower part of the module frame.

[0021] A fire extinguishing member of a battery module according to another embodiment of the present invention may be in contact with the upper surface of the first battery cell and the lower surface of the second battery cell.

[0022] The above-mentioned fire extinguishing member can bond the upper part of the module frame and the upper surface of the first battery cell, and bond the lower part of the module frame and the lower surface of the second battery cell.

[0023] The above-mentioned extinguishing member can bond the first battery cell and the second battery cell to each other.

[0024] The above-mentioned fire extinguishing member may be interposed between the side portion of the module frame and the outermost battery cell.

[0025] The above-mentioned firefighting member can bond the side portion of the module frame and the outermost battery cell.

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

[0027] A battery module according to one embodiment of the present invention has a fire suppression member interposed between a pair of adjacent battery cells in a battery cell stack, and the fire suppression member is formed to wrap the battery cells in a zigzag shape, thereby preventing the propagation of thermal runaway between battery cells or effectively delaying the propagation of thermal runaway when thermal runaway occurs.

[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 drawing showing a battery cell and an adhesive member included in a conventional battery module. FIG. 2 is a perspective view showing a battery module according to one embodiment of the present invention. FIG. 3 is a perspective view showing a battery cell included in the battery module of FIG. 2. Figure 4 is a drawing showing a cross-section cut along the cutting line a-a' of Figure 2. FIG. 5 is a drawing showing a battery module according to another embodiment of the present invention. FIG. 6 is a perspective view showing a part of a battery cell stack included in the battery module of FIG. 5. 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.

[0036] The first and second terms used in this application may be used to describe various components, but the components should not be limited by the terms. The terms are used solely for the purpose of distinguishing one component from another.

[0038] Hereinafter, the battery module of the present invention will be described with reference to FIGS. 2 to 6.

[0039] FIG. 2 is a perspective view showing a battery module according to an embodiment of the present invention. FIG. 3 is a perspective view showing a battery cell included in the battery module of FIG. 2. FIG. 4 is a cross-sectional view taken along the cutting line a-a' of FIG. 2.

[0040] Referring to FIGS. 2 to 4, 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, and a module frame (200) that surrounds the battery cell stack (120).

[0041] First, the battery cell (110) is preferably a pouch-type battery cell and can be formed into a rectangular sheet-type structure. For example, referring to FIG. 3, the battery cell (110) according to the present embodiment has a structure in which two electrode leads (111, 112) protrude from one end (114a) and the other end (114b) of the cell body (113) facing each other. That is, the battery cell (110) includes electrode leads (111, 112) protruding in directions 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).

[0042] Meanwhile, the battery cell (110) can be manufactured by bonding the two ends (114a, 114b) of the cell case (114) and the one side (114c) connecting them, while the electrode assembly (not shown) is housed in the cell case (114). In other words, the battery cell (110) according to the present embodiment has a total of three sealing parts (114sa, 114sb, 114sc), and the sealing parts (114sa, 114sb, 114sc) are sealed by a method such as heat fusion, and the other side can be formed as a connecting part (115). The cell case (114) can be made of a laminate sheet including a resin layer and a metal layer.

[0043] Additionally, the connecting portion (115) may extend along one edge of the battery cell (110), and a bat ear (110p) may be formed at the end of the connecting portion (115). Additionally, as the cell case (114) is sealed with the protruding electrode leads (111, 112) in between, a terrace portion (116) may be formed between the electrode leads (111, 112) and the cell body (113). That is, the battery cell (110) may include a terrace portion (116) that extends from the cell case (114) in the direction in which the electrode leads (111, 112) protrude.

[0044] These battery cells (110) may be composed of multiple units, and multiple battery cells (110) may be stacked so as to be electrically connected to each other to form a battery cell stack (120). In particular, as shown in FIG. 2, multiple battery cells (110) may be stacked along a direction parallel to the x-axis. Accordingly, electrode leads (111, 112) may protrude in the y-axis direction and the -y-axis direction, respectively.

[0045] Meanwhile, the module frame (200) may be a monoframe that surrounds the battery cell stack (120), excluding the front and rear sides. However, the module frame (200) is not limited thereto and may include an L-shaped frame, a U-shaped frame with the top, front, and rear sides open to cover the bottom and sides of the battery cell stack (120), and a frame shape including an upper plate that covers the top of the battery cell stack (120). The battery cell stack (120) housed inside the module frame (200) can be physically protected through the module frame (200). At this time, the module frame (200) may include a bottom (200a) of the module frame (200), a side portion (200b) of the module frame (200), and a top (200c) of the module frame (200).

[0046] The end plate (150) can cover the front and rear surfaces 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 edges of the module frame (200) through welding.

[0047] A bus bar frame (not shown) may be formed between the end plate (150) and the front and rear surfaces of the battery cell stack (120). A plurality of bus bars mounted on the bus bar frame may be formed protruding from the battery cells (110) and may come into contact with electrode leads (111, 112) mounted on the bus bar frame.

[0048] Additionally, the battery module (100) according to the present embodiment further includes a thermally conductive resin layer (310) located between the lower surface of the battery cell stack (120) and the lower surface (200c) of the module frame (200), and the thermally conductive resin layer (310) can serve to transfer heat generated from the battery cell (110) to the bottom of the battery module (100).

[0050] Meanwhile, referring to FIG. 4, the battery module (100) according to the present embodiment includes a extinguishing member (300) interposed between battery cells (110).

[0051] At this time, the battery cell (110) includes a first battery cell (110a) and a second battery cell (110b) that are adjacent to each other. Additionally, the first battery cell (110a) may be formed to be adjacent to the second battery cell (110b) again. Thus, the first battery cell (110a) and the second battery cell (110b) may be formed alternately.

[0052] Additionally, referring to FIG. 4, the fire extinguishing member (300) wraps the upper surface of the first battery cell (110a), the space between the first battery cell (110a) and the second battery cell (110b), and the lower surface of the second battery cell (110b) in a zigzag shape. That is, the fire extinguishing member (300) can wrap the upper surface of the first battery cell (110a) and the lower surface of the second battery cell (110b), and may be formed to wrap the space between the first battery cell (110a) and the second battery cell (110b). In particular, since the first battery cell (110a) and the second battery cell (110b) can be formed alternately, the fire extinguishing member (300) can wrap the space between the alternately formed first battery cell (110a) and the second battery cell (110b), respectively.

[0053] At this time, the extinguishing member (300) may include a extinguishing agent and a case that accommodates the extinguishing agent. What is depicted as the extinguishing member (300) in FIG. 4 may be the case. Accordingly, the extinguishing agent may be formed inside the case of the extinguishing member (300).

[0054] The above case may melt when high temperatures occur inside the battery module (100) and battery cell (110), and the fire extinguishing agent contained in the case may be released outside the case. In particular, the case may melt when thermal runaway occurs inside the battery module (100). At this time, the fire extinguishing agent released from the case can achieve the effect of preventing thermal runaway phenomena occurring in the battery cell (110) and delaying the propagation of thermal runaway. In addition, by suppressing fire and flames, the effect of preventing and delaying the propagation of fire and flames to adjacent battery cells (110) can be achieved.

[0055] Accordingly, the above case may be formed of a material capable of melting in the event of a thermal runaway phenomenon. Additionally, the fire extinguishing agent may be a liquid fire extinguishing agent and / or a commonly used powder-form fire extinguishing agent. For example, the fire extinguishing agent material may be a liquid fire extinguishing agent including a foam fire extinguishing agent, and may be any one of sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), ammonium phosphate (NH4H2PO3), and a mixture of “potassium bicarbonate (KHCO3) and urea ((NH2)2CO).” However, the fire extinguishing agent is not limited thereto and may be used without restriction as long as it is a substance that performs a fire extinguishing function.

[0056] Additionally, the fire extinguishing member (300) may have double-sided adhesive properties. In particular, the case of the fire extinguishing member (300) may have double-sided adhesive properties. Therefore, as described below, it can perform the function of fixing the first battery cell (110a) and the second battery cell (110b) formed on both sides of the fire extinguishing member (300) with the fire extinguishing member (300) at the center.

[0057] Additionally, referring to FIG. 4, the fire extinguishing member (300) can come into contact with the upper part (200c) of the module frame (200) and the lower part (200a) of the module frame (200). Additionally, since a thermally conductive resin layer (310) can be formed on the lower part (200a) of the module frame (200), the fire extinguishing member (300) can come into contact with the thermally conductive resin layer (310).

[0058] Additionally, the fire extinguishing member (300) can be formed to surround the space between the first battery cell (110a) and the second battery cell (110b), and can be formed to be interposed between the first battery cell (110a) and the second battery cell (110b), so that the first battery cell (110a) and the second battery cell (110b) can be bonded together.

[0059] Additionally, the extinguishing member (300) may be interposed between the side portion (200b) of the module frame (200) and the outermost battery cell (110). That is, the extinguishing member (300) may be formed to be in contact with the side portion (200b) of the module frame (200) and may also be formed to be in contact with the side of the outermost battery cell (110). Accordingly, the extinguishing member (300) can bond the side portion (200b) of the module frame (200) and the outermost battery cell (110) included in the battery cell stack (120), and can fix the battery cell stack (120) inside the module frame (200).

[0060] Accordingly, when an ignition phenomenon or thermal runaway phenomenon occurs within the battery module (100) according to the present embodiment, the extinguishing member (130) is positioned above or below the battery cell (110) and interposed between adjacent battery cells (110), thereby effectively suppressing the flame generated in the battery cell (110). In addition, carbon dioxide and water vapor may be generated during the process of extinguishing the flame generated in the battery cell (110) by the extinguishing member (130). This reaction is an endothermic reaction that can absorb the heat of the thermal runaway phenomenon generated in the battery cell (110) and can also block the oxygen supply, thereby effectively delaying the propagation of flame and heat between the battery cells (110). Furthermore, the safety of the battery module (100) can also be improved.

[0062] Hereinafter, a battery module according to another embodiment of the present invention will be described with reference to FIGS. 5 and FIGS. Since there is overlap with the content described above, the description will focus on the differences.

[0063] FIG. 5 is a drawing showing a battery module according to another embodiment of the present invention. FIG. 6 is a perspective view showing a part of a battery cell stack included in the battery module of FIG. 5.

[0064] Referring to FIG. 5, the fire extinguishing member (300) can come into contact with the upper part (200c) of the module frame (200) and the lower part (200a) of the module frame (200). Additionally, since a thermally conductive resin layer (310) can be formed on the lower part (200a) of the module frame (200), the fire extinguishing member (300) can come into contact with the thermally conductive resin layer (310).

[0065] Additionally, referring to FIGS. 5 and 6, the extinguishing member (300) of the present embodiment may come into contact with the upper surface of the first battery cell (110a) and the lower surface of the second battery cell (110b).

[0066] Accordingly, the fire extinguishing member (300) has double-sided adhesive properties as described above, so that the upper surface (200c) of the module frame (200) and the upper surface of the first battery cell (110a) can be bonded, and the lower surface (200a) of the module frame (200) and the lower surface of the second battery cell (110b) can be bonded.

[0067] Additionally, the fire extinguishing member (300) can be formed to surround the space between the first battery cell (110a) and the second battery cell (110b), and can be formed to be interposed between the first battery cell (110a) and the second battery cell (110b), so that the first battery cell (110a) and the second battery cell (110b) can be bonded together.

[0068] At this time, through the above adhesion, the battery cells (110) can be fixed to each other, and a battery cell stack (120) formed by stacking multiple battery cells (110) can be fixed on the module frame (200).

[0069] Accordingly, each battery cell (110) can be isolated through a fire suppression member (300) that surrounds the battery cell (110) in a zigzag shape. Therefore, even if a thermal runaway phenomenon occurs in one battery cell (110), the thermal runaway phenomenon can be suppressed through the fire suppression member (300), and the propagation of the thermal runaway phenomenon can be delayed. In addition, by bonding and fixing the battery cell stack (120) and the battery cell (110) formed within the module frame (200), the movement of the battery cell stack (120) and the battery cell (110) and the resulting damage can be minimized, thereby improving the stability of the battery module.

[0071] Hereinafter, a battery pack according to another embodiment of the present invention will be described.

[0072] The battery pack according to the present embodiment includes the battery module described above. In addition, the battery pack of the present invention may have a structure in which one or more battery modules according to the present embodiment are assembled and packed with a Battery Management System (BMS) that manages the temperature or voltage of the battery, and a cooling device, etc.

[0073] The above-described battery pack 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 battery modules, and this also falls within the scope of the present invention.

[0074] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. It is understood that various modifications can be made by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention. Explanation of the symbols

[0076] 100: Battery module 110: Battery cell 120: Battery cell stack 150: End plate 200: Module Frame 300: Absence of digestion

Claims

Claim 1 A battery module comprising: a battery cell stack having a plurality of stacked battery cells; a module frame surrounding the battery cell stack; and a fire extinguishing member interposed between the battery cells, wherein the battery cells include a first battery cell and a second battery cell adjacent to each other, and the fire extinguishing member surrounds the upper surface of the first battery cell, the space between the first battery cell and the second battery cell, and the lower surface of the second battery cell in a zigzag shape, and the fire extinguishing member includes a fire extinguishing agent; and a case containing the fire extinguishing agent, wherein the case melts when a high temperature is generated and the fire extinguishing agent contained in the case is released to the outside of the case, and the fire extinguishing member has double-sided adhesive properties and adheres the first battery cell and the second battery cell to each other. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 In claim 1, the case is a battery module having double-sided adhesive properties. Claim 6 In claim 1, the fire extinguishing member is a battery module in contact with the upper part of the module frame and the lower part of the module frame. Claim 7 In claim 1, the extinguishing member is a battery module in contact with the upper surface of the first battery cell and the lower surface of the second battery cell. Claim 8 In claim 1, the battery module in which the fire-fighting member bonds the upper part of the module frame to the upper surface of the first battery cell and bonds the lower part of the module frame to the lower surface of the second battery cell. Claim 9 delete Claim 10 In claim 1, the fire extinguishing member is a battery module interposed between the side portion of the module frame and the outermost battery cell. Claim 11 In paragraph 10, the above-mentioned fire-fighting member is a battery module that bonds the side portion of the module frame and the outermost battery cell. Claim 12 A battery pack comprising a battery module according to paragraph 1.

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