Battery module and battery pack including said battery module

Abstract

To provide a battery module.SOLUTION: A battery module according to the present invention includes: a battery cell stack in which a plurality of battery cells are stacked in one direction; and a module frame that houses the battery cell stack and has an inner surface and an outer surface, wherein at least one venting portion penetrating the inner surface and the outer surface is formed on one surface of the module frame, and a cover layer including a barrier layer and a refractory layer is positioned between the one surface of the module frame in which the venting portion is formed and the battery cell stack.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0089269 filed on July 7, 2021, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

[0002] 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 Art

[0003] Due to the technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. Accordingly, many studies on secondary batteries capable of meeting various requirements have been conducted.

[0004] Secondary batteries have attracted much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, and notebook computers, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0005] Recently, in addition to the utilization of secondary batteries as an energy storage source, the need for a large - capacity secondary battery structure has increased, and the demand for medium - sized or large - sized modular battery packs formed by aggregating battery modules in which a number of secondary batteries are connected in series / parallel has been increasing. A battery pack mainly comprises a battery module composed of at least one battery cell, and other components are added using at least one battery module. Since the battery cells constituting the battery module are secondary batteries capable of charge and discharge, such high - output large - capacity secondary batteries generate a large amount of heat during the charge - discharge process.

[0006] Figure 1 shows an exploded perspective view of a conventional battery module. Figure 2 shows how thermal runaway occurs during internal ignition in a conventional battery module.

[0007] Referring to Figures 1 and 2, a conventional battery module 10 includes a battery cell stack 12 in which multiple battery cells 11 are stacked, a frame 20 that houses the battery cell stack 12, and end plates 40 formed on the front and rear surfaces of the battery cell stack 12.

[0008] The battery cell stack 12 may be located within a structure sealed by the connection of the frame 20 and the end plate 40. In this case, the frame 20 may have an empty internal space as shown in the AA cross section of Figure 1, and the battery cells 11 may be stacked in one direction within the empty internal space of the frame 20 as shown in Figure 2.

[0009] On the other hand, since the multiple battery cells 11 are not isolated from each other within the frame 20 and are densely located in one space, even if a thermal runaway phenomenon occurs in only one of the multiple battery cells 11 located inside the frame 20 due to reasons such as overcharging, the thermal runaway phenomenon will rapidly transfer to the other adjacent battery cells 11, etc.

[0010] Furthermore, since multiple battery modules 10 within the battery pack are arranged so that at least two end plates 40 face each other, if heat, gas, or flames generated within a battery module 10 are discharged to the outside of the battery module 10, it can affect the performance and stability of multiple battery cells 11 in other adjacent battery modules 10.

[0011] Therefore, there is a need to develop a battery module 10 with improved durability and safety by effectively delaying the thermoelectric rate during internal ignition of the battery module 10, thereby allowing the generated heat, gas, or flame to be rapidly discharged to the outside of the battery module 10. [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] The problem that the present invention aims to solve is to provide a battery module and a battery pack including said battery module that prevent thermal runaway phenomena from transferring between battery cells when an ignition phenomenon occurs within the battery module.

[0013] However, the problems that the embodiments of the present invention aim to solve are not limited to those described above, and can be broadly expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0014] A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked in one direction, and a module frame that houses the battery cell stack and has an inner surface and an outer surface, wherein at least one venting portion is formed on one surface of the module frame, penetrating the inner surface and the outer surface, and a cover layer including a barrier layer and a refractory layer is located between the surface of the module frame on which the venting portion is formed and the battery cell stack.

[0015] The venting portion may be formed on the upper surface of the module frame.

[0016] The barrier layer may be located beneath the refractory layer.

[0017] The refractory layer may have at least one sub-venting portion formed therein.

[0018] The barrier layer may cover the holes in the subventing section.

[0019] The barrier layer includes a projection that partially protrudes from one surface of the barrier layer, and the projection may be inserted into the sub-venting portion.

[0020] At least a part of the bending portion and the sub-bending portion may overlap in the longitudinal direction of the battery module.

[0021] At least a part of the bending portion and the sub-bending portion may overlap in the width direction of the battery module.

[0022] The holes in the sub-bending portion or the bending portion may form an acute angle with one surface of the module frame.

[0023] The refractory layer includes a first refractory layer and a second refractory layer, and the first refractory layer may be located closer to the barrier layer than the second refractory layer.

[0024] At least one first sub-bending portion may be formed in the first refractory layer, and at least one second sub-bending portion may be formed in the second refractory layer.

[0025] At least a part of the first sub-bending portion and the second sub-bending portion may overlap in the longitudinal direction of the battery module.

[0026] At least a part of the first sub-bending portion and the second sub-bending portion may overlap in the width direction of the battery module.

[0027] The barrier layer may contain a substance with a melting point of about 300°C or lower.

[0028] The barrier layer may contain one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates.

[0029] The refractory layer may contain aluminum, SUS (Stainless Use Steel), or clad metal.

[0030] Another embodiment of the present invention includes a battery pack containing the aforementioned battery module. [Effects of the Invention]

[0031] According to the embodiment, when an ignition phenomenon occurs inside the battery module, gas and other substances can be quickly discharged to the outside of the battery module through holes in the module frame, thereby preventing a continuous thermal runaway phenomenon inside the battery module.

[0032] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims. [Additional note 1] A battery cell stack in which multiple battery cells are stacked in one direction, A module frame for housing the aforementioned battery cell stack, comprising a module frame having an internal surface and an external surface, A battery module including, One surface of the module frame has at least one venting portion that penetrates the inner surface and the outer surface. A battery module in which a cover layer including a barrier layer and a refractory layer is located between the one surface of the module frame on which the venting portion is formed and the battery cell stack. [Additional note 2] The battery module according to Appendix 1, wherein the one surface of the module frame is the upper surface of the module frame. [Additional note 3] The barrier layer is located below the refractory layer and is the battery module described in Appendix 1. [Additional note 4] The battery module according to Appendix 1, wherein at least one sub-venting portion is formed in the refractory layer. [Additional note 5] The barrier layer covers the holes in the subventing portion, as described in Appendix 4 of the battery module. [Additional note 6] The battery module according to Appendix 4, wherein the barrier layer includes a projection that partially protrudes from one surface of the barrier layer, and the projection is inserted into the sub-venting portion. [Additional note 7] The battery module described in Appendix 4, wherein at least a portion of the venting portion and the sub-venting portion overlap in the longitudinal direction of the battery module. [Additional note 8] The battery module described in Appendix 4, wherein at least a portion of the venting portion and the sub-venting portion overlap in the width direction of the battery module. [Additional note 9] The battery module as described in Appendix 4, wherein the sub-venting portion or the hole in the venting portion forms an acute angle with the one surface of the module frame. [Additional Note 10] The refractory layer includes a first refractory layer and a second refractory layer, The battery module according to Appendix 1, wherein the first refractory layer is located closer to the barrier layer than the second refractory layer. [Additional Note 11] The first refractory layer has at least one first sub-venting portion formed therein. The battery module according to Appendix 10, wherein at least one second sub-venting portion is formed in the second refractory layer. [Additional Note 12] The battery module according to Appendix 11, wherein at least a portion of the first sub-venting portion and the second sub-venting portion overlap in the longitudinal direction of the battery module. [Additional Note 13] The battery module according to Appendix 11, wherein at least a portion of the first sub-venting portion and the second sub-venting portion overlap in the width direction of the battery module. [Additional Note 14] The battery module according to Appendix 1, wherein the barrier layer contains a substance with a melting point of approximately 300°C or lower. [Additional Note 15] The battery module according to Appendix 1, wherein the barrier layer comprises one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates. [Additional Note 16] The battery module as described in Appendix 1, wherein the refractory layer includes aluminum, SUS (Stainless Use Steel), or clad metal. [Additional Note 17] A battery pack including at least one battery module described in any of the appendices 1 through 16. [Brief explanation of the drawing]

[0033] [Figure 1] This diagram shows a disassembled perspective view of a conventional battery module. [Figure 2] This diagram illustrates how thermal runaway occurs during internal ignition in a conventional battery module. [Figure 3] This is a perspective view showing a battery module according to one embodiment of the present invention. [Figure 4] Figure 3 is an exploded perspective view of the battery module. [Figure 5] Figure 3 is a perspective view of the battery cells included in the battery module. [Figure 6] This is a cross-sectional view taken along the cutting line BB in Figure 3. [Figure 7] This is a cross-sectional view taken along the cutting line CC in Figure 3. [Figure 8] Figure 3 shows the state of the battery module during internal fire. [Modes for carrying out the invention]

[0034] In the following, various embodiments of the present invention will be described in detail, with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily implement them. The present invention can be embodied in various other forms besides those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0035] To clearly explain the present invention, irrelevant parts have been omitted, and the same or similar reference numerals have been used throughout the specification for identical or similar components.

[0036] Furthermore, the dimensions and thicknesses of each component shown in the drawings have been arbitrarily enlarged or reduced for the sake of explanation, and it is obvious that the content of the present invention is not limited to what is shown in the drawings. In the following drawings, the thickness of each layer is shown enlarged in order to clearly represent the various layers and regions. In the following drawings, the thickness of some layers and regions is shown in an exaggerated manner for the sake of explanation.

[0037] Furthermore, when describing a layer, membrane, region, plate, or other part as being "on top of" or "above" another part, this should be interpreted to include not only cases where the layer, membrane, region, plate, or other part is "directly above" the other part, but also cases where the other part lies between them. Conversely, when describing a layer, membrane, region, plate, or other part as being "directly above" another part, it can mean that there is no other part between them. Also, being "on top of" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on top of" or "above" in the opposite direction of gravity. On the other hand, describing something as being "below" or "below" another part can be understood by referring to the above, just as describing something as being "on top of" or "above" another part can be understood by referring to the above.

[0038] Furthermore, since the upper and lower surfaces of a particular component can be determined to differ depending on the direction used as the reference, throughout this specification, "upper surface" or "lower surface" is defined to mean two surfaces that face each other on the z-axis of the component in question.

[0039] Furthermore, when a specification as a whole states that a certain part "includes" a certain component, unless otherwise specifically stated, this does not exclude other components, but rather means that other components may be included as well.

[0040] Furthermore, throughout the specification, "on a plane" means when the part in question is viewed from above, and "on a cross-section" means when the cross-section of the part in question is viewed from the side.

[0041] The following describes a battery module according to one embodiment of the present invention.

[0042] Figure 3 is a perspective view showing a battery module according to one embodiment of the present invention. Figure 4 is an exploded perspective view of the battery module according to Figure 3. Figure 5 is a perspective view of the battery cells included in the battery module of Figure 3.

[0043] Referring to Figures 3 and 4, a battery module 100 according to one embodiment of the present invention may include a battery cell stack 120 in which a plurality of battery cells 110 are stacked in one direction, a module frame 200 that houses the battery cell stack 120, a busbar frame 300 located on the front and / or rear surface of the battery cell stack 120, an end plate 400 that covers the front and / or rear surface of the battery cell stack 120, and busbars 510, 520 mounted on the busbar frame 300.

[0044] Referring to Figure 5, the battery cell 110 may be supplied in a pouch form that maximizes the number of cells stacked per unit area. The battery cell 110 supplied in a pouch form may be manufactured by housing an electrode assembly, including a positive electrode, a negative electrode, and a separator membrane, in a laminate sheet cell case 114, and then heat-sealing the cell case 114. However, the battery cell 110 does not necessarily have to be supplied in a pouch form; it may be supplied in prismatic, cylindrical, or other various forms, provided that the storage capacity required by the device to be attached is achieved.

[0045] The battery cell 110 may include two electrode leads 111 and 112. The electrode leads 111 and 112 may have a structure that protrudes from one end of the cell body 113, respectively. Specifically, one end of each electrode lead 111 and 112 may be located inside the cell case 114 and electrically connected to the positive or negative electrode of the electrode assembly, while the other end of each electrode lead 111 and 112 may be drawn out to the outside of the cell case 114 and electrically connected to a separate component, such as a busbar 510 or 520. On the other hand, Figure 4 shows that the positive and negative electrode leads of the battery cell 110 protrude in opposite directions, but this is not necessarily the case, and it is also possible for the electrode leads of the battery cell 110 to protrude in the same direction.

[0046] The electrode assembly inside the cell case 114 may be sealed by sealing portions 114sa, 114sb, and 114sc. The sealing portions 114sa, 114sb, and 114sc of the cell case 114 may be located on both ends 114a, 114b and one side portion 114c connecting them.

[0047] The cell case 114 generally consists of a laminated structure of a resin layer / metal thin film layer / resin layer. For example, if the surface of the cell case is made of an O(oriented)-nylon layer, when stacking a large number of battery cells 110, etc. to form a medium or large battery module 100, it tends to slip due to external impact. Therefore, in order to prevent slippage due to external impact and maintain a stable stacked structure of the battery cells 110, etc., an adhesive member such as double-sided tape or a chemical adhesive that bonds through a chemical reaction during bonding can be attached to the surface of the cell case 114 to form a battery cell stack 120.

[0048] The connecting portion 115 may refer to a region extending along the length direction at one end of the cell case 114 where the aforementioned sealing portions 114sa, 114sb, and 114sc are not located. A projection 110p of the battery cell 110, called a bat-ear, may be formed at the end of the connecting portion 115. The terrace portion 116 may refer to a region between the electrode leads 111 and 112, which partially protrude outside the cell case 114, and the cell body 113 located inside the cell case 114, with the edge of the cell case 114 as the reference point.

[0049] The battery cell stack 120 may be a stack of electrically connected battery cells 110 stacked in one direction. The direction in which the multiple battery cells 110 are stacked (hereinafter referred to as the "stack direction") may be the y-axis direction (or the -y-axis direction, and hereinafter the expression "axis direction" may be interpreted as including both the + and - directions).

[0050] On the other hand, because the battery cells 110 are arranged along one direction, the electrode leads of the battery cells 110 may be located on one surface of the battery cell stack 120, or on one surface and another surface opposite to that surface. Thus, the surface on the battery cell stack 120 where the electrode leads 111, 112, etc. are located may be the front or rear surface of the battery cell stack 120, and here, the direction from the front to the rear surface of the battery cell stack 120, or the opposite direction, may be defined as the longitudinal direction of the battery cell stack 120, or it may be the x-axis direction. The longitudinal direction of the battery cell stack 120 may be substantially the same as the longitudinal direction of the battery cells 110.

[0051] Furthermore, the surface on which the outermost battery cell 110 is located in the battery cell stack 120 can be referred to as the side surface of the battery cell stack 120, and the side surface of the battery cell stack 120 can be described as two surfaces facing each other on the y-axis.

[0052] The module frame 200 may be for protecting the battery cell stack 120 and the electrical components connected to the battery cell stack 120 from external physical shocks. The module frame 200 may be housed in the internal space of the module frame 200 connected to the battery cell stack 120. Here, the module frame 200 includes internal and external surfaces, and the internal space of the module frame 200 may be defined by the internal surface.

[0053] The structure of the module frame 200 may be diverse. For example, the structure of the module frame 200 may be a monoframe structure. Here, the monoframe may be in the form of a metal sheet material in which the top surface, bottom surface and both sides are integrated. The monoframe may be manufactured by press forming. As another example, the structure of the module frame 200 may be a structure in which a U-shaped frame and an upper plate (top surface) are joined together. In the case of a structure in which a U-shaped frame and an upper plate are joined together, the structure of the module frame 200 may be formed by joining the upper plate to the upper side of a U-shaped frame which is a metal sheet material in which the bottom surface and both sides are joined or integrated, and each frame or plate may be manufactured by press forming. Furthermore, the structure of the module frame 200 may be provided as an L-shaped frame structure other than a monoframe or a U-shaped frame, and may be provided in a variety of structures not described in the examples above.

[0054] The structure of the module frame 200 may be provided in an open form along the longitudinal direction of the battery cell stack 120. The front and rear surfaces of the battery cell stack 120 do not have to be shielded by the module frame 200. The front and rear surfaces of the battery cell stack 120 may be shielded by a busbar frame 300 or end plate 400, etc., which will be described later, and the front and rear surfaces of the battery cell stack 120 should be protected from external physical shocks, etc., through the busbar frame 300 or end plate 400, etc.

[0055] The top / bottom, front / rear, and both sides of the module frame 200 can be described based on the contents of the battery cell stack 120 described above. Specifically, the top / bottom of the module frame 200 can be described as two surfaces facing each other on the z-axis, the front / rear of the module frame 200 as two surfaces facing each other on the x-axis, and the both sides of the module frame 200 as two surfaces facing each other on the y-axis. Here, the direction from the front to the rear or from the rear to the front may be the longitudinal direction of the module frame 200.

[0056] On the other hand, although not shown in the figures, a compression pad may be located between the battery cell stack 120 and the inner surface of the module frame 200. In this case, the compression pad may be located between the side surface of the battery cell stack 120 and the side surface of the module frame 200, and may face at least one of the two battery cells 110 located at both ends of the battery cell stack 120.

[0057] Furthermore, a thermally conductive resin may be injected between the battery cell stack 120 and the inner surface of the module frame 200, and a thermally conductive resin layer (not shown) may be formed between the battery cell stack 120 and the inner surface of the module frame 200 by the injected thermally conductive resin. In this case, the thermally conductive resin layer may be formed between the lower surface of the battery cell stack 120 and the lower surface (or bottom surface, or bottom portion) of the module frame 200.

[0058] The busbar frame 300 may be located on one side of the battery cell stack 120, covering one side of the battery cell stack 120 and guiding the connection between the battery cell stack 120 and external equipment. The busbar frame 300 may be located on the front or rear side of the battery cell stack 120. At least one of the busbars 510, 520 and module connectors may be attached to the busbar frame 300. One side of the busbar frame 300 may be connected to the front or rear side of the battery cell stack 120, and the other side of the busbar frame 300 may be connected to the busbars 510, 520. There may be two busbar frames 300, one located on the front and the other on the rear side of the battery cell stack 120.

[0059] The busbar frame 300 may include an electrically insulating material. The busbar frame 300 can restrict the busbars 510 and 520 from contacting other parts such as the battery cell 110, other than the parts joined to the electrode leads 111 and 112, thereby preventing electrical short circuits.

[0060] The end plate 400 may also serve to protect the battery cell stack 120 and the electrical components connected to the battery cell stack 120 from external physical shocks by sealing the open surface of the module frame 200. For this purpose, the end plate 400 may be made of a material having a predetermined strength. For example, the end plate 400 may contain a metal such as aluminum.

[0061] The end plate 400 may be joined (bonded, sealed, or enclosed) to the module frame 200 by covering the busbar frame 300 or busbars 510, 520 located on one surface of the battery cell stack 120. Each corner of the end plate 400 may be joined to the corresponding corner of the module frame 200 by welding or other means. An insulating cover 700 for electrical insulation may also be located between the end plate 400 and the busbar frame 300. The insulating cover 700 may be located on the inner surface of the end plate 400, or it may be in close contact with the inner surface of the end plate 400, but this is not required.

[0062] The end plate 400 may consist of two parts, including a first end plate located on the front surface of the battery cell stack 120 and a second end plate located on the rear surface of the battery cell stack 120.

[0063] Busbars 510 and 520 may be mounted on one surface of the busbar frame 300 and may be used to electrically connect the battery cell stack 120 or battery cells 110, etc., to external equipment circuits. By positioning the busbars 510 and 520 between the battery cell stack 120 or busbar frame 300 and the end plate 400, they can be protected from external impacts, minimizing the reduction in durability due to external moisture, etc.

[0064] Busbars 510 and 520 may be electrically connected to the battery cell stack 120 through the electrode leads 111 and 112 of the battery cells 110. Specifically, the electrode leads 111 and 112 of the battery cells 110 may pass through slits formed in the busbar frame 300, be bent, and then connected to the busbars 510 and 520. The battery cells 110 and the like that make up the battery cell stack 120 by the busbars 510 and 520 may be connected in series or in parallel.

[0065] On the other hand, the busbars 510 and 520 may include terminal busbars 520 for forming electrical connections between the battery modules 100. To connect to other external battery modules 100, at least a portion of the terminal busbars 520 may be exposed outside the end plate 400, and the end plate 400 may be provided with terminal busbar openings 400H for this purpose. The terminal busbars may be connected to other battery modules 100 or BDUs (Battery Disconnect Units) through the protrusions exposed through the terminal busbar openings 400H, forming HV (High Voltage) connections with them.

[0066] Although not shown in the diagram, the battery module 100 may include a sensing element that detects and controls phenomena such as overvoltage, overcurrent, and overheating of the battery cell 110. The sensing element is for LV (Low Voltage) connection, where LV connection can mean a sensing connection for sensing and controlling the voltage of the battery cell. Voltage and temperature information of the battery cell 110 may be transmitted to an external BMS (Battery Management System) through the sensing element.

[0067] The sensing component may include a temperature sensor for sensing the temperature inside the battery module, sensing terminals for sensing the voltage values ​​of busbars 510 and 520, a module connector for transmitting the collected data to an external control device and receiving signals from the external control device, and / or a connecting member for connecting the module connector.

[0068] Here, the connecting member is arranged on the upper surface of the battery cell stack 120 in a manner that extends along the length direction, and may be a flexible printed circuit board (FPCB) or a flexible flat cable (FFC).

[0069] Furthermore, the module connector may be attached to the aforementioned busbar frame 300, and at least a portion of the module connector may be exposed to the outside through a module connector opening formed in the end plate 400.

[0070] On the other hand, as mentioned above, ignition can occur inside a battery module 100 in which battery cells 110 are densely stacked. If ignition occurs in one battery module 100, the heat, gas, or flame from that battery module 100 may be transmitted to adjacent battery modules 100, potentially leading to a series of ignitions between battery modules 100. This can result in a decrease in the durability and stability of the battery modules 100 or the battery pack containing the battery modules 100.

[0071] Therefore, the following will describe the cover layer 800 and venting part 900, which can improve the durability and stability of the battery module 100 by eliminating the aforementioned ignition phenomenon.

[0072] Furthermore, referring to Figures 3 and 4, the module frame 200 according to one embodiment of the present invention may include a venting portion 900 that penetrates the inner surface and the outer surface of the module frame 200. The venting portion 900 may have a hole shape that connects an inlet 900a formed on the inner surface of the module frame 200 and an outlet 900b formed on the outer surface. The venting portion 900 may be for connecting the inside of the battery module 100, which is sealed by the module frame 200 and the end plate 400, to the outside of the battery module 100.

[0073] The venting section 900 is provided to discharge heat, gas, or flames generated when ignition occurs inside the battery module 100 to the outside of the battery module 100. The venting section 900 can mitigate the internal ignition phenomenon of the module frame 200 and prevent the continuous occurrence or transition of thermal runaway by minimizing the rise in pressure or temperature. Specifically, when ignition occurs inside the module frame 200, the heat, gas, sparks, and flames from the ignition of the battery cell 110 are discharged to the outside of the battery module 100 through the venting section 900, thereby quickly suppressing the internal fire and further mitigating the ignition phenomenon. In addition, by discharging heat, gas, etc. through the venting section 900, it is possible to prevent the pressure or temperature inside the battery module 100 from rising excessively, and the rate at which thermal runaway transitions in the internal space can also be delayed.

[0074] The venting portion 900 may be formed on at least one surface of the module frame 200. The venting portion 900 may be formed on the upper surface of the module frame 200. The venting portion 900 may be formed on a surface of the module frame 200 that extends along the stacking direction or longitudinal direction of the battery cell stack 120.

[0075] The venting section 900 formed on the upper surface of the module frame 200 may be at least one. The more venting sections 900 formed on the module frame 200, the more rapidly the ignition phenomenon of the module frame 200 can be mitigated. If there are multiple venting sections 900, they may be arranged in rows aligned along one direction and columns aligned along a direction perpendicular to the aforementioned direction. In this case, the venting section 900 may be formed over the entire surface of the module frame 200 as shown in the drawings above, but this is not necessarily the case; it may also be formed on a part of one surface of the module frame 200.

[0076] The inlet 900a and outlet 900b of the venting section 900 may be rounded with curvature as shown in the aforementioned drawings, but this is not necessarily the case. The inlet 900a and outlet 900b of the venting section 900 may be circular, elliptical, or polygonal with vertices. Furthermore, since it is preferable that the heat, gas, or flame discharged through the venting section 900 disperses more quickly to the outside of the battery module 100, the size of the outlet 900b may be made even larger than the size of the inlet 900a.

[0077] On the other hand, the direction from the inlet 900a to the outlet 900b of the venting section 900 may be the discharge direction in which gas inside the battery module 100 is discharged to the outside. In the aforementioned drawings, the direction from the inlet 900a to the outlet 900b of the venting section 900 is shown to be perpendicular to one surface of the module frame 200 on which the venting section 900 is formed, but this is not necessarily the case. By changing the positions of the inlet 900a and outlet 900b of the venting section 900, the hole structure may be formed so that the discharge direction forms an acute angle with one surface of the module frame 200. By having the holes of the venting section 900 have an oblique structure in this way, the exposure of the inside of the battery module 100 can be minimized, and the phenomenon of foreign matter floating in the air entering the inside of the battery module 100 due to gravity can be prevented.

[0078] By changing the positions of the inlet 900a and outlet 900b of the venting section 900, the discharge direction can be made to form an angle (acute angle), thereby switching (adjusting) the direction of heat, gas, or flame discharged from the venting section 900. This increases the length of the discharge path, allowing the gas, etc., discharged through the outlet 900b of the venting section 900 to have a lower temperature. Furthermore, if the discharge direction of the venting section 900 is formed in a direction where adjacent battery modules 100 are not located, the phenomenon of heat propagation between adjacent battery modules 100 can be minimized.

[0079] If there are multiple venting sections 900, the discharge directions of the multiple venting sections 900 may be the same or different. When the discharge directions of the multiple venting sections 900 are formed to be different from each other, the gas discharged from the venting sections 900 can be diffused in various directions into a wider space outside the battery module 100. This allows for rapid gas discharge from the battery module 100, achieving effects such as preventing overheating of the battery module 100.

[0080] On the other hand, in this embodiment, when the module frame 200 is provided with a venting section 900 for communication between the inside and outside, dust, impurities, etc. from outside the module frame 200 may enter the module frame 200 through the hole structure of the venting section 900, or external oxygen may be supplied along the venting section 900 during internal ignition, which may accelerate thermal runaway. Furthermore, since the gas and sparks discharged through the venting section 900 of the module frame 200 may be at very high temperatures and pressures, there is a problem that the discharged gas and sparks may be transmitted to adjacent battery modules 100, inducing thermal runaway in the adjacent battery modules 100.

[0081] Therefore, the venting section 900 of this embodiment may be provided with a cover layer 800 that can close the holes before a thermal runaway phenomenon occurs and open the holes when a thermal runaway phenomenon occurs, thereby lowering the temperature and pressure of the released gas.

[0082] Furthermore, referring to Figure 4, the battery module 100 according to one embodiment of the present invention may include a cover layer 800 that covers the openings of the hole structure of the venting portion 900.

[0083] Here, the term "cover layer" is used to describe the membrane-like structure that seals the holes in the venting section 900, and it should be noted in advance that it can be replaced with other similar words such as lid, hood, lid, cap, etc.

[0084] The cover layer 800 may be located beneath one surface of the module frame 200 or end plate 400 on which the venting portion 900 is formed. For example, the cover layer 800 may be located between the upper surface of the battery cell stack 120 and the upper surface of the module frame 200.

[0085] The cover layer 800 can cover the holes in the venting section 900 by being positioned to cover the inlet 900a. The cover layer 800 may be provided in a plate-like form for covering the holes in the venting section 900. The cover layer 800 may be provided in a pad-like form for covering the holes in the venting section 900.

[0086] The cover layer 800 may include multiple layers. The cover layer 800 may include a barrier layer 810 that can be partially broken by heat or pressure, and refractory layers 820, 830 made of refractory material that can withstand a predetermined temperature or pressure. Here, the barrier layer 810 may be located closer to the battery cell stack 120 than the refractory layers 820, 830, and taking that location into consideration, the barrier layer 810 can be referred to as the first layer and the refractory layers 820, 830 as the second layer. Also, here the refractory layer may include two or more layers as shown in Figure 4, and for the sake of explanation, the layer located relatively closer to the barrier layer 810 can be referred to as the first refractory layer 820, and the layer located further away can be referred to as the second refractory layer 830. Alternatively, based on their positions, the barrier layer 810 may be positioned as the first layer, the first refractory layer 820 as the second layer, and the second refractory layer 830 as the third layer.

[0087] On the other hand, numerous venting sections may be formed in the refractory layers 820 and 830. To distinguish them from the venting section 900 formed in the module frame 200, the venting sections formed in the refractory layers 820 and 830 can be referred to as sub-venting sections 822 and 832. Each of the sub-venting sections 822 and 832 may have an inlet and an outlet, and the inlet may be located relatively below the outlet. The sub-venting sections 822 and 832 formed in the refractory layers 820 and 830 can guide the gas discharge path so that gases, sparks, etc., generated in the battery cell 110 do not move in other spaces within the battery module 100 but are discharged to the venting section 900.

[0088] The refractory layers 820 and 830 may be manufactured from materials that can withstand high temperature and high pressure environments for a certain period of time. For example, the refractory layers 820 and 830 may be manufactured from aluminum, SUS (Stainless Use Steel), or clad metal. The refractory layers 820 and 830 may also be injection-molded materials that can withstand high temperature and high pressure environments for a certain period of time.

[0089] The barrier layer 810 is located between the refractory layers 820 and 830 and the battery cell laminate 120. Before thermal runaway occurs in the battery module 100, it prevents foreign matter from entering the battery module 100. After thermal runaway occurs in the battery module 100, it can be removed by heat or pressure, thereby opening the venting section 900 and the sub-venting sections 822 and 832. Although not specifically shown in Figure 4, the upper surface of the barrier layer 810 may protrude partially, and the protruding portion can be inserted into the first sub-venting section 822 formed in the first refractory layer 820, thereby minimizing the inflow of foreign matter into the battery module 100.

[0090] The barrier layer 810 may contain a material that melts due to the internal temperature of the battery module 100. The barrier layer 810 may contain a material that melts due to heat, high-temperature gas, or sparks released from the battery cell 110. The barrier layer 810 may be manufactured from a substance whose melting point is below a predetermined range. The barrier layer 810 may be provided from a substance whose melting point is 300°C or less. To give a specific example, the barrier layer 810 may contain a thermoplastic polymer resin whose melting point is about 200°C or less. More specifically, the barrier layer 810 may be manufactured from a substance such as polyethylene or polypropylene whose melting point is about 100°C or more and 200°C or less.

[0091] The barrier layer 810 may contain a substance to mitigate the ignition phenomenon in the event of internal ignition of the battery module 100. For example, the barrier layer 810 may contain a fire extinguishing agent. If the barrier layer 810 contains a fire extinguishing agent, the battery module 100 can have a self-extinguishing function. Here, the fire extinguishing agent may be a fire extinguishing agent substance in powder form. The fire extinguishing agent can generate carbon dioxide and water vapor through a thermal decomposition reaction when internal ignition occurs in the battery module 100, and the generated carbon dioxide and water vapor can suppress the flame by preventing external oxygen from flowing into the battery module 100. The fire extinguishing agent can absorb the heat generated inside the battery module by performing a thermal decomposition reaction, which is an endothermic reaction, and can also cut off the supply of external oxygen by generating carbon dioxide and water vapor. This can effectively delay the flame and thermal wave velocity inside the battery module 100, thereby improving the safety of the battery module.

[0092] The barrier layer 810 may contain one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates. More specific examples of fire extinguishing agents include sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), ammonium phosphate (NH4H2PO3), and a mixture of potassium bicarbonate (KHCO3) and iodine ((NH2)2CO). If the cover layer 800 contains potassium bicarbonate (KHCO3), potassium carbonate (K2CO3), water vapor (H2O), and carbon dioxide (CO2) may be produced through the thermal decomposition reaction of potassium bicarbonate. The produced water vapor can extinguish the flame inside the battery module 100, and the produced carbon dioxide can block the flame from coming into contact with oxygen, etc. However, the fire extinguishing agent in this embodiment is not limited to this, and any substance that performs a fire extinguishing function can be used without restriction.

[0093] Thus, the barrier layer 810 may be manufactured and provided from a material having the aforementioned physical properties, but it may also be provided as a material containing multiple physical properties or a composite material containing each of these physical properties.

[0094] The following describes in more detail the effects that result from providing a cover layer to the battery module of this embodiment.

[0095] Figure 6 is a cross-sectional view taken along the cutting line BB in Figure 3. Figure 7 is a cross-sectional view taken along the cutting line CC in Figure 3. Figure 8 shows the state of the battery module during internal ignition as shown in Figure 3. Here, Figure 6 shows a cross-section of the battery module 100 in the longitudinal direction, and Figure 7 shows a cross-section of the battery module 100 in the width direction.

[0096] Referring to Figures 6 and 7, at least a portion of the venting portion 900 formed on the module frame 200 and the sub-venting portions 822 and 832 formed on the refractory layers 820 and 830 may overlap in the longitudinal direction (x-axis) of the battery module 100. At least a portion of the venting portion 900 and the sub-venting portions 822 and 832 may overlap in the width direction (y-axis) of the battery module 100.

[0097] At least a portion of the venting portion 900 formed on the module frame 200 and the second sub-venting portion 832 formed on the second refractory layer 830, or the second sub-venting portion 832 and the first sub-venting portion 822 formed on the first refractory layer 820, may overlap in the longitudinal direction (x-axis) of the battery module 100. At least a portion of the venting portion 900 and the second sub-venting portion 832, or the second sub-venting portion 832 and the first sub-venting portion 822, may overlap in the width direction (y-axis).

[0098] When holes formed in the module frame 200 and the refractory layers 820 and 830 partially overlap, the path of gases and other substances discharged to the outside of the battery module 100 through the holes can be switched. Specifically, because the holes formed in the module frame 200 and the refractory layers 820 and 830 do not completely correspond to each other, the path through which gases and other substances are discharged can form an angle with the z-axis, as shown by the arrows in Figures 6 and 7. The path through which gases and other substances are discharged can be formed in a zigzag shape. Because the holes formed in the module frame 200 and the refractory layers 820 and 830 do not completely correspond to each other, the discharge path can be made even longer compared to the case where they correspond to each other. The gas discharge path may be made even longer than the shortest distance between the top surface of the battery cell stack 120 and the module frame 200. By making the gas discharge path longer, the temperature and pressure of the gas discharged to the outside of the battery module 100 can be made even lower, and it can have energy low enough not to affect adjacent battery modules 100.

[0099] Although not specifically shown, the venting sections 900 and sub-venting sections 822 and 832 formed in the module frame 200 and the refractory layers 820 and 830 may have a slanted hole structure. If the holes in each venting section 900 and sub-venting sections 822 and 832 are formed to form an acute angle with one surface of the module frame 200, the aforementioned switching of the discharge path can be realized even more effectively.

[0100] Referring to Figure 8, if flames, gases, or sparks occur inside the battery module 100, specifically in some of the battery cells 110, the barrier layer 810 around the ignition phenomenon may be physically ruptured or chemically melted and penetrated by heat or pressure, which may open the venting section 900 and the sub-venting sections 822 and 832. The heat, gases, or sparks inside the battery module 100 can be released through the opened venting section 900 and the sub-venting sections 822 and 832, which can mitigate the ignition phenomenon of the battery module 100. Here, the process of the barrier layer 810 being penetrated, i.e., opened, may be accompanied by an endothermic reaction, and the temperature inside the battery module 100 may decrease as the barrier layer 810 absorbs the internal heat. The heat and gases released to the outside of the venting section 900 through the endothermic reaction of the barrier layer 810 may lose enough energy to not affect the adjacent battery module 100, and the sparks may lose energy and change into particles, thus not promoting thermal runaway in the adjacent battery module 100.

[0101] On the other hand, while the above explanation of the effect of the barrier layer 810 has mainly focused on its release through a chemical reaction, even if the barrier layer 810 is physically released by pressure or the like, the kinetic energy of the gas or spark will decrease during the process of removing the barrier layer 810. As a result, the heat and gas released to the outside of the battery module 100 will lose energy to the extent that they do not affect adjacent battery modules 100, and the spark will lose energy and change into particles, thus suppressing thermal runaway in adjacent battery modules 100.

[0102] On the other hand, since the barrier layer 810 can only be opened when heat or pressure exceeding a predetermined range is applied, only the barrier layer 810 located around the area where the ignition phenomenon occurs can be opened individually. By opening only a portion of the numerous venting sections 900 and sub-venting sections 822 and 832, the barrier layer 810 can prevent the acceleration of the thermal runaway phenomenon due to further oxygen inflow.

[0103] Specifically, when ignition occurs in the first battery cell 110a, the first portion 810a of the barrier layer 810 corresponding to the first battery cell 110a opens, allowing the gas, flames, etc. generated in the first battery cell 110a to be discharged. At this time, the second portion 810b of the barrier layer 810 located above the second battery cell 110b, where ignition has not occurred within the battery module 100, may not open, and the first sub-venting portion 822 corresponding to the second portion 810b may remain closed. In this way, by maintaining the closed state of the barrier layer 810 in other parts where ignition has not occurred, it is possible to further block external oxygen from flowing into the battery module 100, thereby suppressing the amplification of flames, etc., generated inside the battery module 100 by the incoming oxygen.

[0104] On the other hand, the barrier layer 810 may include a projection 812 that partially protrudes from one surface of the barrier layer 810. The projection 812 may be formed on the upper surface of the barrier layer 810. In this case, the size of the projection 812 may be similar to or smaller than the size of the first sub-venting portion 822, so that the projection 812 may be inserted into the first sub-venting portion 822 formed in the first refractory layer 820. The outer shape of the projection 812 may correspond to the inner shape of the first sub-venting portion 822, so that the hole in the first sub-venting portion 822 may be closed by the projection 812. When the projection 812 of the barrier layer 810 is provided to fill the hole in the first sub-venting portion 822 of the first refractory layer 820, the region of the barrier layer 810 in which the projection 812 is formed will have a thicker thickness. When protrusions 812 are formed on the barrier layer 810, the space occupied by the barrier layer 810 inside the battery module 100 remains the same, but because the thicker barrier layer 810 must be opened for the battery module 100 to release gases and other substances to the outside, the fire suppression effect of the barrier layer 810 may be even greater. However, this is not necessarily the case, and it is also possible to provide the barrier layer 810 without protrusions 812, so that the barrier layer 810 has a flat shape.

[0105] On the other hand, the aforementioned battery module 100 may be included in a battery pack. The battery pack may include one or more battery modules according to this embodiment, and may also have a structure in which a battery management system (BMS) for managing the temperature and voltage of the batteries, a cooling device, etc., are added and packed together.

[0106] Battery modules and battery packs containing such battery modules are applicable to a variety of devices. Such devices include means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and is applicable to a variety of devices using battery modules and battery packs containing such battery modules, and this also falls within the scope of the present invention.

[0107] While preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, using the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of Symbols]

[0108] 10 Battery Modules 11 battery cells 12 Battery cell stack 20 frames 40 End Plates 100 Battery Modules 110a First battery cell 110b Second battery cell 110p protrusion 110 battery cells 111 Electrode Leads 112 Electrode Leads 113 Cell body 114 Cell Case 114a Both ends 114b Both ends 114c One side 114sa sealing part 114sb Sealing section 114sc sealing part 115 Connection section 116 copies 120 Battery Cell Stack 200 Module Frames 300 Busbar Frame 400 End Plate 400H Terminal bus bar opening 510 Bus Bar 520 Bus Bar 700 Insulation Cover 800 Cover Layer 810 Barrier layer 810a Part 1 810b Part 2 812 Protrusion 820 (1st) Refractory layer 822 (1st) Subventing Section 830 Second refractory layer 832 (2nd) Subventing Section 900 Venting section 900a inlet 900b outlet BB cutting line BMS external CC cutting line

Claims

1. A battery pack comprising a battery module, wherein the battery module is A battery cell stack in which multiple battery cells are stacked in one direction, A battery cover that covers the battery cell stack and has a first surface facing the battery cell stack and a second surface located on the opposite side of the first surface, The battery pack includes, The aforementioned battery cover is A venting portion that penetrates the first and second surfaces of the battery cover, The first surface of the battery cover covers the venting portion and has a barrier layer having an inner surface exposed to the battery cell stack, A refractory layer is disposed on the outer surface of the barrier layer, which is located on the opposite side of the inner surface of the barrier layer, Includes, The barrier layer prevents foreign matter from entering the battery cell stack before the battery cell stack undergoes thermal runaway, and after the battery cell stack undergoes thermal runaway, it is removed by heat or pressure or chemically melted and penetrated. The barrier layer is located below the refractory layer, The refractory layer has a plurality of sub-venting portions that penetrate the refractory layer, The barrier layer covers the holes in the subventing section. The barrier layer is opened in the battery pack in the portion corresponding to the area where the ignition phenomenon occurred when an ignition phenomenon occurs in the battery cell stack.

2. A battery pack comprising a battery module, wherein the battery module is A battery cell stack in which multiple battery cells are stacked in one direction, A battery cover that covers the battery cell stack and has a first surface facing the battery cell stack and a second surface located on the opposite side of the first surface, The battery pack includes, The aforementioned battery cover is A venting portion that penetrates the first and second surfaces of the battery cover, The first surface of the battery cover covers the venting portion and has a barrier layer having an inner surface exposed to the battery cell stack, A refractory layer is disposed on the outer surface of the barrier layer, which is located on the opposite side of the inner surface of the barrier layer, Includes, The refractory layer has at least one sub-venting section formed therein. The barrier layer prevents foreign matter from entering the battery cell stack before the battery cell stack undergoes thermal runaway, and after the battery cell stack undergoes thermal runaway, it is removed by heat or pressure or chemically melted and penetrated. The battery pack comprises a barrier layer including a projection that partially protrudes from one surface of the barrier layer, the projection being inserted into the sub-venting portion.

3. The battery pack according to claim 2, wherein at least a portion of the venting portion and the sub-venting portion overlap in the longitudinal direction of the battery cell stack.

4. The battery pack according to claim 2, wherein at least a portion of the venting portion and the sub-venting portion overlap in the width direction of the battery cell stack.

5. A battery pack comprising a battery module, wherein the battery module is A battery cell stack in which multiple battery cells are stacked in one direction, A battery cover that covers the battery cell stack and has a first surface facing the battery cell stack and a second surface located on the opposite side of the first surface, The battery pack includes, The aforementioned battery cover is A venting portion that penetrates the first and second surfaces of the battery cover, The first surface of the battery cover covers the venting portion and has a barrier layer having an inner surface exposed to the battery cell stack, A refractory layer is disposed on the outer surface of the barrier layer, which is located on the opposite side of the inner surface of the barrier layer, Includes, The refractory layer has at least one sub-venting section formed therein. The barrier layer prevents foreign matter from entering the battery cell stack before the battery cell stack undergoes thermal runaway, and after the battery cell stack undergoes thermal runaway, it is removed by heat or pressure or chemically melted and penetrated. A battery pack in which the sub-venting portion or the holes in the venting portion form an acute angle with one surface of the battery cover.

6. The refractory layer includes a first refractory layer and a second refractory layer, The battery pack according to claim 1, wherein the first refractory layer is located closer to the barrier layer than the second refractory layer.

7. The first refractory layer has at least one first sub-venting portion formed therein. The battery pack according to claim 6, wherein at least one second sub-venting portion is formed in the second refractory layer.

8. The battery pack according to claim 7, wherein at least a portion of the first sub-venting portion and the second sub-venting portion overlap in the longitudinal direction of the battery cell stack.

9. The battery pack according to claim 7, wherein at least a portion of the first sub-venting portion and the second sub-venting portion overlap in the width direction of the battery cell stack.

10. The battery pack according to claim 1, wherein the barrier layer contains a substance having a melting point of 300°C or less.

11. A battery pack comprising a battery module, wherein the battery module is A battery cell stack in which multiple battery cells are stacked in one direction, A battery cover that covers the battery cell stack and has a first surface facing the battery cell stack and a second surface located on the opposite side of the first surface, The battery pack includes, The aforementioned battery cover is A venting portion that penetrates the first and second surfaces of the battery cover, The first surface of the battery cover covers the venting portion and has a barrier layer having an inner surface exposed to the battery cell stack, A refractory layer is disposed on the outer surface of the barrier layer, which is located on the opposite side of the inner surface of the barrier layer, Includes, The barrier layer prevents foreign matter from entering the battery cell stack before the battery cell stack undergoes thermal runaway, and after the battery cell stack undergoes thermal runaway, it is removed by heat or pressure or chemically melted and penetrated. The barrier layer comprises one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates, in a battery pack.

12. The battery pack according to claim 1, wherein the refractory layer comprises aluminum, stainless steel (SUS), or clad metal.

Images