Battery module and battery pack capable of delaying heat propagation

Abstract

The invention provides a battery module structure. The battery module structure comprises a battery cell laminating piece; a bus bar frame, which is connected to a front portion of the battery cell laminate, and which is provided with a terminal; a module frame which is open at the front part thereof and accommodates the battery cell laminate; an end plate which covers the front part of the module frame and is provided with a terminal exposure hole for exposing the terminal part to the outside; and a thermal expansion member fastened together with the terminal, in which the thermal expansion member expands when the thermal expansion member is heated.

Description

Technical Field

[0001] This application claims the priority benefit of Korean Patent Application No. 10-2022-0182336, filed on December 22, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a structure of a battery module capable of delaying heat propagation between battery modules and a battery pack including a plurality of battery modules. Background Art

[0003] Secondary batteries are easily applicable according to product groups and have electrical characteristics such as high energy density. They are widely used not only in portable devices but also in electric vehicles or hybrid vehicles driven by an electric drive source and power storage devices. These secondary batteries are attracting attention as new energy sources for improving eco-friendliness and energy efficiency because they have the main advantage of being able to significantly reduce the use of fossil fuels and do not produce any by-products due to energy use.

[0004] While small mobile devices use one or two or three battery cells per device, medium to large-sized devices (such as vehicles) require high output and large capacity. Therefore, medium to large-sized battery modules using a plurality of battery cells electrically connected are used.

[0005] Since it is desired to manufacture medium to large-sized battery modules with as small a size and weight as possible, rectangular batteries and pouch-type batteries that can be stacked in a highly integrated manner and have a small weight-to-capacity ratio are mainly used as battery cells for medium to large-sized battery modules.

[0006] Figure 1 And Figure 2 are an exploded perspective view and a perspective view illustrating the structure of a battery module, respectively. Referring to Figure 1 and Figure 2 , the battery module is manufactured by accommodating a battery cell laminate 1 in a module frame 2 having an opening at the front, and the battery cell laminate 1 has a plurality of pouch-type battery cells 11 stacked therein.

[0007] A bus bar frame 12 is connected to the front of the battery cell laminate 1. The bus bar frame 12 is provided with a module bus bar 122, and electrode leads 111 protruding from the battery cells 11 are welded to the module bus bar 122. The module bus bar 122 can be connected to a pair of terminals 123 having different polarities to be connected to external components.

[0008] The front portion of the module frame 2 is covered by an end plate 3, and the end plate 3 includes a first plate 31 made of a synthetic resin material and a second plate 32 made of a metal material. The second plate 32 is disposed in front of the first plate 31. The first plate 31 and the second plate 32 are respectively provided with a first terminal exposure port 311 and a second terminal exposure port 321 for exposing the terminal 123. Here, in order to insulate the terminal 123 from the second plate 32, a terminal insulator 312 provided at the first plate 31 is exposed through the second terminal exposure port 321.

[0009] Figure 3 The fastening structure of the terminal of the battery module and the battery pack bus bar is shown, Figure 4 and Figure 5 is a partially enlarged cross-sectional view of the battery module with the second plate removed Figure 3 of. Referring to Figures 3 to 5 , the battery pack bus bar 400 is fastened to the terminal 123. Here, the terminal 123 and the battery pack bus bar 400 are respectively provided with a first fastening hole 123H and a second fastening hole 400H vertically penetrating therethrough, and a fastening member 410 passes through the first fastening hole 123H and the second fastening hole 400H and is fixed to a fixing portion 313 provided on the end plate 3, thereby fastening the terminal 123 and the battery pack bus bar 400 to each other. A plurality of battery modules are arranged facing each other front and back, and are connected in series or in parallel through the battery pack bus bar 400 to form a battery pack.

[0010] In addition, the battery cell 11 may catch fire due to short circuit, impact, temperature rise, etc. When the battery cell 11 catches fire, high-temperature gas is discharged from the inside of the battery cell 11. Here, the first plate 31 can be heated and melted by the gas. Therefore, as the internal pressure of the module frame 2 increases explosively, the gas can be discharged in the forward direction through the gap between the first fastening hole 123H and the fastening member 410, the gap between the second fastening hole 400H and the fastening member 410, and the cavity generated when the first plate 31 melts.

[0011] In this case, another battery module provided in front of the burning battery module in the battery pack may be heated by the gas. The high-temperature gas generated inside the battery module is easily discharged to the outside through the front portion, and the high-temperature gas outside the battery module is also easily introduced into the inside through the front portion of the battery module. Due to this heat transfer between the battery modules, thermal runaway in which the battery modules catch fire successively may occur. Summary of the Invention

[0012] Technical Problem

[0013] In order to solve the problems of the above-mentioned prior art, an object of the present invention is to provide a structure of a battery module that can delay or prevent the discharge of gas in a certain direction during a fire. Specifically, the object of the present invention is to provide a battery module that can delay or prevent the discharge of gas through the front part of the battery module where a terminal exposure port is provided.

[0014] Another object of the present invention is to provide a structure of a battery module that can delay or prevent the discharged gas from flowing back into an adjacent battery module.

[0015] Another object of the present invention is to provide a structure of a battery module that can guide the discharge of gas in a direction other than the forward direction during a fire.

[0016] Yet another object of the present invention is to provide a structure of a battery module and a battery pack that can delay or prevent heat transfer between battery modules.

[0017] The technical problems to be solved by the present invention are not limited to the above objects. Other objects and advantages not described in the present invention can be understood through the following description, and will be more clearly understood through the examples of the present invention. In addition, it is obvious that the objects and advantages of the present invention can be achieved by the devices and their combinations shown in the claims.

[0018] To solve the above problems, the present invention provides a battery module, which includes: a battery cell laminate; a bus bar frame connected to the front part of the battery cell laminate and provided with terminals; a module frame having an open front part and accommodating the battery cell laminate; an end plate covering the front part of the module frame and provided with a terminal exposure port for exposing the terminals to the outside; and a thermal expansion member fastened together with the terminals, wherein the thermal expansion member expands when heated.

[0019] The above technical solution can be applied to a battery module where there is a risk of high-temperature gas discharging to the exposed terminals when the battery cells catch fire. In particular, the above technical solution can be applied to a battery module including a synthetic resin material, and the synthetic resin material can be provided at the exposed terminals and can be melted by gas.

[0020] The thermal expansion member can be directly connected to the terminals or can be connected through a battery pack bus bar. The battery pack bus bar can be electrically connected to the terminals. The thermal expansion member can be fastened at a position higher than the terminals.

[0021] The terminal, the battery pack bus bar, and the thermal expansion member may respectively include first fastening holes, second fastening holes, and third fastening holes vertically penetrating therethrough, and the battery module may further include a fastening member that simultaneously penetrates the first fastening hole, the second fastening hole, and the third fastening hole to fasten the terminal, the battery pack bus bar, and the thermal expansion member.

[0022] The fastening member may include a head that interferes with the thermal expansion member and may be fixed at its lower end portion by engaging with a fixing portion provided at the end plate.

[0023] The end plate may include: a first plate that includes a synthetic resin material and is provided with a first terminal exposure port; and a second plate that is disposed more outward in the length direction than the first plate, the second plate includes a metal material, and is provided with a second terminal exposure port.

[0024] The first plate may include a terminal insulator that is exposed to the outside through the second terminal exposure port for insulation between the second plate and the terminal. Here, the thermal expansion member may include: a first portion that contacts the battery pack bus bar; and a second portion that contacts the terminal insulator.

[0025] When the battery module catches fire, the volume of the thermal expansion member may expand to fill empty spaces such as the gap between the fastening hole and the fastening member, the gap generated when the first plate melts, and the gap between the terminal and the second plate, thereby delaying or preventing the discharge of high-temperature gas through the front portion of the battery module.

[0026] The battery module may further include a pressing member that is fastened together with the thermal expansion member and the terminal on the thermal expansion member.

[0027] The terminal, the battery pack bus bar, the thermal expansion member, and the pressing member may respectively include first fastening holes, second fastening holes, third fastening holes, and fourth fastening holes vertically penetrating therethrough, and the battery pack may further include a fastening member that simultaneously penetrates the first fastening hole, the second fastening hole, the third fastening hole, and the fourth fastening hole to fasten the terminal, the battery pack bus bar, the thermal expansion member, and the pressing member.

[0028] Here, the fastening member may include a head that interferes with the thermal expansion member and may be fixed at its lower end by engaging with a fixing portion provided on the end plate.

[0029] The pressing member may include a flame retardant material. That is, the pressing member may be made of a material that maintains its shape even when heated to a high temperature to provide a reaction force against the expansion of the thermal expansion member.

[0030] The pressing member may have a shape corresponding to that of the thermal expansion member to cover and press inwardly a part of the surface of the thermal expansion member. As a result, compared with the case where the pressing member is not provided, the thermal expansion member can further expand inwardly and can more closely fill the gap existing in the front part of the battery module.

[0031] The battery module may further include: a flame retardant cover that covers the surface of the module frame; and a pressing fixing portion that protrudes and extends from the front end of the flame retardant cover and is fastened to the thermal expansion member and the terminal on the thermal expansion member.

[0032] The flame retardant cover may include a flame retardant material. The flame retardant cover may have a rigid body or a flexible body. The flame retardant cover may cover the upper surface of the module frame. Additionally, the flame retardant cover may cover the side surface of the module frame.

[0033] Exhaust holes may be provided on the upper surface of the flame retardant cover to discharge the gas generated in the module frame. When the flame retardant cover has a flexible body, the exhaust holes may have a slit shape. Here, the exhaust holes may be provided not only on the flame retardant cover but also on the upper surface of the module frame. By providing the exhaust holes on the upper surfaces of the flame retardant cover and the module frame, the gas that is not discharged in the forward direction in the battery module can be discharged in the upward direction. Here, the exhaust holes provided in the flame retardant cover may be smaller than the exhaust holes provided in the module frame.

[0034] The flame retardant cover may include a pressing fixing portion that protrudes and extends from its front end and is fastened together with the terminal, the battery pack bus bar, and the thermal expansion member. The pressing fixing portion may include a flame retardant material and may have a rigid body or a flexible body. Alternatively, the pressing fixing portion may also have a reinforcing structure by combining a rigid body with a flexible body.

[0035] The terminal, the battery pack bus bar, the thermal expansion member, and the pressing fixing portion may respectively include first fastening holes, second fastening holes, third fastening holes, and fifth fastening holes vertically penetrating therethrough, and the battery module may further include a fastening member that simultaneously penetrates the first fastening hole, the second fastening hole, the third fastening hole, and the fifth fastening hole to fasten the terminal, the battery pack bus bar, the thermal expansion member, and the pressing fixing portion.

[0036] Here, the fastening member may include a head that interferes with the thermal expansion member and may be fixed at its lower end portion by engaging with a fixing portion provided on the end plate.

[0037] The pressing member may have a shape corresponding to that of the thermal expansion member to cover and press inwardly a part of the surface of the thermal expansion member. Thus, compared with the case where the pressing fixing portion is not provided, the thermal expansion member can expand further inwardly and can more tightly fill the gap existing at the front portion of the battery module.

[0038] The battery module may not include the pressing member and the pressing fixing portion, or may include only one of the pressing member and the pressing fixing portion, or may include both the pressing member and the pressing fixing portion. Alternatively, the pressing fixing portion may be integrated with the pressing member or may replace the pressing member. In the case where both the pressing member and the pressing fixing portion are provided, the pressing fixing portion may be disposed above or below the pressing member.

[0039] The thermal expansion member may include a material selected from the group of thermal expansion resins, the group of thermal expansion resins including soft urethane, hard urethane, rigid polyurethane, and phosphorus-based flame retardant. The thermal expansion member may include a foam material. However, the thermal expansion member may include any material as long as the volume of the material expands when heated and is not limited to any of the above materials.

[0040] The present invention also provides a battery pack including the battery module and a structure of a vehicle including the battery pack.

[0041] A plurality of battery modules may be built into a battery pack frame to form a high-voltage and / or high-capacity battery pack. Within the battery pack, the battery modules may be arranged to face each other in the front-rear direction. Here, a plurality of battery pack busbars may electrically connect in series or in parallel a plurality of terminals of the plurality of battery modules.

[0042] The battery pack may be used as an energy source built into a vehicle including an electric vehicle and a hybrid vehicle.

[0043] Advantageous Effects

[0044] The present invention can provide a structure of a battery module in which a space existing at the front portion of the battery module provided with terminals is filled with a thermal expansion member, thereby delaying or preventing the discharge and inflow of gas in the forward direction.

[0045] The present invention can provide a structure of a battery module that can prevent gas from being discharged through an empty space generated when the first plate melts due to the high-temperature heat of the thermal expansion member that expands in the event of a fire.

[0046] The present invention can provide a structure of a battery module, which can prevent gas from being discharged through the gap between the terminal exposure port and the terminal by means of a thermal expansion member that expands in the event of a fire.

[0047] The present invention can provide a structure of a battery module, which can prevent gas from being discharged through the gap between the fastening member provided at the terminal and the fastening hole and the battery pack bus bar by means of a thermal expansion member that expands when on fire.

[0048] In the battery module according to an embodiment of the present invention, the high-temperature gas generated in the event of a fire can be guided to be discharged in the upward direction rather than the forward direction.

[0049] In the battery module according to an embodiment of the present invention, the pressing and fixing portion fixes the flame retardant cover so that the flame retardant cover does not fall off from the module frame even under high pressure.

[0050] The present invention can provide a structure of a battery module and a battery pack, in which heat transfer between battery modules is delayed or prevented.

[0051] In addition, the present invention can also have various other effects, which are described in the respective embodiments, and the description of the effects that can be easily inferred by those skilled in the art can also be omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 and Figure 2 are an exploded perspective view and a perspective view respectively showing the structure of the battery module.

[0053] Figure 3 Shows the fastening structure of the terminal of the battery module and the battery pack bus bar.

[0054] Figure 4 and Figure 5 are partial enlarged cross-sectional views of the battery module with the second plate removed Figure 3 of.

[0055] Figure 6 and Figure 7 are an exploded perspective view and a perspective view respectively illustrating the structure of the battery module according to the first embodiment of the present invention.

[0056] Figure 8 and Figure 9 are partial enlarged cross-sectional views of the battery module with the second plate removed according to the first embodiment of the present invention.

[0057] Figure 10 Shows the expansion effect of the thermal expansion member according to the first embodiment of the present invention, where the arrow indicates the expansion direction of the thermal expansion member.

[0058] Figure 11 and Figure 12 are an exploded perspective view and a perspective view respectively illustrating the structure of a battery module according to a second embodiment of the present invention.

[0059] Figure 13 and Figure 14 is a partially enlarged cross-sectional view of a battery module from which a second plate is removed according to a second embodiment of the present invention.

[0060] Figure 15 Illustrates the expansion effect of a thermal expansion member according to a second embodiment of the present invention, where the arrow indicates the expansion direction of the thermal expansion member.

[0061] Figure 16 and Figure 17 are an exploded perspective view and a perspective view respectively illustrating the structure of a battery module according to a third embodiment of the present invention.

[0062] Figure 18 Shows a battery pack including the battery module according to the present invention, and Figure 19 shows a vehicle including a Figure 18 battery pack.

[0063] [Description of reference numerals]

[0064] 1: Battery cell laminate

[0065] 11: Battery cell

[0066] 111: Electrode lead

[0067] 12: Bus bar frame

[0068] 121: Slit

[0069] 122: Module bus bar

[0070] 123: Terminal

[0071] 123H: First fastening hole

[0072] 2: Module frame

[0073] 3: End plate

[0074] 31: First plate

[0075] 311: First terminal exposure port

[0076] 312: Terminal insulator

[0077] 313: Fixing part

[0078] 32: Second plate

[0079] 321: Second terminal exposure port

[0080] 400: Battery pack bus bar

[0081] 400H: Second fastening hole

[0082] 410: Fastening member

[0083] 411: Head

[0084] 412: Body

[0085] 420: Thermal expansion member

[0086] 420H: Third fastening hole

[0087] 421: First part

[0088] 422: Second part

[0089] 430: Pressing member

[0090] 430H: Fourth fastening hole

[0091] 440: Flame retardant cover

[0092] 441: Pressing and fixing part

[0093] 441H: Fifth fastening hole

[0094] M: Battery module

[0095] P: Battery pack

[0096] V: Vehicle

[0097] X: Longitudinal / forward / backward direction

[0098] Y: Width direction / left - right direction

[0099] Z: Height direction / up - down direction Detailed implementation manners

[0100] The above - mentioned objects, features, and advantages will be described in detail with reference to the accompanying drawings, enabling those skilled in the art to implement the technical idea of the present invention. When determining that the detailed description of the prior art related to the present invention unnecessarily obscures the gist of the present invention, its detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0101] Although "first", "second", etc. are used to describe various elements, these elements are of course not limited by these terms. These terms are only used to distinguish one element from another, and unless otherwise specifically stated, the first element may also be the second element.

[0102] Throughout the specification, unless otherwise specified, each element may be singular or plural.

[0103] Hereinafter, "arranging an element above (or below) another element" or "arranging an element on top of (or at the bottom of) another element" not only means "arranging an element in contact with the upper surface (or lower surface)", but also means "arranging an element above the upper surface (or lower surface) with another element interposed therebetween".

[0104] In addition, when an element is described as "connected", "coupled" or "contacted" to another element, it should be understood that the element may be "directly connected", "directly coupled" or "directly contacted" to the other element, or the element may be "connected", "coupled" or "contacted" to the other element with yet another element interposed therebetween or the element may be "connected", "coupled" or "contacted" to the other element via yet another element.

[0105] Unless the context clearly dictates otherwise, expressions in the singular form as used herein include the plural form. Terms such as "consisting of" or "comprising" as used herein should not be construed as necessarily including all of the elements or steps described herein, but should be construed as not including some elements or steps, or including additional elements or steps.

[0106] Throughout the specification, unless otherwise specifically stated, "A and / or B" means A, B, or A and B, and "C to D" means from above C to below D, unless otherwise specifically stated.

[0107] Figure 1 and Figure 2 are respectively an exploded perspective view and a perspective view illustrating the structure of a battery module. Referring to Figure 1 and Figure 2 , the battery module includes: a battery cell laminate 1; a module frame 2 having an open front portion and accommodating the battery cell laminate 1; and end plates 3 covering the front portion of the module frame 2.

[0108] The battery cell laminate 1 may be manufactured by stacking a plurality of pouch-type battery cells 11. Here, the battery cells 11 may include electrode leads 111 protruding outwardly. However, regardless of the name, the battery cell laminate 1 is not limited to a specific structure or shape and may be one or more components constituting a battery.

[0109] The battery cell laminate 1 according to the first to third embodiments of the present invention may also be manufactured by stacking a plurality of battery cells 11. Here, the battery cells 11 may include electrode leads 111 protruding in the forward direction from their front ends.

[0110] The bus bar frame 12 can be connected to the front portion of the battery cell laminate 1. The bus bar frame 12 can include a slit 121 through which the electrode lead 111 passes and a module bus bar 122 connected to the electrode lead 111. The module bus bar 122 connects the electrode leads 111 in series or in parallel and can be connected to a pair of terminals 123 having different polarities. The bus bar frame 12 does not have to have the same structure as the above structure, as long as there are terminals 123 connected to the electrode leads 111 to connect the battery cell laminate 1 to an external device.

[0111] The bus bar frame 12 according to the first to third embodiments of the present invention can include: a plurality of slits 121 through which the electrode leads 111 pass; and a plurality of module bus bars 122 welded to the electrode leads 111. Here, the module bus bars 122 can be connected to a pair of terminals 123 having different polarities, and the pair of terminals 123 can be bent forward.

[0112] The module frame 2 can have an open front portion. The module frame 2 can be, for example, a box shape with an open front. The module frame 2 can be made of a metallic material. The module frame 2 can be formed by joining or assembling a plurality of members.

[0113] The module frame 2 according to the first to third embodiments of the present invention can be made of a metallic material and can include: a U-shaped frame (U-frame) having an open front and rear and an open upper portion; and a top plate covering the upper portion. Here, the U-frame and the top plate can also be joined to each other by welding.

[0114] The end plate 3 can include a first plate 31 and a second plate 32 provided in front of the first plate 31. Here, the first plate 31 can include a synthetic resin material, and the second plate 32 can include a metallic material. The first plate 31 and the second plate 32 can be respectively provided with a first terminal exposure port 311 and a second terminal exposure port 321 for exposing the terminals 123.

[0115] The first plate 31 can include a terminal insulator 312 exposed by the second terminal 123 as a part thereof. The terminal insulator 312 can be provided between the terminal 123 and the first plate 31 to electrically insulate them from each other. The terminal insulator 312 can include portions extending in the vertical direction at the longitudinal end and / or the widthwise end of the terminal 123.

[0116] According to the first to third embodiments of the present invention, the end plate 3 may include a first plate 31 and a second plate 32. The first plate 31 includes a synthetic resin material, and the second plate 32 includes a metal material. The first plate 31 and the second plate 32 may respectively include a first terminal exposure port 311 and a second terminal exposure port 321 that expose the terminal 123. The first plate 31 may include a terminal insulator 312 that is exposed through the second terminal exposure port 321 and includes a portion extending in the vertical direction at the lengthwise end and / or the widthwise end of the terminal 123.

[0117] The present invention provides a structure of a battery module, the battery module including a thermal expansion member containing a material that expands when heated, and the thermal expansion member being fastened together with the terminal to prevent high-temperature gas from discharging toward the terminal.

[0118] The above technical solution can be applied to a battery module with exposed terminals that has a risk of high-temperature gas discharging toward the exposed terminals in the event of a fire, and in particular, to a battery module including a synthetic resin material in an area where the terminals are exposed and that may be melted by the gas.

[0119] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0120] [First Embodiment]

[0121] Figure 6 And Figure 7 are respectively an exploded perspective view and a perspective view illustrating the structure of a battery module according to the first embodiment of the present invention, Figure 8 And Figure 9 is a partial enlarged cross-sectional view of the battery module according to the first embodiment of the present invention with the second plate removed. Referring to Figures 6 to 9 , the battery pack bus bar 400 and the thermal expansion member 420 may be fastened to the terminal 123.

[0122] The battery pack bus bar 400 may be fastened to be in direct contact with the terminal 123 such that the battery pack bus bar 400 is electrically connected to the terminal 123.

[0123] The thermal expansion member 420 may be fastened to the terminal 123 on top of the terminal 123. Here, the thermal expansion member 420 is fastened to the terminal 123 and the battery pack bus bar 400 is interposed between the thermal expansion member 420 and the terminal 123.

[0124] The thermal expansion member 420 may include a material that expands in volume when heated. For example, the thermal expansion member 420 may include a material selected from the group of thermal expansion resins, which group of thermal expansion resins includes soft polyurethane, hard polyurethane, rigid polyurethane, and phosphorus-based flame retardants. Here, the thermal expansion member 420 may include a foam material. However, the thermal expansion member 420 may include any material as long as the volume of the material expands when heated, and is not limited to any one of the materials listed above.

[0125] When heated, the thermal expansion member 420 may expand in its specific region or in a specific direction. For example, the lower portion of the thermal expansion member 420 may include a thermal expansion resin, and the upper portion of the thermal expansion member 420 may include a heat-resistant resin instead of a thermal expansion resin, such that when heated, its bottom surface expands in the downward direction and its upper surface does not expand.

[0126] The thermal expansion member 420 may include: a first portion 421 that contacts the battery pack bus bar 400; and a second portion 422 that contacts the terminal insulator 312. Here, the first portion 421 may be a horizontal portion that contacts the surface of the battery pack bus bar 400, and the second portion 422 may be a vertical portion that contacts the surface of the terminal insulator 312. The thermal expansion member 420 preferably covers as much as possible the area where the first plate 31 is exposed and the gap between the second plate 32 and the terminal 123.

[0127] The terminal 123, the battery pack bus bar 400, and the thermal expansion member 420 may be respectively provided with a first fastening hole 123H, a second fastening hole 400H, and a third fastening hole 420H that vertically penetrate therethrough. Here, the battery module may further include a fastening member 410 that simultaneously passes through the first fastening hole 123H, the second fastening hole 400H, and the third fastening hole 420H to fasten the terminal 123, the battery pack bus bar 400, and the thermal expansion member 420.

[0128] The fastening member 410 may include: a head 411 that interferes with the thermal expansion member 420; and a body 412 that passes through the second fastening hole 400H and the third fastening hole 420H. Here, the diameter of the head 411 may be greater than the diameter of the third fastening hole 420H in the horizontal direction. The body 412 may be fixed by engaging with a fixing portion 313 provided at the end plate 3. For example, the fastening member 410 may be a bolt having an external thread at its lower end portion, and the fixing portion 313 may be a nut having an internal thread mounted on the first plate 31, such that the outer peripheral surface of the lower end portion of the fastening member 410 and the inner peripheral surface of the fixing portion 313 may be fixed by engaging with each other. Thus, the battery pack bus bar 400, the thermal expansion member 420, and the pressing member 430 are vertically pressed inward between the head 411 and the terminal 123 to be fastened to the terminal 123.

[0129] However, the fastening between the terminal 123, the battery pack bus bar 400, and the thermal expansion member 420 can be any method as long as the terminal 123 and the battery pack bus bar 400 are electrically connected to each other, and the thermal expansion member 420 is fastened to the terminal 123, and the fastening does not have to be achieved according to the above - specific method.

[0130] According to the first embodiment, the first fastening hole 123H can be provided at the terminal 123. The battery pack bus bar 400 provided with the second fastening hole 400H and the thermal expansion member 420 provided with the third fastening hole 420H can be sequentially stacked on the terminal 123. The fastening member 410 can include a bolt having a head 411 with a diameter larger than the third fastening hole 420H and a body 412 having an external thread at its lower end portion. The body 412 is fixed by engaging with a fixing portion 313 having an internal thread on its inner peripheral surface. Thus, the battery pack bus bar 400 and the thermal expansion member 420 can be fastened to the terminal 123. Here, the thermal expansion member 420 can include a foam material containing any one of soft polyurethane, hard polyurethane, and a phosphorus - based flame - retardant material. The thermal expansion member 420 can include a first portion 421 that contacts the surface of the battery pack bus bar 400 in the horizontal direction and a second portion 422 that contacts the surface of the terminal insulator 312 in the vertical direction.

[0131] Figure 10 The expansion effect of the thermal expansion member according to the first embodiment of the present invention is shown. Here, the arrow indicates the expansion direction of the thermal expansion member. Referring to Figure 10 , when the battery cell 11 catches fire in the battery module according to the first embodiment, high - temperature gas can be discharged from the front portion of the battery cell 11 where the electrode lead 111 is provided. Here, the first plate 31 can also be melted by the gas.

[0132] The thermal expansion member 420 can be heated by the gas and expand in volume. The thermal expansion member 420 expands in all directions to fill the space through which the gas can pass, including the space between the terminal 123 and the end plate 3, the space between the first fastening hole 123H and the fastening member 410, and the space generated when the first plate 31 melts. When the thermal expansion member 420 fills the space through which the gas can pass, the discharge of the gas through the front portion of the battery module can be delayed or prevented.

[0133] [Second Embodiment]

[0134] Hereinafter, components not separately described in the second embodiment are the same as those in the first embodiment.

[0135] Figure 11 and Figure 12are an exploded perspective view and a perspective view illustrating the structure of a battery module according to a second embodiment of the present invention, respectively, Figure 13 and Figure 14 is a partially enlarged cross-sectional view of a battery module from which a second plate is removed according to a second embodiment of the present invention. Referring to Figures 11 to 14 , in addition to the battery pack bus bar 400 and the thermal expansion member 420, the pressing member 430 may also be fastened to the terminal 123.

[0136] The pressing member 430 may be fastened to the terminal 123 on the thermal expansion member 420, and the thermal expansion member 420 and the battery pack bus bar 400 are interposed between the pressing member 430 and the terminal 123.

[0137] The pressing member 430 may be arranged to be in partial contact with the surface of the thermal expansion member 420. Specifically, the bottom surface of the pressing member 430 may cover a horizontally extending portion of the surface of the first portion 421 of the thermal expansion member 420, and the side surface of the pressing member 430 may cover a vertically extending portion of the surface of the second portion 422 of the thermal expansion member 420. To achieve this, the pressing member 430 may have a shape corresponding to the surface of the thermal expansion member 420.

[0138] The pressing member 430 may be provided with a fourth fastening hole 430H vertically penetrating therethrough. Here, the fastening member 410 may simultaneously penetrate through the first fastening hole 123H, the second fastening hole 400H, the third fastening hole 420H, and the fourth fastening hole 430H.

[0139] The head 411 may be formed to have a diameter larger than that of the fourth fastening hole 430H and may interfere with the pressing member 430. The lower end portion of the main body 412 may be fixed by engaging with the fixing portion 313. Thus, the battery pack bus bar 400, the thermal expansion member 420, and the pressing member 430 may be vertically pressed inward between the head 411 and the terminal 123 to be fastened to the terminal 123.

[0140] However, the fastening between the terminal 123, the battery pack bus bar 400, the thermal expansion member 420, and the pressing member 430 may be any method as long as the terminal 123 and the battery pack bus bar 400 are electrically connected to each other, the thermal expansion member 420 is fastened to the terminal 123, and the pressing member 430 is fastened to the thermal expansion member 420, and it is not necessary to implement the fastening according to the above specific method.

[0141] According to the first embodiment, the first fastening hole 123H may be provided at the terminal 123, and the battery pack bus bar 400 provided with the second fastening hole 400H, the thermal expansion member 420 provided with the third fastening hole 420H, and the pressing member 430 provided with the fourth fastening hole 430H may be sequentially stacked on the terminal 123. The fastening member 410 may include a bolt having a head 411 with a diameter larger than the fourth fastening hole 430H and a body 412 having an external thread at its lower end, and the body 412 is fixed by engaging with a fixing portion 313 having an internal thread on its inner circumferential surface. Thus, the battery pack bus bar 400, the thermal expansion member 420, and the pressing member 430 may be fastened to the terminal 123. Here, the thermal expansion member 420 may include a first portion 421 that contacts the battery pack bus bar 400 in the horizontal direction and a second portion 422 that contacts the terminal insulator 312 in the vertical direction. The pressing member 430 may have a rectangular parallelepiped shape corresponding to the shape of the thermal expansion member 420 such that its bottom surface covers the surface of the first portion 421, and its side surface may cover the surface of the second portion 422.

[0142] Figure 15 The expansion effect of the thermal expansion member according to the second embodiment of the present invention is shown, where the arrow indicates the expansion direction of the thermal expansion member. Referring to Figure 15 , when the battery cell 11 catches fire in the battery module according to the second embodiment, the pressing member 430 covers and presses the surface of the thermal expansion member 420 inward to suppress the expansion of the expansion member 420 in the upward and forward directions and increase the volume expanding in the downward, backward, and length directions. As a result, the thermal expansion member 420 can fill the space through which the gas passes faster and more densely.

[0143] [Third Embodiment]

[0144] Hereinafter, components not separately described in the third embodiment are the same as those in the first embodiment and the second embodiment.

[0145] Figure 16 And Figure 17 are an exploded perspective view and a perspective view respectively illustrating the structure of the battery module according to the third embodiment of the present invention. Referring to ​ And ​ , the battery module may include a flame retardant cover 440 covering the surface of the module frame 2.

[0146] The flame retardant cover 440 may include a flame retardant material. The flame retardant cover 440 may have a rigid body or a flexible body. The flame retardant cover 440 may cover the upper surface of the module frame 2. In addition, the flame retardant cover 440 may cover the side surface of the module frame 2.

[0147] Exhaust holes can be provided on the upper surface of the flame retardant cover 440 to discharge the gas generated in the module frame 2. When the flame retardant cover 440 has a flexible body, the exhaust holes can have a slit shape. Here, the exhaust holes can be provided not only on the flame retardant cover 440 but also on the upper surface of the module frame 2. By providing the exhaust holes on the upper surfaces of the flame retardant cover 440 and the module frame 2, the gas that is not discharged in the forward direction in the battery module can be discharged in the upward direction. Here, the exhaust holes provided in the flame retardant cover 440 can be smaller than the exhaust holes provided in the module frame 2, thereby facilitating the discharge of gas from the battery module and making it difficult for the gas to flow back into the battery module.

[0148] The flame retardant cover 440 can include a pressing and fixing portion 441 that protrudes and extends from its front end and is fastened together with the terminal 123, the battery pack bus bar 400, and the thermal expansion member 420. The pressing and fixing portion 441 can include a flame retardant material and can have a rigid body or a flexible body. Alternatively, the pressing and fixing portion 441 can also have a reinforcing structure by combining a rigid body with a flexible body.

[0149] The battery module can include neither the pressing member 430 nor the pressing and fixing portion 441, or only include one of the pressing member 430 and the pressing and fixing portion 441, or include both the pressing member 430 and the pressing and fixing portion 441. Alternatively, the pressing and fixing portion 441 can be integrated with the pressing member 430 or can also replace the pressing member 430.

[0150] When both the pressing member 430 and the pressing and fixing portion 441 are provided, the pressing and fixing portion 441 can be arranged above or below the pressing member 430.

[0151] Hereinafter, the third embodiment illustrates the separate provision of the pressing member 430 and the pressing and fixing portion 441. However, through the following description, it should be understood that the technical solution of the present invention can be applied to the case where the pressing member 430 and the pressing and fixing portion 441 are integrated or combined as described above.

[0152] The pressing and fixing portion 441 can also be provided with a fifth fastening hole 441H vertically penetrating therethrough. Here, the fastening member 410 can penetrate through the first fastening hole 123H, the second fastening hole 400H, the third fastening hole 420H, the fifth fastening hole 441H, and the fifth fastening hole 430H simultaneously.

[0153] When a pressing member 430 is provided on the pressing fixing portion 441, as in the second embodiment, the head 411 of the fastening member 410 interferes with the pressing member 430, and the lower end portion of the main body 412 of the fastening member 410 is fixed to the fixing portion 313, so that the battery pack bus bar 400, the thermal expansion member 420, the pressing member 430, and the pressing fixing portion 441 can be vertically pressed inward between the head 411 and the terminal 123 to be fastened to the terminal 123.

[0154] When there is no pressing member 430 or when the pressing fixing portion 441 is provided on the pressing member 430, the head 411 can be formed to have a diameter larger than the fifth fastening hole 441H and can interfere with the pressing fixing portion 441. The lower end portion of the main body 412 can be fixed by engaging with the fixing portion 313. As a result, the battery pack bus bar 400, the thermal expansion member 420, the pressing member 430, and the pressing fixing portion 441 can be vertically pressed inward between the head 411 and the terminal 123 to be fastened to the terminal 123.

[0155] However, the fastening between the terminal 123, the battery pack bus bar 400, the thermal expansion member 420, the pressing member 430, and the pressing fixing portion 441 can be any method as long as the terminal 123 and the battery pack bus bar 400 are electrically connected to each other, the thermal expansion member 420 is fastened to the terminal 123, and the pressing member 430 and / or the pressing fixing portion 441 is fastened to the thermal expansion member 420, and it is not necessary to implement the fastening according to the above specific method.

[0156] According to the third embodiment, a first fastening hole 123H may be provided at the terminal 123. A battery pack bus bar 400 having a second fastening hole 400H is stacked in sequence on the terminal 123, a thermal expansion member 420 having a third fastening hole 420H, a pressing and fixing portion 441 having a fifth fastening hole 441H and protruding and extending from the front end of the flame retardant cover 440 having a flexible body containing a flame retardant material and covering the upper surface and both sides of the module frame 2, and a pressing member 430 having a fourth fastening hole 430H. The fastening member 410 may include a bolt having a head 411 with a diameter larger than the fourth fastening hole 430H and a body 412 having an external thread at its lower end portion, and the body 412 is fixed by engaging with a fixing portion 313 having an internal thread on its inner circumferential surface. Thus, the battery pack bus bar 400, the thermal expansion member 420, and the pressing member 430 can be fastened to the terminal 123. Here, the thermal expansion member 420 may include a first portion 421 that contacts the battery pack bus bar 400 in the horizontal direction and a second portion 422 that contacts the terminal insulator 312 in the vertical direction. The pressing member 430 may have a rectangular parallelepiped shape corresponding to the shape of the thermal expansion member 420 such that its bottom surface covers the surface of the first portion 421, and its side surface may cover the surface of the second portion 422.

[0157] According to the third embodiment, the pressing member 430 and the pressing and fixing portion 441 cover and press the surface of the thermal expansion member 420 inward to suppress the expansion of the expansion member 420 in the upward and forward directions and increase the volume of expansion in the downward, backward, and longitudinal directions. As a result, the thermal expansion member 420 can fill the space through which the gas passes faster and more densely.

[0158] In addition, due to the flame retardant cover 440, the heat transfer between the battery modules can be delayed. Since the pressing and fixing portion 441 is fastened to the terminal 123 by the fastening member 410, the flame retardant cover 440 can be prevented from separating from the module frame 2 in the case where the pressure of the battery module increases sharply.

[0159] The present invention also provides a structure of a battery pack including the battery module according to the first to third embodiments of the present invention and a vehicle including the battery pack.

[0160] ​ A battery pack including the battery module according to the present invention is shown, and ​ A vehicle including ​ the battery pack is shown. Refer to ​ and ​, multiple battery modules M can be built into a battery pack frame to form a high-voltage and / or high-capacity battery pack P. Inside the battery pack P, the battery modules M can be arranged to face each other in the front-rear direction. Here, multiple battery pack busbars 400 can electrically connect multiple terminals 123 provided in the multiple battery modules M in series or in parallel with each other. The battery pack P can be built in as an energy source for a vehicle V including an electric vehicle and a hybrid vehicle.

[0161] According to the present invention, even in the case where the battery module M catches fire, heat propagation between the battery modules M can be delayed or prevented, thereby delaying or preventing thermal runaway of the battery pack P, and thus improving the safety of the vehicle V.

[0162] It should be understood that the described embodiments are exemplary in all aspects and not restrictive, and the scope of the present invention will be indicated by the appended claims rather than the described detailed description. The meaning and scope of the claims described subsequently, as well as all variations and modifications derived from the equivalent concept, should be interpreted as being included within the scope of the present invention.

[0163] Although the present invention has been described with reference to the exemplary drawings, it should be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and those skilled in the art will understand that various modifications can be made without departing from the scope and spirit of the present invention. In addition, although the operating effects of the configuration according to the present invention are not explicitly described when describing the embodiments of the present invention, it should be understood that predictable effects will also be achieved by the configuration.

Claims

1. A battery module, the battery module comprising: A battery cell laminate; A bus bar frame, the bus bar frame being connected to the front of the battery cell laminate and provided with terminals; A module frame, the module frame having an open front and accommodating the battery cell laminate; An end plate, the end plate covering the front of the module frame and provided with a terminal exposure opening for exposing the terminals to the outside; And A thermal expansion member, the thermal expansion member being fastened together with the terminals, Wherein the thermal expansion member expands when heated.

2. The battery module according to claim 1, the battery module further comprising a battery pack bus bar, the battery pack bus bar being inserted between the terminals and the thermal expansion member to be fastened together with the terminals and the thermal expansion member.

3. The battery module according to claim 2, wherein: The thermal expansion member is disposed at a position higher than the terminals.

4. The battery module according to claim 3, wherein, The terminals, the battery pack bus bar, and the thermal expansion member respectively include first fastening holes, second fastening holes, and third fastening holes vertically penetrating therethrough, and The battery module further comprises a fastening member, the fastening member simultaneously penetrating the first fastening hole, the second fastening hole, and the third fastening hole to fasten the terminals, the battery pack bus bar, and the thermal expansion member.

5. The battery module according to claim 4, wherein, The fastening member includes a head interfering with the thermal expansion member and is fixed at the lower end portion of the fastening member by engaging with a fixing portion provided at the end plate.

6. The battery module according to claim 1, wherein, The end plate includes: A first plate, the first plate including a synthetic resin material and provided with a first terminal exposure opening; and A second plate, the second plate being disposed more outward in the length direction than the first plate, the second plate including a metal material and provided with a second terminal exposure opening.

7. The battery module according to claim 6, wherein, The first plate includes a terminal insulator exposed to the outside through the second terminal exposure opening, and The thermal expansion member includes: A first portion in contact with the battery pack bus bar; and A second portion in contact with the terminal insulator.

8. The battery module according to claim 1, the battery module further comprising a pressing member, the pressing member being fastened together with the thermal expansion member and the terminals on the thermal expansion member.

9. The battery module according to claim 8, wherein: The terminals, the battery pack bus bar, the thermal expansion member, and the pressing member respectively include first fastening holes, second fastening holes, third fastening holes, and fourth fastening holes vertically penetrating therethrough, and The battery module further comprises a fastening member, the fastening member simultaneously penetrating the first fastening hole, the second fastening hole, the third fastening hole, and the fourth fastening hole to fasten the terminals, the battery pack bus bar, the thermal expansion member, and the pressing member.

10. The battery module according to claim 9, wherein, The fastening member includes a head interfering with the thermal expansion member and is fixed at the lower end portion of the fastening member by engaging with a fixing portion provided at the end plate.

11. The battery module according to claim 8, wherein, The pressing member includes a flame retardant material.

12. The battery module according to claim 8, wherein, The pressing member has a shape corresponding to the shape of the thermal expansion member to cover and press inward a part of the surface of the thermal expansion member.

13. The battery module according to claim 1, the battery module further comprising: A flame-retardant cover that covers the surface of the module frame; and A pressing and fixing part that protrudes and extends from the front end of the flame-retardant cover and is fastened to the thermal expansion member and the terminal on the thermal expansion member.

14. The battery module according to claim 13, wherein: The terminal, the battery pack bus bar, the thermal expansion member, and the pressing and fixing part respectively include first fastening holes, second fastening holes, third fastening holes, and fifth fastening holes vertically penetrating therethrough, and The battery module further includes a fastening member that simultaneously penetrates the first fastening hole, the second fastening hole, the third fastening hole, and the fourth fastening hole to fasten the terminal, the battery pack bus bar, the thermal expansion member, and the pressing and fixing part.

15. The battery module according to claim 14, wherein, The fastening member includes a head that interferes with the thermal expansion member and is fixed at the lower end part of the fastening member by engaging with a fixing part provided at the end plate.

16. The battery module according to claim 12, wherein, The pressing member has a shape corresponding to the shape of the thermal expansion member to cover and press inward a part of the surface of the thermal expansion member.

17. The battery module according to claim 1, wherein, The thermal expansion member includes a foam material that contains a material selected from the group of thermally expandable resins, and the group of thermally expandable resins includes soft polyurethane, hard polyurethane, rigid polyurethane, and a phosphorus-based flame retardant.

18. A battery pack, the battery pack comprising the battery module according to any one of claims 1 to 17, wherein, A plurality of the terminals are electrically connected in series or in parallel through a plurality of the battery pack bus bars.

19. A vehicle that includes the battery pack according to claim 18.

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