Explosion-proof battery module structure

Abstract

The present invention provides a battery module (1) having an expansion member (31) and a spring member (32) so as to prevent or delay the release and explosion of thermal energy and flames and to prevent the occurrence of a chain fire between other battery modules. The expansion member (31) may be a reverse disk (31R), and the reverse disk (31R) is shaped to reverse with respect to an internal pressure greater than or equal to a predetermined yield pressure that is less than an explosion pressure defined as a minimum pressure that enables explosion of the battery module (1) to expand the internal space of the battery module (1), thus, an increase in internal pressure and an explosion are prevented or delayed.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0088814 filed on July 19, 2022, and all contents disclosed in this patent application document are expressly incorporated herein.

[0002] The present invention relates to a battery module having an expanded internal space structure and a venting structure that reduces explosion risk. Background Art

[0003] Secondary batteries, which are easy to apply depending on product groups and have electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles or hybrid vehicles driven by electric drive sources and power storage devices. These secondary batteries have attracted attention as new energy sources that improve eco-friendliness and energy efficiency, not only because they have the main advantage of being able to significantly reduce the use of fossil fuels, but also because they do not produce any byproducts due to energy use.

[0004] Although small mobile devices use one, two or three battery cells per device, medium and large devices such as vehicles require high output and large capacity. Therefore, medium and large battery modules in which a plurality of battery cells are electrically connected are used.

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

[0006] Figure 1 and Figure 2 The three-dimensional diagram and the exploded three-dimensional diagram respectively show a general battery module. Figure 1 and Figure 2 The battery module 1 may generally include: a battery cell laminate 2; a U-shaped frame 41 that accommodates the battery cell laminate 2; a pair of end plates 42 that respectively cover the front and rear ends of the U-shaped frame 41; and a top plate 3 that covers the upper end of the U-shaped frame 41.

[0007] The battery cell laminate 2 may be formed by stacking a plurality of pouch-type battery cells 21, and each battery cell 21 may include a pair of electrode leads. Electrode leads having the same polarity may be connected to each other through a bus bar frame, or electrode leads having different polarities may be connected to each other through a bus bar frame, and the bus bar may be electrically connected to the terminal 5 exposed to the outside of the battery module 1 through a terminal exposure portion 51 provided at the end plate 42. Thus, the battery cell laminate 2 may be connected to other external battery modules.

[0008] In addition, there is a risk that the battery cell 21 may overheat and catch fire due to a short circuit. When the battery cell 21 catches fire, heat, flame, and exhaust gas generated by evaporation of the electrolyte charged in the battery cell 21 may be discharged from the battery cell 21. The heat, flame, and exhaust gas may increase the internal pressure of the battery module 1, and therefore, there is a risk that the battery module 1 may explode. Such an explosion of a battery module (especially a battery close to a passenger of an electric vehicle) has the potential to cause a fatal accident.

[0009] In addition, as a way to prevent the explosion problem of the battery module as described above, a method of reducing the internal pressure of the battery module by a venting structure that intentionally discharges heat, flames, and exhaust gas caused by fire has been widely used. However, due to this venting structure, there is a problem that flames and heat energy may be transferred between adjacent battery modules in the battery pack, resulting in a series fire.

[0010] Figure 4 and Figure 5 is a schematic diagram showing the transfer of heat and flame between battery modules. Figure 4 and Figure 5 , heat energy and flames generated by ignition of the battery cell laminate 2 can be discharged mainly through the terminal exposure portion 51 provided at the end plate 42 and the connection area between the end plate 42, the top plate 3 and the U-shaped frame 41. In a battery pack, battery modules are generally arranged adjacent to each other in the length direction or the width direction, so that when exhaust is achieved horizontally as described above, there is a high risk of series fire.

[0011] In addition, even when the internal pressure of the battery module 1 is sufficiently reduced due to exhaust, heat energy and flame generated from other battery modules are likely to be transmitted to the battery module 1 if the battery module 1 remains open for exhaust. Summary of the invention

[0012] Technical issues

[0013] In order to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a structure of a battery module in which an increase in internal pressure can be prevented or delayed, thereby delaying explosion and flame eruption during fire.

[0014] Another object of the present invention is to provide a structure of a battery module in which exhaust gas is directed in a vertical direction in the event of a fire.

[0015] It is yet another object of the present invention to provide a structure of a battery module that can be resealed after venting occurs.

[0016] The aspects of the present disclosure are not limited to the above aspects, and other aspects and advantages not mentioned above can be clearly understood from the following description, and can be more clearly understood from the embodiments described herein. In addition, the aspects and advantages of the present disclosure can be achieved through the means described in the attached claims and their combinations.

[0017] Technical Solution

[0018] In order to solve the above problems, the present invention provides a battery module including a battery cell laminate, the battery module including: a frame having an open upper portion; a top plate connected to the frame and covering the upper portion of the opening; a spring member that applies pressure in a downward direction and fixes the top plate to contact the upper end of the side wall of the frame; and an expansion member that is disposed at a portion of the top plate.

[0019] An explosion pressure defined as a minimum value of internal pressure at which the battery module explodes may be provided to the battery module.

[0020] In addition to disconnecting the top plate from the frame to open the frame and cause exhaust before the internal pressure of the module reaches the explosion pressure, the battery module according to the present invention is also provided with an expansion member and a spring member, so that in the event of a fire in the battery cell laminate, the increase in the internal pressure of the battery module can be delayed.

[0021] The spring member may apply pressure to the top plate in a downward direction to fix the top plate so that the top plate contacts the upper ends of the side walls of the frame to cover an upper portion of the opening of the frame.

[0022] One or more spring members may be installed.

[0023] The spring member may be a coil spring made of metal, but is not limited thereto.

[0024] The spring member may be installed to be embedded in the upper end of the side wall of the frame. The embedded installation may be achieved by insert injection, or may be achieved by providing and assembling a separate member for fixing.

[0025] Here, an upper end of the spring member may be fixed to the top plate.

[0026] As described above, by fixing the two ends of the spring member to the upper end of the side wall of the frame and the top plate, the spring member is stretched when the top plate moves away from the upper end of the side wall of the frame. Therefore, the spring member can provide a restoring force to restore the top plate toward the upper end of the side wall of the frame.

[0027] Instead of the spring member, the lower end of the spring shaft can be installed to be embedded in the upper end of the side wall of the frame. In this case, the embedded installation can be achieved by inserting injection, or can be achieved by providing and assembling a separate member for fixing.

[0028] Here, the spring shaft may be disposed to vertically penetrate the top plate, and the fixed end may be disposed at an upper end of the spring shaft located above the top plate.

[0029] Here, the spring member can be installed to be penetrated by the spring shaft between the top plate and the fixed end. That is, the spring member can be installed in the following manner: the upper end of the spring member contacts the fixed end, and the lower end of the spring member contacts the top plate to be vertically interposed between the fixed end and the top plate.

[0030] As described above, by arranging the spring member between the fixed end at the upper end of the spring shaft and the top plate, the top plate is connected to the upper end of the side wall of the frame and penetrated by the spring shaft that penetrates the top plate, when the top plate moves away from the upper end of the side wall of the frame, the spring member is compressed to have a restoring force that pushes the top plate toward the upper end of the side wall of the frame.

[0031] The maximum allowable pressure limit of the battery module may be defined as a maximum value of the internal pressure of the battery module that maintains the bonding between the top plate and the frame.

[0032] The maximum allowable pressure limit may be lower than the explosion pressure. Therefore, the internal pressure of the battery module may reach the maximum allowable pressure limit before reaching the explosion pressure, so that the top plate is separated from the frame and an opening is formed in the upward direction of the battery module. Therefore, the flame, heat energy, and exhaust gas generated from the battery cell laminate are discharged in the upward direction, thereby reducing the internal pressure.

[0033] The spring member may include a prestressed spring that is pre-tensioned or pre-compressed so as to have a predetermined restoring force even when the top plate and the frame are in full contact. Therefore, the maximum allowable pressure limit may be defined as the minimum value of the internal pressure that causes additional tension or compression in the spring member.

[0034] The top plate and the frame may be connected and coupled to each other by an additional fixing member in addition to the spring member.

[0035] The fixing member may be designed to be damaged under a load exceeding a predetermined level. Therefore, the maximum allowable pressure limit may be defined as the minimum value of the internal pressure of the battery module that causes the fixing member to be damaged.

[0036] When venting occurs due to the internal pressure of the battery module exceeding the maximum allowable pressure limit as described above, the internal pressure of the battery module is further reduced due to the venting. Therefore, as the top plate is reconnected to the frame by the restoring force provided by the spring member, the battery module can be sealed.

[0037] One edge of the top plate and one edge of the upper end of the side wall of the frame may be connected to each other by a hinge. Therefore, the battery module may be provided with an opening between the other edge of the top plate and the other edge of the upper end of the side wall of the frame.

[0038] The expansion member may be provided as part of the top plate.

[0039] The expansion member may be coupled to the top plate to cover and seal the hole provided at the top plate. Alternatively, the expansion member may be integrally formed with the top plate.

[0040] The expansion member may be made of a heat resistant and / or flame retardant material. For example, the expansion member may be made of metal.

[0041] As the internal pressure of the battery module increases, the expansion member may expand outward to expand the internal space of the battery module.

[0042] One or more expansion members may be provided.

[0043] The expansion member may include an elastic membrane that expands outward as the internal pressure of the battery module increases. Alternatively, the expansion member may include a reverse disk that yields and protrudes outward when the internal pressure of the battery module is greater than a yield pressure.

[0044] As the expansion member expands, the internal space of the battery module expands, thereby delaying an increase in the internal pressure of the battery module due to exhaustion of gas and heat energy generated when the battery cell laminate is ignited.

[0045] The above scheme can also be applied to a battery pack including the battery module according to the present invention and a vehicle including the battery pack. Since the manufacturing method of such a battery pack and vehicle is well known, no description will be given herein.

[0046] Beneficial Effects

[0047] The present invention can provide a structure of a battery module, wherein, by providing an expansion member at the top plate, in the event of a fire, the internal space can expand, thereby preventing or delaying an increase in internal pressure to prevent or delay the spread of flames and explosion while maintaining a sealed state.

[0048] The present invention can provide a structure of a battery module in which exhaust gas when a case catches fire is guided in an upward direction by adopting a structure in which a top plate is opened when internal pressure exceeds a maximum allowable pressure limit.

[0049] As another effect of the present invention, the present invention may provide a structure of a battery module in which a frame and a top plate are coupled by a spring member so that the battery module is resealed after venting occurs.

[0050] In addition to the above-described effects, various other effects may be produced according to the present disclosure, and a description of the effects is provided with reference to each embodiment, or a description of effects that are easily predicted by a person of ordinary skill in the art is omitted, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a perspective view showing a general battery module.

[0052] Figure 2 It is an exploded perspective view showing a general battery module.

[0053] Figure 3 is a schematic diagram showing the transfer of heat energy and flame between battery modules.

[0054] Figure 4 is a schematic diagram showing the transfer of heat energy and flame between battery modules.

[0055] Figure 5 is a perspective view showing a battery module provided with an elastic diaphragm at a top plate according to a first embodiment of the present invention.

[0056] Figure 6 is a side sectional view showing a battery module provided with an elastic diaphragm at a top plate before ignition according to a first embodiment of the present invention.

[0057] Figure 7 is a side sectional view showing a battery module provided with an elastic diaphragm at a top plate after a fire according to the first embodiment of the present invention.

[0058] Figure 8 is a perspective view showing a battery module provided with a reverse plate at a top plate according to a second embodiment of the present invention.

[0059] Fig. 9 is a side sectional view showing a battery module provided with a reverse plate at a top plate before ignition according to a second embodiment of the present invention.

[0060] Fig.10 is a side sectional view showing a battery module provided with a reverse plate at a top plate after a fire according to a second embodiment of the present invention.

[0061] Fig.11 is a perspective view showing a battery module provided with a reverse plate and a spring member according to a third embodiment of the present invention.

[0062] Fig.12 is a side sectional view showing a battery module provided with a reverse plate and a spring member before ignition according to a third embodiment of the present invention.

[0063] Fig.13 is a side sectional view showing a battery module provided with a reverse plate and a spring member after a fire according to a third embodiment of the present invention.

[0064] Fig.14 is a perspective view showing a battery module provided with a reverse plate, a spring member, and a spring shaft according to a fourth embodiment of the present invention.

[0065] Fig.15 is a side sectional view showing a battery module provided with a reverse plate, a spring member, and a spring shaft before ignition according to a fourth embodiment of the present invention.

[0066] Fig.16 is a side sectional view showing a battery module provided with a reverse plate, a spring member, and a spring shaft after a fire according to a fourth embodiment of the present invention.

[0067] Fig.17 is a perspective view showing a battery module provided with a reverse plate, a spring member, and a hinge according to a fifth embodiment of the present invention.

[0068] Fig.18 is a perspective view showing a battery pack including a battery module according to the present invention.

[0069] Fig.19 It is shown that Fig.18 A perspective view of a vehicle with a battery pack.

[0070] [Explanation of Reference Numerals]

[0071] 1: Battery module

[0072] 2: Battery cell laminates

[0073] 21: Battery cells

[0074] 3: Top plate

[0075] 31: Expansion member

[0076] 31E: Elastic diaphragm

[0077] 31R: Reverse disc

[0078] 32: Spring component

[0079] 32A: Spring shaft

[0080] 322: Spring fixed end

[0081] 4: Framework

[0082] 41: U-shaped frame

[0083] 411: Spring installation part

[0084] 412: Hinge

[0085] 42: End plate

[0086] 5: Terminal

[0087] 51: Exposed terminal part

[0088] P: Battery pack

[0089] V: Vehicle DETAILED DESCRIPTION

[0090] The above aspects, features and advantages are described in detail below with reference to the accompanying drawings, so that a person skilled in the art in the field to which the present disclosure belongs can easily implement the technical spirit of the present disclosure. In the present disclosure, if it is considered to make the main points of the present disclosure unnecessarily obscure, the detailed description of the known technology about the subject matter of the present disclosure is omitted. The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals may represent the same or similar parts.

[0091] The terms "first", "second", etc. are used herein only to distinguish one component from another component. Therefore, the components should not be limited by the terms. Of course, unless otherwise specified to the contrary, the first component may be the second component.

[0092] Throughout the specification, each component may be provided as a single component or as a plural component unless explicitly stated otherwise.

[0093] When any component is described as being "in an upper part (or lower part)" or "on (or under) another component", any component may be directly on (or under) the other component, but other components may be inserted between any component and the other component on (or under) the any component.

[0094] When any component is described as being “connected,” “coupled” or “linked” to another component, any component may be directly connected or coupled to the other component, but other components may be “interposed” between the two components, or the two components may be “connected,” “coupled” or “linked” through other components.

[0095] Unless otherwise expressly indicated, the singular forms "a", "an" and "the" are intended to include the plural forms as well. It should be understood that the terms "include" or "comprises" and the like as set forth herein are not to be interpreted as necessarily including all of the components or steps, but may be interpreted as excluding some of the components or steps, or may be interpreted as including other components or steps.

[0096] Throughout this disclosure, unless otherwise stated to the contrary, as used herein, the phrase "A and / or B" may mean A, B, or A and B, and the phrase "C to D" may mean C or greater and D or less.

[0097] The present invention provides a battery module structure, wherein:

[0098] preventing or delaying an increase in internal pressure to prevent or delay the dissipation of heat energy and flames by including an expansion member that expands within a predetermined maximum allowable pressure limit to increase the internal space as the internal pressure increases;

[0099] When the internal pressure exceeds the maximum allowable pressure limit, opening the top plate to direct the exhaust gas in an upward direction, thereby preventing heat energy and flame from being transferred to other battery modules; and

[0100] After venting is complete, the battery module is resealed by the spring member, thereby preventing the risk of heat energy and flame being transferred from other battery modules.

[0101] Hereinafter, the explosion pressure of a battery module is defined as the minimum value of the internal pressure at which the battery module explodes.

[0102] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0103] [First embodiment]

[0104] Figure 5 is a perspective view showing a battery module provided with an elastic diaphragm at the top plate according to a first embodiment of the present invention. Figure 5 , a battery module 1 according to the present invention may include: a battery cell laminate; a frame 4 having an open upper portion and accommodating the battery cell laminate therein; and a top plate 3 covering the open upper portion of the frame 4; a spring member (not shown) applying pressure in a downward direction and fixing the top plate 3 so that the top plate 3 contacts the upper end of the side wall of the frame 4; and an expansion member 31, which is arranged at a portion of the top plate 3.

[0105] The frame 4 may have an opened upper portion, and specifically, may have a box shape with an opened upper portion.

[0106] The frame 4 may include a U-shaped frame 41 having an open front portion, an open rear portion, and an open upper portion, and a pair of end plates 42 coupled to the U-shaped frame 41 and covering the open front portion and the open rear portion of the U-shaped frame 41, respectively.

[0107] The U-shaped frame 41 may be made of various materials and by various methods. For example, the U-shaped frame may be made of a single metal plate that is plastically deformed into a U-shape by a press.

[0108] The end plate 42 and the U-shaped frame 41 may be coupled to each other in various ways. For example, the end plate 42 and the U-shaped frame 41 may be coupled to each other by welding or friction fitting.

[0109] The top plate 3 may cover an upper portion of the opening of the frame 4 .

[0110] The battery module 1 is sealed by the frame 4 and the top plate coupled to each other in a fully assembled state, thereby blocking the entry and exit of gas or flame between the inside and the outside, except in special circumstances.

[0111] The expansion member 31 may be provided as part of the top plate 3 .

[0112] The expansion member 31 may be coupled to the top plate 3 to cover and seal the hole provided at the top plate 3. Alternatively, the expansion member 31 may be integrally formed with the top plate 3.

[0113] The expansion member 31 may be made of a heat-resistant and / or fire-resistant material. For example, the expansion member 31 may be made of metal.

[0114] As the internal pressure of the battery module increases, the expansion member 31 may expand outward to expand the internal space of the battery module 1 .

[0115] One or more expansion members 31 may be provided.

[0116] The expansion member 31 may include an elastic diaphragm that expands outward as the internal pressure of the battery module 1 increases.

[0117] Figure 6 and Figure 7 1 and 2 are side sectional views respectively showing a battery module provided with an elastic diaphragm at the top plate before ignition and a battery module provided with an elastic diaphragm at the top plate after ignition according to the first embodiment of the present invention. Figure 6 and Figure 7, in the battery module 1 provided with the elastic diaphragm 31E, a large amount of exhaust gas is generated when the battery cell laminate is ignited and the internal temperature rises rapidly, resulting in an increase in the internal pressure of the battery module 1. Here, as the internal pressure increases, the elastic diaphragm 31E can expand to increase the internal space of the battery module 1. Since the pressure of the same amount of gas is inversely proportional to its volume, as the internal space of the battery module 1 expands as described above, the increase in the internal pressure of the battery module 1 due to the exhaust gas and heat energy can be prevented or delayed.

[0118] By preventing the internal pressure of the battery module 1 from increasing, the internal pressure of the battery module 1 may not reach its explosion pressure. Alternatively, by delaying the increase of the internal pressure of the battery module 1, the time taken until the internal pressure of the battery module 1 reaches the explosion pressure can be delayed.

[0119] In addition, when the elastic diaphragm 31E is provided at the top plate 3, the expansion direction is also directed upward, and even when the elastic diaphragm 31E is ruptured, flames, heat energy, and exhaust gas generated by the ignition can be discharged in the upward direction.

[0120] When the internal temperature and internal pressure of the battery module 1 decrease as the fire is extinguished, the elastic diaphragm 31E may contract and return to its original state.

[0121] [Second Embodiment]

[0122] Figure 8 2 is a perspective view showing a battery module provided with a reverse plate at the top plate according to a second embodiment of the present invention. Figure 8 The expansion member 31 may include a reverse disk 31R that is generally recessed toward the inside of the battery module 1 , and when the internal pressure of the battery module 1 is higher than the yield pressure, the reverse disk 31R yields and reversely protrudes outward.

[0123] For example, the reverse disk 31R may include a cup-shaped metal member having a peripheral portion, a recessed portion recessed in a first direction relative to the peripheral portion, and a protruding portion protruding in a second direction opposite to the first direction relative to the peripheral portion.

[0124] When a pressure greater than the yield pressure is applied to the protruding portion in the first direction, the reversing disk 31R is reversed so that the concave portion becomes a protruding portion protruding in the second direction relative to the peripheral portion, and the protruding portion becomes a concave portion protruding in the first direction relative to the peripheral portion. However, some portions of the reversing disk 31R may not be reversed.

[0125] The reverse disk 31R may include a reverse-acting bursting disk that reverses when the internal pressure is higher than the designed reverse pressure, and ruptures when the internal pressure is higher than the designed bursting pressure. Preferably, the reverse disk 31R may include a reverse-acting bursting disk that has a designed reverse pressure less than the explosion pressure of the battery module 1 and a designed rupture pressure greater than the explosion pressure. Here, the designed reverse pressure is equal to the yield pressure.

[0126] Fig. 9 and Fig.10 1 and 2 are side sectional views showing a battery module provided with a reverse plate at the top plate before ignition and a battery module provided with a reverse plate at the top plate after ignition, respectively. Fig. 9 and Fig.10 , in the battery module 1 provided with the reverse disk 31R, when the battery cell laminate is ignited, a large amount of exhaust gas is generated and the internal temperature rises rapidly, resulting in an increase in the internal pressure of the battery module 1. Here, when the internal pressure of the battery module 1 is higher than the yield pressure of the reverse disk 31R, the reverse disk 31R may expand by reversing and protruding outward to increase the internal space of the battery module 1. Since the pressure of the same amount of gas is inversely proportional to its volume, as the internal space of the battery module 1 expands as described above, the increase in the internal pressure of the battery module 1 due to the exhaust gas and heat energy may be prevented or delayed.

[0127] By preventing the internal pressure of the battery module 1 from increasing, the internal pressure of the battery module 1 may not reach its explosion pressure. Alternatively, by delaying the increase of the internal pressure of the battery module 1, the time period for the internal pressure of the battery module 1 to reach the explosion pressure can be extended.

[0128] In addition, when the reverse disc 31R is provided at the top plate 3, the expansion direction is also the upward direction, and even when the reverse disc 31R is ruptured, the flame, heat energy, and exhaust gas due to the ignition can be discharged in the upward direction.

[0129] [Third Embodiment]

[0130] Fig.11 2 is a perspective view showing a battery module provided with a reverse plate and a spring member according to a third embodiment of the present invention. Fig.11 , the battery module 1 according to the third embodiment of the present invention may include a spring member 32 that applies pressure to the top plate 3 in a downward direction to fix the top plate 3 so that the top plate 3 contacts the upper end of the side wall of the frame 4 to cover the upper portion of the opening of the frame 4.

[0131] One or more spring members 32 may be installed.

[0132] The spring member 32 may be a coil spring made of metal, but is not limited thereto.

[0133] The spring member 32 can be installed to be embedded in the upper end of the side wall of the frame. The embedded installation can be achieved by insert injection, or can be achieved by providing and assembling a separate member for fixing. Here, the upper end of the spring member 32 can be fixed to the top plate 3.

[0134] When the thickness of the side wall of the frame 4 is sufficient, the spring member 32 can be installed directly to be embedded in the upper end of the side wall, and when the thickness of the side wall of the frame 4 is insufficient, the spring member 32 can be installed to be embedded in the spring mounting portion 411 protruding inward from the upper end of the side wall.

[0135] As described above, by fixing both ends of the spring member 32 to the upper end of the side wall of the frame 4 and the top plate 3, respectively, when the top plate 3 moves away from the upper end of the side wall of the frame, the spring member 32 is tightened. Therefore, the spring member 32 can provide a restoring force to restore the top plate 3 toward the upper end of the side wall of the frame.

[0136] A compressible filler may be additionally installed at the upper end of the side wall of the frame 4 so that sealing between the space between the top plate 3 and the frame 4 is promoted by pressure applied by the spring member 32 .

[0137] Fig.12 and Fig.13 1 and 2 are side sectional views showing a battery module provided with a reverse plate and a spring member before ignition and a battery module provided with a reverse plate and a spring member after ignition, respectively. Fig.12 and Fig.13 , the maximum allowable pressure limit of the battery module 1 may be defined as the maximum value of the internal pressure of the battery module 1 that maintains the bonding between the top plate 3 and the frame 4 .

[0138] The spring member 32 may include a prestressed spring that is pre-tensioned or pre-compressed so as to have a predetermined restoring force even when the top plate 3 and the frame 4 are in full contact. Therefore, the maximum allowable pressure limit may be defined as the minimum value of the internal pressure that causes additional tension or compression in the spring member 32.

[0139] Alternatively, the top plate 3 and the frame 4 may be connected and coupled to each other by an additional fixing member in addition to the spring member 32. Here, the fixing member may be designed to be damaged under a load exceeding a predetermined level. Therefore, the maximum allowable pressure limit may be defined as the minimum value of the internal pressure of the battery module 1 that damages the fixing member.

[0140] The maximum allowable pressure limit may be set to be lower than the explosion pressure. Therefore, in the event of a fire in the battery module 1, the internal pressure of the battery module 1 reaches the maximum allowable pressure limit before reaching the explosion pressure, so that the top plate 3 is separated from the frame 4 and an opening is generated in the upward direction of the battery module 1. As a result, the flame, heat energy, and exhaust gas generated from the battery cell laminate are discharged in the upward direction, thereby reducing the internal pressure of the battery module 1.

[0141] In the battery module 1 according to the present embodiment, when the internal pressure of the battery module 1 increases due to the heat energy, flame and exhaust generated by the ignition of the battery cell laminate: the reverse disk 31R reverses at an internal pressure higher than the yield pressure of the reverse disk 31R to expand the internal space of the battery module 1, thereby reducing the internal pressure or delaying the increase in the internal pressure; although the reverse disk 31R reverses, as the internal pressure increases and exceeds the maximum allowable pressure limit, the top plate 3 and the frame 4 separate, thereby opening the upper part of the battery module 1 for exhaust; and as the internal pressure is reduced to below the maximum allowable pressure limit through exhaust, the top plate 3 and the frame 4 are reconnected by the spring member 32, thereby resealing the battery module 1.

[0142] [Fourth Embodiment]

[0143] Fig.14 2 is a perspective view showing a battery module provided with a reverse plate, a spring member and a spring shaft according to a fourth embodiment of the present invention. Fig.14 , instead of the spring member 32, the spring shaft 32A can be installed to be embedded in the upper end of the side wall of the frame. In this case, the embedded installation can also be achieved by inserting injection, or can be achieved by providing and assembling a separate member for fixing.

[0144] When the thickness of the side wall of the frame 4 is sufficient, the spring shaft 32A can be directly installed to be embedded in the upper end of the side wall, and when the thickness of the side wall of the frame 4 is insufficient, the spring shaft 32A can be installed to be embedded in the spring mounting portion 411 protruding inward from the upper end of the side wall.

[0145] The spring shaft 32A may be provided to vertically penetrate the top plate 3 .

[0146] A fixing end 322 capable of fixing the spring member 32 by having a radius greater than that of the spring member 32 may be provided at an upper end of the spring shaft 32A.

[0147] The spring member 32 may be installed so that the spring shaft 32A penetrates between the top plate 3 and the fixed end 322. That is, the spring member 32 may be installed in such a manner that the upper end of the spring member 32 contacts the fixed end 322, and the lower end of the spring member 32 contacts the top plate 3 so as to be vertically interposed between the fixed end 322 and the top plate 3.

[0148] As described above, by arranging the spring member 32 between the fixed end 322 at the upper end of the spring shaft 32A and the top plate 3, the top plate 3 is connected to the upper end of the side wall of the frame 4 and penetrated by the spring shaft 32A of the top plate 3, when the top plate 3 moves away from the upper end of the side wall of the frame 4, the spring member 32 is compressed to have a restoring force that pushes the top plate 3 toward the upper end of the side wall of the frame.

[0149] A compressible filler may be additionally installed at the upper end of the side wall of the frame 4 so that sealing between the space between the top plate 3 and the frame 4 is promoted by the pressure applied by the spring member 32 .

[0150] Fig.15 and Fig.16 1 are side sectional views respectively showing a battery module provided with a reverse plate, a spring member and a spring shaft before ignition and a battery module provided with a reverse plate, a spring member and a spring shaft after ignition according to a fourth embodiment of the present invention. Fig.15 and Fig.16 , the spring member 32 may include a prestressed spring that is pre-tensioned or pre-compressed so as to have a predetermined restoring force even when the top plate 3 and the frame 4 are in full contact. Therefore, the maximum allowable pressure limit may be defined as the minimum value of the internal pressure that causes additional tension or compression in the spring member 32.

[0151] Alternatively, the top plate 3 and the frame 4 may be connected and coupled to each other by an additional fixing member in addition to the spring member 32. Here, the fixing member may be designed to be damaged in the event of a load exceeding a predetermined level. Therefore, the maximum allowable pressure limit may be defined as the minimum value of the internal pressure of the battery module 1 that damages the fixing member.

[0152] The maximum allowable pressure limit may be set to be lower than the explosion pressure. Therefore, in the event of a fire in the battery module 1, the internal pressure of the battery module 1 reaches the maximum allowable pressure limit before reaching the explosion pressure, so that the top plate 3 is separated from the frame 4 and an opening is created in the upward direction of the battery module 1. As a result, the flame, heat energy, and exhaust gas generated from the battery cell laminate are discharged in the upward direction, thereby reducing the internal pressure of the battery module 1.

[0153] In the battery module 1 according to the present embodiment, when the internal pressure of the battery module 1 increases due to the heat energy, flame and exhaust generated by the ignition of the battery cell laminate: the reverse disk 31R reverses at an internal pressure higher than the yield pressure of the reverse disk 31R to expand the internal space of the battery module 1, thereby reducing the internal pressure or delaying the increase in the internal pressure; although the reverse disk 31R reverses, as the internal pressure increases and exceeds the maximum allowable pressure limit, the top plate 3 and the frame 4 separate, thereby opening the upper part of the battery module 1 for exhaust; and as the internal pressure is reduced to below the maximum allowable pressure limit through exhaust, the top plate 3 and the frame 4 are reconnected by the spring member 32, thereby resealing the battery module 1.

[0154] [Fifth Embodiment]

[0155] Fig.17 is a perspective view showing a battery module provided with a reverse plate, a spring member and a hinge according to a fifth embodiment of the present invention. Fig.17 , one edge of the top plate 3 and one edge of the upper end of the side wall of the frame 4 may be connected to each other by a hinge 412. Therefore, the top plate 3 may be rotatably opened and closed about the hinge 412 between the other edge of the top plate 3 and the other edge of the upper end of the side wall of the frame 4. Therefore, the stability of the opening and closing operations of the top plate 3 may be improved, and heat energy, flames, and exhaust gas generated in the event of a fire in the battery module 1 may be guided in an upward direction and then in a horizontal direction relative to the battery module 1.

[0156] Fig.18 and Fig.19 The figures are perspective views respectively showing a battery pack including a battery module according to the present invention and a vehicle including the battery pack. Fig.18 and Fig.19 , a plurality of battery modules 1 according to the present invention may be connected to each other in series or in parallel to manufacture a battery pack P having an increased voltage or charge and discharge capacity, and the battery pack P may be included in a vehicle V and used as a power source. Since these manufacturing methods of the battery pack P and the vehicle V are known to those skilled in the art, a detailed description thereof is omitted herein.

[0157] It should be understood that the described embodiments are illustrative and non-restrictive in all aspects, and the scope of the present invention will be indicated by the appended claims rather than the detailed description described. And the meaning and scope of the claims described later and all changes and modifications derived from equivalent concepts should be interpreted as included in the scope of the present invention.

[0158] The above describes the embodiments with reference to its multiple illustrative embodiments. However, the embodiments are not limited to the embodiments and drawings set forth herein, and those skilled in the art can draw many other modifications and embodiments within the technical scope of the present disclosure. In addition, although not explicitly described in the description of the embodiments, the effects and predictable effects based on the configurations in the present disclosure will be included within the scope of the present disclosure.

Claims

1. A battery module comprising a battery cell laminate, the battery module comprising: a frame having an open upper portion; a top plate coupled to the frame and covering an upper portion of the opening; a spring member that applies pressure in a downward direction and fixes the top plate in contact with the upper ends of the side walls of the frame; as well as an expansion member provided at a portion of the top plate, The expansion member can expand outwardly according to the internal pressure of the battery module to increase the internal space of the battery module.

2. The battery module according to claim 1, wherein: The expansion member includes an elastic diaphragm that expands outward as the internal pressure of the battery module increases.

3. The battery module according to claim 2, wherein: The maximum allowable pressure limit is less than the explosion pressure, the maximum allowable pressure limit is defined as the maximum value of the internal pressure of the battery module that maintains the connection between the top plate and the frame, and the explosion pressure is defined as the minimum value of the internal pressure that causes the battery module to explode.

4. The battery module according to claim 3, wherein: The spring member includes a prestressed spring which is pre-tensioned or pre-compressed to have a predetermined restoring force, and The maximum allowable pressure limit is defined as the minimum value of the internal pressure that causes additional tension or compression in the spring member to occur.

5. The battery module according to claim 3, wherein: The top plate and the frame are connected and coupled to each other by an additional fixing member in addition to the spring member, The fixing member is designed to fail under a load exceeding a predetermined level, and The maximum allowable pressure limit is defined as a minimum value of the internal pressure of the battery module at which the fixing member is damaged.

6. The battery module according to claim 1, wherein: The expansion member yields and protrudes outward when the internal pressure of the battery module is greater than a yield pressure.

7. The battery module according to claim 2, wherein: The maximum allowable pressure limit is greater than the yield pressure and less than the explosion pressure, and the maximum allowable pressure limit is defined as the maximum value of the internal pressure of the battery module that maintains the connection between the top plate and the frame, and the explosion pressure is defined as the minimum value of the internal pressure that causes the battery module to explode.

8. The battery module according to claim 7, wherein: The spring member includes a prestressed spring which is pre-tensioned or pre-compressed to have a predetermined restoring force, and The maximum allowable pressure limit is defined as the minimum value of the internal pressure that causes additional tension or compression in the spring member to occur.

9. The battery module according to claim 7, wherein: The top plate and the frame are connected and coupled to each other by an additional fixing member in addition to the spring member, The fixing member is designed to fail under a load exceeding a predetermined level, and The maximum allowable pressure limit is defined as a minimum value of the internal pressure of the battery module at which the fixing member is damaged.

10. The battery module according to any one of claims 1 to 9, wherein: The spring member is installed to be embedded in the upper end of the side wall of the frame, thereby fixing the top plate by applying a tensile pressure toward the upper end of the side wall of the frame.

11. The battery module according to any one of claims 1 to 9, further comprising a spring shaft extending from the side wall of the frame through the top plate in an upward direction, in, A spring fixing end for fixing the spring member is provided at the upper end of the spring shaft, and The spring member is installed between the spring fixing end and the top plate to fix the top plate by applying a compressive pressure toward the upper end of the side wall of the frame.

12. The battery module according to claim 10, wherein: One edge of the top plate and one edge of the upper end of the side wall of the frame are connected to each other by a hinge, thereby enabling an opening to be provided between the other edge of the top plate and the other edge of the upper end of the side wall of the frame.

13. The battery module according to claim 11, wherein: One edge of the top plate and one edge of the upper end of the side wall of the frame are connected to each other by a hinge, thereby enabling an opening to be provided between the other edge of the top plate and the other edge of the upper end of the side wall of the frame.

14. A battery pack comprising the battery module according to any one of claims 1 to 9.

15. A vehicle comprising the battery pack according to claim 14.

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