Battery module

Abstract

The present invention discloses a battery module. The battery module of the present invention comprises: a housing having a plurality of battery cells accommodated therein and a vent hole portion formed therein; a top cover movably installed in the housing to open and close the vent hole portion; an elastic member installed to apply elastic force to the top cover in a direction in which the top cover opens the vent hole portion; and a stopper that supports the top cover to maintain the state in which the top cover closes the vent hole portion and loses the supporting force of the top cover due to a change in temperature or pressure.

Description

Technology Field

[0001] The present invention relates to a battery module capable of improving thermal energy discharge performance, suppressing an increase in internal pressure, and reducing the possibility of ignition. Background Technology

[0002] Generally, secondary batteries consist of a positive electrode, a negative electrode, and an electrolyte, and generate electrical energy through chemical reactions. The use of secondary batteries is gradually increasing due to their advantage of being rechargeable and dischargeable. Among these secondary batteries, lithium-ion batteries are widely used as power sources for electronic communication devices or as driving forces for high-output hybrid and electric vehicles, as they possess a high energy density per unit weight.

[0003] In terms of battery shape, there is increasing demand for prismatic and pouch-type batteries, which can be applied to products such as mobile phones due to their thin profiles. Regarding battery materials, there is growing demand for lithium-ion batteries, such as lithium-ion polymer batteries, which offer high energy density, discharge voltage, and output stability.

[0004] A battery module of a secondary battery contains multiple pouch cells embedded inside a housing. The pouch cells are formed with a structure in which an electrode stack is sealed inside the pouch. Electrode leads are connected to the electrode stack, and the electrode leads protrude outside the pouch. Multiple busbars are secured to the front and rear sides of the housing, and two or more electrode leads are welded to each busbar. The multiple busbars are arranged in a line on the front and rear sides of the housing.

[0005] Multiple battery modules may be installed in vehicles or large equipment. Since a battery module contains multiple pouch cells within a housing, if some pouch cells overheat or ignite, other pouch cells within the housing may also ignite or explode in a chain reaction. To delay or prevent such ignition or explosion of the battery module, insulation may be interposed between the pouch cells. Additionally, various cooling structures may be applied to suppress the overheating of the pouch cells.

[0006] However, conventional battery modules are manufactured with a structure that is almost completely sealed and surrounded by a housing. Consequently, if some of the pouch cells embedded in the housing overheat or ignite, it is difficult to dissipate thermal energy, which can lead to rapid ignition or explosion of the battery module. Additionally, as the rate at which the pressure inside the housing rises accelerates, the explosion of the battery module can occur relatively quickly.

[0007] The background technology of the present invention is disclosed in Korean Published Patent Application No. 2020-0030964 (published on March 23, 2020; Title of Invention: Battery Module Including Heat-Shrinkable Tube). The battery module improves cooling efficiency by applying a heat-shrinkable tube and a heat sink, which serve as a module housing, to the battery module. However, since this battery module also has a structure in which the housing seals the battery module, there may be limitations in delaying overheating or ignition of the pouch cell inside the housing. The problem to be solved

[0008] The present invention was devised to solve the aforementioned problems and aims to provide a battery module capable of improving the thermal energy discharge performance.

[0009] The present invention aims to provide a battery module capable of suppressing an increase in internal pressure.

[0010] The present invention aims to provide a battery module capable of reducing the possibility of ignition.

[0011] The technical problems of the present invention are not limited to the purposes mentioned above, and other unmentioned purposes and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0012] To solve the above-mentioned problem, the battery module of the present invention comprises: a housing in which a plurality of battery cells are accommodated and a vent hole portion is formed; a top cover movably installed in the housing to open and close the vent hole portion; an elastic member installed to apply elastic force to the top cover in a direction in which the top cover opens the vent hole portion; and a stopper that supports the top cover to maintain the state in which the top cover closes the vent hole portion and loses the supporting force of the top cover due to a change in temperature or pressure.

[0013] The above vent hole portion may be formed on the upper surface or side of the housing.

[0014] The top cover can be slidably installed on the upper surface or side of the housing.

[0015] The above stopper may be formed of a material that undergoes thermal decomposition at temperatures above a preset temperature, thereby reducing its rigidity.

[0016] The above stopper may be formed of a material that melts at a preset temperature or higher, thereby reducing its rigidity.

[0017] The elastic force applied by the above elastic member to the top cover may decrease as the top cover is opened.

[0018] The elastic member is installed in an extended state on the top cover and the housing, and the stopper can support the top cover to prevent the elastic member from contracting.

[0019] A pair of the above top covers may be installed so as to slide in opposite directions along the longitudinal direction of the housing.

[0020] A pair of the above elastic members may be installed to apply elastic force to each of the pair of top covers.

[0021] One or a pair of the top covers are installed so as to be movable along the longitudinal direction of the housing, and the elastic members may be arranged parallel to the longitudinal direction of the housing.

[0022] The top cover is installed to be movable along the width direction of the housing, and the elastic member can be arranged parallel to the width direction of the housing. Effects of the invention

[0023] According to the present invention, when the internal temperature of the housing exceeds a set temperature or a set pressure, the contraction force of the elastic member increases more than the stiffness of the stopper. Accordingly, since the stopper loses its support force for the top cover, the elastic member can move the top cover to open the vent hole.

[0024] According to the present invention, since the top cover is moved to open the vent hole portion by the elastic force of the elastic member, it is possible to delay the increase in temperature or pressure caused by the battery cell overheating or ignition.

[0025] According to the present invention, when a battery cell ignites, the vent hole is opened, allowing thermal energy or flames inside the housing to be rapidly discharged to the outside.

[0026] According to the present invention, the rapid increase in temperature or pressure inside the housing can be suppressed, and the explosion of the battery module can be delayed.

[0027] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0028] FIG. 1 is a schematic perspective view illustrating a first embodiment of a battery module according to the present invention. FIG. 2 is a cross-sectional view schematically illustrating the battery module of FIG. 1. FIG. 3 is a schematic perspective view illustrating the state in which the top cover of the battery module of FIG. 1 is moved to open the vent hole portion. FIG. 4 is a cross-sectional view schematically illustrating the state in which the top cover of the battery module of FIG. 1 is moved to open the vent hole portion. FIG. 5 is a cross-sectional view schematically illustrating a second embodiment of a battery module according to the present invention. FIG. 6 is a schematic perspective view illustrating a third embodiment of a battery module according to the present invention. FIG. 7 is a cross-sectional view schematically illustrating a third embodiment of the battery module of FIG. 6. Specific details for implementing the invention

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0030] The present invention is not limited to the embodiments disclosed below, but can be modified and implemented in various different forms. The embodiments provided are merely intended to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Accordingly, the present invention should be understood not to be limited to the embodiments disclosed below, but to include all modifications, equivalents, and substitutions that fall within the technical spirit and scope of the present invention, as well as substituting or adding the configuration of any one embodiment with the configuration of another embodiment.

[0031] The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; rather, it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention. In the drawings, components may be depicted as being exaggeratedly large or small in size or thickness for the sake of convenience of understanding, but the scope of protection of the invention should not be interpreted restrictively as a result thereof.

[0032] The terms used in this specification are used merely to describe specific embodiments or examples and are not intended to limit the invention. Furthermore, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "includes" or "consists of" in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this specification. That is, terms such as "includes" or "consists of" in this specification should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0033] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0034] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0035] When it is stated that one component is "above" or "below" another component, it should be understood that it is not only placed directly above the other component, but that another component may also exist in between.

[0036] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0037] Hereinafter, a first embodiment of a battery module according to an embodiment of the present invention will be described.

[0038] FIG. 1 is a perspective view schematically illustrating a first embodiment of a battery module according to the present invention, FIG. 2 is a cross-sectional view schematically illustrating the battery module of FIG. 1, FIG. 3 is a perspective view schematically illustrating a state in which the top cover of the battery module of FIG. 1 is moved to open the vent hole portion, and FIG. 4 is a cross-sectional view schematically illustrating a state in which the top cover of the battery module of FIG. 1 is moved to open the vent hole portion.

[0039] Referring to FIGS. 1 to 4, a battery module (100) according to the first embodiment of the present invention includes a housing (120), a top cover (130), an elastic member (140), and a stopper (150).

[0040] A housing (120) accommodates a plurality of battery cells (110) inside it and forms a vent hole portion (123). The housing (120) may be formed of a non-conductive synthetic resin material. The housing (120) may be formed in the shape of a rectangular parallelepiped. FIG. 2 is a cross-sectional view of a battery module (100) cut in the longitudinal direction.

[0041] The vent hole portion (123) can be formed in the housing (120) in various shapes, such as a rectangular shape, an elongated shape, or a rounded shape. The size of the vent hole portion (123) can be varied depending on the size of the housing (120), the capacity of the battery module (100), etc.

[0042] The battery cell (110) may be structured such that an electrode stack (not shown) is accommodated inside a pouch (not shown). For example, the electrode stack may be formed by sequentially stacking a negative electrode, a separator, a positive electrode, and a separator. Additionally, an electrolyte is accommodated inside the battery cell (110). Electrode leads (112) protrude from both sides of a plurality of battery cells (110), and the plurality of electrode leads (112) are connected to a busbar (not shown). A plurality of battery cells (110) may be arranged in a line with slight spacing between them.

[0043] An insulating panel (not shown) may be interposed between multiple battery cells (110). The insulating panel blocks heat transfer to adjacent battery cells (110) and delays the ignition time. Additionally, an insulating cover (not shown) may be installed to wrap around the outer surface (122) of the battery cells (110). The insulating panel or the insulating cover may be made of a polyimide film.

[0044] A top cover (130) is movably installed on the housing (120) to open and close the vent hole portion (123). The top cover (130) is formed larger than the vent hole portion (123) to cover the entire vent hole portion (123). The top cover (130) may be formed in the shape of a square plate, or in a shape that covers a portion of the upper surface (121) and side surface (122) of the housing (120). The top cover (130) may be formed from a non-conductive synthetic resin material. Such a top cover (130) may be formed in various shapes as long as it covers the vent hole portion (123). A separate sealing member (not shown) may be installed between the top cover (130) and the housing (120) to seal the inside of the housing (120).

[0045] The elastic member (140) is installed to apply elastic force to the top cover (130) in a direction that causes the top cover (130) to open the vent hole portion (123). Accordingly, the direction of the elastic member (140) may change depending on the direction in which the top cover (130) opens. A coil spring capable of extending in the longitudinal direction may be applied as this elastic member (140).

[0046] The stopper (150) supports the top cover (130) to maintain the state in which the top cover (130) has the vent hole portion (123) closed, and loses its supporting power due to changes in temperature or pressure. One end of the stopper (150) is fixed to the top cover (130), and the other end of the stopper (150) is fixed to the housing (120). The stopper (150) has a stiffness greater than the elastic force of the elastic member (140) when the temperature is below a preset temperature and pressure is below a preset pressure. On the other hand, when the temperature is above a preset temperature and pressure is above a preset pressure, the stopper (150) deforms and its stiffness becomes less than the elastic force of the elastic member (140). The temperature or pressure at which the stopper (150) loses its supporting power of the top cover (130) can be varied depending on the material, thickness, and shape of the stopper (150). Additionally, the elastic modulus of the elastic member (140) can be set based on the temperature or pressure at which the stopper (150) loses its support force.

[0047] A portion of the stopper (150) is supported by a supporter portion (125) that constitutes a portion of the housing (120). The supporter portion (125) supports the lower surface of the stopper (150) to prevent the stopper (150) from sagging. Additionally, the supporter portion (125) can minimize the vibration of the elastic member (140) by external force during vehicle operation.

[0048] As described above, when the internal temperature of the housing (120) exceeds the set temperature or the set pressure, the contraction force of the elastic member (140) increases more than the rigidity of the stopper (150). At this time, the top cover (130) is moved to open the vent hole portion (123) by the elastic force of the elastic member (140). Accordingly, if the temperature or pressure increases due to the battery cell (110) overheating or igniting inside the housing (120), the heat energy or flame inside the housing (120) can be rapidly discharged to the outside as the vent hole portion (123) opens. In addition, the rapid increase in temperature or pressure inside the housing (120) can be suppressed, and the explosion time of the battery module (100) can be extended.

[0049] A vent hole portion (123) is formed on the upper surface (121) or side surface (122) of the housing (120), and a top cover (130) is slidably installed on the upper surface (121) or side surface (122) of the housing (120). Of course, the vent hole portion (123) and the top cover (130) may also be positioned on the lower surface of the housing (120). The positions of the vent hole portion (123) and the top cover (130) may be appropriately changed to account for the possibility of injury to the driver when heat energy or flames are discharged. Of course, the positions of the vent hole portion (123) and the top cover (130) may also be appropriately designed to account for the possibility of damage to the vehicle, the installation location of the battery module (100), etc.

[0050] The stopper (150) may be formed of a material that undergoes thermal decomposition at a temperature above a preset temperature, thereby reducing its rigidity. For example, a lithium polymer battery module (100) typically explodes at approximately 170°C, and a lithium-ion battery module (100) typically explodes at approximately 187°C. Polyvinyl resin, polypropylene resin, and polyethylene resin undergo thermal changes at temperatures significantly lower than the explosion temperature. Therefore, polyvinyl resin, polypropylene resin, polyethylene resin, etc., may be used as the material for the stopper (150). Additionally, the elastic modulus of the elastic member (140) may be set based on the reduced rigidity at the thermal decomposition temperature of the stopper (150).

[0051] Additionally, the stopper (150) may be formed of a material that melts at a preset temperature or higher, thereby reducing its rigidity. Even if the stopper (150) melts at a preset temperature or higher, the elastic member (140) can move the top cover (130). Therefore, the material of the stopper (150) is sufficient if it melts at a preset temperature or higher, and it does not need to be a synthetic resin material.

[0052] The elastic force applied by the elastic member (140) to the top cover (130) decreases as the top cover (130) opens. That is, when the top cover (130) closes the vent hole portion (123), the elastic member (140) is extended to its longest length, so the elastic force of the elastic member (140) is at its greatest. On the other hand, as the top cover (130) opens, the length of the elastic member (140) gradually shortens, so the elastic force of the elastic member (140) gradually decreases.

[0053] When the interior of the housing (120) is below a preset temperature or pressure, the elastic member (140) is installed in an extended state on the top cover (130) and the housing (120), and the stopper (150) supports the top cover (130) to prevent the elastic member (140) from contracting. However, when the interior of the housing (120) becomes above a preset temperature or pressure, the elastic member (140) contracts as the stopper (150) contracts or deforms, thereby moving the top cover (130).

[0054] A pair of top covers (130) are installed to slide in opposite directions along the longitudinal direction of the housing (120). At this time, a pair of elastic members (140) are installed to apply elastic force to each of the pair of top covers (130). Additionally, at this time, the elastic members (140) are each installed to support the top cover (130) between each top cover (130) and the stopper (150). Accordingly, the vent hole portion (123) formed in the housing (120) can be formed larger. Furthermore, this structure can be applied as the size of the battery module (100) increases.

[0055] FIG. 5 is a cross-sectional view schematically illustrating a second embodiment of a battery module according to the present invention.

[0056] Since the second embodiment is substantially identical to the first embodiment except for the configuration in which a top cover is installed, the same reference numerals are assigned to identical components, and their descriptions are omitted.

[0057] Referring to FIG. 5, a top cover (130) is installed so as to be movable along the longitudinal direction of the housing (120), and an elastic member (140) may be arranged parallel to the longitudinal direction of the housing (120). At this time, the elastic member (140) is installed to support the top cover (130) between the top cover (130) and the stopper (150). A battery module (100) with this structure can be applied to a structure in which the surrounding structure of the battery module (100) blocks one side of the longitudinal direction of the housing (120) or the top cover (130) can be opened in only one direction. Additionally, the battery module (100) can be applied to a form in which the size of the vent hole portion (123) is small.

[0058] FIG. 6 is a perspective view schematically illustrating a third embodiment of a battery module according to the present invention, and FIG. 7 is a cross-sectional view schematically illustrating a third embodiment of the battery module of FIG. 6.

[0059] Since the third embodiment is substantially identical to the first embodiment except for the configuration in which the top cover moves in the width direction of the housing, the same reference numerals are assigned to identical configurations and their descriptions are omitted.

[0060] Referring to FIGS. 6 and 7, the top cover (130) is installed to be movable along the width direction of the housing (120), and the elastic member (140) is arranged parallel to the width direction of the housing (120). At this time, two top covers (130) may be installed or one may be installed so as to be movable along the width direction of the housing. A battery module (100) with this structure can be applied to a structure in which the surrounding structure of the battery module (100) blocks one side of the width direction of the housing (120) or the top cover (130) can be opened in only one direction. Additionally, the battery module (100) can be applied to a form in which the size of the vent hole portion (123) is small.

[0061] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized. Explanation of the symbols

[0062] 100: Battery module 110: Battery cell 112: Electrode lead 120: Housing 121: Top surface 122: Side 123: Vent Hall 125: Supporter Department 130: Top cover 132: Fixed part 140: Elastic member 150: Stopper

Claims

Claim 1 A battery module comprising: a housing having a plurality of battery cells accommodated therein and a vent hole formed therein; a top cover movably installed in the housing to open and close the vent hole; an elastic member installed to apply elastic force to the top cover in a direction in which the top cover opens the vent hole; and a stopper that supports the top cover to maintain the state in which the top cover closes the vent hole and loses the supporting force of the top cover due to a change in temperature or pressure; wherein a pair of top covers are installed to slide in opposite directions along the longitudinal direction of the housing. Claim 2 A battery module according to claim 1, wherein a pair of elastic members are installed to apply elastic force to each of the pair of top covers. Claim 3 A battery module comprising: a housing having a plurality of battery cells accommodated therein and a vent hole formed therein; a top cover movably installed in the housing to open and close the vent hole; an elastic member installed to apply elastic force to the top cover in a direction in which the top cover opens the vent hole; and a stopper that supports the top cover to maintain the state in which the top cover closes the vent hole and loses the supporting force of the top cover due to a change in temperature; wherein the stopper pyrolyzes or melts at a temperature above a preset temperature. Claim 4 A battery module according to any one of claims 1 to 3, wherein the vent hole portion is formed on the upper surface or side of the housing, and the top cover is slidably installed on the upper surface or side of the housing. Claim 5 A battery module according to any one of claims 1 to 3, wherein the elastic force applied by the elastic member to the top cover decreases as the top cover is opened. Claim 6 A battery module according to any one of claims 1 to 3, wherein the elastic member is installed in an extended state on the top cover and the housing, and the stopper supports the top cover to prevent the elastic member from contracting. Claim 7 delete Claim 8 delete Claim 9 A battery module according to any one of claims 1 to 3, wherein a pair of top covers are installed so as to be movable along the longitudinal direction of the housing, and the elastic member is arranged parallel to the longitudinal direction of the housing. Claim 10 A battery module according to paragraph 3, wherein the top cover is installed to be movable along the width direction of the housing, and the elastic member is arranged parallel to the width direction of the housing.

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