Battery pack and vehicle including same

Abstract

A battery pack according to the present invention comprises: a pack case having an accommodation space in which multiple battery cells are accommodated and an opening formed at one side thereof; a pack lead covering the opening; a partition frame which is coupled to the pack case so as to partition the accommodation space; a first fastening member having at least a portion extending through the pack lead and coupled to the partition frame; and a second fastening member fixed to the partition frame and having the first fastening member fastened thereto, wherein the second fastening member includes at least one reinforcing member protruding in a direction different from a penetration direction of the first fastening member to allow the second fastening member to be caught by the partition frame, and at least a portion of the second fastening member is made of a material having properties changed in a predetermined high temperature environment to weaken a coupling force between the first fastening member and the partition frame.

Description

Battery pack and vehicle including same

[0001] The present invention relates to a battery pack, and more particularly, to a battery pack in which a pack lead swells in response to increased internal pressure when a thermal event occurs in the battery pack, thereby reducing the internal pressure of the battery pack or reducing the rate of increase in internal pressure and delaying heat transfer.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0047646, filed April 8, 2024, the entire disclosure of which is incorporated herein by reference.

[0003] A semi-permanent battery that converts electrical energy into chemical energy and can be repeatedly charged and discharged is called a secondary battery, to distinguish it from a primary battery that cannot be reused after a single use.

[0004] In particular, lithium-ion secondary batteries have been actively utilized as electric vehicle batteries recently due to their high energy storage density, lightweight and miniaturized design, excellent safety, low discharge rate, and long lifespan. Lithium-ion secondary batteries are generally classified into cylindrical, prismatic, and pouch types depending on their manufacturing form. Their applications are diverse, encompassing not only electric vehicle batteries but also energy storage system (ESS) batteries and other electrical devices.

[0005] Currently, the operating voltage of a single lithium-ion secondary battery cell is approximately 2.5 V to 4.5 V. Therefore, in order to apply a secondary battery as an energy source for an electric vehicle, a battery module is formed by connecting multiple lithium-ion secondary battery cells in series and / or parallel, and a battery pack is formed by connecting the battery modules in series and / or parallel.

[0006] Meanwhile, secondary batteries undergo chemical reactions during charging and discharging, which can lead to performance degradation if used in environments above their optimal temperature. Furthermore, if thermal control fails to maintain optimal temperatures, there's a constant risk of unexpected fire or explosion. Furthermore, battery packs, which are a collection of secondary batteries, are structured to house these batteries as tightly as possible within the pack case, making them vulnerable to thermal events.

[0007] Accordingly, if a thermal event such as overheating or thermal runaway occurs in a specific battery module, the internal pressure within the battery pack increases due to venting gases and flames generated from the battery module where the event occurred, accelerating the accumulation of thermal energy and easily causing thermal propagation to adjacent battery modules. This can lead to a problem of cascading thermal runaway of battery modules and explosion of the entire battery pack.

[0008] Accordingly, it is necessary to improve the structure of the battery pack to lower the internal pressure increased inside the battery pack due to venting gas and flames generated from thermal events in the first ignited battery module, and to effectively disperse the thermal energy, thereby delaying the thermal transfer phenomenon that propagates chain reaction to neighboring battery modules.

[0009] The present invention was created in consideration of the above-described problems, and has as its primary purpose the provision of a battery pack having further enhanced structural rigidity and an automobile including the same.

[0010] In addition, another object of the present invention is to provide a battery pack having reinforced fixing force between a second fastening member and a partition frame and a vehicle including the same.

[0011] In addition, another object of the present invention is to provide a battery pack and a vehicle including the same that can effectively prevent a heat transfer phenomenon when a thermal event occurs inside the battery pack.

[0012] In addition, another object of the present invention is to provide a battery pack and a vehicle including the same, which improve the assemblability and productivity of the pack case.

[0013] Another purpose is to provide a battery pack with improved structural stability and a vehicle including the same.

[0014] In addition, another object of the present invention is to provide a battery pack and a vehicle including the same, which can effectively prevent heat transfer by preventing the inflow of oxygen and the emission of flame.

[0015] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0016] A battery pack according to the present invention comprises: a pack case having a space for accommodating a plurality of battery cells therein and an opening formed at one side thereof; a pack lid covering the opening; a partition frame coupled to the pack case to partition the space; a first fastening member at least partially penetrating the pack lid and coupled to the partition frame; and a second fastening member fixedly disposed on the partition frame and fastened to the first fastening member, wherein the second fastening member has at least one reinforcing member protruding in a direction different from a penetrating direction of the first fastening member so as to allow the second fastening member to be caught on the partition frame, and at least a portion of the second fastening member is made of a material whose properties change in a predetermined high-temperature environment to weaken a bonding force between the first fastening member and the partition frame.

[0017] The above pack lead may be configured to swell when the internal pressure of the receiving space increases.

[0018] The first fastening member may be formed to penetrate the pack lead in a vertical direction, and the reinforcing member may be formed to protrude in a horizontal direction.

[0019] The above reinforcing member may be composed of a material comprising one or more of resin, ceramic, and cement, or a composite of two or more of them.

[0020] The second fastening member has an insertion portion into which an end of the first fastening member is inserted, and the reinforcing member can be connected to the insertion portion.

[0021] The above reinforcing member can be formed integrally with the insertion portion.

[0022] The partition frame may have a recessed portion formed in a shape corresponding to the second fastening member, and the second fastening member may be fixedly positioned in the recessed portion.

[0023] The above reinforcing member can be placed through the partition frame.

[0024] The above reinforcing member may be provided in multiple pieces.

[0025] The above reinforcing member can be formed by extending it in a column shape.

[0026] The above reinforcing member can be formed into a plate shape.

[0027] The second fastening member is formed by hardening the insert material after the insert material is injected into the partition frame, and the first fastening member is inserted into the insert material before the insert material is hardened, and can then be fastened to the second fastening member as the insert material is hardened.

[0028] It may further include an intermediate member disposed between the pack lead and the second fastening member and through which the first fastening member passes.

[0029] The above intermediate member can be in close contact with the pack lead and the second fastening member.

[0030] The above intermediate member may be configured as a joint nut having a female thread formed on the inside and at least a portion of which is joined to the pack lead.

[0031] A sealing member may be further placed between the pack lead and the first fastening member to seal them.

[0032] A vehicle according to the present invention comprises at least one battery pack according to the present invention.

[0033] According to the present invention, a battery pack and a vehicle including the same can be provided, the structural rigidity of which is further strengthened by the first fastening member and the second fastening member.

[0034] In addition, according to the present invention, a battery pack and a vehicle including the same can be provided in which the bonding force between the first fastening member and the partition frame and the fixing force between the second fastening member and the partition frame are reinforced by a reinforcing member.

[0035] In addition, according to the present invention, a battery pack and a vehicle including the same can be provided that can effectively prevent a heat transfer phenomenon by weakening the bonding force between the first fastening member and the partition frame when a thermal event occurs inside the battery pack.

[0036] In addition, according to the present invention, a battery pack and a vehicle including the same can be provided, which can effectively prevent a heat transfer phenomenon by causing a pack lead to swell when a thermal event occurs inside the battery pack.

[0037] In addition, according to the present invention, a battery pack and an automobile including the same can be provided in which the assembling ability and productivity of the pack case are improved by the first fastening member and the second fastening member.

[0038] In addition, according to the present invention, a battery pack and a vehicle including the same can be provided, in which assembly and productivity are further improved and structural stability is improved by the intermediate member.

[0039] In addition, according to the present invention, a battery pack and a vehicle including the same can be provided that can effectively prevent heat transfer by preventing the inflow of oxygen and the emission of flame by a sealing member.

[0040] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0041] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0042] FIG. 1 is a perspective view showing the overall appearance of a battery pack according to one embodiment of the present invention.

[0043] Figure 2 is a perspective view showing the battery pack of Figure 1 in an exploded state.

[0044] FIG. 3 is a side cross-sectional view showing a first fastening member and a second fastening member combined in a battery pack according to one embodiment of the present invention.

[0045] FIG. 4 is a perspective view showing the first fastening member and the second fastening member in an exploded state in a battery pack according to one embodiment of the present invention.

[0046] FIG. 5 is a flowchart showing a process of fastening a first fastening member and a second fastening member in a battery pack according to one embodiment of the present invention.

[0047] Figure 6 is a cross-sectional view taken along line AA' of Figure 1.

[0048] Figure 7 is a cross-sectional side view showing the pack lead inflated in Figure 6.

[0049] FIG. 8 is a perspective view illustrating a second fastening member of a battery pack according to another embodiment of the present invention.

[0050] FIG. 9 is a perspective view illustrating a second fastening member of a battery pack according to another embodiment of the present invention.

[0051] FIG. 10 is a side cross-sectional view illustrating a battery pack according to one embodiment of the present invention in which an intermediate member is further arranged between the first fastening member and the second fastening member.

[0052] FIG. 11 is a side cross-sectional view illustrating a sealing member further arranged on a first fastening member and a second fastening member in a battery pack according to one embodiment of the present invention.

[0053] FIG. 12 is a drawing showing a vehicle according to one embodiment of the present invention.

[0054] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention, they should be interpreted in a way that conforms to the technical spirit of the present invention.

[0055] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0056]

[0057] FIG. 1 is a perspective view showing the overall appearance of a battery pack according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the battery pack of FIG. 1, FIG. 3 is a side cross-sectional view showing a state in which a first fastening member and a second fastening member are combined in a battery pack according to one embodiment of the present invention, and FIG. 4 is a perspective view showing a state in which the first fastening member and the second fastening member are exploded in a battery pack according to one embodiment of the present invention.

[0058] Hereinafter, a battery pack (10) according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. The battery pack (10) according to an embodiment of the present invention includes a pack case (200), a pack lid (lid, 300), a partition frame (210), a first fastening member (400), and a second fastening member (500).

[0059] A receiving space (S) and an opening (O) are formed in the pack case (200). A plurality of battery cells (100) are received in the receiving space (S). The battery cell (100) may be understood as a secondary battery including an electrode assembly, an electrolyte, and a pouch case that receives the electrode assembly. In the present embodiment, a pouch-type battery cell (100) having a high energy density and easy stacking is used, but the present invention is not limited thereto, and it is obvious that a cylindrical or square secondary battery may be applied as the battery cell (100).

[0060] A pouch-type battery cell (100) may include a pair of electrode leads that are connected to an electrode assembly and extend outward from the pouch case and function as electrode terminals. Such a battery cell (100) may further be equipped with electrical components such as a busbar, a busbar frame, and a module connector adjacent to the pair of electrode leads.

[0061] In the accommodation space (S) of the pack case (200), the battery cells (100) may be accommodated as battery modules in module units. In this case, the battery module may include a module case. At least one battery cell (100) may be accommodated in the module case. The module case may be made of a metal material with high rigidity and durability or a plastic material such as ABS resin to physically or chemically protect the accommodated battery cells (100). A terminal of the battery module may be provided on a side of the module case. The terminal may be either a positive or negative terminal, and may be arranged on both sides or one side of the module case.

[0062] The receiving space (S) is formed on the inside of the pack case (200). The pack case (200) includes a bottom portion (201) and a side wall portion (202) surrounding the bottom portion (201), and the bottom portion (201) and the side wall portion (202) form a receiving space (S) on the inside.

[0063] A partition frame (210) is coupled to the pack case (200). The partition frame (210) is coupled to the pack case (200) to partition a receiving space (S). The partition frame (210) may be arranged across the receiving space (S). The partition frame (210) may include a horizontal frame (211) and a vertical frame (212). The horizontal frame (211) may be formed to extend in the Y direction and partition the receiving space (S) along the X direction. The vertical frame (212) may be formed to extend in the X direction and partition the receiving space (S) along the Y direction. In the embodiment of the present invention, the pack case (200) is illustrated as having two horizontal frames (211) and one vertical frame (212), but the number of horizontal frames (211) and vertical frames (212) or the number of battery cells (100) accommodated are not limited thereto and may vary. The horizontal frame (211) or the vertical frame (212) may also be referred to as a cross beam or a center beam.

[0064] In order to withstand the load of the battery cell (100) and protect the battery cell (100) from external force, the pack case (200) and the partition frame (210) may be made of a metal material such as steel or aluminum.

[0065] An opening (O) is formed on one side of the pack case (200). As in the illustrated example, the opening (O) may be formed on the upper side of the pack case (200). A pack lid (300) is arranged in the opening (O). The pack lid (300) is arranged to cover the opening (O). The pack lid (300) may cover the receiving space (S) of the pack case (200) to block the receiving space (S) from the outside. The pack lid (300) may be provided in a shape corresponding to the shape of the opening (O). For example, when the opening (O) has a rectangular shape, the pack lid (300) may also be provided in a rectangular shape. The pack lid (300) may be provided in a shape slightly larger than the opening (O) so as to cover the edge of the opening (O). The pack lid (300) may be provided in a thin plate shape. For example, the pack lid (300) may be provided in the form of a thin rectangular plate. The pack lid (300) may be made of a metal material, such as aluminum, identical or similar to the pack case (200) and the partition frame (210). As another example, the pack lid (300) may be provided of a material capable of elastic deformation or plastic deformation by an external force.

[0066] The first fastening member (400) is configured such that at least a portion of it penetrates the pack lead (300) and is coupled to the partition frame (210). A plurality of first fastening members (400) may be provided. The direction in which the first fastening members (400) penetrate may be formed parallel to the Z direction. The first fastening member (400) may be coupled to the partition frame (210) by being coupled to the second fastening member (500).

[0067] The first fastening member (400) may be provided in a form in which at least a portion thereof is extended toward one end, and at least a portion of the one end thereof may penetrate the pack lead (300). The first fastening member (400) may be provided as a bolt. In this case, the first fastening member (400) may include a screw portion (410) having a male screw portion formed therein and a head portion (420) having a head formed therein, and the screw portion (410) may penetrate the pack lead (300). The first fastening member (400) may be made of a metal material such as steel / SUS. Such a material is resistant to high temperatures, has excellent rigidity, and can secure a high fastening force.

[0068] A through hole (310) may be formed in the pack lid (300) so that the first fastening member (400) may pass through it. The through holes (310) may be formed in a corresponding number at positions corresponding to the first fastening member (400). The first fastening member (400) may be provided as a bolt. When the first fastening member (400) is provided as a bolt, the through hole (310) does not have a female thread, so that the screw portion (410) of the first fastening member (400) can simply pass through the through hole (310), and the head portion (420) may be positioned on the upper side of the pack lid (300) without passing through the through hole (310).

[0069] The second fastening member (500) is fixedly arranged on the partition frame (210) and is configured to be fastened to the first fastening member (400). The second fastening members (500) may be arranged in a corresponding number at positions corresponding to the first fastening members (400). A plurality of second fastening members (500) may be arranged spaced apart from each other. The interval between a pair of adjacent second fastening members (500) may be formed differently from the interval between another pair of adjacent second fastening members (500). The second fastening members (500) may be arranged only in a part of the partition frame (210) or may be arranged in the entire area of ​​the partition frame (210).

[0070] The second fastening member (500) includes at least one reinforcing member (520). The reinforcing member (520) is configured to protrude in a direction different from the penetration direction of the first fastening member (400) so that the second fastening member (500) is caught on the partition frame (210). The reinforcing member (520) can reinforce the fixing force between the second fastening member (500) and the partition frame (210), thereby allowing the second fastening member (500) to be more strongly fixed to the partition frame (210).

[0071] As an example, when the penetration direction of the first fastening member (400) is formed parallel to the Z direction, the reinforcing member (520) may be formed in a direction that is not parallel to the Z direction. For example, the reinforcing member (520) may protrude in a direction perpendicular to the penetration direction of the first fastening member (400), or the reinforcing member (520) may protrude such that the angle (α) between the reinforcing member (520) and the penetration direction of the first fastening member (400) is formed as an acute angle or an obtuse angle.

[0072] The penetration direction of the first fastening member (400) may be formed in a vertical direction, and the reinforcing member (520) may be formed to protrude in a horizontal direction. Here, the vertical direction may be a direction parallel to the Z direction, and the horizontal direction may be understood as a direction parallel to the XY plane. When the first fastening member (400) and the reinforcing member (520) are formed in this manner, the fixing force between the second fastening member (500) and the partition frame (210) may be strengthened.

[0073] The reinforcing member (520) may be formed to be elongated in a columnar shape. The reinforcing member (520) may be formed to be elongated in a straight line, or alternatively, may be formed to be elongated in a curved shape. When the reinforcing member (520) is elongated in a straight line, the manufacturing of the second fastening member (500) or the processing of the partition frame (210) may be facilitated. When the reinforcing member (520) is elongated in a curved shape, the fixing force between the second fastening member (500) and the partition frame (210) may be further strengthened.

[0074] The reinforcing member (520) may be formed with the same cross-section along the extension direction. In this case, the manufacturing of the second fastening member (500) or the processing of the partition frame (210) may be facilitated. The reinforcing member (520) may be formed in a cylindrical shape as illustrated in the drawing, but the shape of the reinforcing member (520) is not limited thereto and may be formed in various shapes.

[0075] The second fastening member (500) may include two reinforcing members (520). In this case, each reinforcing member (520) may be positioned on both sides of the second fastening member (500). When each reinforcing member (520) is positioned on both sides of the second fastening member (500), the fixing force between the second fastening member (500) and the partition frame (210) may be further strengthened.

[0076] The second fastening member (500) is made of a material that can sufficiently secure structural rigidity in a normal state. At least a portion of the second fastening member (500) is made of a material whose properties change in a predetermined high-temperature environment, thereby weakening the bonding force between the first fastening member (400) and the partition frame (210). The material may be referred to as a high-temperature vulnerable material. Here, the predetermined high-temperature environment may be, for example, a temperature environment of 100 to 250 degrees Celsius, and preferably, a temperature environment of 150 to 200 degrees Celsius. When a thermal event occurs inside the battery pack (10), the predetermined high-temperature environment may be generated due to the discharge of venting gas and solid discharge, and at this time, the internal pressure of the battery pack (10) may increase. Here, the change in properties may be understood as, for example, a change in properties such as melting, weakening of brittleness, or melting and weakening of brittleness at the same time.

[0077] When a high temperature and high pressure thermal event occurs inside the battery pack (10), the physical properties of the second fastening member (500) may change, thereby weakening the fixing force between the pack lead (300) and the partition frame (210), thereby securing space for the pack lead (300) to swell. Through this, the heat transfer phenomenon can be prevented.

[0078] Conventionally, steel / SUS bolts and nuts were used to connect the pack case and the pack lid during battery pack manufacturing. However, in these battery packs, even when a thermal event occurred, the pack lid did not swell due to the strong bolting. In other words, because the pack lid was secured against bulging by the strong bolting, conventional battery packs were vulnerable to thermal transfer.

[0079] In contrast, in the battery pack (10) according to one embodiment of the present invention, by improving the second fastening member (500), the structural stability is secured to a degree that the vibration and impact test conditions can be met in normal conditions such as normal conditions, while in the event of a thermal event such as a battery cell (100) ignition, the bonding force between the first fastening member (400) and the partition frame (210) is weakened so that the pack lead (300) can swell, thereby preventing a heat transfer phenomenon. This effect will be discussed in more detail in the following description with reference to FIGS. 6 and 7.

[0080] At least a portion of the second fastening member (500) may be composed of a material comprising one or more of resin, ceramic, and cement. That is, the high-temperature vulnerable material may be composed of a material comprising one or more of resin, ceramic, and cement. The high-temperature vulnerable material may be a moldable material. The melting point of the high-temperature vulnerable material may be formed to be lower than the melting point of the material constituting the partition frame (210).

[0081] The resin may be a natural resin, a synthetic resin, a high-strength resin, or a resin, and may be a thermoplastic resin that can melt in a high-temperature environment. Examples of the resin include, but are not limited to, polycarbonate, polyurethane, and polyester resin. Here, the resin may be a resin that originally has the property of melting or softening in a high-temperature environment, which may be a temperature environment of 100 to 250 degrees Celsius, or a resin that contains an additive that adjusts the melting point or glass transition temperature to a temperature within the high-temperature environment range. Preferred resins may include engineering plastics such as MC (Mono Casting) nylon or polyacetal, and ether and ester polyurethanes.

[0082] MC nylon has a structure that combines imide and ether bonds. The imide bonds provide moderate heat resistance and strength, while the ether bonds exhibit excellent processability. MC nylon has strength similar to metal, is easier to process than typical plastics, and is resistant to wear. It can withstand high temperatures up to 200 degrees Celsius and melts at temperatures higher than that, weakening the bonding between the first fastening member (400) and the partition frame (210) via the second fastening member (500).

[0083] Polyacetal is a high-strength, thermoplastic plastic with a hardness close to that of metal. It can withstand temperatures ranging from approximately 80 to 120 degrees Celsius, but it also has heat resistance that allows it to withstand continuous use temperatures of up to approximately 150 degrees Celsius for short periods of time. Therefore, it can be used without difficulty in temperature environments where a battery pack (10) is used under normal conditions.

[0084] The ceramic may be, for example, bonded ceramic, zirconia ceramic, silica ceramic, etc., but these are only examples and are not limited thereto. The cement may be, for example, alumina cement, refractory cement, composite cement, etc., but these are only examples and are not limited thereto. Here, the ceramic or cement may be processed to become less brittle in a high-temperature environment, which may be a temperature environment of 100 to 250 degrees Celsius.

[0085] High temperature-vulnerable materials may be composed of a composite material of two or more of resin, ceramic, and cement, or may be composed of a bonding agent that is a composite of ceramic and resin, such as ceramic resin cement.

[0086] Here, the weakening of the bonding force between the first fastening member (400) and the partition frame (210) may include the following two cases. The first case is when the bonding force between the portion of the second fastening member (500) excluding the reinforcing member (520) and the reinforcing member (520) is weakened. In this case, the portion of the second fastening member (500) excluding the reinforcing member (520) and the reinforcing member (520) are placed in a state in which they are easily separated from each other (hereinafter referred to as the first state). The second case is when the bonding force between the portion of the second fastening member (500) excluding the reinforcing member (520) and the first fastening member (400) is weakened. In this case, the portion of the second fastening member (500) excluding the reinforcing member (520) and the first fastening member (400) are placed in a state in which they are easily separated from each other (hereinafter referred to as the second state). In the above two cases (first state and second state), the part of the second fastening member (500) excluding the reinforcing member (520) may be understood as the insertion part (510) described later.

[0087] The second fastening member (500) may have an insertion portion (510). The insertion portion (510) is configured such that an end of the first fastening member (400) is inserted. The first fastening member (400) may be placed in close contact with the insertion portion (510). When the first fastening member (400) is configured as a bolt, at least a portion of the screw portion may be inserted, and the insertion portion (510) may be filled and in close contact between the threads of the screw portion. The insertion portion (510) may be formed in a cylindrical groove shape as illustrated in the drawing, but the shape of the insertion portion (510) is not limited thereto and may be formed in various groove shapes.

[0088] The reinforcing member (520) may be connected to the insertion portion (510). The reinforcing member (520) may be connected to the side of the insertion portion (510). However, the present invention is not limited thereto, and the reinforcing member (520) may be connected to the lower or upper portion of the insertion portion (510), and when a plurality of reinforcing members (520) are provided, the reinforcing members (520) may be connected to the insertion portion (510) at different positions.

[0089] The reinforcing member (520) may be formed integrally with the insertion portion (510). In this case, the insertion portion (510) may be made of the same material as the reinforcing member (520).

[0090] A recessed portion (220) may be formed in the partition frame (210). The recessed portion (220) may be formed by being recessed in a shape corresponding to that of the second fastening member (500). The second fastening member (500) may be fixedly arranged in the recessed portion (220). The recessed portion (220) may include a first recessed portion (221) and a second recessed portion (222). The first recessed portion (221) may be formed in a shape corresponding to that of the insertion portion (510) of the second fastening member (500). The second recessed portion (222) may be formed in a shape corresponding to that of the reinforcing member (520) of the second fastening member (500). A screw thread may not be formed in the first insertion portion (221), in which case a separate tap process is unnecessary in the first insertion portion (221), thereby reducing the time and cost required for processing the first insertion portion (221).

[0091] The reinforcing member (520) may be positioned penetrating the partition frame (210). The reinforcing member (520) may be positioned penetrating the partition frame (210) with its end exposed to the receiving space (S). In this case, heat generated in the receiving space (S) is directly exposed to the reinforcing member (520), so that the heat of the receiving space (S) can be more reliably transferred to the reinforcing member (520). In addition, the reinforcing member (520) may be positioned more easily in a portion corresponding to the reinforcing member (520) of the recessed portion (220). For example, in a portion corresponding to the reinforcing member (520) of the recessed portion (220), the reinforcing member (520) may be inserted not only from the inside but also from the outside of the recessed portion (220), so that the reinforcing member (520) may be positioned more easily.

[0092]

[0093] FIG. 5 is a flowchart showing a process of fastening a first fastening member and a second fastening member in a battery pack according to one embodiment of the present invention.

[0094] Hereinafter, with reference to FIG. 5, a process of fastening a first fastening member (400) and a second fastening member (500) to each other in a battery pack (10) according to an embodiment of the present invention will be described in detail. The process of fastening a first fastening member (400) and a second fastening member (500) to each other in a battery pack (10) according to an embodiment of the present invention includes steps S1, S2, and S3 that are sequentially performed. In the above process, the insertion portion (510) and the reinforcing member (520) of the second fastening member (500) can be integrally formed of the same material. In the above process, the manufacturing of the second fastening member (500) can be completed.

[0095] Step S1 is a step in which an insert material is injected into the partition frame (210). The insert material is a material for forming the second fastening member (500) and may include the high-temperature vulnerable material described above. The insert material may be provided in a liquid, gel, or soft solid form to enable forming, and may be provided as a material that can be hardened under certain conditions. In particular, the insert material may be injected into the recessed portion (220) of the partition frame (210). The insert material may be injected through the first recessed portion (221) or the second recessed portion (222) of the recessed portion (220).

[0096] Step S2 is a step in which a first fastening member (400) is inserted into the insert material. Specifically, this step can be understood as a step in which, after step S1, the first fastening member (400) is inserted into the insert material already injected into the partition frame (210). The first fastening member (400) can be inserted into the insert material injected into the recessed portion (220). The first fastening member (400) can push out the insert material while being inserted into the insert material. In this process, the first fastening member (400) can be in close contact with the insert material, and the first recessed portion (221) and the second recessed portion (222) can be evenly filled with the insert material.

[0097] Step S3 is a step in which the insert material is hardened. Specifically, it can be understood as a step in which the insert material with the first fastening member (400) inserted therein is hardened after step S2. Various hardening methods, such as thermal hardening, UV hardening, and natural hardening, can be applied to hardening the insert material, and there is no limitation on the hardening method. The insert material hardened through the above process can form a second fastening member (500), and the first fastening member (400) can be completely fastened to the second fastening member (500). By using the insert material in this way, the formation of the second fastening member (500) and the fastening between the first fastening member (400) and the second fastening member (500) can be performed at once through a simple process step, thereby improving the assembly and productivity of the battery pack (10).

[0098]

[0099] Fig. 6 is a side cross-sectional view taken along line AA' of Fig. 1, and Fig. 7 is a side cross-sectional view showing the pack lead swollen in Fig. 6.

[0100] Hereinafter, with reference to FIGS. 6 and 7, a process of swelling of a pack lead (300) of a battery pack (10) according to one embodiment of the present invention will be described in detail. FIG. 6 illustrates the battery pack (10) before the pack lead (300) is swollen, and FIG. 7 illustrates the battery pack (10) with the pack lead (300) swollen.

[0101] A battery pack (10) in a normal state may have a cross-section as shown in FIG. 6. A battery pack (10) according to one embodiment of the present invention may be configured so that the pack lead (300) swells to a state as shown in FIG. 7 when the internal pressure of the receiving space (S) increases.

[0102] When a thermal event occurs inside the battery pack (10), high temperature heat may be generated and the internal pressure may increase due to the discharge of venting gas and solid discharge. The high temperature heat may be transferred to the first fastening member (400) and the second fastening member (500) that are fastened to each other (see FIG. 6), and thus a predetermined high temperature environment may be created in the second fastening member (500). In this high temperature environment, the bonding force of the first fastening member (400) with the partition frame (210) is weakened. At the same time, when the increased internal pressure inside the pack case (200) acts on the pack lid (300), the first fastening member (400) may be decoupled and separated from the partition frame (210). Then, a space may be created as the pack lid (300) and the partition frame (210) are slightly separated, and the increased internal pressure may be relieved. If the increased internal pressure within the battery pack (10) is not relieved and continues to be maintained, there is a concern that an event such as a fire occurring in some battery cells (100) may be transferred to other battery cells (100). However, according to the present invention, the increase in internal pressure is relieved by spacing out the pack leads (300) through weakening the bonding force between the first fastening member (400) and the partition frame (210), thereby preventing the heat transfer phenomenon.

[0103] In addition, when the pack lid (300) is made of a material capable of elastic deformation or plastic deformation by an external force, the pack lid (300) may be further inflated toward the direction in which the internal pressure is applied (see FIG. 7). As the pack lid (300) inflates, the volume of the space between the pack case (200) and the pack lid (300) increases, so that the increased internal pressure can be alleviated, and at the same time, the flow of venting gas or solid discharge can be formed more smoothly. Through this, the heat transfer phenomenon can be effectively delayed or prevented.

[0104] Meanwhile, in FIG. 7, a first state is illustrated in which the insertion portion (510) and the reinforcing member (520) are separated from each other while the insertion portion (510) is still fastened to the first fastening member (400). However, unlike what is illustrated in FIG. 7, a second state in which the first fastening member (400) is separated from the insertion portion (510) is also possible.

[0105]

[0106] FIG. 8 is a perspective view illustrating a second fastening member of a battery pack according to another embodiment of the present invention, and FIG. 9 is a perspective view illustrating a second fastening member of a battery pack according to another embodiment of the present invention.

[0107] Hereinafter, with reference to FIGS. 8 and 9, the second fastening member (500) of the battery pack (10) according to another embodiment and another embodiment of the present invention will be described in detail.

[0108] Referring to FIG. 8, the second fastening member (500) of the battery pack (10) according to another embodiment of the present invention may include three or four or more reinforcing members (520). In this case, each of the reinforcing members (520) may be connected to the insertion portion (510) of the second fastening member (500). In this way, when the second fastening member (500) includes three or more reinforcing members (520), the second fastening member (500) may be more strongly fastened to the partition frame (210). Accordingly, the fixing force between the second fastening member (500) and the partition frame (210) may be further strengthened.

[0109] A plurality of reinforcing members (520) may be arranged symmetrically with respect to each other. The plurality of reinforcing members (520) may be arranged to form the same angle (β) between them. For example, although not shown in the drawing, if three reinforcing members (520) are provided, each reinforcing member (520) may be arranged to form a 120 degree angle with respect to each other. As shown in FIG. 8, if four reinforcing members (520) are provided, each reinforcing member (520) may be arranged to form a 90 degree angle with respect to each other. In this way, if a plurality of reinforcing members (520) are arranged symmetrically with respect to each other, the second fastening member (500) may be more stably fixed to the partition frame (210).

[0110] Of course, unlike the above, only one reinforcing member (520) may be provided. In this case, the reinforcing member (520) may be provided on either side of the second fastening member (500).

[0111] Referring to FIG. 9, in a battery pack (10) according to another embodiment of the present invention, the second fastening member (500) may be formed as a reinforcing member (520) in a plate shape. In this case, the reinforcing member (520) may be formed in a plate shape surrounding the second fastening member (500), and the reinforcing member (520) may also be formed in a shape surrounding the insertion portion (510) of the second fastening member (500). For example, when the cross-section of the insertion portion (510) is circular, the reinforcing member (520) may be formed in a disk or donut shape surrounding the outer perimeter of the insertion portion (510). In this way, when the reinforcing member (520) is formed in a plate shape surrounding the second fastening member (500), the contact area between the reinforcing member (520) and the partition frame (210) increases, so that the fixing force of the second fastening member (500) can be further strengthened. Meanwhile, although not shown in the drawing, a plurality of reinforcing members (520) of this shape may be arranged in the insertion portion (510) spaced apart from each other in the direction toward the pack lead (300).

[0112]

[0113] FIG. 10 is a side cross-sectional view illustrating a battery pack according to one embodiment of the present invention in which an intermediate member is further arranged between the first fastening member and the second fastening member.

[0114] Hereinafter, with reference to FIG. 10, the intermediate member (600) will be described in detail. The intermediate member (600) is positioned between the pack lead (300) and the second fastening member (500), and is configured such that the first fastening member (400) passes through it. The intermediate member (600) may be made of a metal material such as steel / SUS. Such materials are resistant to high temperatures and have excellent rigidity.

[0115] The intermediate member (600) can support the first fastening member (400). The first fastening member (400) can be supported and fixed by the intermediate member (600) before being fastened to the second fastening member (500).

[0116] The intermediate member (600) can support the pack lead (300) and the second fastening member (500). For example, the intermediate member (600) can support the pack lead (300) from the upper side and the second fastening member (500) from the lower side. In this way, since the intermediate member (600) supports the pack lead (300) and the second fastening member (500), even if shock or vibration is applied to the battery pack (10), these can be effectively buffered, thereby further enhancing structural stability.

[0117] The intermediate member (600) can be in close contact with the pack lid (300) and the second fastening member (500). That is, the intermediate member (600) can be in close contact with the pack lid (300) and at the same time be in close contact with the second fastening member (500). The pack lid (300) and the second fastening member (500) can be spaced apart from each other while maintaining a gap by the intermediate member (600). The intermediate member (600) can also seal the space between the pack lid (300) and the second fastening member (500).

[0118] The intermediate member (600) may be configured as a joint nut having a female thread formed on the inside and at least a portion of which is joined to the pack lid (300). When the first fastening member (400) is a bolt, the male thread of the first fastening member (400) may be joined to the female thread of the joint nut. The joint nut may be joined and fixed to the pack lid (300), and the upper end of the joint nut may be joined to the bottom surface of the pack lid (300). In this way, when the intermediate member (600) is configured as a joint nut joined to the pack lid (300), the fastening force between the first fastening member (400) and the second fastening member (500) may be further strengthened. The first fastening member (400) may be joined to the joint nut fixed to the pack lid (300), so that the first fastening member (400) may be fixed to the pack lid (300) in advance. The first fastening member (400) can be sequentially fastened to the second fastening member (500) while being pre-fixed to the pack lead (300).

[0119] That is, while a plurality of intermediate members (600) are fixed to the bottom surface of the pack lid (300), a plurality of first fastening members (400) are pre-fixed to the pack lid (300) through the intermediate members (600), and then, as the pack lid (300) is arranged to cover the opening (O) of the pack case (200), the plurality of first fastening members (400) can be fastened to a plurality of second fastening members (500) at once. Accordingly, since there is no need to individually align and fasten each of the first fastening members (400), the assembly efficiency of the battery pack (10) is improved, and the assembly accuracy is increased.

[0120]

[0121] FIG. 11 is a side cross-sectional view illustrating a sealing member further arranged on a first fastening member and a second fastening member in a battery pack according to one embodiment of the present invention.

[0122] Hereinafter, with reference to FIG. 11, the sealing member (700) will be described in detail. The sealing member (700) is configured to seal the pack lid (300) and the first fastening member (400) between them. Unlike the previously described high-temperature vulnerable material, the sealing member (700) may be formed of a material that can maintain its properties even at high temperatures.

[0123] The sealing member (700) may be placed on the outer surface of the pack lid (300) that is far from the partition frame (210). When the first fastening member (400) is composed of a bolt, the sealing member (700) may be placed between the head portion (420) of the bolt and the outer surface of the pack lid (300).

[0124] The sealing member (700) may be placed on the inner surface of the pack lid (300). In this case, the sealing member (700) may be placed between the inner surface of the pack lid (300) and the partition frame (210).

[0125] Although not shown in Fig. 11, the sealing member (700) may be placed inside the through hole (310) of the pack lead (300).

[0126] Conventional battery packs have the disadvantage of being susceptible to heat transfer phenomena, such as the inflow of oxygen or the emission of flames through bolting holes for bolting. In a battery pack (10) according to an embodiment of the present invention, the sealing member (700) implements a seal between the first fastening member (400) and the pack lid (300), thereby preventing the inflow of oxygen or the emission of flames, thereby effectively preventing the heat transfer phenomenon.

[0127] Meanwhile, a combination of FIGS. 10 and 11 is also possible. That is, a battery pack (10) equipped with both an intermediate member (600) and a sealing member (700) can also be implemented. In this case, a portion of the sealing member (700) may be configured to seal the space between the pack lead (300) and the intermediate member (600) and / or the space between the intermediate member (600) and the second fastening member (500).

[0128]

[0129] Meanwhile, the battery pack (10) according to the present invention may further include various devices for controlling charging and discharging of battery cells (100), such as a BMS (Battery Management System), a current sensor, a fuse, etc., although not shown.

[0130]

[0131] FIG. 12 is a drawing showing a vehicle according to one embodiment of the present invention.

[0132] Referring to FIG. 12 below, the battery pack (10) according to the present invention can be applied to a vehicle (V), such as an electric vehicle or a hybrid vehicle. That is, the vehicle (V) according to the present invention can include the battery pack (10) according to the present invention. The battery pack (10) can be installed in the body frame under the vehicle seat or in the trunk space, and when installed in the vehicle, the battery pack (10) can be arranged in a reversed order as needed.

[0133] In this specification, terms indicating directions such as up, down, left, right, front, and back are used, but these terms are only for convenience of explanation, and it is obvious to those skilled in the art that these terms may vary depending on the location of the target object or the location of the observer.

[0134] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by a person having ordinary skill in the art to which the present invention pertains within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below.

[0135] [Explanation of symbols]

[0136] 10: Battery pack

[0137] 100: Battery Cell

[0138] 200: Pack Case

[0139] 201: Bottom

[0140] 202: Side wall

[0141] 210: Partition Frame

[0142] 211: Horizontal frame

[0143] 212: Vertical frame

[0144] 220: Indentation

[0145] 221: First inlet

[0146] 222: Second inlet

[0147] 300: Pack Lead

[0148] 310: Through hole

[0149] 400: First fastening member

[0150] 410: Screw

[0151] 420: Head

[0152] 500: Second fastener

[0153] 510: Insertion part

[0154] 520: Reinforcing member

[0155] 600: Intermediate member

[0156] 700: Sealing member

[0157] O: opening

[0158] S: Reception space

[0159] V: Car

Claims

1. A pack case having a space for accommodating multiple battery cells on the inside and an opening formed on one side; A pack lid covering the above opening; A partition frame coupled to the pack case to partition the above-mentioned accommodation space; A first fastening member, at least a portion of which penetrates the pack lead and is joined to the partition frame; and A second fastening member is fixedly arranged on the above partition frame and includes a first fastening member to which the first fastening member is fastened. The above second fastening member is, At least one reinforcing member is provided that protrudes in a direction different from the penetration direction of the first fastening member, so that the second fastening member is caught on the partition frame, A battery pack, at least in part, composed of a material whose properties change in a predetermined high temperature environment, thereby weakening the bonding force between the first fastening member and the partition frame.

2. In paragraph 1, The above pack lead is, A battery pack configured to swell when the internal pressure of the above-mentioned receiving space increases.

3. In paragraph 1, The above first fastening member penetrates the pack lead in a vertical direction, A battery pack in which the above reinforcing member is formed by protruding in a horizontal direction.

4. In paragraph 1, The above reinforcing member is, A battery pack composed of one or more of resin, ceramic, and cement, or a composite material.

5. In paragraph 1, The above second fastening member is, It has an insertion part into which the end of the first fastening member is inserted, The above reinforcing member is, A battery pack connected to the above insert.

6. In paragraph 5, The above reinforcing member is, A battery pack formed integrally with the above insert.

7. In paragraph 1, In the above partition frame, a recessed portion is formed in a shape corresponding to the second fastening member, The above second fastening member is a battery pack fixedly placed in the recessed portion.

8. In paragraph 1, The above reinforcing member is, A battery pack positioned through the above partition frame.

9. In paragraph 1, The above reinforcing member is, A battery pack equipped with multiple units.

10. In paragraph 1, The above reinforcing member is, A battery pack formed by extending long columns.

11. In paragraph 1, The above reinforcing member is, A battery pack formed into a plate shape.

12. In paragraph 1, The above second fastening member is, After the insert material is injected into the above partition frame, the insert material is hardened and formed, The above first fastening member is, A battery pack inserted into the insert material before the insert material is cured, and then fastened to the second fastening member as the insert material is cured.

13. In paragraph 1, A battery pack further comprising an intermediate member disposed between the pack lead and the second fastening member and through which the first fastening member passes.

14. In paragraph 13, The above intermediate member is, A battery pack in close contact with the above pack lead and the second fastening member.

15. In paragraph 13, The above intermediate member is, A battery pack comprising a connecting nut having a female thread formed therein and at least a portion of which is connected to the pack lead.

16. In paragraph 1, A battery pack in which a sealing member is further arranged between the pack lead and the first fastening member to seal them.

17. A vehicle comprising at least one battery pack according to any one of claims 1 to 16.

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