Battery pack and device including same

Abstract

A battery pack according to one embodiment of the present invention comprises: at least one battery module including a plurality of battery cells; a pack frame which has an open top and in which the at least one battery module is accommodated; and a pack cover for covering the open top of the pack frame. A venting part for discharging venting gas is formed on the upper surface of the battery module, and the battery module includes a protrusion part protruding upward from the upper surface of the battery module.

Description

Battery pack and device including same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0190998, filed December 26, 2023, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a battery pack and a device including the same, and more specifically, to a battery pack capable of securing a venting space and a device including the same.

[0004] In modern society, the widespread use of portable devices like cell phones, laptops, camcorders, and digital cameras has fueled active development of technologies related to these devices. Furthermore, rechargeable secondary batteries are increasingly being used as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) to address air pollution caused by conventional gasoline-powered vehicles. This, in turn, heightens the need for further development of these batteries.

[0005] Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based secondary batteries.

[0006] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative electrode active materials, respectively. The lithium secondary battery comprises an electrode assembly comprising a positive electrode plate and a negative electrode plate, each coated with the positive and negative electrode active materials, with a separator interposed between them, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0007] In general, lithium secondary batteries can be classified into can-type secondary batteries in which the electrode assembly is built into a metal can and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

[0008] In the case of secondary batteries used in small devices, 2-3 battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module in which multiple battery cells are electrically connected is used. Such a battery module improves capacity and output by forming a battery cell stack by connecting multiple battery cells in series or parallel. One or more battery modules can be mounted together with various control and protection systems such as a battery management system (BMS), a battery disconnect unit (BDU), and a cooling system to form a battery pack.

[0009] A battery pack may include battery modules as a sub-concept, and a battery module may include battery cells as a sub-concept. The number of battery cells contained in a battery module or the number of battery modules contained in a battery pack may vary depending on the output or capacity of the battery pack required for the electric vehicle.

[0010] However, safety is a key issue for these battery packs. Specifically, if a thermal event occurs in at least one of the multiple battery cells contained within the pack, high-temperature venting gases and heat are generated. To protect the battery pack from these high-temperature venting gases and heat, and to dissipate them to the outside, venting space must be secured and maintained within the battery pack.

[0011] The problem to be solved by the present invention is to provide a battery pack and a device including the same that can secure and maintain a venting space so that high-temperature venting gas and heat generated inside the battery pack due to a thermal event can be smoothly discharged to the outside.

[0012] However, the problems to be solved by the embodiments of the present invention are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0013] A battery pack according to one embodiment of the present invention comprises: at least one battery module including a plurality of battery cells; a pack frame having an open top and housing at least one battery module; and a pack cover covering the open top of the pack frame. A venting portion for venting gas discharge is formed on an upper surface of the battery module, and the battery module includes a protrusion protruding upward from the upper surface of the battery module.

[0014] The above protrusion may protrude from the upper surface of the battery module toward the pack cover.

[0015] The above battery pack may further include a heat-resistant sheet attached to the lower surface of the pack cover.

[0016] The above protrusion may protrude from the upper surface of the battery module toward the heat-resistant sheet.

[0017] The above protrusion may face the heat-resistant sheet.

[0018] A nut hole may be formed on the upper surface of the battery module, and the protrusion may include a flange bolt inserted into the nut hole.

[0019] The above nut hole may be in the form of a rivet nut inserted into a through hole formed on the upper surface of the battery module.

[0020] The above flange bolt may include a fastening portion having threads formed therein and a flange portion located at one end of the fastening portion.

[0021] The protrusion may include a spacer positioned between the flange portion and the upper surface of the battery module.

[0022] The above battery module may include a module frame that accommodates the battery cells, and the venting portion may be formed on an upper surface of the module frame.

[0023] The battery module may include a module frame that accommodates the battery cells, and the module frame may include a bottom frame on which the battery cells are placed and a top cover assembly that covers the upper portions of the battery cells. The venting portion may be formed in the top cover assembly.

[0024] The top cover assembly may include a top plate positioned above the battery cells and a top cover covering an upper surface of the top plate.

[0025] The above venting portion may include a venting hole formed in the top plate and a rupture portion formed in the top cover and positioned corresponding to the venting hole. The rupture portion may have a structure that ruptures when a certain pressure is exceeded.

[0026] An opening may be formed in an area excluding a connecting portion among the perimeter of the above-mentioned rupture portion, and the above-mentioned rupture portion may be connected to the top cover by the connecting portion.

[0027] When viewed in a direction perpendicular to one surface of the top cover, the opening may be located on the outer periphery of the venting hole.

[0028] A nut hole may be formed in the top cover assembly, and the protrusion may include a flange bolt inserted into the nut hole. The top cover may be fixed between the top plate and the flange bolt.

[0029] The above venting portion may be a portion that is thinner than the adjacent area or a portion that has a groove formed along the periphery.

[0030] A device according to one embodiment of the present invention includes the battery pack.

[0031] According to embodiments of the present invention, a protrusion protruding upwardly from the upper portion of a battery module within a battery pack can be provided, thereby securing and maintaining a venting space between the battery module and the pack cover. Accordingly, high-temperature venting gas and heat generated within the battery pack due to a thermal event can be smoothly discharged to the outside of the battery pack, thereby ensuring the safety of the battery pack and the device including the battery pack.

[0032] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0033] FIG. 1 is a partial perspective view showing a portion of a battery pack according to one embodiment of the present invention.

[0034] Figure 2 is a perspective view showing a battery module according to one embodiment of the present invention.

[0035] Figure 3 is a plan view of the battery module of Figure 2 viewed from above.

[0036] Figure 4 is an exploded perspective view of the battery module of Figure 2.

[0037] FIG. 5 is a perspective view showing a battery cell stack, a first busbar frame, and a second busbar frame included in the battery module of FIGS. 2 and 4.

[0038] FIG. 6 is a perspective view showing one of the battery cells included in the battery cell stack of FIG. 5.

[0039] Fig. 7 is a cross-sectional view showing a portion of a cross-section taken along the cutting line A-A' of Fig. 1.

[0040] Fig. 8 is a cross-sectional view showing a portion of a cross-section taken along the cutting line B-B' of Fig. 1.

[0041] FIG. 9 is a perspective view showing a top cover assembly included in a battery module according to one embodiment of the present invention.

[0042] Figure 10 is an exploded perspective view of a top cover assembly according to one embodiment of the present invention.

[0043] Fig. 11 is a perspective view showing the top plate of the top cover assembly of Fig. 10.

[0044] Figure 12 is a partial perspective view showing an enlarged portion of “C” in Figure 11.

[0045] Fig. 13 is a perspective view showing the top cover of the top cover assembly of Fig. 10.

[0046] Fig. 14 is a partial perspective view showing an enlarged portion of “D” of Fig. 13.

[0047] FIG. 15 is a partial perspective view showing a top plate and a rivet nut according to one embodiment of the present invention.

[0048] FIG. 16 is a partial perspective view showing a top plate, a rivet nut, and a protrusion according to one embodiment of the present invention.

[0049] FIG. 17 is a partial perspective view showing a top cover assembly, a rivet nut, and a protrusion according to one embodiment of the present invention.

[0050] Figure 18 is a plan view from above of a top plate according to one embodiment of the present invention.

[0051] Figure 19 is a plan view from above of a top cover according to one embodiment of the present invention.

[0052] FIGS. 20 and 21 are cross-sectional views of a battery pack according to a modified embodiment of the present invention.

[0053] Figures 22 and 23 are cross-sectional views showing a venting part according to other embodiments of the present invention.

[0054] FIG. 24 is a perspective view showing first and second end plates and first and second insulating covers according to one embodiment of the present invention.

[0055] FIG. 25 is a perspective view showing a bottom frame and a heat sink according to one embodiment of the present invention.

[0056] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0057] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0058] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0059] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on" or "over" another part, this includes not only cases where it is "directly on" the other part, but also cases where there are other parts in between. Conversely, when we say that a part is "directly on" another part, it means that there are no other parts in between. Furthermore, saying that a part is "on" or "over" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "over" the direction opposite to gravity.

[0060] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0061] Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

[0062] FIG. 1 is a partial perspective view showing a portion of a battery pack according to one embodiment of the present invention. FIG. 2 is a perspective view showing a battery module according to one embodiment of the present invention. FIG. 3 is a plan view of the battery module of FIG. 2 as viewed from above. FIG. 4 is an exploded perspective view of the battery module of FIG. 2. FIG. 5 is a perspective view showing a battery cell stack, a first busbar frame, and a second busbar frame included in the battery modules of FIGS. 2 and 4. FIG. 6 is a perspective view showing one of the battery cells included in the battery cell stack of FIG. 5.

[0063] Referring to FIGS. 1 to 6, a battery pack (1000) according to one embodiment of the present invention includes at least one battery module (100) including a plurality of battery cells (110); a pack frame (1100) having an open top and housing at least one battery module (100); and a pack cover (1200) covering the open top of the pack frame (1100). Although FIG. 1 illustrates only one battery module (100) housed in the pack frame (1100), a plurality of battery modules (100) may be housed inside the pack frame (1100).

[0064] The pack frame (1100) may include a bottom frame (1110) on which at least one battery module (100) is placed, and a side frame (1120) extending along an edge of the bottom frame (1110). The side frame (1120) may extend in a direction perpendicular to one side of the bottom frame (1110). An internal space having an open upper portion is provided by the bottom frame (1110) and the side frame (1120), and at least one battery module (100) may be stored in this internal space. Meanwhile, the pack cover (1200) may cover the open upper portion of the pack frame (1100).

[0065] A venting portion (220V) for venting gas discharge is formed on the upper surface of the battery module (100) according to the present embodiment. That is, the battery module (100) according to the present embodiment may have a structure of upper venting that discharges high-temperature venting gas and heat caused by a thermal event upward. In addition, the battery module (100) according to the present embodiment includes a protrusion (600) that protrudes upward from the upper surface of the battery module (100). The protrusion (600) may protrude from the upper surface of the battery module (100) toward the pack cover (1200). Due to this protrusion (600), a venting space through which high-temperature venting gas and heat can flow can be secured and maintained between the battery module (100) and the pack cover (1200). The venting portion (220V) and the protrusion (600) will be described in detail later.

[0066] The battery module (100) according to the present embodiment includes a plurality of battery cells (110), as described above. The battery cell (110) according to the present embodiment may be a battery cell of various shapes, for example, a pouch-shaped battery cell, a square battery cell, or a cylindrical battery cell. For example, as illustrated in FIGS. 4 to 6 , the battery cell (110) according to the present embodiment may be a pouch-shaped battery cell. Hereinafter, a pouch-shaped battery cell will be described, but the battery cell (110) according to the present embodiment is not limited thereto, and various types of battery cells may be applied.

[0067] The battery cell (110) according to the present embodiment may be in the form of an electrode assembly having electrode leads (111) protruding in one or both directions, housed in a pouch case (114). Such a battery cell (110) may have a rectangular sheet shape. The battery cell (110) may be formed by housing the electrode assembly in a pouch case (114) of a laminate sheet including a resin layer and a metal layer, and then bonding the outer periphery of the pouch case (114). For example, the battery cell (110) may have a structure in which two electrode leads (111) face each other and protrude from one end (114a) and the other end (114b) of the cell body (113), respectively. As another embodiment, a structure in which all electrode leads (111) of the battery cell (110) protrude in one direction is also possible. One of the electrode leads (111) is a positive electrode lead, and the other is a negative electrode lead.

[0068] The battery cell (110) can be manufactured by bonding the two ends (114a, 114b) of the pouch case (114) and one side (114c) connecting them while the electrode assembly (not shown) is stored in the pouch case (114). In other words, the battery cell (110) according to one embodiment of the present invention has a total of three sealing portions (114s), and the sealing portions (114s) have a structure in which they are sealed by a method such as fusion, and the remaining other side may be formed as a folding portion (115). That is, the battery cell (110) according to the present embodiment can be a pouch-type secondary battery in which the electrode assembly is stored inside the pouch case (114) and the outer periphery of the pouch case (114) is sealed to form the sealing portion (114s). In Fig. 6, only the sealing portions (114s) formed at both ends (114a, 114b) of the pouch case (114) are shown, and the sealing portion is not shown on the side facing the folding portion (115), but the sealing portion of the side facing the folding portion (115) is folded to one side after the sealing is completed for space utilization.

[0069] The pouch case (114) of the laminate sheet may include an inner resin layer for sealing, a metal layer for preventing penetration of materials, and an outermost outer resin layer. Based on the electrode assembly inside the pouch case (114), the inner resin layer may be positioned at the innermost side, the outer resin layer may be positioned at the outermost side, and the metal layer may be positioned between the inner resin layer and the outer resin layer.

[0070] The outer resin layer may have excellent tensile strength and weather resistance relative to its thickness and may exhibit electrical insulation properties to protect the electrode assembly from the outside. The outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer may prevent air, moisture, etc. from entering the pouch-type secondary battery. The metal layer may include aluminum (Al). The inner resin layers may be thermally bonded to each other by heat and / or pressure applied while the electrode assembly is embedded. The inner resin layer may include cast polypropylene (CPP) or polypropylene (PP).

[0071] A pouch case (114) may be divided into two parts, and a concave receiving portion in which an electrode assembly can be mounted may be formed in at least one of the two parts. Along the outer periphery of the receiving portion, the inner resin layers of the two parts of the pouch case (114) may be bonded to each other to form a sealing portion (114s). In this manner, the pouch case may be sealed, and a battery cell (110), which is a pouch-type secondary battery, may be manufactured.

[0072] The battery cells (110) may be configured in plurality within the battery module (100). For example, the plurality of battery cells (110) may be stacked along one direction so as to be electrically connected to each other to form a battery cell stack (120). For example, the plurality of battery cells (110) may be stacked along a direction parallel to the x-axis while standing upright. The battery cells (110) may be stacked from one side portion (212) of the bottom frame (210) to the other side portion (212) in a state where one side of the battery cells (110) is parallel to the side portions (212) of the bottom frame (210). Accordingly, the electrode leads (111) may protrude in a direction perpendicular to the direction in which the battery cells (110) are stacked. In a battery cell (110), one electrode lead (111) may protrude in the y-axis direction, and the other electrode lead (111) may protrude in the -y-axis direction. If the battery cell has electrode leads (111) protruding in only one direction, the electrode leads (111) may protrude in the y-axis direction or the -y-axis direction.

[0073] Meanwhile, the battery module (100) according to the present embodiment may include a module frame (200) that accommodates battery cells (110). For example, a battery cell stack (120) may be accommodated inside the module frame (200). The venting portion (220V) according to the present embodiment may be formed on the upper surface of the module frame (200).

[0074] Specifically, the module frame (200) according to the present embodiment may include a bottom frame (210) on which battery cells (110) are placed and a top cover assembly (220) that covers the upper portions of the battery cells (110). The venting portion (220V) according to the present embodiment may be formed in the top cover assembly (220). The battery cells (110) may be accommodated in a space formed by the bottom frame (210) and the top cover assembly (220). The bottom frame (210) and the top cover assembly (220) may be joined by welding or the like at corresponding corners, so that the module frame (200) may cover the upper portion, the lower portion, and both sides of the battery cell stack (120).

[0075] For example, the bottom frame (210) according to the present embodiment may include a bottom portion (211) and both side portions (212). The both side portions (212) may extend upward from opposite sides of the bottom portion (211) in a direction perpendicular to one side of the bottom portion (211). The bottom portion (211) and both side portions (212) may cover the lower surface and both side surfaces of the battery cell stack (120). As described above, one surface of the battery cells (110) in the battery cell stack (120) is parallel to the side portions (212) of the bottom frame (210), and the battery cells (110) may be stacked along a direction from one side portion (212) to the other side portion (212). The detailed structure of the top cover assembly (220) according to the present embodiment will be described later with reference to FIGS. 9 to 19.

[0076] Meanwhile, in the battery module (100) according to the present embodiment, a first end plate (310) and a second end plate (320) may be arranged on one side of the battery cell stack (120) in the direction in which the electrode lead (111) protrudes and on the opposite side, respectively. The first end plate (310) and the second end plate (320) may be joined to the module frame (200) by a method such as welding. The module frame (200), the first end plate (310), and the second end plate (320) may include a metal material to have a predetermined strength. The battery cell stack (120) may be covered by the module frame (200), the first end plate (310), and the second end plate (320) to be protected from external shocks or vibrations.

[0077] Meanwhile, the battery module (100) according to the present embodiment may include a first busbar frame (410) and a second busbar frame (420) that cover one side of the battery cell stack (120) in the direction in which the electrode leads (111) protrude and the opposite side, respectively. The first busbar frame (410) may be positioned between the battery cell stack (120) and the first end plate (310), and the second busbar frame (420) may be positioned between the battery cell stack (120) and the second end plate (320). The first busbar frame (410) and the second busbar frame (420) may include an electrically insulating material, and may prevent a busbar (510) or a terminal busbar (520) described below from coming into contact with other parts of the battery cell (110) other than the electrode leads (111), thereby causing a short circuit.

[0078] A bus bar (510), a terminal bus bar (520), a module connector (530), etc. may be mounted on each of the first bus bar frame (410) and the second bus bar frame (420). Specifically, the bus bar (510), the terminal bus bar (520), and the module connector (530) may be mounted on the opposite side of the side of the first and second bus bar frames (410, 420) that faces the battery cell stack (120). The bus bar (510) may be electrically connected to the electrode lead (111) of the battery cell (110). For example, the bus bar (510) and the electrode lead (111) may be joined by welding. A slit may be formed in the first and second bus bar frames (410, 420), and the electrode lead (111) may pass through the slit and be connected to the bus bar (510). The battery cells (110) can be electrically connected in series or parallel via the bus bar (510).

[0079] The terminal bus bar (520) can be electrically connected to the electrode lead (111), and a portion thereof can be exposed to the outside of the battery module (100). The battery module (100) can form an HV (High voltage) connection with another battery module or electrical equipment through the terminal bus bar (520). Here, the HV connection is a connection that serves as a power source to supply power requiring high voltage, and refers to a connection between battery cells or a connection between battery modules.

[0080] The module connector (530) may be responsible for transmitting voltage information of battery cells (110) or temperature information inside the battery module (100) to the outside. Accordingly, a portion of the module connector (530) may also be exposed to the outside of the battery module (100).

[0081]

[0082] Below, the venting portion and the protrusion portion according to this embodiment will be described.

[0083] Fig. 7 is a cross-sectional view showing a portion of a cross-section taken along the cutting line A-A' of Fig. 1. Fig. 8 is a cross-sectional view showing a portion of a cross-section taken along the cutting line B-B' of Fig. 1. However, Figs. 7 and 8 illustrate a state in which the pack cover (1200) of Fig. 1 covers the upper portion of the pack frame (1100).

[0084] Referring to FIGS. 1, 2, 4, 7 and 8 together, as described above, a venting portion (220V) for venting gas (VG) discharge and a protrusion (600) protruding upward from the upper surface of the battery module (100) are provided on the upper surface of the battery module (100).

[0085] The venting unit (220V) in the present invention refers to a mechanism for discharging high-temperature venting gas (VG) and heat generated inside the battery module (100) to the outside of the battery module (100). That is, as long as it is possible to discharging high-temperature venting gas (VG) and heat generated inside the battery module (100) due to a thermal event, there is no particular limitation on the structure or shape of the venting unit (220V). In the case of the battery module (100) according to the present embodiment, high-temperature venting gas and heat due to a thermal event can be discharged upward through the venting unit (220V).

[0086] At this time, the protrusion (600) protruding upward from the upper surface of the battery module (100) can secure and maintain a venting space (VS) through which high-temperature venting gas (VG) and heat can flow between the battery module (100) and the pack cover (1200). In order to protect the battery pack (1000) from high-temperature venting gas (VG) and heat generated due to a thermal event or thermal runaway and to stably discharge them to the outside of the battery pack (1000), the venting space (VS) must be stably secured and maintained within the battery pack (1000). If the pack cover (1200) is bent inward or adheres closely to the battery module (100) and sufficient venting space (VS) is not secured and maintained, it is difficult for the high-temperature venting gas (VG) and heat discharged from the venting portion (220V) of the battery module (100) to be discharged to the outside of the battery pack (1000). If the high-temperature venting gas (VG) and heat are not smoothly discharged to the outside of the battery pack (1000), it may lead to an explosion or fire of the battery pack (1000). Therefore, in the present embodiment, a structure capable of supporting the pack cover (1200) is implemented by providing a protrusion (600) that protrudes upward from the upper surface of the battery module (100). As long as the minimum venting space (VS) can be secured, there is no special limitation on the degree of protrusion of the protrusion (600). The degree of protrusion of the protrusion (600) can be adjusted in consideration of the size of the battery module (100) and the gap between the battery module (100) and the pack cover (1200), and the protrusion (600) can be in contact with the pack cover (1200) or spaced apart from the pack cover (1200). That is, in the case of the battery pack (1000) according to the present embodiment, since a high-temperature venting gas (VG) and a venting space (VS) through which heat flows can be secured and maintained between the battery module (100) and the pack cover (1200), the safety of the battery pack (1000) is improved.

[0087] There is no particular limitation on the number of protrusions (600), but it is preferable that there be multiple protrusions so that they can be evenly distributed across the entire upper surface of the battery module (100) to secure and maintain the venting space (VS).

[0088]

[0089] There is no particular limitation on the specific shape or configuration of the protrusion (600), as long as it protrudes from the upper surface of the battery module (100). Hereinafter, as an example of the present invention, the specific shape of the protrusion (600) will be described in detail.

[0090] FIG. 9 is a perspective view illustrating a top cover assembly included in a battery module according to an embodiment of the present invention. FIG. 10 is an exploded perspective view of a top cover assembly according to an embodiment of the present invention. FIG. 11 is a perspective view illustrating a top plate of the top cover assembly of FIG. 10. FIG. 12 is a partial perspective view illustrating an enlarged portion “C” of FIG. 11. FIG. 13 is a perspective view illustrating a top cover of the top cover assembly of FIG. 10. FIG. 14 is a partial perspective view illustrating an enlarged portion “D” of FIG. 13. FIG. 15 is a partial perspective view illustrating a top plate and a rivet nut according to an embodiment of the present invention. FIG. 16 is a partial perspective view illustrating a top plate, a rivet nut, and a protrusion according to an embodiment of the present invention. FIG. 17 is a partial perspective view illustrating a top cover assembly, a rivet nut, and a protrusion according to an embodiment of the present invention.

[0091] Referring to FIGS. 4, 7 to 17 together, the protrusion (600) according to the present embodiment can be formed on the module frame (200). More specifically, the protrusion (600) can be formed on the top cover assembly (220) of the module frame (200).

[0092] A nut hole (221NH) may be formed on the upper surface of the battery module (100) according to the present embodiment, and the protrusion (600) may include a flange bolt (610) inserted into the nut hole (221NH).

[0093] The nut hole (221NH) refers to a hole having a screw thread formed therein, and a flange bolt (610) can be inserted into the nut hole (221NH) by bolting. The flange bolt (610) can include a screw threaded column-shaped fastening portion (611) and a flange portion (612) located at one end of the fastening portion (611). The fastening portion (611) of the flange bolt (610) can be inserted into the nut hole (221NH) by bolting.

[0094] If a screw thread is formed inside, there is no particular limitation on the specific shape of the nut hole (221NH). For example, the nut hole (221NH) may be in the form of a rivet nut (221N) inserted into a through hole (221H) formed on the upper surface of the battery module (100). Specifically, the top cover assembly (220) according to the present embodiment may include a top plate (221) positioned on the upper portion of the battery cells (110) and a top cover (222) covering the upper surface of the top plate (221). A through hole (221H) may be formed in the top plate (221), and a rivet nut (221N) having a screw thread inside may be fitted into the through hole (221H), thereby providing the nut hole (221NH) according to the present embodiment. FIG. 15 illustrates a state before a rivet nut (221N) is fitted into the through hole (221H) of the top plate (221), and FIG. 16 illustrates a state after a rivet nut (221N) is fitted into the through hole (221H) of the top plate (221). Through the structure of the through hole (221H) and the rivet nut (221N), a nut hole (221NH) can be easily provided on the upper surface of the battery module (100). Although not specifically illustrated, as another embodiment of the present invention, it is also possible to form a screw thread directly inside the through hole (221H) of the top plate (221). However, due to the material characteristics of the top plate (221), it may be difficult to form a screw thread directly inside the through hole (221H) in terms of the process, and therefore, a structure in which a rivet nut (221N) is fitted into the through hole (221H) may be more appropriate.

[0095] In this embodiment, a protrusion (600) protruding upward from the upper surface of the battery module (100) can be easily implemented through a nut hole (221NH) and a flange bolt (610) coupled thereto.

[0096] Meanwhile, a top cover hole (222H) positioned to correspond to the through hole (221H) of the top plate (221) may be formed in the top cover (222). When the top cover (222) is placed on the upper surface of the top plate (221), a rivet nut (221N) or a flange bolt (610) may pass through this top cover hole (222H).

[0097] In addition, the protrusion (600) according to the present embodiment may further include a spacer (620) positioned between the flange portion (612) of the flange bolt (610) and the upper surface of the battery module (100). Specifically, the spacer (620) may be positioned between the flange portion (612) of the flange bolt (610) and the top cover (222) of the top cover assembly (220). The spacer (620) may be a ring-shaped member having a predetermined height, and a rivet nut (221N) or a fastening portion (611) of the flange bolt (610) may be inserted into the central hole of the spacer (620).

[0098] By adjusting the height of the spacer (620), the overall height of the protrusion (600) can be adjusted. As described above, the degree of protrusion of the protrusion (600) to secure a minimum venting space (VS) can be adjusted based on the size of the battery module (100) and the gap between the battery module (100) and the pack cover (1200). At this time, by mounting a spacer (620) having a desired height, the degree of protrusion of the protrusion (600), i.e., the overall height of the protrusion (600), can be easily adjusted.

[0099] Based on FIGS. 15 to 17, the formation process of the top cover assembly (220) and the assembly sequence of the protrusion (600) will be described. First, a through hole (221H) can be formed in the top plate (221). Then, a rivet nut (221N) can be press-fitted into the through hole (221H). This top plate (221) can be joined to the bottom frame (210, see FIG. 4). Welding can be applied to the joining between the top plate (221) and the bottom frame (210). Then, as shown in FIG. 17, the top cover (222) can be placed on the upper surface of the top plate (221), and then a spacer (620) can be fitted to the rivet nut (221N). Finally, the flange bolt (610) can be assembled to the rivet nut (221N) of the nut hole (221NH) by bolting. Through this process, a module frame (200) structure with a protrusion (600) can be implemented.

[0100]

[0101] As described above, the venting unit (220V) is a general term for a mechanism for discharging high-temperature venting gas (VG) and heat generated inside the battery module (100) to the outside of the battery module (100). Hereinafter, a venting unit having a venting hole and a rupture unit as a structure of the venting unit according to the present embodiment will be described in detail.

[0102] Fig. 18 is a plan view from above of a top plate according to one embodiment of the present invention. Fig. 19 is a plan view from above of a top cover according to one embodiment of the present invention. Specifically, Figs. 18 and 19 are plan views of the top plate and the top cover, respectively, viewed along the -z-axis direction on the xy plane.

[0103] Referring to FIGS. 3, 4, 7, 8, 10 to 14, 18, and 19 together, as described above, the module frame (200) may include a bottom frame (210) on which battery cells (110) are placed and a top cover assembly (220) that covers the upper portions of the battery cells (110), and the venting portion (220V) may be formed in the top cover assembly (220). The top cover assembly (220) may include a top plate (221) positioned on the upper portions of the battery cells (110) and a top cover (222) that covers the upper surface of the top plate (221).

[0104] The venting portion (220V) according to the present embodiment may include a venting hole (221VH) formed in the top plate (221) and a rupture portion (222R) formed in the top cover (222) and positioned corresponding to the venting hole (221VH). The rupture portion (222R) may have a structure that ruptures when a certain pressure is applied or higher.

[0105] The venting hole (221VH) may be a through-hole formed in the top plate (221). The rupture portion (222R) may cover the venting hole (221VH) at the upper portion of the top plate (221).

[0106] An opening (222P) may be formed in an area excluding the connecting portion (222C) from the periphery of the rupture portion (222R). The opening portion (222P) refers to a perforated portion of the top cover (222). The rupture portion (222R) according to the present embodiment may be connected to the top cover (222) by the connecting portion (222C). In other words, the rupture portion (222R) may be provided in the top cover (222) in such a way that the opening portion (222P) is formed in a perforated form in the top cover (222) excluding only the connecting portion (222C).

[0107] In addition, when viewed along a direction perpendicular to one surface of the top cover (222), the opening (222P) may be located on the outer periphery of the venting hole (221VH). Viewing along a direction perpendicular to one surface of the top cover (222) may correspond to viewing along the -z-axis direction on the xy plane, as in FIGS. 3, 18, and 19. In addition, FIGS. 8, 18, and 19, etc., it is expressed that in one of the venting holes (221VH), the opening (222P) is provided outside the venting hole (221VH).

[0108] When looking at the venting portion (220V) from inside the battery module (100) through the above structure, the venting hole (221VH) is blocked by the rupture portion (222R), and the opening portion (222P) is covered by the top plate (221). In other words, since the venting hole (221VH) is formed in an area inside the opening portion (222P), when looking at the inside of the battery module (100), only the rupture portion (222R) is exposed through the venting hole (221VH), and the opening portion (222P) is not exposed.

[0109] Accordingly, in a normal state where no thermal event occurs, the venting portion (220V) does not discharge internal gas because the venting hole (221VH) is blocked by the rupture portion (222R). However, if a thermal event or thermal runaway phenomenon causes high-temperature venting gas and heat to be generated inside the battery module (100) and the internal pressure of the battery module (100) increases, the rupture portion (222R) may rupture. Specifically, if the increased internal pressure of the battery module (100) exceeds the limit strength of the connecting portion (222C), the connecting portion (222C) may break, causing the rupture portion (222R) to be separated from the top cover (222). Accordingly, the venting hole (221VH) is opened, and high-temperature venting gas (VG) and heat may be discharged to the outside of the battery module (100) through the venting hole (221VH). More specifically, high-temperature venting gas (VG) and heat can be discharged into the venting space (VS) between the pack cover (1200) and the battery module (100) through the venting hole (221VH). The high-temperature venting gas (VG) and heat flowing along the venting space (VS) can be discharged to the outside of the battery pack (1000) through a venting device (not shown) provided in the pack frame (1100) or the pack cover (1200).

[0110]

[0111] Meanwhile, referring again to FIGS. 7 to 10 and 14 to 17, the top cover (222) according to the present embodiment can be fixed between the top plate (221) and the flange bolt (610). Specifically, the top cover (222) can be fixed between the top plate (221) and the flange portion (612) of the flange bolt (610). More specifically, the top cover (222) can be fixed between the top plate (221) and the spacer (620).

[0112] The flange bolt (610) and spacer (620) according to the present embodiment can perform the function of securing and maintaining the venting space (VS) described above, as well as the function of fixing the top cover (222) to the battery module (100). If the top cover (222) is detached from the upper portion of the battery module (100), the venting space (VS) may not be maintained. That is, fixing the top cover (222) to the battery module (100) can help secure and maintain the venting space (VS) between the battery module (100) and the pack cover (1200).

[0113] For example, the top plate (221) according to the present embodiment may be welded to the bottom frame (210, see FIG. 4) by including a metal material. On the other hand, the top cover (222) may include an FRB-silicone material or a MICA material. In order to induce the connection part (222C) connecting the rupture part (222R) to break under a certain pressure, the top cover (222) may not be made of a metal material. Even if welding between the top plate (221) and the top cover (222) is not possible, the top cover (222) may be fixed to the top plate (221) by using a flange bolt (610) and a spacer (620). Fixing the top cover (222) using the flange bolt (610) and the spacer (620) may be useful in terms of the materials of the top plate (221) and the top cover (222).

[0114]

[0115] FIGS. 20 and 21 are cross-sectional views of a battery pack according to a modified embodiment of the present invention.

[0116] Referring to FIGS. 1, 20, and 21, a battery pack according to a modified embodiment of the present invention may further include a heat-resistant sheet (1300) attached to the lower surface of the pack cover (1200) between the battery module (100) and the pack cover (1200). The heat-resistant sheet (1300) may protect the pack cover (1200) from high-temperature venting gas (VG) and heat discharged from the battery module (100). For example, the heat-resistant sheet (1300) may be a thin plate-shaped sheet including a MICA material, and may be attached to the lower surface of the pack cover (1200) using a heat-resistant adhesive.

[0117] The protrusion (600) according to the present embodiment may protrude from the upper surface of the battery module (100) toward the heat-resistant sheet (1300). The protrusion (600) may face the heat-resistant sheet (1300). The heat-resistant sheet (1300) is provided to protect the pack cover (1200) from high-temperature venting gas (VG) and heat, but as time passes and the performance of the heat-resistant adhesive deteriorates due to heat, the heat-resistant sheet (1300) may be separated from the pack cover (1200).

[0118] If there is no protrusion (600) protruding toward the heat-resistant sheet (1300), the detached heat-resistant sheet (1300) covers the venting portion (220V), and the high-temperature venting gas (VG) and heat cannot be properly discharged. On the other hand, in the case of the present embodiment, even if the heat-resistant sheet (1300) is separated from the pack cover (1200), the protrusion (600) can secure and maintain the venting space (VS) between the battery module (100) and the heat-resistant sheet (1300) while supporting the separated heat-resistant sheet (1300). That is, in the case of the battery pack (1000) according to the present embodiment, the safety of the battery pack (1000) is improved because the venting space (VS) through which the high-temperature venting gas (VG) and heat flow can be secured and maintained between the battery module (100) and the heat-resistant sheet (1300).

[0119]

[0120] Figures 22 and 23 are cross-sectional views showing a venting part according to other embodiments of the present invention.

[0121] Referring to FIGS. 22 and 23, as described above, the venting portion (220V', 220V") collectively refers to a mechanism for discharging high-temperature venting gas and heat generated inside the battery module to the outside of the battery module. The venting portion (220V') according to another embodiment of the present invention may be a portion that is thinner than an adjacent area in order to discharging high-temperature venting gas and heat. Specifically, the top cover assembly (220') of the module frame (200) may be in the form of a single plate, and the venting portion (220V') may be a portion of the top cover assembly (220') that is thinner than the surrounding area. When high-temperature venting gas and heat are generated and the internal pressure of the battery module increases, the venting portion (220V') having a relatively thin thickness may rupture, thereby discharging the high-temperature venting gas and heat.

[0122] Meanwhile, the venting portion (220V”) according to another embodiment of the present invention may be a portion having a groove (220G) formed along the circumference to discharge high-temperature venting gas and heat. Specifically, the top cover assembly (220”) of the module frame (200) may be in a single plate shape, and the venting portion (220V”) may be an inner portion of the groove (220G) formed in the top cover assembly (220”). When high-temperature venting gas and heat are generated and the internal pressure of the battery module increases, the groove (220G) may first rupture, opening the venting portion (220V”) to discharge the high-temperature venting gas and heat.

[0123]

[0124] FIG. 24 is a perspective view showing first and second end plates and first and second insulating covers according to one embodiment of the present invention.

[0125] Referring to FIGS. 4, 5, and 24 together, a battery module (100) according to one embodiment of the present invention may include a first insulating cover (810) covering an inner surface of a first end plate (310) and a second insulating cover (820) covering an inner surface of a second end plate (320). The first insulating cover (810) may be positioned between the first end plate (310) and the first busbar frame (410), and the second insulating cover (820) may be positioned between the second end plate (320) and the second busbar frame (420). The first insulating cover (810) and the second insulating cover (820) may include an electrically insulating material, and may prevent a short circuit from occurring when the first end plate (310) and the second end plate (320) come into contact with an electrode lead (111) or a busbar (510).

[0126] FIG. 25 is a perspective view showing a bottom frame and a heat sink according to one embodiment of the present invention.

[0127] Referring to FIGS. 4 and 25, a battery module (100) according to one embodiment of the present invention may further include a heat sink (700) positioned below a bottom portion (211) of a bottom frame (210). The heat sink (700) may include a base portion (710) that is joined to the bottom portion (211) and a recessed portion (720) that is formed downward from the base portion (710). A welding joint may be applied to the joint between the bottom portion (211) and the base portion (710).

[0128] As the coolant flows in the space between the bottom portion (211) and the recessed portion (720), the battery module (100) can be cooled. The coolant is a medium for cooling, and although there is no particular limitation, it may be coolant. That is, the battery module (100) according to the present embodiment may have a water-cooling structure. An inlet (730) and an outlet (740) may be provided in the bottom portion (211). The coolant introduced through the inlet (730) may flow along the space between the bottom portion (211) and the recessed portion (720) and then be discharged through the outlet (740).

[0129] In addition, the battery module (100) may further include a thermal resin layer (900) positioned between the battery cells (110) and the bottom portion (211) of the bottom frame (210). The thermal resin layer (900) may include thermal resin. The thermal resin layer (900) may be formed on the bottom portion (211). The thermal resin may include a thermally conductive adhesive material, and specifically, may include at least one of a silicone material, a urethane material, or an acrylic material. Such a thermal resin may be in a liquid state when applied or may be hardened after application to serve to fix the battery cells (110). In addition, since it has excellent thermal conductivity, it can quickly transfer heat generated from the battery cells (110) to the coolant of the heat sink (700), thereby preventing overheating of the battery module (100).

[0130] In this example, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0131] One or more battery modules according to the above-described embodiment can be mounted together with various control and protection systems such as a BMS (Battery Management System), a BDU (Battery Disconnect Unit), and a cooling system to form a battery pack.

[0132] The above battery pack can be applied to various devices. Specifically, it can be applied to transportation vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, as well as ESS (Energy Storage Systems), but is not limited thereto. It can also be applied to various devices that can use secondary batteries.

[0133] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0134] Description of the symbol

[0135] 100: Battery module

[0136] 110: Battery cell

[0137] 120: Battery cell stack

[0138] 200: Module Frame

[0139] 210: Bottom Frame

[0140] 220: Top cover assembly

[0141] 220V: Venting part

[0142] 600: Protrusion

[0143] 610: Flange bolt

[0144] 620: Spacer

[0145] 1000: Battery pack

[0146] 1100: Pack Frame

[0147] 1200: Pack Cover

Claims

1. At least one battery module comprising a plurality of battery cells; A pack frame having an open top and housing at least one of the above battery modules; and A pack cover covering the open upper portion of the pack frame; A venting portion is formed on the upper surface of the above battery module for venting gas discharge. The above battery module is a battery pack including a protrusion protruding upward from the upper surface of the battery module.

2. In paragraph 1, The above protrusion is a battery pack that protrudes from the upper surface of the battery module toward the pack cover.

3. In paragraph 1, A battery pack further comprising a heat-resistant sheet attached to the lower surface of the pack cover.

4. In paragraph 3, The above protrusion is a battery pack that protrudes from the upper surface of the battery module toward the heat-resistant sheet.

5. In paragraph 3, The above protrusion is a battery pack facing the heat-resistant sheet.

6. In paragraph 1, A nut hole is formed on the upper surface of the above battery module, The above protrusion is a battery pack including a flange bolt inserted into the nut hole.

7. In paragraph 6, The above nut hole is a battery pack in which a rivet nut is inserted into a through hole formed on the upper surface of the battery module.

8. In paragraph 6, The above flange bolt is a battery pack including a fastening portion having threads formed therein and a flange portion located at one end of the fastening portion.

9. In paragraph 8, A battery pack, wherein the protrusion includes a spacer positioned between the flange portion and the upper surface of the battery module.

10. In paragraph 1, The above battery module includes a module frame that accommodates the battery cells, The above venting portion is a battery pack formed on the upper surface of the module frame.

11. In paragraph 1, The above battery module includes a module frame that accommodates the battery cells, The above module frame includes a bottom frame on which the battery cells are placed and a top cover assembly that covers the upper portion of the battery cells. The above venting portion is a battery pack formed on the top cover assembly.

12. In Article 11, The top cover assembly is a battery pack including a top plate positioned above the battery cells and a top cover covering an upper surface of the top plate.

13. In paragraph 12, The above venting portion includes a venting hole formed in the top plate and a rupture portion formed in the top cover and positioned corresponding to the venting hole, A battery pack having a structure in which the above-mentioned rupture part ruptures when a certain pressure is exceeded.

14. In paragraph 13, An opening is formed in the area around the above ruptured portion excluding the connecting portion, A battery pack in which the above-mentioned rupture portion is connected to the top cover by the above-mentioned connecting portion.

15. In paragraph 14, A battery pack in which, when viewed in a direction perpendicular to one surface of the top cover, the opening is located on the outer periphery of the venting hole.

16. In paragraph 12, A nut hole is formed in the above top cover assembly, The above protrusion includes a flange bolt inserted into the above nut hole, The above top cover is a battery pack secured between the top plate and the flange bolt.

17. In paragraph 1, A battery pack in which the above venting portion is a portion that is thinner than the adjacent area or a portion in which a groove is formed along the periphery.

18. A device comprising a battery pack according to paragraph 1.

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