Battery module and battery pack including the same

Abstract

A battery module according to one embodiment of the present invention comprises a battery cell stack in which a plurality of battery cells are stacked in one direction, a module frame that accommodates the battery cell stack and has an inner surface and an outer surface, and an end plate that is coupled to the module frame and covers the front or rear surface of the battery cell stack, wherein at least one hole-shaped venting portion is formed in the module frame, defining an inlet formed on the inner surface and an outlet formed on the outer surface, and the end region of the venting portion including the inlet or the outlet has an inverted taper shape.

Description

Technology Field

[0001] The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module with improved safety and a battery pack including the same. Background Technology

[0002] As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are receiving a lot of attention as an energy source not only for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0003] When rechargeable batteries are primarily used in devices such as mobile devices, there is no difficulty in achieving the storage capacity and energy output levels required by each device even with the use of one, two, or four battery cells. However, since medium-to-large devices such as automobiles require high output and large-capacity storage, using such a small number of battery cells can cause significant problems in terms of energy storage capacity and energy output. Therefore, it is common practice to equip medium-to-large devices with battery modules in which multiple battery cells are electrically connected, or battery packs containing multiple such modules.

[0004] Figure 1 is an exploded perspective view of a conventional battery module.

[0005] Referring to FIG. 1, a conventional battery module (10) includes a battery cell stack (12) in which a plurality of battery cells (11) are stacked, a module frame (20) for protecting the battery cell stack (12) from external shock, heat or vibration, and an end plate (40) for covering the front and / or rear of the battery cell stack (12).

[0006] The battery cell stack (12) is located within a sealed structure formed by the combination of the module frame (20) and the end plate (40). To maximize the energy storage capacity of the battery module (10), each battery cell (11) is located mainly at a narrow spacing within the battery cell stack (12).

[0007] However, this design of the battery module (10) may impair the durability or long-term stability of the battery module (10). Specifically, when the internal pressure of the battery cell (11) increases due to reasons such as overcharging, high-temperature heat, gas, or flame may be released to the outside of the battery cell (11). At this time, the heat, gas, or flame released from one battery cell (11) may be transferred to another adjacent battery cell (11) with a narrow gap, thereby inducing a continuous ignition phenomenon. Additionally, the heat, gas, or flame released from each battery cell (11) may be discharged toward an opening formed in the end plate (40), and in this process, a problem may occur in which a bus bar (not shown), etc., located between the end plate (40) and the battery cell (11) is damaged.

[0008] Furthermore, since a plurality of battery modules (10) within a battery pack are arranged such that at least two end plates (40) face each other, if heat, gas, or flame generated within a battery module (10) is discharged outside the battery module (10), it may affect the performance and stability of a plurality of battery cells (11) within an adjacent battery module (10).

[0009] Therefore, it is necessary to develop a battery module (10) with improved durability and safety by effectively delaying the heat propagation speed when the battery module (10) ignites internally and allowing the generated heat, gas, or flame to be quickly discharged to the outside of the battery module (10). The problem to be solved

[0010] The problem to be solved by the present invention is to provide a battery module that effectively suppresses flames when ignition occurs within the battery module and effectively discharges internal heat, gas, or flames, and a battery pack including the same.

[0011] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art from this specification and the attached drawings. means of solving the problem

[0012] A battery module according to one embodiment of the present invention comprises a battery cell stack in which a plurality of battery cells are stacked in one direction, a module frame that accommodates the battery cell stack and has an inner surface and an outer surface, and an end plate that is coupled to the module frame and covers the front or rear surface of the battery cell stack, wherein at least one hole-shaped venting portion is formed in the module frame, defining an inlet formed on the inner surface and an outlet formed on the outer surface, and the end region of the venting portion including the inlet or the outlet has an inverted taper shape.

[0013] Based on the axial cross-section of the venting portion, the side of the venting portion extending between the inlet and the outlet has a rounded shape, and the effluent introduced through the inlet can move to the outlet along the rounded shape.

[0014] The above venting part may be provided with a cover for opening and closing the hole of the above venting part.

[0015] The above cover may be located at a portion corresponding to the inlet of the above venting section.

[0016] The above covers may be provided in pairs.

[0017] The above cover is in the form of a plate, and one corner of the cover can be fixed to the module frame.

[0018] Based on the axial cross-section of the venting portion, the side of the venting portion extending between the inlet and the outlet has a rounded shape, and depending on the internal pressure of the battery module, the cover may be curved along the side of the venting portion having a rounded shape.

[0019] The above cover may include aluminum.

[0020] When the direction in which the plurality of battery cells are stacked is defined as the stacking direction, the venting portion may be formed on one side of the module frame that extends along the stacking direction.

[0021] When the direction from the front to the rear of the battery cell stack is defined as the longitudinal direction, the longitudinal position of the venting portion may be closer to the front or rear of the battery cell stack than the center of the battery cell stack having the same longitudinal distance as the front and rear of the battery cell stack.

[0022] The above battery cell includes an electrode lead protruding from one end of the battery cell, and the electrode lead may be located on the front or rear side of the battery cell stack.

[0023] A battery pack according to one embodiment of the present invention includes at least one battery module. Effects of the invention

[0024] According to the embodiments, a venting portion is formed in the module frame to provide a path for the discharge of heat, gas, or flame within the battery module, thereby effectively suppressing the flame when ignition occurs within the battery module and effectively discharging internal gas.

[0025] According to other embodiments, a venting section providing a path for discharging heat, gas, or flame within a battery module and a cover for opening and closing a hole in the venting section are formed on the module frame, thereby effectively suppressing flames in the event of ignition within the battery module and effectively discharging internal gas.

[0026] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the accompanying drawings. Brief explanation of the drawing

[0027] Figure 1 is an exploded perspective view of a conventional battery module. FIG. 2 is a perspective view of a battery module according to one embodiment of the present invention. Figure 3 is an exploded perspective view of the battery module of Figure 2. Figure 4 is a drawing showing a battery cell included in the battery module of Figure 2. Figure 5 is a cross-sectional view of the battery module of Figure 2 cut along line AA. FIG. 6 is a diagram illustrating the direction in which heat, gas, or flame, etc., generated in the internal space of a battery module according to one embodiment of the present invention are discharged through a venting part. FIG. 7 is a drawing illustrating examples of a venting section of a battery module according to one embodiment of the present invention. FIG. 8 is a perspective view of a battery module according to another embodiment of the present invention. Figure 9 is a drawing for explaining the cover of Figure 8. FIG. 10 is a drawing illustrating examples of a cover for a battery module according to another embodiment of the present invention. Specific details for implementing the invention

[0028] Hereinafter, various embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms other than those described below, and the scope of the present invention is not limited by the embodiments described herein.

[0029] To clearly explain the present invention, parts unrelated to the description have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0030] In addition, the size and thickness of each component shown in the drawings have been arbitrarily enlarged or reduced for convenience of explanation, so it is obvious that the content of the present invention is not limited to what is illustrated. In the drawings below, the thickness of each layer has been enlarged to clearly represent various layers and regions. Also, in the drawings below, the thickness of some layers and regions has been exaggerated for convenience of explanation.

[0031] Furthermore, when describing a part such as a layer, membrane, region, or plate as being "above" or "on" another part, this should be interpreted to include not only cases where the corresponding part is "directly above" the other part, but also cases where there is another part in between. Conversely, when describing a corresponding part such as a layer, membrane, region, or plate as being "directly above" another part, it may mean that there is no other part in between. Additionally, stating that a part is "above" or "on" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" or "on" in the opposite direction of gravity. Meanwhile, just as describing a part as being "above" or "on" another part can be understood by referring to the aforementioned content, describing a part as being "below" or "under" another part can also be understood.

[0032] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0033] Additionally, throughout the specification, "planar" refers to the part as viewed from above, and "cross-sectional" refers to the cross-section of the part cut vertically as viewed from the side.

[0035] A battery module according to one embodiment of the present invention will be described below.

[0036] FIG. 2 is a perspective view of a battery module according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of the battery module of FIG. 2. FIG. 4 is a drawing showing a battery cell included in the battery module of FIG. 2.

[0037] Referring to FIGS. 2 and 3, a battery module (100) according to one embodiment of the present invention may include a battery cell stack (120) in which a plurality of battery cells (110) are stacked along one direction, a module frame (200) that accommodates the battery cell stack (120), a busbar frame (300) located on the front and / or rear of the battery cell stack (120), an end plate (400) covering the front and / or rear of the battery cell stack (120), and a busbar (510, 520) mounted on the busbar frame (300).

[0038] The battery cell (110) may be provided in a pouch type such that the number of stacked cells per unit area can be maximized. The battery cell (110) provided in a pouch type may be manufactured by housing an electrode assembly including a positive electrode, a negative electrode, and a separator in a cell case (114) of a laminate sheet and then heat-sealing the sealing portion of the cell case (114). However, it is obvious that the battery cell (110) must not necessarily be provided in a pouch type, and may be provided in a prismatic, cylindrical, or various other shapes as long as the storage capacity required by the device to be mounted in the future is achieved.

[0039] Referring to FIG. 4, the battery cell (110) may include two electrode leads (111, 112). The electrode leads (111, 112) may each have a structure protruding from one end of the cell body (113). Specifically, one end of each electrode lead (111, 112) is located inside the battery cell (110) and is electrically connected to the positive or negative electrode of the electrode assembly, and the other end of each electrode lead (111, 112) is extended outside the battery cell (110) and can be electrically connected to a separate component, for example, a bus bar (510, 520).

[0040] The electrode assembly inside the cell case (114) can be sealed by sealing portions (114sa, 114sb, 114sc). The sealing portions (114sa, 114sb, 114sc) of the cell case (114) may be located on both ends (114a, 114b) and one side (114c) connecting them.

[0041] The cell case (114) is generally composed of a laminate structure of a resin layer / metal thin film layer / resin layer. For example, when the surface of the cell case is composed of an O(oriented)-nylon layer, when stacking multiple battery cells (110) to form a medium-to-large battery module (100), they tend to slide easily due to external impact. Therefore, to prevent this and maintain a stable stacking structure of the battery cells (110), an adhesive member such as a double-sided adhesive or a chemical adhesive that bonds through a chemical reaction upon bonding can be attached to the surface of the cell case (114) to form a battery cell stack (120).

[0042] The connection portion (115) may refer to an area extending along the longitudinal direction from one end of the cell case (114) where the aforementioned sealing portions (114sa, 114sb, 114sc) are not located. A protrusion (110p) of the battery cell (110), called a bat-ear, may be formed at the end of the connection portion (115). Additionally, the terrace portion (116) may refer to an area between the electrode leads (111, 112), which are partially protruding outside the cell case (114) based on the edge of the cell case (114), and the cell body (113) located inside the cell case (114).

[0044] Meanwhile, the battery cell (110) provided in a pouch form may have a length, width, and thickness, and the length direction, width direction, and thickness direction of the battery cell (110) may be mutually perpendicular directions.

[0045] Here, the longitudinal direction of the battery cell (110) can be defined according to the direction in which the electrode leads (111, 112) protrude from the cell case (114). For example, one electrode lead (111) may protrude in one direction (x-axis direction) from one end (114a) of the cell case (114), and another electrode lead (112) may protrude in the opposite direction (-x-axis direction) from one end (114b) of the cell case (114). In this case, the longitudinal direction of the battery cell (110) can be defined as the x-axis direction or the -x-axis direction.

[0046] Also, here, the width direction of the battery cell (110) may be a z-axis direction or a -z-axis direction extending from one side (114c) of the battery cell (110) to the connecting part (115) or from the connecting part (115) to one side (114c), as shown in FIG. 4. Also, here, the thickness direction of the battery cell (110) may be defined as a y-axis direction or a -y-axis direction perpendicular to the width direction and the length direction.

[0047] Meanwhile, although the length, width, and thickness directions have been explained above with respect to the direction of the axis indicated in the drawing, this is merely for the convenience of explanation, so the thickness, length, and width directions described above may be defined differently from the drawing depending on the structure of the battery cell (110).

[0049] The battery cell stack (120) may be a plurality of electrically connected battery cells (110) stacked along one direction. The direction in which the plurality of battery cells (110) are stacked (hereinafter referred to as the ‘stacking direction’) may be the y-axis direction (or -y-axis direction, and the expression ‘axis direction’ may be interpreted as including both + / - directions) as shown in FIGS. 2 and 3.

[0050] Here, the stacking direction of the battery cell stack (120) may be the thickness direction of the battery cell (110). This may be because the thickness of the battery cell (110) is designed to have a value smaller than the length and width of the battery cell (110), so that the volume can be minimized when stacked along the aforementioned direction. Therefore, the stacking direction of the battery cell stack (120) and the thickness direction of the battery cell (110) will not always be interpreted as being the same, and the stacking direction may be determined according to the shape of the battery cell (110).

[0051] The battery cell stack (120) may have a shape similar to a rectangular prism overall. Each face of the battery cell stack (120) may be defined by the stacking direction (y-axis direction).

[0052] For example, two surfaces facing each other in the stacking direction among the surfaces of the battery cell stack (120) can be defined as the sides of the battery cell stack (120). On the sides of the battery cell stack (120), one surface of a single battery cell (110) having a length and a width may be located.

[0053] Additionally, among the surfaces of the battery cell stack (120), the surfaces facing each other on an axis perpendicular to the stacking direction may be defined as the front / rear surface or the top / bottom surface. The front, rear, top, or bottom surface of the battery cell stack (120) may be surfaces that extend along the stacking direction of the battery cell stack (120). A plurality of battery cells (110) may be positioned side by side on the front, rear, top, and bottom surfaces of the battery cell stack (120). Here, the side surface of the battery cells (110) positioned side by side may be a surface parallel to the thickness direction.

[0054] The direction from the front to the rear of the battery cell stack (120), or the opposite direction, can be defined as the length direction of the battery cell stack (120) and may be the x-axis direction. Additionally, the direction from the upper surface to the lower surface of the battery cell stack (120), or the opposite direction, can be defined as the width direction of the battery cell stack (120) and may be the z-axis direction.

[0055] The longitudinal direction of the battery cell stack (120) may be substantially the same as the longitudinal direction of the battery cell (110). The electrode leads (111, 112) of the battery cell (110) may be located on the front and rear of the battery cell stack (120). When the electrode leads (111, 112) of each battery cell (110) are concentrated on the front and rear of the battery cell stack (120) as shown in FIG. 3, the busbars (510, 520) of the battery module (100) may be designed to be located close to the front and rear of the battery cell stack (120). Through this, the busbars (510, 520) can more easily provide an electrical connection between the electrode leads (111, 112) located inside the battery module (100) and the electrical components located outside the battery module (100).

[0056] The battery cell stack (120) may include a peripheral region (120a) and a central region (120b) defined according to a position along the longitudinal direction. Specifically, the battery cell stack (120) may include a central region (120b) that includes a central plane (or center) spaced apart from the front and rear of the battery cell stack (120) by the same distance, and a peripheral region (120a) spaced apart from the central region. Here, the peripheral region (120a) may be located closer to the busbar frame (300), end plate (400), and busbar (510, 520) described later than the central region (120b). Also, here, the peripheral region (120a) may include an area where electrode leads (111, 112) are located, but is not necessarily so.

[0057] The module frame (200) may be intended to protect the battery cell stack (120) and the electrical components connected thereto from external physical impact. The module frame (200) may accommodate the battery cell stack (120) and the electrical components connected thereto within the internal space of the module frame (200). Here, the module frame (200) includes an inner surface (see FIG. 5, 200a) and an outer surface (see FIG. 5, 200b), and the internal space of the module frame (200) may be defined by the inner surface (200a). One surface (200c, 200d) of the module frame (200) is located in the XZ plane of the drawing, and two surfaces (200c, 200d) face each other along the Z-axis direction. Additionally, the side surfaces (200e, 200f) of the module frame (200) have the Y-axis direction as their normal vector. The front (200g) and rear (200h) of the module frame (200) have the X-axis direction as the normal vector. The venting section (210) includes an inlet (210a) and an outlet (210b) formed on one side (200c) of the module frame (200).

[0058] The structure of the module frame (200) can be varied. For example, the structure of the module frame (200) may be a monoframe structure. Here, the monoframe may be in the form of a metal plate with an integrated top surface, a bottom surface, and both sides. The monoframe may be manufactured by extrusion molding. As another example, the structure of the module frame (200) may be a structure in which a U-shaped frame and an upper plate are combined. In the case of a structure in which a U-shaped frame and an upper plate are combined, the structure of the module frame (200) may be formed by combining an upper plate to the upper side of a U-shaped frame, which is a metal plate with an integrated bottom surface and both sides, and each frame or plate may be manufactured by press molding. Additionally, the structure of the module frame (200) may be provided as an L-shaped frame structure in addition to a monoframe or U-shaped frame, and may be provided as various structures not described in the examples above.

[0059] The structure of the module frame (200) may be provided in an open form along the longitudinal direction of the battery cell stack (120). The front and rear of the battery cell stack (120) may not be covered by the module frame (200). The electrode leads (111, 112) of the battery cell (110) may not be covered by the module frame (200). The front and rear of the battery cell stack (120) may be covered by a busbar frame (300), end plate (400), or busbar (510, 520), etc., which will be described later, and thereby the front and rear of the battery cell stack (120) may be protected from external physical impacts.

[0060] Meanwhile, a compression pad (150) may be positioned between one side of the inner surface of the battery cell stack (120) and the module frame (200). At this time, the compression pad (150) may be positioned on the y-axis of the battery cell stack (120) and may face at least one of the two battery cells (110) located at both ends of the battery cell stack (120).

[0061] Additionally, although not shown, a thermally conductive resin may be injected between the inner surface of the battery cell stack (120) and the module frame (200), and a thermally conductive resin layer (not shown) may be formed between one side of the inner surface of the battery cell stack (120) and the module frame (200) by the injected thermally conductive resin. At this time, the thermally conductive resin layer may be located on the z-axis of the battery cell stack (120), and the thermally conductive resin layer may be formed between the bottom surface (or may be referred to as a bottom part) located on the -z-axis of the battery cell stack (120) and the module frame (200).

[0062] The busbar frame (300) may be positioned on one side of the battery cell stack (120) to cover one side of the battery cell stack (120) and to guide the connection between the battery cell stack (120) and an external device. The busbar frame (300) may be positioned on the front or rear side of the battery cell stack (120). At least one of a busbar (510, 520) and a module connector may be mounted on the busbar frame (300). For a specific example, referring to FIGS. 2 and 3, one side of the busbar frame (300) may be connected to the front or rear side of the battery cell stack (120), and the other side of the busbar frame (300) may be connected to the busbar (510, 520).

[0063] The busbar frame (300) may include an electrically insulating material. The busbar frame (300) may restrict the busbar (510, 520) from contacting other parts of the battery cells (110) other than the part joined to the electrode leads (111, 112), and may prevent an electrical short circuit from occurring.

[0064] Although not shown, the busbar frame (300) may be two, and may include a first busbar frame located on the front of the battery cell stack (120) and a second busbar frame located on the rear of the battery cell stack (120).

[0065] The end plate (400) may be intended to protect the battery cell stack (120) and the electrical components connected thereto from external physical impact by sealing the open side of the module frame (200). To this end, the end plate (400) may be manufactured from a material having a certain strength. For example, the end plate (400) may include a metal such as aluminum.

[0066] The end plate (400) can be combined (bonded, sealed, or sealed) with the module frame (200) while covering the busbar frame (300) or busbar (510, 520) located on one side of the battery cell stack (120). Each corner of the end plate (400) can be joined to the corresponding corner of the module frame (200) by means such as welding. Additionally, an insulating cover (800) for electrical insulation can be located between the end plate (400) and the busbar frame (300).

[0067] Although not shown, the end plate (400) may be two, and may include a first end plate located on the front of the battery cell stack (120) and a second end plate located on the rear of the battery cell stack (120).

[0068] The first end plate can be combined with the module frame (200) while covering the first busbar frame on the front surface of the battery cell stack (120), and the second end plate can be combined with the module frame (200) while covering the second busbar frame. In other words, the first busbar frame can be positioned between the first end plate and the front surface of the battery cell stack (120), and the second busbar frame can be positioned between the second end plate and the rear surface of the battery cell stack (120).

[0069] The busbar (510, 520) is mounted on one side of the busbar frame (300) and may be for electrically connecting the battery cell stack (120) or battery cells (110) to an external device circuit. The busbar (510, 520) can be protected from external impacts, etc. by being positioned on the battery cell stack (120) or the busbar frame (300) and the end plate (400), and the degradation of durability due to external moisture, etc. can be minimized.

[0070] The busbar (510, 520) can be electrically connected to the battery cell stack (120) through the electrode leads (111, 112) of the battery cell (110). Specifically, the electrode leads (111, 112) of the battery cell (110) can be bent and connected to the busbar (510, 520) after passing through a slit formed in the busbar frame (300). The battery cells (110) constituting the battery cell stack (120) can be connected in series or in parallel by the busbar (510, 520).

[0071] One battery module (100) may include a terminal busbar (520) for electrically connecting another battery module (100). In order to be connected to another external battery module (100), at least a portion of the terminal busbar (520) may be exposed to the outside of the end plate (400), and the end plate (400) may be provided with a terminal busbar opening (400H) for this purpose.

[0072] The terminal busbar (520) may include an additional upwardly protruding portion, unlike the other busbar (510), and the protrusion may be exposed to the outside of the battery module (100) through the terminal busbar opening (400H). The terminal busbar (520) may be connected to another battery module (100) or a BDU (Battery Disconnect Unit) through the protrusion exposed through the terminal busbar opening (400H), and may form a High Voltage (HV) connection with them.

[0074] Meanwhile, as described above, a fire may occur inside a battery module (100) in which battery cells (110) are stacked at a high density. When a fire occurs in one battery module (100), heat, gas, or flame of the battery module (100) can be transferred to an adjacent battery module (100), so a continuous fire may occur between battery modules (100), and consequently, there was a problem of reduced durability and stability of the battery module (100) or the battery pack containing it.

[0075] Therefore, below, we will describe a venting part (210) that can improve the durability and stability of the battery module (100) by resolving the above-mentioned ignition phenomenon.

[0076] FIG. 5 is a cross-sectional view of the battery module of FIG. 2 cut along line AA, FIG. 6 is a diagram showing the direction in which heat, gas, or flame, etc. generated in the internal space of the battery module according to one embodiment of the present invention is discharged through the venting part, and FIG. 7 is a diagram showing examples of the venting part of the battery module according to one embodiment of the present invention.

[0077] Referring to FIGS. 5 and 6, a module frame (200) according to one embodiment of the present invention may include a venting portion (210) that penetrates the inner surface (200a) and the outer surface (200b) of the module frame (200).

[0078] The venting section (210) may be for communicating the interior of the battery module (100), which is sealed by the module frame (200) and the end plate (400), with the exterior of the battery module (100). The venting section (210) may be for discharging heat, gas, or flames generated during internal ignition of the battery module (100) to the exterior of the battery module (100).

[0079] The venting section (210) may have a hole shape that connects an inlet (210a) formed on the inner surface (200a) of the module frame (200) and an outlet (210b) formed on the outer surface (200b). The inlet (210a), outlet (210b) of the venting section (210), and the side (210c) of the venting section (210) extending between the inlet (210a) and the outlet (210b) may be defined by the hole structure (shape) of the venting section (210). In FIG. 5, the shape of the hole of the venting section (210) is indicated by a dotted line to explain the shape of the inlet (210a), outlet (210b), and side (210c).

[0080] Meanwhile, the hole of the venting portion (210) may have a cylinder shape, but may also have a deformed cylinder shape as shown in FIG. 5. Here, a deformed cylinder shape means that the size and shape of the radial cross-section are not uniform, so that at least a portion of the circumferential surface is deformed to be convex or concave in the radial direction. In a conventional cylinder shape, the axial cross-section may have an angular shape, but in a deformed cylinder shape, the axial cross-section may have a round shape.

[0081] For a specific example, the venting portion (210) may have a shape in which its radial cross-section (or diameter) increases toward the axial end, such as the neck of a gourd. As illustrated in FIGS. 5, 6(b), and 6(c), the end region of the venting portion (210) may be extended outwardly in a radial direction. The end region of the venting portion (210) may have a reverse tapered shape. Here, the end region of the venting portion (210) may refer to an area located at the end of the axis of the venting portion (210), and the central region of the venting portion (210) may refer to an area located between the two end regions mentioned above.

[0082] If the two end regions of the venting section (210) have an inverse taper shape, internal gases of the battery module (100) can be rapidly moved to the outside of the battery module (100) through the venting section (210). Specifically, the central region located between the two end regions may have a relatively smaller volume per unit length along the axis than the end regions. Gases can enter the central region through one end region near the inlet (210a), and as the volume is reduced, their pressure may increase, allowing them to rapidly move to the other end region near the outlet (210b), which is a relatively low-pressure environment. Through this, the gas inside the battery module (100) can be rapidly discharged to the outside.

[0083] Additionally, in the drawings described above, both end regions of the venting section (210) are shown as having an inverted taper shape, but only one of the two end regions of the venting section (210) may have an inverted taper shape. Even if only one of the two end regions of the venting section (210) has an inverted taper shape, it can promote the outflow of gas more than a conventional cylinder shape, so the gas discharge effect of the venting section (210) provided as in FIG. 6(b) and FIG. 6(c) may be greater than that of the venting section (210) provided as in FIG. 6(a).

[0085] Meanwhile, as illustrated in FIG. 6(a), if the hole of the venting section (210) is in the shape of a cylinder, internal gas, etc. may collide with the corner section (212) between the hole of the venting section (210) and the module frame (200) during the process of discharging heat, gas, or flame, etc. inside the battery module (100) to the outside, and the collided gas, etc. may re-enter the interior of the battery module (100) and impede the ventilation function of the venting section (210). Here, the corner section (212) may refer to an area including the boundary between the venting section (210) and the module frame (200), or an area extending from the hole structure of the venting section (210) to the module frame (200).

[0086] On the other hand, when a hole in the venting portion (210) is provided as illustrated in FIG. 6(b) and FIG. 6(c), the side (210c) of the venting portion (210) included in the corner portion (212) may be curved as the end region of the venting portion (210) spreads outwardly radially. In the axial cross-section of the venting portion (210), the side (210c) of the venting portion (210) included in the corner portion (212) may have a round shape. An internal gas lamp that collides with the corner portion (212) may be attracted toward the outlet (210b) along the direction guided by the round shape of the corner portion (212).

[0087] As such, since the discharge path of the gas lamp is formed according to the shape of the corner portion (212) near the inlet (210a), the effect of the venting portion (210) may vary depending on the angle (hereinafter referred to as the 'diffraction angle') that the corner portion (212) makes with the inlet (210a) based on the axial cross-section of the venting portion (210). The diffraction angle of FIG. 6(b) can be described as being larger than that of FIG. 6(a), and FIG. 6(c) as being larger than that of FIG. 6(b). In this case, the diffraction angle can be calculated based on the tangent at a point on the corner portion (212). The larger the diffraction angle, the better the ventilation function of the venting portion (210) may be; however, the ventilation function may also be influenced by the size of the round shape of the corner portion (212) and the diameter of the central area. Therefore, the ventilation function of the venting portion (210) may not necessarily improve as the diffraction angle increases.

[0089] A venting portion (210) may be formed on at least one surface of the module frame (200). Here, the module frame (200) may have two surfaces that are open and positioned to face each other along the x-axis, which is the longitudinal direction of the battery cell stack (120). The module frame (200) may have two surfaces positioned to face each other along the y-axis (hereinafter referred to as "surfaces on the y-axis") and two surfaces positioned to face each other along the z-axis (hereinafter referred to as "surfaces on the z-axis").

[0090] Here, a surface on the y-axis of the module frame (200) may face the side of the battery cell stack (120). One surface on the y-axis of the module frame (200) may be a surface extending along the width or length direction of the battery cell stack (120). One surface on the y-axis of the module frame (200) may face one surface of a single battery cell (110). For convenience of explanation, one surface on the y-axis of the module frame (200) may be referred to as the side of the module frame (200).

[0091] Also, here, one surface on the z-axis of the module frame (200) may face the upper or lower surface of the battery cell stack (120). The one surface on the z-axis of the module frame (200) may be a surface that extends along the stacking direction or length direction of the battery cell stack (120). The one surface on the z-axis of the module frame (200) may face each of the one surfaces of a plurality of battery cell stacks (120) arranged side by side along one direction. For convenience of explanation, the one surface on the z-axis of the module frame (200) may be referred to as the upper surface or lower surface (bottom surface or bottom part).

[0092] As illustrated in FIGS. 5 and 6, it may be preferable for the venting section (210) to be formed on one side of the module frame (200) along the z-axis. This is because when the venting section (210) is located on one side of the module frame (200) along the z-axis, the inlet (210a) of the venting section (210) can be located closer to the multiple battery cells (110) of the battery cell stack (120) than when it is located on one side of the y-axis, so that heat, gas, or flame emitted from the multiple battery cells (110) can be quickly discharged to the outside. Thus, the location of the venting section (210) on the module frame (200) can be determined according to the location of one side of the battery cell stack (120) where one side of the multiple battery cells (110) is located side by side.

[0093] Meanwhile, the location of the venting section (210) on the module frame (200) may be determined according to the arrangement of the battery modules (100) within the battery pack. For example, a plurality of battery modules (100) may be arranged along the y-axis or x-axis within the battery pack and not arranged in the z-axis direction. In this case, as shown in FIGS. 5 and 6, if the venting section (210) is formed on one side of the module frame (200) on the z-axis, other adjacent battery modules (100) are not located on the discharge path extending from the inlet (210a) of the venting section (210) to the outlet (210b), thereby minimizing the impact that discharged heat, gas, or flame may have on other battery modules (100). Meanwhile, if the side on the -z-axis among the two sides on the z-axis is the mounting surface connected to the battery pack, the venting section (210) may be formed on the +z-axis.

[0095] The venting section (210) may be formed entirely on one side of the module frame (200) or may be formed on a part of one side of the module frame (200). Here, when the venting section (210) is formed on a part of one side of the module frame (200), it may be preferable for the venting section (210) to be located at the periphery of the module frame (200). Specifically, when high-temperature gas or flame is generated from the battery cell (110), the high-temperature gas or flame may be transmitted to an adjacent battery module (100) through the terminal busbar opening (400H), etc., and the performance of the adjacent battery module (100) may be degraded. In addition, if the flame is directly discharged, the flame may be transmitted to an adjacent battery module, thereby causing a chain reaction of ignition and explosion. Accordingly, if a venting section (210) is formed in the periphery of a module frame (200) close to a busbar frame (300), an end plate (400), and busbars (510, 520), the ignition phenomenon within the battery module (100) can be relieved through the venting section (210), thereby minimizing the impact of heat, gas, or flame on other battery modules (100). Additionally, the venting section (210) may be provided at a longitudinal position corresponding to the periphery of the electrode leads (111, 112) included in the battery cell stack (120). In this case, heat, gas, or flame generated in the periphery of the electrode leads (111, 112) can be discharged more effectively through the venting section (210). Here, the surrounding area of ​​the electrode leads (111, 112) may refer to an area that includes the electrode leads (111, 112) and is spaced apart from the electrode leads (111, 112) by a predetermined distance or less.

[0096] At this time, the peripheral part of the module frame (200) may refer to a part of the module frame (200) that corresponds to the peripheral area (120a) of the battery cell stack (120) based on the battery module (100) combined into a complete body. Here, the peripheral area (120a) of the battery cell stack (120) may include the peripheral area of ​​the electrode leads (111, 112), but is not necessarily so. Also, at this time, the central part of the module frame (200) may refer to a part of the module frame (200) that corresponds to the central area (120b) of the battery cell stack (120).

[0098] Meanwhile, although the venting section (210) is depicted as having four parts in FIGS. 2 to 6 described above, this is not necessarily the case, and the number of venting sections (210) may vary. For example, the venting section (210) may be one, as shown in FIGS. 7(a) and FIGS. 7(b) (in FIGS. 7, the location where the venting section (210) is provided is exemplified as area B). For another example, the venting section (210) may be two or more, as shown in FIGS. 2 to 6, FIGS. 7(c), and FIGS. 7(d) described above.

[0099] When there are multiple venting sections (210), the venting sections (210) may be arranged in rows or columns. As a specific example, the venting sections (210) may be arranged to form a single row as shown in FIGS. 2 and FIGS. 3. As another specific example, the venting sections (210) may be arranged to form two or more rows as shown in FIGS. 7(c) and FIGS. 7(d). In this case, each row may be extended along the stacking direction. The venting sections (210) arranged in rows or columns may be positioned at a distance from each other, and it may be desirable for the spacing between each venting section (210) to be even in order to effectively discharge gas inside the battery module (100).

[0100] At this time, the direction in which multiple rows are arranged may follow the length direction (x-axis direction) of the battery cell stack (120). Also, the direction in which multiple columns are arranged may follow a direction perpendicular to the length direction of the battery cell stack (120) (y-axis direction or z-axis direction), and may be determined differently depending on one side of the module frame (200) where the venting section (210) is located. For example, if the venting section (210) is formed on one side of the module frame (200) on the z-axis, the direction in which multiple columns are arranged may be the stacking direction (y-axis direction) of the battery cell stack (120).

[0101] The shape of the inlet (210a) or outlet (210b) of the venting section (210) may be provided in various ways. For example, the shape of the inlet (210a) or outlet (210b) may be provided as a curve having curvature, as shown in FIG. 7(a). Also, the shape of the inlet (210a) or outlet (210b) may be provided as a circular or elliptical shape. As another example, the shape of the inlet (210a) or outlet (210b) may be provided as a polygon with vertices, as shown in FIG. 7(b). However, if the aforementioned corner section (212) has a rounded shape, each vertex of the polygon may not have a pointed shape. The shape of the inlet (210a) or outlet (210b) may be provided differently from what is described above, and the shape will not be limited by the illustrated drawings.

[0102] Here, the shape of the inlet (210a) or outlet (210b) formed on the upper surface of the z-axis of the module frame (200) may have a shape in which the length on the y-axis is longer than the length on the x-axis, but is not necessarily so.

[0104] Meanwhile, the direction in which gas inside the battery module (100) is discharged to the outside through the venting section (210) may be a direction from the inlet (210a) toward the outlet (210b), and by changing the position of the inlet (210a) and the outlet (210b) of the venting section (210), the direction of heat, gas, or flame discharged from the venting section (210) can be controlled.

[0105] If the inlet (210a) and the outlet (210b) on the z-axis are formed at different positions in the longitudinal direction (x-axis direction) or the stacking direction (y-axis direction), the direction of discharge of gas, etc. is designed to be different from the direction of gravity of the Earth, so the phenomenon of foreign substances from outside the battery module (100) entering the interior of the battery module (100) along the direction of gravity can be minimized. In addition, since the discharge direction forms an angle with the direction from the battery cell stack (120) toward the inlet (210a), the direction of high-temperature heat, gas, and flame introduced from the battery cell stack (120) can be diverted, and the length of the discharge path can be increased, so the gas, etc. discharged through the outlet (210b) can have a lower temperature.

[0106] Additionally, the inlet (210a) and the outlet (210b) are formed such that the discharge direction of the venting section (210) forms an angle with the direction in which one side of the module frame (200) on which the venting section (210) is formed is located, which may be intended to minimize the influence on adjacent battery modules (100) within the battery pack. Specifically, a plurality of battery modules (100) may be arranged along the x-axis direction within the battery pack, and at this time, the venting section (210) may be formed on one side of the module frame (200) located on the x-axis for various reasons such as design. Since it is easy to affect other adjacent battery modules (100) when the venting section (210) is located on the x-axis, it may be desirable to form the discharge path of the venting section (210) at an angle with the x-axis, or more specifically, to form the discharge path of the venting section (210) in a direction where the adjacent battery module (100) is not located.

[0107] Here, since it is desirable for the heat, gas, or flame discharged from the venting section (210) to spread more rapidly to the outside of the battery module (100), the size of the outlet (210b) may be provided larger than the size of the inlet (210a).

[0108] In addition, if multiple venting sections (210) are provided, the discharge directions of each venting section (210) may be the same, but depending on the embodiment, they may be designed to be different. If the discharge directions of each venting section (210) are formed differently, the gas discharged from the venting section (210) can spread to a wider space outside the battery module (100) in various directions. Accordingly, gas discharge from the battery module (100) can be achieved quickly, and effects such as preventing heat generation of the battery module (100) can be achieved.

[0110] Meanwhile, if a venting section (210) is provided to communicate the interior and exterior of the module frame (200), dust, impurities, etc. from outside the module frame (200) may enter the interior of the module frame (200) through the hole structure of the venting section (210). Additionally, when ignition occurs inside the module frame (200), external oxygen may be supplied along the venting section (210), thereby promoting internal ignition. Therefore, it may be desirable to provide a cover on the venting section (210) to prevent foreign substances from entering through the hole of the venting section (210).

[0112] Accordingly, a battery module according to another embodiment of the present invention including the cover described above will be described below. The battery module described below may include each component of the battery module according to the embodiment described above, and is indicated by the same reference numerals in the drawings described below. Therefore, among the components of the battery module according to another embodiment of the present invention, those indicated by the same reference numerals as in FIGS. 1 to 7 can be explained by referring to the above description, so a detailed description is omitted to avoid redundancy.

[0114] FIG. 8 is a perspective view of a battery module according to another embodiment of the present invention, and FIG. 9 is a drawing for explaining the cover of FIG. 8. FIG. 10 is a drawing illustrating examples of a cover of a battery module according to another embodiment of the present invention.

[0116] Referring to FIG. 8, a battery module (100) according to another embodiment of the present invention may include a battery cell stack (120), a module frame (200), a busbar frame (300), an end plate (400), and busbars (510, 520). A battery module (100) according to another embodiment of the present invention may include a venting section (210) and a cover (220) provided on the venting section (210), through which high-temperature gas generated inside the battery module (100) is quickly discharged to the outside, and external foreign substances may be prevented from entering the battery module (100). The venting section (210) and cover (220) according to another embodiment of the present invention may improve the durability and long-term safety of the battery module (100) by minimizing the temperature rise inside the battery module (100) and compensating for the disadvantages of the hole structure of the venting section (210).

[0118] The cover (220) may be provided in the form of a membrane for covering the hole of the venting section (210). The cover (220) may be provided in the form of a plate extending from one corner to another. The cover (220) may cover the hole of the venting section (210) by being positioned to cover the inlet (210a) or the outlet (210b).

[0119] The covers (220) may be provided in pairs, and a pair of covers (220a, 220b) may be arranged symmetrically with respect to each other on the radial cross-section of the venting section (210). In this case, one cover (220a) and the other cover (220b) may be positioned apart. In this case, although not illustrated, one cover (220a) and the other cover (220b) may be positioned close together with one corner facing each other. It may be possible for the covers (220) to be provided individually, but it will be easier to open the venting section (210) if the covers (220) are provided in pairs.

[0120] One end of the cover (220) may be connected to the module frame (200) or the corner portion (212), wherein the part of the cover (220) connected to the module frame (200) or the corner portion (212) may be referred to as the connecting portion (221). The connecting portion (221) of the cover (220) may be fixed to the inner surface (200a) or the corner portion (212) of the module frame (200) in a portion adjacent to the inner surface (200a). Here, the connecting portion (221) of the cover (220) may be located along the corner of the inlet (210a) or may be located outside the corner of the inlet (210a).

[0121] The other end of the cover (220) may not be connected to the module frame (200) or the corner portion (212). The portion of the cover (220) that is not connected to other components of the battery module (100) may be referred to as the deformable portion (222). The deformable portion (222) of the cover (220) may be deformable according to an external force, and for this purpose, the cover (220) may be manufactured from a flexible material. The cover (220) may be manufactured from a bendable metal material. For example, the cover (220) may be manufactured from aluminum.

[0122] Referring to FIG. 9, the cover (220) can open or close the hole of the venting section (210). When no ignition occurs in the battery module (100) as in FIG. 9(a), the cover (220) can prevent external impurities or oxygen from entering the interior of the battery module (100) by closing the hole of the venting section (210). Additionally, when the internal pressure increases due to effluent generated during internal ignition of the battery module (100), the cover (220) can release the effluent to the outside by opening the hole of the venting section (210) as in FIG. 9(b). Here, the effluent may be internal heat, gas, flame, or combustion effluent resulting therefrom.

[0123] As described above, the end region of the venting portion (210) in which the corner portion (212) is formed may have an inverted taper shape. When the venting portion (210) is formed as described in FIG. 5, FIG. 6(b), FIG. 6(c), or FIG. 9, the deformation portion (222) of the cover (220) may be curved along the shape of the corner portion (212) to open the hole of the venting portion (210). By the deformation portion (222) being curved along the corner portion (212), the gas entering through the inlet (210a) can be moved more easily to the outlet (210b).

[0125] The inlet (210a) of the venting section (210) provided with the cover (220) may include a curve as illustrated in FIG. 8. In this case, if the connecting portion (221) of the cover (220) is formed in the curved area of ​​the inlet (210a), the cover (220) may be difficult to deform along the shape of the corner as illustrated in FIG. 9. Therefore, as illustrated in FIG. 10(a), the connecting portion (221) of the cover (220) may be positioned along the straight portion of the inlet (210a). Additionally, the cover (220) may include a cut line to facilitate deformation. FIG. 10(b) illustrates a case where the cover (220) including the cut line is completely separated through the cut line, and each separated cover (220) is connected to the module frame (220) through a separate connecting portion (221). However, since the cover (220) does not necessarily need to be separated by the cut lines, it may be possible to have multiple cut lines on a single cover (220). Also, since the cover (220) does not necessarily need to cover most of the inlet (210a), it may be possible to provide the cover (220) to be positioned along only the straight portion of the inlet (210a) as in FIG. 10(c).

[0126] The inlet (210a) of the venting section (210) provided with the cover (220) may not include a curve, unlike as illustrated in FIG. 8. Specifically, as shown in FIG. 10(d), the inlet (210a) may be provided in a polygonal shape. At this time, the cover (220) may be provided as a pair as shown in FIG. 10(d), but may also be provided as two or more pairs as shown in FIG. 10(e) and FIG. 10(f), and the manner in which the hole of the venting section (210) opens may be varied by changing the position of the connecting part (221). Meanwhile, although FIG. 10 described above is illustrated as having the connecting part (221) located along the corner of the inlet (210a), this is merely for convenience of explanation, so it is obvious that the connecting part (221) may be located outside the corner of the inlet (210a).

[0128] Meanwhile, the battery module (100) described above may be included in a battery pack. The battery pack may be a structure packed by adding a Battery Management System (BMS) that manages the temperature or voltage of the battery and a cooling device, etc., to the battery module according to the present embodiment.

[0129] Within the battery pack, the battery modules (100) may be arranged in rows and columns. For example, the battery modules (100) may be positioned so that they face each other's end plates (400) with other battery modules (100). When referring to the position of the end plates (400) in the drawing described above, it can be understood that at least two battery modules (100) are arranged along the length direction (x-axis direction). As another example, the battery modules (100) may be arranged along the y-axis or z-axis in addition to the different x-axis. Since the direction in which the battery modules (100) are stacked within the battery pack may vary depending on the volume and shape of the battery pack or the internal structure of the device in which the battery pack is mounted, the stacking direction of the battery modules (100) may differ from the example described above.

[0130] At this time, the location of the venting section (210) and the discharge direction of the venting section (210) can be determined to prevent continuous ignition between battery modules (100) within the battery pack. Specifically, the location and discharge direction of the venting section (210) included in one battery module (100) can be designed so as not to face an adjacent other battery module (100). More detailed information regarding this can be explained by referring to the description above.

[0131] Battery modules and battery packs containing the same can be applied to various devices. Such devices may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and can be applied to various devices capable of using battery modules and battery packs containing the same, and this also falls within the scope of the present invention.

[0132] Although 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 by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0134] 100: Battery module 110: Battery cell 120: Battery cell laminate 200: Module Frame 210: Venting Department 210a: Inlet 210b: Outlet 210c: Side 212: Corner 220: Cover 221: Connection 222: Modified part 300: Busbar Frame 400: End plate 510: Busbar 520: Terminal Bus Bar

Claims

Claim 1 A battery cell stack comprising a plurality of battery cells stacked in a unidirectional manner, a module frame having an inner surface and an outer surface that accommodates the battery cell stack, and an end plate coupled to the module frame and covering the front or rear surface of the battery cell stack, wherein at least one hole-shaped venting portion is formed in the module frame defining an inlet formed on the inner surface and an outlet formed on the outer surface, and the two end regions of the venting portion including the inlet and the outlet have an inverse taper shape, wherein the venting portion is provided with a cover for opening and closing the hole of the venting portion, and the side of the venting portion extending between the inlet and the outlet has a round shape based on the axial cross-section of the venting portion, and the battery module wherein the cover is curved along the side of the venting portion having a round shape according to the internal pressure of the battery module. Claim 2 A battery module according to claim 1, wherein, based on the axial cross-section of the venting portion, the side of the venting portion extending between the inlet and the outlet has a rounded shape, and the effluent introduced through the inlet moves to the outlet along the rounded shape. Claim 3 delete Claim 4 In claim 1, the cover is a battery module located in a portion corresponding to the inlet of the venting portion. Claim 5 In claim 1, the cover is a battery module provided in pairs. Claim 6 In claim 1, the cover is in the form of a plate, and one corner of the cover is a battery module fixed to the module frame. Claim 7 delete Claim 8 In claim 1, the cover is a battery module comprising aluminum. Claim 9 In claim 1, the venting portion is a battery module formed on one surface facing the upper or lower surface of the battery cell stack of the module frame. Claim 10 In claim 1, when the direction from the front to the rear of the battery cell stack is defined as the longitudinal direction, the longitudinal position of the venting portion is a battery module that is closer to the front or rear of the battery cell stack than the center of the battery cell stack having the same longitudinal distance as the front and rear of the battery cell stack. Claim 11 In claim 1, the battery cell includes an electrode lead protruding from one end of the battery cell, and the electrode lead is a battery module located on the front or rear of the battery cell stack. Claim 12 A battery pack comprising at least one battery module according to claim 1.

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