Battery module and battery pack including same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, a module frame that houses the battery cell stack, and at least one vent formed in an upper portion of the module frame, wherein at least one corner of the vent is connected to an upper portion of the module frame and the remaining corners are formed by cutting open the upper portion of the module frame.

Description

[Technical field]

[0001] The present invention relates to a battery module and a battery pack including the same, and more particularly to a battery module and a battery pack including the same that minimizes the continuity of ignition between adjacent battery modules by guiding the direction of gas and flame emission. [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0009239 dated January 22, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0002] With technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting much attention not only for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also as an energy source for power devices such as electric bicycles, electric cars, and hybrid electric cars.

[0003] Small mobile devices use one, two, three, or four battery cells per device, while medium- to large-sized devices such as automobiles require high output and large capacity. Therefore, medium- to large-sized battery modules that electrically connect multiple battery cells are used.

[0004] Since it is preferable that medium- to large-sized battery modules are manufactured with as small a size and weight as possible, prismatic batteries, pouch-shaped batteries, etc., which can be stacked with a high degree of integration and have a small weight compared to their capacity, are mainly used as battery cells for medium- to large-sized battery modules. Meanwhile, the battery module may include a module frame that has an open front and rear and stores the battery cell stack in an internal space to protect the battery cell stack from external impact, heat, or vibration.

[0005] Fig. 1 is a perspective view showing a conventional battery module. Fig. 2 is a cross-sectional view taken along the a-a' axis in Fig. 1 when the battery module ignites. Fig. 3 is a diagram showing the battery module of Fig. 1 mounted in a conventional battery pack when it ignites.

[0006] 1 and 2, a conventional battery module 10 includes a battery cell stack (not shown) in which a plurality of battery cells 11 are stacked, a module frame 20 that houses the battery cell stack, and end plates 41, 42 that cover the front and rear surfaces of the battery cell stack.

[0007] Here, the module frame 20 and the end plates 41, 42 are joined to be hermetically sealed by welding. However, when the battery module 10 is overcharged, if the internal pressure of the battery cells 11 increases and exceeds the limit value of the fusion strength of the battery cells 11, high temperature heat, gas, and flames generated in the battery cells 11 can be discharged to the outside of the battery module 10.

[0008] 2 and 3, high temperature heat, gas, and flames are ejected to the outside through weak parts included in the end plates 41, 42 located on both sides of the battery module 10, and may affect the end plates 41, 42 of adjacent battery modules, causing continuous ignition. At this time, there is a problem that gas, flames, etc. may enter the module frame 20 through the weak parts included in the end plates 41, 42 of the adjacent battery modules, damaging the multiple battery cells 11.

[0009] Therefore, it is necessary to develop a battery module that can guide the direction of gas and flame emission to minimize the continuity of ignition between adjacent battery modules. Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a battery module and a battery pack including the same, which minimize the continuity of ignition between adjacent battery modules by guiding the direction of gas and flame emission.

[0011] The problems to be solved by the present invention are not limited to those described above, and problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings. [Means for solving the problem]

[0012] According to an embodiment of the present invention, a battery module includes a battery cell stack in which a plurality of battery cells are stacked, a module frame that houses the battery cell stack, and at least one venting portion formed on an upper portion of the module frame. The venting portion includes at least one Side is connected to the top of the module frame, and the remaining Side is formed by cutting the upper part of the module frame.

[0013] Each of the cut portions is cut at the venting portion. Side are connected to each other.

[0014] The vent is connected to the upper part of the module frame. Side Based on this, the venting portion is lifted obliquely from the upper portion of the module frame toward the outside.

[0015] The battery module may further include a first bus bar frame covering a front surface of the battery cell stack and to which a terminal bus bar is connected, a second bus bar frame covering a rear surface of the battery cell stack and to which a module connector is connected, and a first end plate and a second end plate coupled to the module frame and covering the first bus bar frame and the second bus bar frame, respectively.

[0016] The vent is connected to the upper part of the module frame. Side can be located adjacent to the first end plate.

[0017] The vent is connected to the upper part of the module frame. Side extends along the width direction of the module frame.

[0018] The venting portion is raised so as to be vented in a direction in which the second end plate is disposed.

[0019] At least two of the venting portions are included, and the at least two venting portions are spaced apart from each other along the longitudinal direction of the module frame.

[0020] At least two of the venting portions are arranged in the same direction relative to each other.

[0021] The first venting portion and the second venting portion are arranged in the same direction.

[0022] The terminal bus bar is connected to an external bus bar that allows the battery module including the terminal bus bar to be connected to another battery module adjacent to the battery module including the terminal bus bar.

[0023] A battery pack according to another embodiment of the present invention includes the battery module described above. Effect of the Invention

[0024] According to an embodiment, the present invention includes a venting portion on the upper portion of the module frame that guides the discharge direction of gas and flame in a predetermined direction, thereby minimizing the continuity of ignition between adjacent battery modules.

[0025] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view showing a conventional battery module. [Diagram 2] 2 is a cross-sectional view taken along the a-a' axis in FIG. 1 when the battery module ignites. [Diagram 3] FIG. 2 is a diagram showing a state in which the battery module of FIG. 1 mounted in a conventional battery pack ignites. [Figure 4] 1 is a perspective view showing a battery module according to an embodiment of the present invention; [Diagram 5] FIG. 5 is an exploded perspective view of the battery module of FIG. [Figure 6] 5 is a perspective view of a battery cell included in the battery module of FIG. 4. [Figure 7] 5 is a perspective view showing a second end plate of the battery module in FIG. 4 from a different angle so as to be seen from the front. [Figure 8] 8 is a cross-sectional view taken along the AA' axis in FIG. 7. [Figure 9] 5 is a diagram showing a state in which the battery module of FIG. 4 mounted in a battery pack according to another embodiment of the present invention catches fire. [Figure 10] FIG. 4 is a perspective view of a battery module according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0028] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0029] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are enlarged to clearly express various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0030] In addition, when a part such as a layer, film, region, or plate is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. Furthermore, being "on" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" in the opposite direction of gravity.

[0031] In addition, throughout the specification, when a part "comprises" a certain element, this means that it can further include other elements, not excluding other elements, unless specifically stated to the contrary.

[0032] Furthermore, throughout the specification, a reference to "in a plane" means that the part is viewed from above, and a reference to "in cross section" means that the part is viewed from the side through a vertical cut.

[0033] Hereinafter, a battery module according to an embodiment of the present invention will be described. However, the description will be made based on the front side of the battery module, but the description is not limited thereto. The same or similar content can be applied to the rear side of the battery module.

[0034] Fig. 4 is a perspective view showing a battery module according to an embodiment of the present invention, Fig. 5 is an exploded perspective view of the battery module of Fig. 4, Fig. 6 is a perspective view of a battery cell included in the battery module of Fig. 4.

[0035] 4 to 6, a battery module 100 according to one embodiment of the present invention includes a battery cell stack 120 in which a plurality of battery cells 110, each having electrode leads 111, 112 protruding in opposite directions, are stacked, a module frame 200 that houses the battery cell stack 120, and a first bus bar frame 310 arranged on one side of the battery cell stack 120 in one direction (x-axis direction) in which the electrode leads 111 protrude.

[0036] 6, the battery cell 110 is preferably a pouch-type battery cell. For example, the battery cell 110 according to this embodiment has a structure in which two electrode leads 111 and 112 face each other in opposite directions and protrude from one end 114a and the other end 114b of a cell body 113, respectively. More specifically, the electrode leads 111 and 112 are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell 110.

[0037] Meanwhile, the battery cell 110 is manufactured by bonding both ends 114a, 114b of the cell case 114 to one side 114c connecting them with each other in a state where an electrode assembly (not shown) is housed in the cell case 114. In other words, the battery cell 110 according to this embodiment has a total of three sealing parts 114sa, 114sb, 114sc, and the sealing parts 114sa, 114sb, 114sc are structured to be sealed by a method such as heat fusion, and the remaining other side part is formed of a connecting part 115. The cell case 114 is formed of a laminate sheet including a resin layer and a metal layer.

[0038] In addition, the connecting portion 115 may extend long along one edge of the battery cell 110, and a protruding portion 110p of the battery cell 110 called a bat-ear is formed at an end of the connecting portion 115. Furthermore, as the cell case 114 is sealed with the protruding electrode leads 111, 112 sandwiched therebetween, a terrace portion 116 is formed between the electrode leads 111, 112 and the cell body 113. In other words, the battery cell 110 includes the terrace portion 116 formed by extending from the cell case 114 in the direction in which the electrode leads 111, 112 protrude.

[0039] The battery cell 110 may be configured in a plurality of pieces, and the plurality of battery cells 110 may be stacked to be electrically connected to each other to form the battery cell stack 120. Referring to FIG. 4, the battery cells 110 may be stacked along the y-axis direction to form the battery cell stack 120. A first bus bar frame 310 may be positioned on one side of the battery cell stack 120 in a direction in which the electrode leads 111 protrude (x-axis direction). Although not shown in detail, a second bus bar frame may be positioned on the other side of the battery cell stack 120 in a direction in which the electrode leads 112 protrude (-x-axis direction). The battery cell stack 120 and the first bus bar frame 310 may be accommodated together in the module frame 200. The module frame 200 may protect the battery cell stack 120 accommodated inside the module frame 200 and electrical equipment connected thereto from external physical impacts.

[0040] The module frame 200 according to the embodiment of the present invention may have a monoframe structure. First, the monoframe may be in the form of a metal plate material with an upper surface, a lower surface, and both side surfaces integrated together, or may be manufactured by extrusion molding. However, the structure of the module frame 200 is not limited thereto, and may be a structure in which a U-shaped frame and an upper plate are combined together. In the case of a structure in which a U-shaped frame and an upper plate are combined together, the upper plate may be combined to the top of the U-shaped frame, which is a metal plate material with a lower surface and both side surfaces combined or integrated together, or may be manufactured by press molding.

[0041] A thermally conductive resin is injected between the battery cell stack 120 and the underside of the module frame 200, and a thermally conductive resin layer (not shown) is formed between the battery cell stack 120 and the underside of the module frame 200 via the injected thermally conductive resin.

[0042] Meanwhile, the module frame 200 may be opened in the direction in which the electrode leads 111 and 112 protrude (x-axis direction, -x-axis direction), and a first end plate 410 and a second end plate 420 may be positioned on both sides of the open portion of the module frame 200, respectively. The first end plate 410 is joined to the module frame 200 while covering the first bus bar frame 310, and the second end plate 420 is joined to the module frame 200 while covering a second bus bar frame (not shown). That is, the first bus bar frame 310 may be positioned between the first end plate 410 and the battery cell stack 120, and the second bus bar frame (not shown) may be positioned between the second end plate 420 and the battery cell stack 120. In addition, an insulating cover 800 (see FIG. 4) for electrical insulation may be positioned between the first end plate 410 and the first bus bar frame 310.

[0043] The first end plate 410 and the second end plate 420 are positioned to cover the one side and the other side of the battery cell stack 120, respectively. The first end plate 410 and the second end plate 420 can protect the first bus bar frame 310 and various electrical components connected thereto from external impacts, and for this purpose, must have a certain strength and can include a metal such as aluminum. Also, the first end plate 410 and the second end plate 420 are positioned to cover the corresponding sides of the module frame 200, respectively. Side The material can be joined by a method such as welding.

[0044] The first busbar frame 310 is located on one side of the battery cell stack 120 to cover the battery cell stack 120 and at the same time guide the connection between the battery cell stack 120 and an external device. Specifically, at least one of a busbar, a terminal busbar, and a module connector is attached to the first busbar frame 310. In particular, at least one of a busbar, a terminal busbar, and a module connector is attached to a surface of the first busbar frame 310 opposite to a surface facing the battery cell stack 120. As an example, FIG. 5 shows a state in which a busbar 510 and a terminal busbar 520 are attached to the first busbar frame 310.

[0045] The battery cells 110 constituting the battery cell stack 120 can be connected in series or parallel by the bus bar 510 and the terminal bus bar 520, and the battery cells 110 can be electrically connected to external devices or circuits through the terminal bus bar 520 exposed to the outside of the battery module 100. As an example, the terminal bus bar 520 is connected to an external bus bar that connects the battery module including the terminal bus bar 520 to another adjacent battery module.

[0046] The first bus bar frame 310 may include an electrically insulating material. The first bus bar frame 310 may prevent a short circuit by restricting contact between the bus bar 510 and the terminal bus bar 520 and the battery cell 110, except for the portion where the bus bar 510 and the terminal bus bar 520 are joined to the electrode lead 111.

[0047] Meanwhile, as described above, a second bus bar frame may be positioned on the other surface of the battery cell stack 120, and a bus bar and a module connector may be attached to the second bus bar frame. An electrode lead 112 may be joined to the bus bar.

[0048] According to the present embodiment, an opening is formed in the first end plate 410 through which the terminal bus bar 520 is exposed. The opening may be a terminal bus bar opening. As an example, as shown in Figs. 3 and 4, a terminal bus bar opening 410H through which the terminal bus bar 520 is exposed is formed in the first end plate 410. The terminal bus bar 520 further includes an upwardly protruding portion compared to the bus bar 510, and the upwardly protruding portion may be exposed to the outside of the battery module 100 through the terminal bus bar opening 410H. The terminal bus bar 520 exposed through the terminal bus bar opening 410H may be connected to another battery module or a Battery Disconnect Unit (BDU) to form a High Voltage (HV) connection.

[0049] FIG. 7 is a perspective view showing the second end plate of the battery module in FIG. 4 from a different angle so that the second end plate is seen from the front.

[0050] 7, according to this embodiment, an opening is formed in the second end plate 420 to expose at least one of the module connectors. The opening may be a module connector opening. As an example, as shown in FIG. 7, a module connector opening 420H is formed in the second end plate 420 to expose the module connector 600. This means that the module connector 600 is attached to the second bus bar frame mentioned above. In addition, an insulating cover 800 for electrical insulation may be positioned between the second end plate 420 and the second bus bar frame 320.

[0051] Meanwhile, although not shown in detail, the module connector 600 can be connected to a temperature sensor, a voltage measuring member, etc., installed inside the battery module 100. The module connector 600 is connected to an external BMS (Battery Management System) to form a LV (Low voltage) connection, and has a function of transmitting temperature information and voltage measured by the temperature sensor and voltage measuring member to the external BMS.

[0052] The following description will focus on the venting portion 250 formed in the module frame 200.

[0053] 4, 5, and 7, the battery module 100 according to the present embodiment has at least one venting portion 250 formed on the upper portion of the module frame 200. The venting portion 250 has at least one Side is connected to the top of the module frame 200, and the remaining Side is formed by cutting the upper part of the module frame 200.

[0054] Also, the vent 250 is connected to the upper part of the module frame 200. Side may be located adjacent to the first end plate 410. That is, the venting portion 250 is connected to the upper portion of the module frame 200. Side is formed adjacent to the terminal bus bar 520. In addition, the bent portion 250 is connected to the upper portion of the module frame 200. Side extends along the width direction of the module frame 200. However, being located adjacent to the first end plate 410 can also be explained as being located away from the second end plate 420.

[0055] In other words, the remaining portion cut at the venting portion 250 Side The second end plate 420 is cut along the longitudinal direction of the module frame 200 to a position adjacent to the second end plate 420. That is, the remaining portion of the cut at the venting portion 250 is cut. Side A portion of the connector 600 is formed adjacent to the module connector 600 .

[0056] As a result, the battery module 100 according to the present embodiment has a remaining portion cut at the vent portion 250. Sideis cut adjacent to the second end plate 420 to guide an exhaust path for the gas and flame exhausted by the venting portion 250.

[0057] More specifically, each of the cutouts at the venting portion 250 Side In one example, the venting portion 250 has a rectangular shape and is connected to one another. Side is connected to the top of the module frame 200, and the remaining Side However, the shape of the venting portion 250 is not limited to this, and any shape that can guide the exhaust direction of gas and flames in the battery module 100 in a predetermined direction can be used.

[0058] Accordingly, the battery module 100 according to the present embodiment can form the venting portion 250 by cutting a portion of the upper portion of the module frame 200, which is advantageous in that the manufacturing process is simple and the manufacturing cost is reduced.

[0059] Fig. 8 is a cross-sectional view taken along the A-A' axis in Fig. 7. Fig. 8(a) is a cross-sectional view taken along the A-A' axis in Fig. 7 when the battery module 100 is operating normally, and Fig. 8(b) is a cross-sectional view taken along the A-A' axis in Fig. 7 when the battery module 100 is igniting.

[0060] 8(a), during normal operation of the battery module 100, the venting portion 250 may be located on the same plane as the upper portion of the module frame 200. That is, the venting portion 250 seals the upper portion of the module frame 200 during normal operation of the battery module 100.

[0061] Accordingly, the venting portion 250 can prevent external gas from entering the module frame 200 when the battery module 100 is operating normally.

[0062] Referring to FIG. 8(b), when the battery module 100 ignites, the venting portion 250 connected to the upper portion of the module frame 200 is exposed to the air. Side 8(b), the venting portion 250 is lifted obliquely from the top of the module frame 200 toward the outside. That is, when the battery module 100 ignites, the internal pressure of the module frame 200 increases, and the venting portion 250 is lifted as shown in FIG. 8(b).

[0063] As a result, a gap is generated between the venting portion 250 and the upper portion of the module frame 200, and such a gap can become a discharge path for gas and flames in the module frame 200. In addition, the gap generated between the venting portion 250 and the upper portion of the module frame 200 is caused by the Side , the exhaust area of ​​the gas and flame is large, and the exhaust effect of the gas and flame can be significantly improved.

[0064] FIG. 9 is a diagram showing a state in which the battery module of FIG. 4 mounted in a battery pack according to another embodiment of the present invention catches fire.

[0065] 2 and 3, in the case of a conventional battery module 10, high temperature heat, gas, and flames generated in the event of a fire within the battery module 10 increase the pressure inside the module frame 200, which causes weak parts of the end plates 41 and 42 on both sides of the battery module 10 to burst, resulting in the problem of the fire spreading to adjacent battery modules 10.

[0066] In particular, for HV connection, the battery modules 10 are arranged so that the end plates 41, on which the terminal bus bars (not shown) are located, face each other, and when the above-mentioned ignition phenomenon occurs, damage may occur to the terminal bus bars (not shown) located within the opposing end plates 41, the battery cells 11, and other components.

[0067] 8 and 9, in a battery module 100 according to an embodiment of the present invention, the venting portion 250 is raised so as to be vented in a direction in which the second end plate 420 is disposed. More specifically, the venting portion 250 may guide an exhaust path for gas and flames in the module frame 200 so as to be exhausted in a direction in which the second end plate 420 is disposed.

[0068] As a result, a gap is formed between the venting portion 250 and the upper part of the module frame 200 adjacent to the module connector 600 (see FIG. 7), thereby preventing high temperature heat, gas, flames, etc. caused by the battery cells 110 from being discharged through an opening in the first end plate 410, such as the terminal bus bar opening 410H (see FIG. 5).

[0069] This is because if a fire spreads to the terminal bus bar 520 (see FIG. 5), the external bus bar connecting the adjacent battery modules may also melt, causing an internal short circuit and further ignition, which may spread to the adjacent battery module. In other words, the battery module 100 according to this embodiment can significantly reduce damage to the adjacent battery modules and the HV connection structure.

[0070] FIG. 10 is a perspective view of a battery module according to another embodiment of the present invention.

[0071] 10, the battery module 100 according to another embodiment of the present invention includes at least two venting portions 250, which are spaced apart from each other along the longitudinal direction of the module frame. More specifically, the at least two venting portions 250 are arranged in the same direction. The number of venting portions 250 may be two as shown in FIG. 10(a) or four as shown in FIG. 10(b), but is not limited thereto and various numbers may be applied.

[0072] As a result, gaps are formed between at least two venting parts 250 and the upper part of the module frame 200, and these gaps can provide more diverse exhaust paths for the gas and flame inside the module frame 200. In other words, the gas and flame inside the module frame 200 can be exhausted through their respective paths, and the speed at which the gas and flame are exhausted can be adjusted.

[0073] A battery pack according to another embodiment of the present invention includes the battery module described above. Meanwhile, one or more of the battery modules according to this embodiment may be packaged in a pack case to form a battery pack.

[0074] The above-mentioned battery module and the battery pack including the same can be applied to various devices, such as vehicles including electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto, and the battery module and the battery pack including the same can be applied to various devices that can use the battery module, and these are also within the scope of the present invention.

[0075] 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. [Explanation of symbols]

[0076] 200: Module frame 250: Venting section 310: First bus bar frame (bus bar frame) 410: First end plate 420: 2nd end plate 520: Terminal busbar 600: Module connector

Claims

1. a battery cell stack in which a plurality of battery cells are stacked; a module frame that houses the battery cell stack; At least one vent formed in an upper portion of the module frame; a first bus bar frame that covers a front surface of the battery cell stack and to which a terminal bus bar is connected; a second bus bar frame that covers a rear surface of the battery cell stack and is connected to a module connector; a first end plate and a second end plate coupled to the module frame and covering the first bus bar frame and the second bus bar frame, respectively; Equipped with At least one side of the venting portion is connected to an upper portion of the module frame, and the remaining side is formed by cutting the upper portion of the module frame, The venting portion is lifted obliquely from the upper portion of the module frame toward the outside based on a side connected to the upper portion of the module frame at the venting portion, The venting portion is raised so as to be vented in a direction in which the second end plate is disposed.

2. The battery module according to claim 1 , wherein each side cut at the vent is connected to each other.

3. The battery module of claim 1 , wherein the edge connected to the upper portion of the module frame at the vent is located adjacent to a first end plate.

4. The battery module according to claim 1 , wherein the side connected to the upper portion of the module frame at the vent extends along a width direction of the module frame.

5. The battery module according to claim 1 , comprising at least two of the venting portions, the at least two venting portions being spaced apart from each other along a longitudinal direction of the module frame.

6. The battery module according to claim 5 , wherein at least two of the venting portions are arranged in the same direction.

7. The battery module of claim 1 , wherein the terminal bus bar is connected to an external bus bar that allows the battery module including the terminal bus bar to be connected to another battery module adjacent to the battery module including the terminal bus bar.

8. A battery pack comprising the battery module according to claim 1 .

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