Battery module and battery pack including same

Abstract

The present invention relates to a battery module and a battery pack including same, the battery module comprising: a module case for accommodating a battery cell stack; an end plate disposed at each of two sides of the module case; an insulating cover disposed inside the end plate; and a fastening part which includes a fastening protrusion protruding from the insulating cover, and a protrusion fastening hole formed in the end plate such that the fastening protrusion is fastened thereto through insertion, and which fastens the end plate with the insulating cover, wherein a plurality of fastening parts are provided and disposed at left-right asymmetric positions.

Description

Battery module and battery pack including the same

[0001] The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module and a battery pack including the same in which the venting gas is smoothly discharged in an upward direction when the venting gas is discharged through the fastening portion of the end plate and the insulating cover, and the heat transfer problem is improved.

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries refer to batteries that can be charged and discharged, and they are used in various applications, including portable devices as well as electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0003] Currently widely used rechargeable batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of a unit rechargeable battery cell (i.e., a unit battery cell) is approximately 2.5V to 4.6V. If a higher output voltage is required, a battery pack can be formed by connecting multiple battery cells in series. Additionally, a battery pack can be formed by connecting multiple battery cells in parallel, depending on the required charge / discharge capacity. The number of battery cells constituting the battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0004] When configuring a battery pack by connecting multiple battery cells in series or parallel, it is common practice to first construct a battery module consisting of battery cells and then form the battery pack including the battery module. Here, a battery module refers to a component in which multiple battery cells are connected in series or parallel, and a battery pack refers to a component in which multiple battery modules are connected in series or parallel to increase capacity and output.

[0005] As illustrated in FIGS. 1 and 2, the battery module (10) may include a battery cell stack (11), a module case (12), a busbar frame (13), an insulating cover (14), and an end plate (15).

[0006] A battery cell stack (11) is formed by stacking a plurality of electrically connected battery cells along one direction and housing them in a module case (12). The battery cells may be pouch-type as shown in FIG. 3.

[0007] The module case (12) accommodates a battery cell stack (11) inside. End plates (15) are attached to the front and rear of the module case (12) to cover the front and rear of the module case (12).

[0008] The busbar frame (13) is located on one side of the battery cell stack (11) and can cover one side of the battery cell stack (11) while simultaneously guiding the connection between the battery cell stack (11) and an external device.

[0009] The insulating cover (14) may include an electrical insulating material and may block the busbar of the busbar frame (13) from contacting the end plate (15).

[0010] The end plate (15) can protect the battery cell stack (11) and the electrical components connected thereto from external physical impact by sealing the open side of the module case (12).

[0011] Meanwhile, battery modules or battery packs are inevitably vulnerable to thermal events because multiple battery cells or modules are densely packed in a space-intensive manner. In particular, if thermal runaway (TR) occurs within a battery module, high-temperature gases, flames, and heat are generated; if these are not promptly controlled, thermal propagation (TP) can lead to a chain reaction of fires or explosions affecting not only the affected module but also adjacent modules.

[0012] In a battery module having the above configuration, the insulating cover and the end plate are fastened through a fastening portion consisting of a fastening projection and a fastening hole. Therefore, if a large amount of venting gas is generated due to a thermal event within the module case, the venting gas can be discharged to the outside of the module case through the fastening portion.

[0013] In conventional battery modules, the fastening parts are located in the center of the end plate. Specifically, the fastening holes constituting the fastening parts are located on an imaginary horizontal line passing through the center of the end plate from left to right.

[0014] As described above, since the battery modules are mounted within the battery pack and multiple modules are connected in series or parallel, the movement of venting gas to the bottom and sides of the modules is not smooth; therefore, it is desirable to move the venting gas to the top of the modules and then discharge it to the outside through the top of the battery pack.

[0015] However, if the fastening portion containing the fastening hole is located in the center of the end plate, as in conventional battery modules, the venting gas discharged through the fastening portion is sprayed toward the center of the adjacent battery module, hindering its smooth movement toward the top of the module. Furthermore, when battery modules are arranged facing each other within a battery pack, the positions of the fastening portions of the two opposing modules coincide. Consequently, venting gas discharged from one battery module is sprayed toward the fastening portion of the opposite battery module, causing the fastening portion to melt and allowing the venting gas to flow into the other battery module, which can lead to the spread of heat transfer phenomena.

[0016] The present invention aims to solve the problems of the prior art as described above by providing a battery module and a battery pack including the same, which allows for a smooth flow of venting gas to the upper part of the battery module when venting gas is discharged through a fastening part, and prevents the spread of heat transfer phenomena to other battery modules.

[0017] A battery module according to one embodiment of the present invention for achieving the above-mentioned purpose comprises: a module case in which a battery cell stack is accommodated; end plates disposed on both sides of the module case; an insulating cover disposed on the inner side of the end plate; and a fastening part for fastening the end plate and the insulating cover, comprising a fastening protrusion protruding from the insulating cover and a protrusion fastening hole formed in the end plate into which the fastening protrusion is inserted and fastened; wherein a plurality of fastening parts are provided and disposed at positions that are mutually asymmetrical left and right.

[0018] At least one of the fastening parts is positioned above a virtual horizontal line passing through the center of the end plate.

[0019] The fastening protrusion is in the shape of a hook.

[0020] The fastening portions are provided on the left and right sides, respectively, based on a virtual vertical line passing through the center of the end plate, with one fastening portion positioned above the virtual horizontal line and the other fastening portion positioned below the virtual horizontal line.

[0021] One side fastening part and the other side fastening part are positioned at equal distances based on a virtual horizontal line and a virtual vertical line.

[0022] The end plate is made of metal, and the fastening protrusion is made of plastic.

[0023] A battery pack according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a battery module including a module case in which a battery cell stack is accommodated, end plates disposed on both sides of the module case, an insulating cover disposed on the inner side of the end plates, and a fastening portion for fastening the end plates and the insulating cover; and a pack case accommodating at least one battery module; wherein the fastening portion includes a fastening protrusion formed protruding from the insulating cover and a protrusion fastening hole formed in the end plates into which the fastening protrusion is inserted and fastened, and a plurality of fastening portions are arranged in positions that are mutually asymmetrical left and right.

[0024] Multiple battery modules are arranged in series or parallel within the pack case.

[0025] When a battery module is positioned so that its end plate faces the end plate of another battery module, the positions of the fastening parts formed on the two facing battery modules do not face each other and are offset.

[0026] The battery pack according to the present invention further includes a venting gas discharge portion provided on the upper part of the pack case.

[0027] The pack case includes: a pack housing that is open at the top and accommodates battery modules inside; and a pack cover that covers the open top of the pack housing and is equipped with a venting gas discharge port.

[0028] According to the battery module of the present invention and the battery pack including the same, the venting gas discharged from the battery module is smoothly discharged to the outside of the battery pack through the upper part of the battery module, thereby preventing the spread of the heat transfer phenomenon caused by the delay in the discharge of the venting gas.

[0029] In particular, when battery modules are arranged facing each other within a battery pack, if the positions of the connecting parts formed on the opposing battery modules are different, when venting gas is discharged through the connecting parts of the battery modules, it is discharged toward the end plate rather than toward the connecting parts of the opposite battery module, allowing the venting gas to flow smoothly toward the top of the battery modules and preventing the spread of heat transfer to other battery modules.

[0030] In other words, if the positions of the connection parts differ when battery modules face each other, there is no concern that venting gas emitted from one battery module will melt the connection protrusion of the opposite battery module, and thus there is no concern that venting gas will flow into the opposite battery module through the connection part of the opposite battery module.

[0031] In addition, since some of the fastening parts are positioned above a virtual horizontal line passing through the center of the end plate, venting gas discharged through the fastening parts positioned above the virtual horizontal line can flow smoothly to the top of the battery module.

[0032] FIG. 1 is a perspective view of a battery module according to the prior art.

[0033] Figure 2 is an exploded view of Figure 1.

[0034] Figure 3 is a perspective view of the battery cell shown in Figure 2.

[0035] FIG. 4 is a perspective view of a battery module according to a preferred embodiment of the present invention.

[0036] FIG. 5 is an exploded perspective view of an insulating cover and an end plate constituting a battery module according to a preferred embodiment of the present invention.

[0037] Fig. 6 is a side view of Fig. 4.

[0038] FIG. 7 is a perspective view with a partial cutaway of the fastening structure of the insulating cover and the end plate.

[0039] FIG. 8 is a perspective view showing battery modules seated in a pack housing of a battery pack according to a preferred embodiment of the present invention.

[0040] FIG. 9 is a cross-sectional view schematically showing the venting gas being discharged from a battery pack according to a preferred embodiment of the present invention.

[0041] Figure 10 is a diagram showing the venting gas discharged from one battery module being ejected to the opposite battery module.

[0042] Hereinafter, a battery module according to a preferred embodiment of the present invention and a battery pack including the same will be described in detail with reference to the attached drawings.

[0043]

[0044] FIG. 4 is a perspective view of a battery module according to a preferred embodiment of the present invention, FIG. 5 is an exploded perspective view of an insulating cover and an end plate constituting a battery module according to a preferred embodiment of the present invention, FIG. 6 is a side view of FIG. 4, and FIG. 7 is a perspective view with a partial cutaway of the fastening structure of the insulating cover and the end plate.

[0045] A battery module (100) according to a preferred embodiment of the present invention includes a module case (110), an insulating cover (120), an end plate (130), and a fastening part (140).

[0046] The module case (110) can safely protect the battery cell stack (not shown) and the connected electrical components from external physical impact by accommodating them in the internal space.

[0047] The structure of the module case (110) can be implemented in various ways. For example, the module case (110) may have a monoframe structure. The monoframe may have an integrated form of the top surface, bottom surface, and both sides, and may be manufactured using an extrusion molding method with metal. As another example, the module case (110) may have a structure in which a U-shaped frame and an upper plate are combined. That is, it may have a structure in which a flat upper plate is combined to the upper side of a U-shaped metal frame formed by combining or integrating the bottom surface and both sides. The U-shaped frame and the upper plate may be manufactured using a press molding method. In addition, the module case (110) may be modified into various structures other than an L-shaped frame structure.

[0048] An insulating cover (120) may be positioned between the busbar frame (not shown) and the end plate (130) for electrical insulation between the busbar frame and the end plate (130). That is, the busbar frame, the insulating cover (120), and the end plate (130) may be positioned sequentially outward from the battery cell stack. Similar to the end plate (130), the busbar frame and the insulating cover (120) may each be composed of multiple units.

[0049] The insulating cover (120) may include an electrical insulating material and may block the busbar (not shown) from contacting the end plate (130). The insulating cover (120) may include an opening (121) and a seating portion (122). The opening (121) may be positioned on each of the upper sides of the insulating cover (120), and one end of the terminal busbar may be exposed through the opening (121). A connector opening may be positioned between the openings (121) located on both sides of the insulating cover (120), and a module connector may be exposed to the outside through the connector opening.

[0050] The insulating cover (120) may be positioned on the inner surface of the end plate (130) and may be in close contact with the inner surface of the end plate (130), but is not necessarily so. The insulating cover (120) may be made of plastic material.

[0051] The end plate (130) protects the battery cell stack and the electrical components connected thereto from external physical impact by sealing the open side of the module case (110). To this end, the end plate (130) may be made of a metal material, such as aluminum, having a certain strength. The material of the end plate (130) is not limited to metal, and a heat-resistant synthetic resin material may also be used. In this embodiment, the case where a metal material is used as the material of the end plate (130) is described.

[0052] A terminal opening (131) may be formed in the end plate (130). The terminal opening (131) may be positioned on each side of the end plate (130), and a portion of the insulating cover (120) and one end of the terminal busbar may be exposed through the terminal opening (131). A connector opening may be positioned between the terminal openings (131) located on both sides of the end plate (130), and a module connector may be exposed to the outside through the connector opening.

[0053] The end plate (130) can be combined with the module case (110) while covering a busbar frame or busbar located on one side of the battery cell stack. Each corner of the end plate (130) can be combined with a corresponding corner of the module case (110) by means such as welding, bolting, or hooking.

[0054] The fastening portion (140) is for fastening the insulating cover (120) and the end plate (130) and includes a fastening protrusion (141) formed protruding from one side of the insulating cover (120), and a protrusion fastening hole (142) formed in the end plate (130) into which the fastening protrusion (141) is inserted and fastened. Here, the fastening protrusion (141) is formed integrally with the insulating cover (120) and is made of plastic material, so it is relatively weak against heat compared to the end plate (130) made of metal material.

[0055] Two fastening parts (140) are provided, one on each side based on a virtual vertical line (L1) passing through the center of the end plate (130). One fastening part (140) is positioned above a virtual horizontal line (L2) passing through the center of the end plate (130) from left to right, and the other fastening part (140) can be positioned below a virtual horizontal line (L2). By positioning the one fastening part (140) and the other fastening part (140) at equal distances based on the virtual horizontal line (L2) and the virtual vertical line (L1) passing through the center of the end plate (130), the fastening between the insulating cover (120) and the end plate (130) can be stably maintained.

[0056] The fastening protrusion (141) is formed in a hook shape so that its end is caught on the edge of the protrusion fastening hole (142) while penetrating the protrusion fastening hole (142) of the end plate (130). A catch (142a) is formed on the part of the edge of the protrusion fastening hole (142) where the end of the fastening protrusion (141) is caught to maintain the caught state.

[0057] As shown in the drawing, the fastening portions (140) may be provided in only two, one on each side, or more. Even in this case, it is preferable that the fastening portions (140) be positioned above and below a virtual horizontal line (L2), rather than at the center of the end plate (130).

[0058] Specifically, for stable fastening between the insulating cover (120) and the end plate (130), the fastening parts (140) are provided in equal numbers on both the left and right sides of the end plate (130) and can be arranged in pairs, one on each side, at equal distances based on a virtual horizontal line and a virtual vertical line passing through the center of the end plate (130).

[0059]

[0060] FIG. 8 is a perspective view showing battery modules seated in a pack housing of a battery pack according to a preferred embodiment of the present invention, FIG. 9 is a cross-sectional view schematically showing venting gas being discharged from a battery pack according to a preferred embodiment of the present invention, and FIG. 10 is a drawing showing venting gas discharged from one battery module being ejected to the opposite battery module.

[0061] The battery pack (200) includes a pack case (210), a battery module (100), and a venting gas discharge section (220).

[0062] The pack case (210) accommodates a plurality of battery modules (100) inside and may include a pack housing (211) that is open upward and has battery modules (100) seated inside, and a pack cover (212) that covers the open upper part of the pack housing (211) and is equipped with a venting gas discharge part (220).

[0063] Both the pack housing (211) and the pack cover (212) may be formed in a U-shape, or the pack housing (211) may be formed in a U-shape and the pack cover (212) may be formed in a flat shape.

[0064] A plurality of battery modules (100) may be provided and arranged in series or in parallel within a pack case (210). FIG. 8 shows an example in which battery modules (100) are arranged in two rows in parallel. As shown in FIG. 8, battery modules (100) may be arranged in the left row and the right row with equal numbers and spacing, respectively, and those arranged in the left row and those arranged in the right row may be arranged to face each other. The two battery modules (100) facing each other may be arranged so that their end plates (130) face each other.

[0065] The venting gas discharge section (220) may be provided on the upper surface of the pack case (210), that is, on the pack cover (212). Since the battery module (100) is seated within the battery pack (200) and has a structure in which multiple units are connected in series or parallel, the movement of venting gas to the lower and lateral directions of the battery module (100) is not smooth; therefore, it is preferable to move the venting gas to the upper part of the battery module (100) and then discharge the venting gas to the outside through the upper part of the battery pack (200). Accordingly, it is preferable to position the venting gas discharge section (220) on the upper part of the pack case (210) as described above.

[0066] In order to move the venting gas discharged from the battery module (100) upward, the battery module (100) according to the present invention has the position of the connecting part (140), which serves as the discharge passage for the venting gas, changed differently from the conventional method so that the venting gas discharged through the connecting part (140) can flow smoothly upward to the battery module (100).

[0067] In other words, conventionally, the connecting part (140) is positioned in the center of the end plate (130), so the venting gas discharged through the connecting part (140) is sprayed toward the opposite battery module (100), and the flow is obstructed, so the flow to the top of the battery module (100) is not smooth. Furthermore, because the venting gas ejected from the battery module (100) is ejected through the connecting protrusion (141) made of plastic rather than the metal end plate (130), the connecting protrusion (141) melts, causing the venting gas to flow into the opposite battery module (100), thus hindering the flow to the top of the battery module (100).

[0068] However, in the present invention, when looking at the arrangement of the fastening parts (140) respectively positioned on the left and right sides of the end plate (130), one fastening part (140) is positioned above the center of the end plate (130), and the other fastening part (140) is positioned below the center of the end plate (130). Therefore, among the fastening parts (140), the venting gas discharged from the other fastening part (140) may be obstructed in flow by the opposite battery module (100), but the venting gas discharged from the one fastening part (140) is less obstructed by the opposite battery module (100) and can move smoothly toward the upper side of the battery module (100). Therefore, compared to the conventional method, since the venting gas flows smoothly from the upper side of the battery module (100) within the battery pack (200), it can be discharged smoothly to the outside of the battery pack (200).

[0069] In addition, as described above, when battery modules (100) are arranged facing each other within a battery pack (200), if the positions of the left fastening part (140) and the right fastening part (140) are different as described above, the positions of the fastening parts (140) of the battery modules (100) facing each other are not the same and are staggered.

[0070] Therefore, when venting gas is discharged from one side battery module (100) (in the direction of the arrow in FIG. 10), the venting gas is discharged to the metal end plate (130) rather than directly to the fastening protrusion (141) of the opposite battery module (100), so the fastening protrusion (141) can be prevented from melting. Through this, since the venting gas discharged from one side battery module (100) does not flow into the opposite battery module (100), the flow of venting gas to the top of the battery module (100) can be smoothly induced, and the heat transfer diffusion phenomenon that may occur when the venting gas flows into the opposite battery module (100) can be prevented.

[0071] As described above, in the present invention, the positions of the fastening parts (140) are arranged staggered based on a virtual horizontal line (L2) and a virtual vertical line (L1) passing through the center of the end plate (130), and some of the fastening parts are positioned above the virtual horizontal line (L2), so that the venting gas discharged from the battery module (100) can be smoothly discharged to the outside of the battery pack (200) through the upper part of the battery module (100). This prevents the heat transfer diffusion phenomenon that may occur when the discharge of the venting gas is delayed and some of the venting gas flows into another battery module (100).

[0072]

[0073] Although a battery module and a battery pack including the same according to a preferred embodiment of the present invention have been described in detail with reference to the attached drawings as above, the present invention is not limited to the above-described embodiment and can be implemented in various modified ways within the scope of the claims.

[0074] [Explanation of the symbol]

[0075] 10: Battery module 11: Battery cell stack

[0076] 12: Module case 13: Busbar frame

[0077] 14: Insulation cover 15: End plate

[0078] 100 : Battery Module 110 : Module Case

[0079] 120: Insulation cover 121: Opening

[0080] 122: Seating portion 130: End plate

[0081] 131 : Terminal opening 140 : Fastening part

[0082] 141 : Fastening protrusion 142 : Protrusion fastening hole

[0083] 200 : Battery pack 210 : Pack case

[0084] 211 : Pack Housing 212 : Pack Cover

[0085] 220: Venting gas exhaust section L1: Imaginary vertical line

[0086] L2: Imaginary horizon

Claims

1. A module case accommodating a battery cell stack; End plates disposed on both sides of the above module case; An insulating cover disposed on the inner side of the above end plate; and A fastening portion for fastening the end plate and the insulating cover, comprising a fastening protrusion protruding from the insulating cover and a protrusion fastening hole formed in the end plate into which the fastening protrusion is inserted and fastened; A battery module having a plurality of the above-mentioned fastening parts arranged in mutually asymmetrical positions.

2. In Paragraph 1, A battery module, wherein at least one of the above-mentioned fastening portions is positioned above a virtual horizontal line passing through the center of the end plate.

3. In Paragraph 1, The above-mentioned fastening protrusion is a hook-shaped battery module.

4. In Paragraph 2, A battery module, wherein the above-mentioned fastening portions are respectively provided on the left and right sides based on a virtual vertical line passing through the center of the end plate, and one fastening portion is positioned above the virtual horizontal line and the other fastening portion is positioned below the virtual horizontal line.

5. In Paragraph 4, A battery module in which the one-sided fastening portion and the other-sided fastening portion are positioned at equal distances based on the virtual horizontal line and the virtual vertical line.

6. In Paragraph 1, A battery module in which the material of the end plate is metal and the material of the fastening protrusion is plastic.

7. A battery module comprising a module case accommodating a battery cell stack, end plates disposed on both sides of the module case, an insulating cover disposed on the inner side of the end plates, and a fastening portion for fastening the end plates and the insulating cover; and A pack case accommodating at least one of the above battery modules; comprising, The above fastening portion includes a fastening protrusion formed protruding from the insulating cover, and a protrusion fastening hole formed in the end plate into which the fastening protrusion is inserted and fastened. A battery pack having a plurality of the above-mentioned fastening parts arranged in mutually asymmetrical positions.

8. In Paragraph 7, A battery pack, wherein at least one of the above-mentioned fastening portions is positioned above a virtual horizontal line passing through the center of the end plate.

9. In Paragraph 8, A battery pack wherein the above-mentioned fastening portions are respectively provided on the left and right sides based on a virtual vertical line passing through the center of the end plate, and one fastening portion is positioned above the virtual horizontal line and the other fastening portion is positioned below the virtual horizontal line.

10. In Paragraph 7, A battery pack in which a plurality of battery modules are arranged in series or parallel within the pack case.

11. In Paragraph 10, A battery pack in which, when the battery module is positioned so that its end plate faces the end plate of another battery module, the positions of the fastening portions formed on the two facing battery modules do not face each other but are offset.

12. In Paragraph 7, A battery pack further comprising a venting gas discharge portion provided on the upper part of the pack case.

13. In Paragraph 12, The above pack case is, A pack housing that is open at the top and has the battery modules seated inside; and A battery pack comprising: a pack cover covering the open upper portion of the pack housing and having the venting gas discharge portion.

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