Battery pack

Abstract

The technical concept of the present invention provides a battery pack comprising: a pack frame having a housing space; a battery cell assembly containing battery cells housed in the housing space of the pack frame; and a venting device mounted on the pack frame and configured to open and close an internal passage in response to the pressure of the housing space of the pack frame, wherein the venting device is entirely housed within a venting passage of the pack frame provided between the inner and outer walls of the pack frame.

Description

Technical Field

[0001] The invention relates to a battery pack, and more particularly to a battery pack including a venting device.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0032552 filed on March 7, 2024, and all the contents disclosed in the document of the Korean patent application are included as part of this specification.

Background Art

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. Secondary batteries are widely used as an energy source for various cordless devices such as handsets, notebook computers, and cordless vacuum cleaners. In recent years, due to the improvement of energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has been significantly reduced, and as the cruising range of BEV (battery electric vehicle) increases to the same level as that of fuel vehicles, the main application of secondary batteries is shifting from mobile devices to mobility.

[0004] As secondary batteries are used for mobility, the requirements for the safety of secondary batteries are increasing. When an accident such as a fire occurs in a secondary battery used for mobility, it may endanger the life of the driver, so research on technologies to improve the safety of secondary batteries is essential.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technical problem to be achieved by the present invention is to provide a battery pack including a venting device.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, the technical concept of the present invention provides a battery pack comprising: a pack frame having a housing space; a battery cell assembly containing battery cells housed in the housing space of the pack frame; and a venting device mounted on the pack frame and configured to open and close an internal passage in response to the pressure of the housing space of the pack frame, wherein the venting device is entirely housed in a venting passage of the pack frame provided between the inner and outer walls of the pack frame.

[0007] In an exemplary embodiment, the venting device is characterized by including a base plate mounted on the inner wall of the pack frame and having a passage communicating with a through hole in the inner wall of the pack frame; an opening / closing cover configured to open and close the passage in the base plate; a spring that provides a restoring force to the opening / closing cover so that the opening / closing cover closes the passage in the base plate; and a cap body fixed to the base plate and supporting the spring.

[0008] In an exemplary embodiment, the opening / closing cover is configured to move between a closed position that closes the passage of the base plate and an open position that opens the passage of the base plate, the closed position of the opening / closing cover is more adjacent to the inner wall than the open position of the opening / closing cover, and the spring is configured to pressurize the opening / closing cover in a direction from the outer wall toward the inner wall.

[0009] In an exemplary embodiment, the spring does not enter the housing space of the pack frame when the opening / closing cover is in the closed position.

[0010] In an exemplary embodiment, one end of the spring contacts the cap body, and the other end of the spring contacts the opening / closing cover.

[0011] In an exemplary embodiment, the cap body is characterized by including a projection that supports the spring.

[0012] In an exemplary embodiment, the base plate further includes a fastening bolt coupled to the inner wall of the pack frame and having a protruding portion that extends from the inner wall of the pack frame toward the outer wall of the pack frame, and a nut fitted to the protruding portion of the fastening bolt, wherein the base plate includes a fastening hole into which the protruding portion of the fastening bolt is inserted, and the base plate is fixed to the inner wall of the pack frame by the nut fitting to the protruding portion of the fastening bolt.

[0013] In an exemplary embodiment, the base plate is characterized by being in close contact with the surface of the inner wall of the pack frame that faces the outer wall of the pack frame.

[0014] In an exemplary embodiment, the outer wall of the pack frame is characterized by including a through-hole that connects the venting passage of the pack frame to an external space outside the pack frame.

[0015] In an exemplary embodiment, the venting device is characterized by being exposed to the outside through the through-hole in the outer wall of the pack frame.

[0016] In an exemplary embodiment, the pack frame includes a bottom frame that supports the battery cell assembly and side frames on the bottom frame, and the venting device is mounted on the side frames.

[0017] In an exemplary embodiment, the present invention further includes a pack lid coupled to the side frame so as to cover the battery cell assembly housed in the pack frame. [Effects of the Invention]

[0018] According to an exemplary embodiment of the present invention, the bending device is mounted on the pack frame so as not to occupy the accommodation space of the pack frame that houses the battery cell, so that the space utilization rate and energy density of the battery pack can be improved.

[0019] According to an exemplary embodiment of the present invention, the bending device is mounted on the pack frame so as not to occupy the accommodation space of the pack frame. Therefore, it is not limited to the installation position and number of the valve structure, and the bending device can be mounted on various parts of the pack frame.

[0020] The effects obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, the unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0021] [Figure 1] It is a perspective view showing a battery pack according to an exemplary embodiment of the present invention. [Figure 2] It is a side view showing a part of a battery pack according to an exemplary embodiment of the present invention. [Figure 3] It is a side view showing a bending device according to an exemplary embodiment of the present invention. [Figure 4] It is a cross-sectional view showing a battery pack in a state where the bending device is closed. [Figure 5] It is a cross-sectional view showing a battery pack in a state where the bending device is open. [Figure 6a] It is a cross-sectional view showing a method of manufacturing a battery pack according to an exemplary embodiment of the present invention. [Figure 6b] It is a cross-sectional view showing a method of manufacturing a battery pack according to an exemplary embodiment of the present invention.

Best Mode for Carrying Out the Invention

[0022] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. On the premise that terms and words used in this specification and the claims should not be construed as being limited to ordinary or dictionary meanings, based on the principle that the inventor can appropriately define the concept of the terms in order to explain his own invention in the best way, they can be construed as meanings and concepts consistent with the technical idea of the present invention.

[0023] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent all of the technical ideas of the present invention. Thus, there may be various equivalents and modifications that can replace them at the time of this application.

[0024] In addition, in the description of the present invention, when it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

[0025] Embodiments of the present invention are provided to more fully explain the present invention to an ordinary technician. Therefore, the shapes and sizes of the components in the drawings may be exaggerated, omitted, or shown schematically for a clearer explanation. Thus, the sizes and ratios of each component do not fully reflect the actual sizes and ratios.

[0026] (First Embodiment) Figure 1 is a perspective view showing a battery pack 10 according to an exemplary embodiment of the present invention. Figure 2 is a side view showing a part of the battery pack 10 according to an exemplary embodiment of the present invention. Figure 3 is a side view showing a venting device 100 according to an exemplary embodiment of the present invention. Figures 4 and 5 are cross-sectional views showing a part of the battery pack 10 according to an exemplary embodiment of the present invention; Figure 4 is a cross-sectional view showing the battery pack 10 with the venting device 100 in a closed state, and Figure 5 is a cross-sectional view showing the battery pack 10 with the venting device 100 in an open state.

[0027] Referring to Figures 1 to 5, the battery pack 10 may include a pack frame 200, a pack lid 310, a battery cell assembly 400, and a venting device 100.

[0028] The pack frame 200 can provide a housing space 291 for housing a battery cell assembly 400 and various electrical components. The pack frame 200 may include a bottom frame 210 and side frames 250. The bottom frame 210 and side frames 250 can define the housing space 291.

[0029] The bottom frame 210 can support the battery cell assembly 400. The bottom frame 210 may generally have a flat plate shape extending in a first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction).

[0030] The side frame 250 is positioned on the edge of the bottom frame 210 and can extend continuously along the edge of the bottom frame 210 so as to surround the battery cell assembly 400. For example, the side frame 250 may include a first segment and a second segment facing each other in a first horizontal direction (e.g., the X direction) and a third segment and a fourth segment facing each other in a second horizontal direction (e.g., the Y direction). The first segment of the side frame 250 may be in front of the battery pack 10, and the second segment of the side frame 250 may be behind the battery pack 10.

[0031] The side frames 250 and bottom frame 210 of the pack frame 200 may each include an inner wall 261 and an outer wall 263. The inner wall 261 may define the housing space 291 of the pack frame 200. The outer wall 263 constitutes the exterior of the pack frame 200 and may be exposed to the external space ES outside the pack frame 200. The inner wall 261 and the outer wall 263 are spaced apart from each other, and a space may be provided between the inner wall 261 and the outer wall 263. A venting passage 265 may be provided between the inner wall 261 and the outer wall 263 of the pack frame 200. The venting passage 265 guides the flow of gas inside the pack frame 200 and may include a mounting space in which a venting device 100 is installed.

[0032] The pack lid 310 can be coupled to the pack frame 200 so as to cover the battery cell assembly 400 housed in the pack frame 200. The pack lid 310 can cover the housing space 291 of the pack frame 200 so as to seal the housing space 291 of the pack frame 200. The pack lid 310 can be coupled to the upper end of the side frame 250. The pack lid 310 can generally have a flat plate shape extending in a first horizontal direction (e.g., the X direction) and a second horizontal direction (e.g., the Y direction).

[0033] The battery cell assemblies 400 can be provided within the housing space 291 of the pack frame 200. The battery cell assemblies 400 may correspond to a battery module or a cell-to-pack structure. The battery pack 10 may include one or more battery cell assemblies 400. In an exemplary embodiment, the battery pack 10 may include a plurality of battery cell assemblies 400 arranged in a first horizontal direction (e.g., the X direction) and / or a second horizontal direction (e.g., the Y direction).

[0034] The battery cell assembly 400 may include multiple battery cells. Each battery cell is the basic unit of a lithium-ion battery, i.e., a secondary battery. Each battery cell may include an electrode assembly, an electrolyte, and a cell case. The electrode assembly housed in the cell case may include a positive electrode, a negative electrode, and a separator membrane interposed between the positive and negative electrodes. Depending on the form of assembly, the electrode assembly may be either a jelly roll type or a stack type. A jelly roll type electrode assembly may include a winding structure of a positive electrode, a negative electrode, and a separator membrane interposed between them. A stack type electrode assembly may include multiple positive electrodes, multiple negative electrodes, and multiple separator membranes interposed between them, stacked sequentially. The positive electrode may include a positive electrode current collector and a positive electrode active material. The negative electrode may include a negative electrode current collector and a negative electrode active material.

[0035] Multiple battery cells can be connected in series and / or in parallel. For example, multiple battery cells can be connected in series with each other. For example, multiple battery cells can be connected in parallel with each other. For example, when defining a bank as a set of two or more battery cells connected in parallel with each other, one bank consisting of two or more battery cells connected in parallel with each other can be connected in series with another bank consisting of two or more battery cells connected in parallel with each other.

[0036] Individual battery cells may be pouch-type, cylindrical, or prismatic battery cells. The electrode assembly of a pouch-type battery cell is housed in a pouch cell case containing an aluminum laminate sheet. The electrode assembly of a cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of a prismatic battery cell is housed in a prismatic metal can.

[0037] The venting device 100 can be mounted on the pack frame 200. In Figure 1, the venting device 100 is illustrated as being mounted on the first segment of the side frame 250, which is located in front of the side frame 250. However, it is not limited to this, and the venting device 100 may be mounted on at least one of the segments of the side frame 250, or on the bottom frame 210.

[0038] The venting device 100 can be configured to open and close an internal passage in response to the pressure in the housing space 291 of the pack frame 200. The venting device 100 can be configured to switch between a closed state and an open state in response to the pressure in the housing space 291 of the pack frame 200.

[0039] In the closed state of the venting device 100, the venting device 100 can close the passage between the external space ES and the housing space 291 of the pack frame 200, thereby blocking the gas flow between the external space ES and the housing space 291 of the pack frame 200. In the open state of the venting device 100, the venting device 100 can open the passage between the external space ES and the housing space 291 of the pack frame 200, thereby allowing the gas flow between the external space ES and the housing space 291 of the pack frame 200.

[0040] When the pressure in the containment space 291 of the pack frame 200 is below a preset standard value, the venting device 100 is in a closed state, and when the pressure in the containment space 291 of the pack frame 200 exceeds a preset standard value, the venting device 100 may be in an open state. When the pressure in the containment space 291 of the pack frame 200 exceeds a preset standard value, the venting device 100 opens, the gas in the containment space 291 of the pack frame 200 is released to the external space ES, and the pressure in the containment space 291 of the pack frame 200 can be reduced. When the pressure in the containment space 291 of the pack frame 200 is reduced and falls below a preset standard value, the venting device 100 can switch from an open state to a closed state.

[0041] The venting device 100 can be installed in a venting passage 265 provided between the inner wall 261 and the outer wall 263 of the pack frame 200. In an exemplary embodiment, the venting device 100 can be mounted on the pack frame 200 so that its entirety is housed within the venting passage 265 of the pack frame 200. In an exemplary embodiment, the venting device 100 can be provided entirely between the inner wall 261 and the outer wall 263 of the pack frame 200. In an exemplary embodiment, the components of the venting device 100 can be mounted on the pack frame 200 so as not to intrude into the housing space 291 of the pack frame 200. When the venting device 100 is mounted on the side frame 250, the thickness of the venting device 100 in the thickness direction of the side frame 250 may be less than the thickness of the side frame 250. When the venting device 100 is mounted on the bottom frame 210, the thickness of the venting device 100 in the thickness direction of the bottom frame 210 may be less than the thickness of the bottom frame 210.

[0042] The inner wall 261 of the pack frame 200 may include a through-hole 2611 that communicates with the housing space 291 of the pack frame 200. The outer wall 263 of the pack frame 200 may include a through-hole 2631 that communicates with the external space ES. The venting passage 265 of the pack frame 200 can communicate with the external space ES through the through-hole 2631 in the outer wall 263. The venting device 100 may be exposed to the outside of the battery pack 10 through the through-hole 2631 in the outer wall 263 of the pack frame 200.

[0043] The venting device 100 may include a base plate 110, an opening / closing cover 120, a spring 130, and a cap body 140.

[0044] The base plate 110 can be attached to the inner wall 261 of the pack frame 200. The base plate 110 can be in close contact with the outer surface of the inner wall 261 of the pack frame 200 that faces the outer wall 263. The base plate 110 may include a passage 111 that communicates with a through hole 2611 in the inner wall 261 of the pack frame 200. The passage 111 of the base plate 110 can communicate with the housing space 291 of the pack frame 200 via the through hole 2611 in the inner wall 261 of the pack frame 200. A sealing ring can be placed between the inner walls 261 of the pack frame 200 to prevent gas leakage.

[0045] The opening / closing cover 120 can open and close the passage 111 of the base plate 110. The opening / closing cover 120 can switch between a closed position that closes the passage 111 of the base plate 110 and an open position that opens the passage 111 of the base plate 110, depending on the pressure in the housing space 291 of the pack frame 200. When the venting device 100 is closed, the opening / closing cover 120 can be in the closed position. When the venting device 100 is open, the opening / closing cover 120 can be in the open position. The opening / closing cover 120 can be configured to move linearly between the open position and the closed position. The closed position of the opening / closing cover 120 can be closer to the inner wall 261 than the open position of the opening / closing cover 120.

[0046] When the opening / closing cover 120 is in the closed position, the opening / closing cover 120 can close the passage 111 of the base plate 110 to the external space ES so that the passage 111 of the base plate 110 does not communicate with the external space ES. When the opening / closing cover 120 is in the closed position, the flow of gas between the containment space 291 of the pack frame 200 and the external space ES can be blocked.

[0047] When the opening / closing cover 120 is in the open position, the opening / closing cover 120 can open the passage 111 of the base plate 110 to the external space ES so that the passage 111 of the base plate 110 communicates with the external space ES. When the opening / closing cover 120 is in the open position, gas can flow from the containment space 291 of the pack frame 200 to the external space ES through the passage 111 of the base plate 110.

[0048] The cap body 140 can be fixed to the base plate 110. The cap body 140 can contact one end of the spring 130 and support one end of the spring 130. The cap body 140 may include a support portion that supports one end of the spring 130 and a connecting portion that extends between the support portion and the base plate 110. The support portion of the cap body 140 may include a projection that supports the spring 130. The connecting portion of the cap body 140 can be fastened to the base plate 110 by bolts 150. By fastening the connecting portion of the cap body 140 to the base plate 110 by bolts 150, the cap body 140 can be fixed to the base plate 110.

[0049] The spring 130 can provide a restoring force to the opening / closing cover 120 in the direction from the open position to the closed position. For example, the spring 130 can be configured to pressurize the opening / closing cover 120 in the direction from the outer wall 263 to the inner wall 261. The spring 130 can be provided between the cap body 140 and the opening / closing cover 120. The cap body 140 can support one end of the spring 130, and the opening / closing cover 120 can support the other end of the spring 130. In exemplary embodiments, the spring 130 may be a coil spring. The spring 130 can be mounted on the cap body 140 such that a portion of it is wound around the projection 141 of the cap body 140.

[0050] As shown in Figure 4, when the pressure in the housing space 291 of the pack frame 200 is below a preset reference value, the opening / closing cover 120 can be pressed by the spring 130 and fixed in the closed position. When the opening / closing cover 120 is in the closed position, the components of the venting device 100, such as the opening / closing cover 120 and the spring 130, do not enter the housing space 291 of the pack frame 200.

[0051] As shown in Figure 5, when the pressure in the containment space 291 of the pack frame 200 exceeds a preset threshold, the opening / closing cover 120 can be gradually moved in the direction from the closed position toward the open position or from the inner wall 261 toward the outer wall 263. When the opening / closing cover 120 is in the open position, the venting gas VG can be discharged into the external space ES through the passage 111 in the base plate 110, the gap between the opening / closing cover 120 and the base plate 110, the passage between the inner wall 261 and the outer wall 263, and the through-hole 2631 in the outer wall 263.

[0052] The pack frame 200 may include fastening bolts 320 for fastening the venting device 100. The fastening bolts 320 may be coupled to the inner wall 261 of the pack frame 200 and may include protrusions that extend from the inner wall 261 of the pack frame 200 toward the outer wall 263. The fastening bolts 320 may be clinching bolts coupled to the inner wall 261 of the pack frame 200 in a self-clinching manner. The protrusions of the fastening bolts 320 may be inserted into fastening holes (113 in Figure 6a) of the base plate 110. The battery pack 10 may further include nuts 330 that fit onto the protrusions of the fastening bolts 320. The inner circumferential surface of the nuts 330 may be provided with threads that engage with the threads provided on the outer circumferential surface of the protrusions of the fastening bolts 320. The base plate 110 of the venting device 100 can be fixed to the inner wall 261 of the pack frame 200 by fitting the nut 330 onto the protruding part of the fastening bolt 320.

[0053] In the case of the comparative example battery pack, a portion of the valve structure attached to the pack frame is configured to intrude into the housing space of the pack frame. In this case, the space occupied by the valve structure within the housing space of the pack frame cannot be used for battery cells, resulting in a problem of reduced space utilization of the battery pack. Furthermore, in order to minimize the space occupied by the valve structure within the housing space of the pack frame, there were restrictions on the installation position and number of valve structures.

[0054] According to an exemplary embodiment of the present invention, the venting device 100 is mounted on the pack frame 200 so as not to occupy the housing space 291 of the pack frame 200 that houses the battery cells, thereby improving the space utilization and energy density of the battery pack 10.

[0055] According to an exemplary embodiment of the present invention, the venting device 100 is mounted on the pack frame 200 so as not to occupy the housing space 291 of the pack frame 200, and the venting device 100 can be mounted on various parts of the pack frame 200, without being limited by the installation position and number of valve structures.

[0056] (Second Embodiment) Figures 6a and 6b are cross-sectional views showing a method for manufacturing a battery pack 10 according to an exemplary embodiment of the present invention.

[0057] Referring to Figure 6a, fastening bolts 320 are connected to the inner wall 261 of the pack frame 200. The fastening bolts 320 can be connected to the inner wall 261 of the pack frame 200 using a self-clinching method. The fastening bolts 320 may have protrusions that extend from the inner wall 261 in the direction toward the outer wall 263.

[0058] Referring to Figures 6b and 4, the venting device 100 is assembled to the pack frame 200. Assembling the venting device 100 to the pack frame 200 may include inserting the venting device 100 into the venting passage 265 of the pack frame 200 through the through-hole 2631 of the outer wall 263, positioning the venting device 100 so that the fastening holes 113 of the base plate 110 of the venting device 100 are inserted into the protrusions of the fastening bolts 320, and fitting nuts 330 onto the protrusions of the fastening bolts 320 to secure the base plate 110 of the venting device 100 to the inner wall 261 of the pack frame 200.

[0059] According to an exemplary embodiment of the present invention, the assembly of the venting device 100 to the pack frame 200 can be performed outside the pack frame 200. In this case, it is not necessary to reserve space in the accommodation space 291 of the pack frame 200 for assembling the venting device 100, and the assembly of the venting device 100 can be performed with the pack lid 310 coupled to the pack frame 200. Since the assembly of the venting device 100 can be performed with the pack lid 310 coupled to the pack frame 200, the venting device 100 can be assembled during the EOL (end-of-line) testing phase.

[0060] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be a variety of equivalents and modifications that can be substituted for them at the time of filing.

Claims

1. A pack frame having storage space, A battery cell assembly, which includes a battery cell, is housed in the aforementioned storage space of the pack frame, A venting device attached to the pack frame and configured to open and close an internal passage in accordance with the pressure of the containment space of the pack frame, Includes, The venting device is a battery pack, the entire of which is housed within a venting passage of the pack frame provided between the inner and outer walls of the pack frame.

2. The aforementioned venting device, A base plate is attached to the inner wall of the pack frame and has a passage that communicates with a through hole in the inner wall of the pack frame, An opening / closing cover configured to open and close the passage of the base plate, A spring that provides a restoring force to the opening / closing cover so that the opening / closing cover closes the passage in the base plate, A cap body fixed to the base plate and supporting the spring, The battery pack according to claim 1, including the following:

3. The opening / closing cover is configured to move between a closed position that closes the passage of the base plate and an open position that opens the passage of the base plate. The closed position of the opening / closing cover is more adjacent to the inner wall than the open position of the opening / closing cover. The battery pack according to claim 2, wherein the spring is configured to pressurize the opening and closing cover in the direction from the outer wall toward the inner wall.

4. The battery pack according to claim 3, wherein when the opening / closing cover is in the closed position, the spring does not enter the housing space of the pack frame.

5. The battery pack according to claim 2, wherein one end of the spring contacts the cap body and the other end of the spring contacts the opening / closing cover.

6. The battery pack according to claim 2, wherein the cap body includes a protrusion that supports the spring.

7. A fastening bolt which is connected to the inner wall of the pack frame and includes a protruding portion that extends from the inner wall of the pack frame in a direction toward the outer wall of the pack frame, The nut fitted onto the protruding portion of the fastening bolt, It further includes, The base plate includes fastening holes into which the protruding portions of the fastening bolts are inserted. The battery pack according to claim 2, wherein the base plate is fixed to the inner wall of the pack frame by the nut fitting into the protruding portion of the fastening bolt.

8. The battery pack according to claim 7, wherein the base plate is in close contact with the surface of the inner wall of the pack frame that faces the outer wall of the pack frame.

9. The battery pack according to claim 1, wherein the outer wall of the pack frame includes a through hole that connects the venting passage of the pack frame to an external space outside the pack frame.

10. The battery pack according to claim 9, wherein the venting device is exposed to the outside through the through-hole in the outer wall of the pack frame.

11. The pack frame includes a bottom frame that supports the battery cell assembly and side frames on the bottom frame, The venting device is a battery pack according to any one of claims 1 to 10, which is mounted on the side frame.

12. The battery pack according to claim 11, further comprising a pack lid coupled to the side frame so as to cover the battery cell assembly housed in the pack frame.

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