Relief valve and battery pack including same

Abstract

The technical idea of the present invention provides a battery pack comprising: a pack housing having an inner space in which battery cells are accommodated; and a relief valve mounted on the pack housing, wherein the relief valve comprises: a fixing frame mounted on the pack housing and having a venting passage communicating with the inner space of the pack housing; a valve cover configured to move according to the pressure of the inner space of the pack housing between an open position in which the venting passage of the fixing frame is opened to an external space outside the pack housing and a closed position in which the venting passage of the fixing frame is closed with respect to the external space; and a mesh plate coupled to the valve cover so as to move together with the valve cover and having a plurality of venting holes, and wherein when the valve cover is in the open position, the inner space of the pack housing communicates with the external space through the plurality of venting holes of the mesh plate.

Description

Relief valve and battery pack containing same

[0001] The present invention relates to a relief valve and a battery pack including the same.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2023-0175078, filed December 6, 2023, and all contents of the document in that Republic of Korea patent application are incorporated herein by reference.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0004] As secondary batteries become increasingly used in mobility, demand for their safety is increasing. Fires and other accidents involving secondary batteries used in mobility vehicles can endanger the lives of drivers, making research into technologies that enhance secondary battery safety essential.

[0005] The technical problem to be solved by the present invention is to provide a relief valve and a battery pack including the same.

[0006] In order to solve the above-described problem, the technical idea of ​​the present invention provides a battery pack including: a pack housing having an internal space in which battery cells are accommodated; and a relief valve mounted on the pack housing; wherein the relief valve comprises: a fixed frame mounted on the pack housing and having a venting passage communicating with the internal space of the pack housing; a valve cover configured to move between an open position for opening the venting passage of the fixed frame to an external space outside the pack housing and a closed position for closing the venting passage of the fixed frame to the external space depending on a pressure of the internal space of the pack housing; and a mesh plate coupled to the valve cover so as to move together with the valve cover and having a plurality of venting holes; wherein when the valve cover is in the open position, the internal space of the pack housing communicates with the external space through the plurality of venting holes of the mesh plate.

[0007] In exemplary embodiments, the width of each of the plurality of venting holes is characterized by being greater than or equal to 0.01 mm and less than or equal to 0.61 mm.

[0008] In exemplary embodiments, the mesh plate is characterized by extending continuously along the perimeter of the valve cover.

[0009] In exemplary embodiments, when the valve cover is in the closed position, the mesh plate is surrounded by the peripheral wall of the fixed frame and is not exposed to the external space, and when the valve cover is in the open position, the mesh plate protrudes from the fixed frame and is exposed to the external space.

[0010] In exemplary embodiments, the relief valve is further characterized by comprising a spring configured to provide a restoring force to the valve cover in a direction from the open position toward the closed position.

[0011] In exemplary embodiments, the valve cover is characterized by including a spring-loaded movable rod.

[0012] In exemplary embodiments, the fixed frame is characterized by including: a ring-shaped body fixed to the housing; and a support structure extending from the ring-shaped body toward the moving rod and supporting a side of the moving rod.

[0013] In exemplary embodiments, the spring is characterized in that it is provided between a catch at an end of the moving rod and the support structure.

[0014] In exemplary embodiments, the valve cover is characterized by moving linearly between the closed position and the open position.

[0015] In order to solve the above-described problem, the technical idea of ​​the present invention provides a relief valve including: a fixed frame having a venting passage; a valve cover movably mounted on the fixed frame and configured to move between a closed position for closing the venting passage of the fixed frame and an open position for opening the venting passage of the fixed frame; a mesh plate coupled to the valve cover so as to move together with the valve cover, the mesh plate having a plurality of venting holes; and when the valve cover is in the open position, the venting passage of the fixed frame is connected to an external space through the plurality of venting holes of the mesh plate.

[0016] In exemplary embodiments, the width of each of the plurality of venting holes is characterized by being greater than or equal to 0.01 mm and less than or equal to 0.61 mm.

[0017] In exemplary embodiments, the valve cover further comprises a spring configured to provide a restoring force to the valve cover in a direction from the open position toward the closed position, the valve cover comprising a blocking plate covering the venting passage of the fixed frame and a moving rod connected to the blocking plate, the spring being wound around the moving rod.

[0018] In exemplary embodiments, the mesh plate is characterized by having a tubular shape extending continuously along the perimeter of the barrier plate.

[0019] In exemplary embodiments, the fixed frame includes a ring-shaped body having a hollow portion; and a support structure extending from the ring-shaped body toward the moving rod and supporting a side of the moving rod; characterized in that one end of the spring is supported on a catch of the moving rod, and the other end of the spring is supported on the support structure.

[0020] In exemplary embodiments, the ring-shaped body includes a peripheral wall, and when the valve cover is in the closed position, the peripheral wall of the ring-shaped body is characterized in that it surrounds the mesh plate.

[0021] According to exemplary embodiments of the present invention, the mesh plate of the relief valve includes a venting hole having a size to block the discharge of spark particles, thereby preventing spark particles generated within the battery pack from escaping into the external space. Since the ignition source, one of the three elements of flame, can be eliminated, flame generation around the battery pack can be suppressed, thereby improving the safety of the battery pack and devices including the same.

[0022] The effects that can be 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 skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0023] FIG. 1 is a perspective view of a relief valve showing the relief valve in a closed state according to exemplary embodiments of the present invention.

[0024] FIG. 2 is a perspective view of a relief valve showing the relief valve in an open state according to exemplary embodiments of the present invention.

[0025] FIG. 3 is a cross-sectional perspective view of a relief valve showing the relief valve in an open state according to exemplary embodiments of the present invention.

[0026] FIG. 4 is a perspective view illustrating a battery pack according to exemplary embodiments of the present invention.

[0027] Figure 5 is a cross-sectional view of a battery pack schematically showing the relief valve of the battery pack in a closed state.

[0028] Figure 6 is a cross-sectional view of a battery pack schematically showing the relief valve of the battery pack in an open state.

[0029] Figure 7 is a cross-sectional view showing a mesh plate of a battery pack.

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0031] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0032] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0033] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0034]

[0035] (Example 1)

[0036] FIGS. 1 to 3 are drawings showing a relief valve (100) according to exemplary embodiments of the present invention, wherein FIG. 1 is a perspective view showing a relief valve (100) in a closed state, FIG. 2 is a perspective view showing a relief valve (100) in an open state, and FIG. 3 is a cross-sectional perspective view showing a cross-section of a relief valve (100) in an open state.

[0037] Referring to FIGS. 1 to 3, a relief valve (100) may be mounted in a housing having a sealed internal space. The relief valve (100) may be configured to switch between a closed state and an open state depending on the pressure in the internal space of the housing.

[0038] In the closed state of the relief valve (100), the relief valve (100) can block the flow of gas between the external space and the internal space of the housing by closing the passage between the external space or the external space of the relief valve (100) and the internal space of the housing. In the open state of the relief valve (100), the relief valve (100) can open the passage between the external space and the internal space of the housing by allowing the flow of gas between the external space and the internal space of the housing.

[0039] When the pressure in the internal space of the housing is lower than or equal to a preset reference value, the relief valve (100) may be in a closed state, and when the pressure in the internal space of the housing exceeds the preset reference value, the relief valve (100) may be in an open state. When the pressure in the internal space of the housing exceeds the preset reference value, the relief valve (100) may be in an open state, and the gas in the internal space of the housing may be released to the external space, thereby reducing the pressure in the internal space of the housing. When the pressure in the internal space of the housing is reduced and the pressure in the internal space of the housing becomes lower than or equal to the preset reference value, the relief valve (100) may be switched from an open state to a closed state.

[0040] The relief valve (100) may include a fixed frame (110), a valve cover (120), a mesh plate (130), and a spring (140).

[0041] A fixed frame (110) can be mounted and fixed to the housing. The fixed frame (110) can have a venting passage (111) that communicates with the internal space of the housing. The venting passage (111) of the fixed frame (110) can communicate the internal space of the housing with the external space.

[0042] The fixed frame (110) may include a ring-shaped body (113) coupled to the housing and a support structure (115) extending inwardly from the ring-shaped body (113). The venting passage (111) of the fixed frame (110) may include a hollow portion of the ring-shaped body (113).

[0043] The valve cover (120) can be switched between a closed position and an open position depending on the pressure in the internal space of the housing. In the closed state of the relief valve (100), the valve cover (120) can be in the closed position. In the open state of the relief valve (100), the valve cover (120) can be in the open position. The valve cover (120) can move linearly between the open position and the closed position.

[0044] When the valve cover (120) is in the closed position, the valve cover (120) can close the venting passage (111) of the fixed frame (110) to the external space so that the venting passage (111) of the fixed frame (110) does not communicate with the external space. When the valve cover (120) is in the closed position, the gas flow between the internal space of the housing and the external space can be blocked.

[0045] When the valve cover (120) is in the open position, the valve cover (120) can open the venting passage (111) of the fixed frame (110) to the external space so that the venting passage (111) of the fixed frame (110) is in communication with the external space. When the valve cover (120) is in the open position, gas can flow from the internal space of the housing to the external space through the venting passage (111) of the fixed frame (110).

[0046] The valve cover (120) may include a blocking plate (121) that covers and closes the venting passage (111) of the fixed frame (110), and a moving rod (123) coupled to the blocking plate (121). A support structure (115) may extend from the ring-shaped body (113) toward the moving rod (123) and support a side of the moving rod (123) so that the moving rod (123) moves linearly along a predetermined path.

[0047] The mesh plate (130) is coupled to the valve cover (120) and can move together with the valve cover (120) when the valve cover (120) moves. The mesh plate (130) can be coupled to the periphery of the valve cover (120). More specifically, the mesh plate (130) can be coupled to the periphery of the blocking plate (121) of the valve cover (120) and can have a ring shape or a tube shape that continuously extends along the periphery of the blocking plate (121) of the valve cover (120).

[0048] When the valve cover (120) is in the closed position, the mesh plate (130) may be surrounded by the peripheral wall (114) of the fixed frame (110) and may not be exposed to the external space. When the valve cover (120) is in the open position, the mesh plate (130) may protrude from the fixed frame (110) and be exposed to the external space.

[0049] The mesh plate (130) may include a plurality of venting holes (131 in FIG. 7). The plurality of venting holes (131) may be regularly arranged within the mesh plate (130). The shape of each venting hole (131) may be circular or polygonal. When the valve cover (120) switches from a closed position to an open position, the mesh plate (130) may protrude from the fixed frame (110) and be positioned between the venting passage (111) of the fixed frame (110) and the external space. When the valve cover (120) is in the open position, the venting passage (111) of the fixed frame (110) may communicate with the external space through the plurality of venting holes (131) of the mesh plate (130). As illustrated in FIG. 3, the venting gas within the housing flows to the external space through the venting passage (111) of the fixed frame (110) and the venting holes (131) of the mesh plate (130), and the flow path (GP) of the venting gas can be generally perpendicular to the movement direction of the valve cover (120).

[0050] The spring (140) can provide a restoring force to the valve cover (120) in a direction from the open position to the closed position of the valve cover (120). For example, the spring (140) can be a coil spring wound around a movable rod (123). The spring (140) can be provided between a support structure (115) of a fixed frame (110) and a catch (125) of the movable rod (123) at an end of the movable rod (123). One end of the spring (140) can be supported by the catch (125) of the movable rod (123), and the other end of the spring (140) can be supported by the support structure (115). When the pressure in the internal space of the housing is lower than a preset reference value, the valve cover (120) can be elastically supported by the spring (140) and fixed in the closed position. When the pressure in the internal space of the housing exceeds a preset reference value, the valve cover (120) can gradually move from the closed position toward the open position.

[0051]

[0052] (Example 2)

[0053] FIGS. 4 to 7 are drawings showing a battery pack (10) according to exemplary embodiments of the present invention, wherein FIG. 4 is a perspective view showing a battery pack (10), FIG. 5 is a cross-sectional view of a battery pack (10) schematically showing a relief valve (100) of the battery pack (10) in a closed state, FIG. 6 is a cross-sectional view of a battery pack (10) schematically showing a relief valve (100) of the battery pack (10) in an open state, and FIG. 7 is a cross-sectional view showing a mesh plate (130) of the battery pack (10).

[0054] Referring to FIGS. 4 to 7, the battery pack (10) may include a pack housing (210), a battery cell assembly (230), and a relief valve (100). For the relief valve (100), refer to FIGS. 1 to 3 together.

[0055] The pack housing (210) may provide a sealed interior space (220). The pack housing (210) may include a lower housing (211) defining the interior space (220) and a pack lid (215) coupled to the lower housing (211) to cover the interior space (220) of the lower housing (211). The lower housing (211) may include a bottom plate and side walls connected to edges of the bottom plate.

[0056] A battery cell assembly (230) may be provided within an internal space (220) of a pack housing (210). The battery cell assembly (230) may correspond to a battery module or a cell-to-pack structure. The battery pack (10) may include one or a plurality of battery cell assemblies (230). In exemplary embodiments, the battery pack (10) may include a plurality of battery cell assemblies (230) arranged in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction).

[0057] The battery cell assembly (230) may include a plurality of battery cells. Each battery cell is a 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 built into the cell case may include a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The electrode assembly may be either a jelly-roll type or a stack type depending on the assembly form. A jelly-roll type electrode assembly may include a winding structure of a positive electrode, a negative electrode, and a separator interposed therebetween. A stack type electrode assembly may include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween. 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 an negative electrode active material.

[0058] Multiple battery cells may be connected in series and / or in parallel. For example, multiple battery cells may be connected in series with each other. For example, multiple battery cells may also be connected in parallel with each other. For example, when a set of two or more battery cells connected in parallel is defined as a bank, one bank consisting of two or more battery cells connected in parallel with each other and another bank consisting of two or more battery cells connected in parallel with each other may be connected in series.

[0059] The individual battery cells may be pouch-type, cylindrical, or prismatic. 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.

[0060] The relief valve (100) can be mounted on the pack housing (210). In exemplary embodiments, the lower housing (211) has a through hole (211H) communicating with the internal space (220) of the pack housing (210), and the relief valve (100) can be mounted on the through hole (211H) of the side wall of the lower housing (211).

[0061] The relief valve (100) can be switched between an open position that opens the venting passage (111) of the fixed frame (110) to the external space (ES) outside the pack housing (210) and a closed position that closes the venting passage (111) of the fixed frame (110) to the external space (ES) depending on the pressure in the internal space (220) of the pack housing (210). When the pressure in the internal space (220) of the pack housing (210) is below a preset reference value, the valve cover (120) is elastically supported by the spring (140) and is positioned in the closed position, so that the venting passage (111) of the fixed frame (110) does not communicate with the external space (ES), and gas flow between the internal space (220) of the pack housing (210) and the external space (ES) can be blocked. When the pressure in the internal space (220) of the pack housing (210) exceeds a preset reference value, the valve cover (120) moves from the closed position toward the open position, the venting passage (111) of the fixed frame (110) communicates with the external space (ES), and the gas in the internal space (220) of the pack housing (210) can be discharged to the external space (ES) through the venting passage (111) of the fixed frame (110). When the pressure in the internal space (220) of the pack housing (210) is reduced and becomes lower than the preset reference value, the valve cover (120) is fixed in the closed position by the restoring force of the spring (140).

[0062] When the valve cover (120) is in the open position, the mesh plate (130) is positioned between the venting passage (111) of the fixed frame (110) and the external space (ES), and the internal space (220) of the pack housing (210) can communicate with the external space (ES) through the plurality of venting holes (131) of the mesh plate (130) and the venting passage (111) of the fixed frame (110). When the valve cover (120) is in the open position, gas in the internal space (220) of the pack housing (210) can be discharged to the external space (ES) through the venting passage (111) of the fixed frame (110) and the plurality of venting holes (131) of the mesh plate (130). When the valve cover (120) is in the closed position, the mesh plate (130) is surrounded by the peripheral wall (114) of the fixed frame (110) and is not exposed to the external space (ES).

[0063] In general, spark particles (SP) generated at the cell level due to a short circuit between the positive and negative electrodes serve as an ignition source that causes a flame. Specifically, oxygen, venting gas generated by the vaporization of the electrolyte, and spark particles (SP) are the three elements of a flame. When the spark particles (SP) and venting gas generated within the battery pack (10) are released into the external space (ES), the spark particles (SP), venting gas, and oxygen in the external space (ES) may meet to cause a flame around the battery pack (10).

[0064] In exemplary embodiments, the width (W1) of the venting hole (131) may be smaller than 0.61 mm. Here, the width (W1) of the venting hole (131) may refer to the maximum width or diameter of the venting hole (131). If the width (W1) of the venting hole (131) is 0.61 mm or more, there is a concern that spark particles (SP) generated at the cell level due to a short circuit between the positive and negative electrodes may escape into the external space (ES), and the spark particles (SP) may meet with the venting gas and oxygen, causing a flame to occur around the battery pack (10). Therefore, by configuring the width (W1) of the venting hole (131) to be smaller than 0.61 mm, the spark particles (SP) within the battery pack (10) may be prevented from escaping into the external space (ES) through the relief valve (100) and may remain within the pack housing (210). When the spark particles (SP) are blocked from escaping to the external space (ES), the spark particles (SP) are blocked from coming into contact with oxygen, so that the occurrence of flames around the battery pack (10) can be suppressed.

[0065] In exemplary embodiments, the width (W1) of the venting hole (131) may be 0.01 mm or more. If the width (W1) of the venting hole (131) is smaller than 0.01 mm, the gas exhaust flow rate through the venting hole (131) may be too small, thereby reducing the exhaust efficiency through the relief valve (100).

[0066] In exemplary embodiments, the width (W1) of the venting hole (131) may be 0.01 mm or more and less than 0.61 mm. Alternatively, the width (W1) of the venting hole (131) may be 0.01 mm or more and 0.59 mm or less, 0.01 mm or more and 0.57 mm or less, 0.01 mm or more and 0.55 mm or less, 0.01 mm or more and 0.53 mm or less, 0.01 mm or more and 0.51 mm or less, 0.01 mm or more and 0.49 mm or less, 0.01 mm or more and 0.47 mm or less, 0.01 mm or more and 0.45 mm or less, or 0.01 mm or more and 0.43 mm or less.

[0067] According to exemplary embodiments of the present invention, the mesh plate (130) of the relief valve (100) includes a venting hole (131) having a size for blocking the discharge of spark particles (SP), thereby blocking spark particles (SP) generated within the battery pack (10) from escaping to the external space (ES). Since the ignition source, which is one of the three elements of a flame, can be removed, the occurrence of flames around the battery pack (10) can be suppressed, and the safety of the battery pack (10) and a device including the same can be improved.

[0068] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. A pack housing having an internal space containing battery cells; and A relief valve mounted on the above pack housing; Including, The above relief valve, A fixed frame mounted on the pack housing and having a venting passage communicating with the internal space of the pack housing; A valve cover configured to move between an open position opening the venting passage of the fixed frame to an external space outside the pack housing and a closed position closing the venting passage of the fixed frame to the external space according to the pressure of the internal space of the pack housing; and A mesh plate having a plurality of venting holes and coupled to the valve cover so as to move together with the valve cover; Including, A battery pack, characterized in that when the valve cover is in the open position, the internal space of the pack housing communicates with the external space through the plurality of venting holes of the mesh plate.

2. In paragraph 1, A battery pack, characterized in that each of the plurality of venting holes has a width of 0.01 mm or more and less than 0.61 mm.

3. In paragraph 1, A battery pack, characterized in that the mesh plate extends continuously along the periphery of the valve cover.

4. In paragraph 1, When the valve cover is in the closed position, the mesh plate is surrounded by the perimeter wall of the fixed frame and is not exposed to the external space. A battery pack characterized in that when the valve cover is in the open position, the mesh plate protrudes from the fixed frame and is exposed to the external space.

5. In paragraph 1, A battery pack characterized in that the relief valve further includes a spring configured to provide a restoring force to the valve cover in a direction from the open position toward the closed position.

6. In paragraph 5, A battery pack, wherein the valve cover comprises a spring-wrapped moving rod.

7. In paragraph 6, The above fixed frame, a ring-shaped body fixed to the above housing; and A support structure extending from the ring-shaped body toward the moving rod and supporting a side of the moving rod; A battery pack comprising:

8. In paragraph 7, A battery pack characterized in that the spring is provided between a catch at an end of the moving rod and the support structure.

9. In paragraph 1, A battery pack, wherein the valve cover moves linearly between the closed position and the open position.

10. Fixed frame with venting passage; A valve cover movably mounted on said fixed frame and configured to move between a closed position for closing said venting passage of said fixed frame and an open position for opening said venting passage of said fixed frame; A mesh plate having a plurality of venting holes and coupled to the valve cover so as to move together with the valve cover; Including, A relief valve characterized in that when the valve cover is in the open position, the venting passage of the fixed frame communicates with the external space through the plurality of venting holes of the mesh plate.

11. In clause 10, A relief valve, characterized in that each of the plurality of venting holes has a width of 0.01 mm or more and less than 0.61 mm.

12. In paragraph 10, Further comprising a spring configured to provide a restoring force to the valve cover in a direction from the open position toward the closed position; The above valve cover comprises a blocking plate covering the venting passage of the above fixed frame and a moving rod connected to the blocking plate, A relief valve characterized in that the spring is wound around the moving rod.

13. In paragraph 12, A relief valve, characterized in that the mesh plate has a tube shape that extends continuously along the periphery of the blocking plate.

14. In paragraph 13, The above fixed frame, a ring-shaped body having a hollow portion; and A support structure extending from the ring-shaped body toward the moving rod and supporting a side of the moving rod; Including, A relief valve, characterized in that one end of the spring is supported on a catch of the moving rod, and the other end of the spring is supported on the support structure.

15. In paragraph 14, The above ring-shaped body includes a peripheral wall, A relief valve characterized in that when the valve cover is in the closed position, the peripheral wall of the ring-shaped body surrounds the mesh plate.

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