Battery, battery pack including the same, and motor vehicle including the battery pack

Abstract

A battery according to an embodiment of the present invention includes an electrode assembly, a housing configured to accommodate the electrode assembly through an opening formed on one side, a cap configured to cover the opening, and a frame coupled to an inner surface of the cap in a state at least partially separated from the cap to form a first space, and having a gas passage portion configured such that gas generated in a second space in which the electrode assembly is accommodated can flow into the first space.

Description

Technical Field

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

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0089124 filed on July 19, 2022, Korean Patent Application No. 10-2022-0089123 filed on July 19, 2022, and Korean Patent Application No. 10-2023-0087994 filed on July 6, 2023, and all the contents disclosed in the specifications and drawings of the applications are incorporated herein by reference.

Background Art

[0003] A secondary battery undergoes a charge / discharge process for activation during its manufacturing process and also undergoes a degassing process to discharge the gas generated inside during charge / discharge.

[0004] Such a degassing process of a secondary battery can be performed by applying a negative pressure to an open portion partially formed in the secondary battery. For example, after partially opening one side of a secondary battery having a sealed structure, the secondary battery can be positioned in a chamber where a negative pressure is formed. In this case, the internal gas can escape through the open portion formed in the secondary battery.

[0005] Thus, when removing the gas generated inside the secondary battery, there is a possibility that the electrolyte inside the secondary battery may leak out to the outside when the gas escapes due to the negative pressure.

[0006] Furthermore, during the manufacturing process of a secondary battery, the secondary battery may be transported in a standing state, a lying state, or a state turned upside down, and in this process, the internal electrolyte may adhere to the inner wall surface of the housing. In this case, when a negative pressure is applied to the open portion of the secondary battery, there is a possibility that the electrolyte adhering to the inner side around the open portion may easily leak out to the outside.

[0007] In contrast, although it is conceivable to arrange the secondary battery in a specific direction during the transportation process, in this case as well, there is a risk that the electrolyte will adhere around the opening for the gas venting process due to the flow of the electrolyte occurring during the transportation process. Therefore, if a negative pressure is applied to the opening to perform the gas venting process, the electrolyte adhering around the opening may leak to the outside.

[0008] Therefore, at present, there is an urgent need to work on the development of a battery having a structure capable of suppressing as much as possible the phenomenon that the electrolyte adheres around the opening for the gas venting process during the manufacturing process.

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a battery having a structure capable of suppressing as much as possible the phenomenon that the electrolyte adheres around the opening for the gas venting process during the manufacturing process.

[0010] However, the technical problems to be solved by the present invention are not limited to the above-described problems at all, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention described below.

Means for Solving the Problems

[0011] A battery according to an embodiment of the present invention for solving the above-described problems includes an electrode assembly, a housing configured to accommodate the electrode assembly through an opening formed on one side, a cap configured to cover the opening, and a frame coupled to an inner surface of the cap in a state at least partially separated from the cap to form a first space, and including a gas passage portion configured such that gas generated in a second space in which the electrode assembly is accommodated can flow into the first space.

[0012] The frame may be configured such that communication between the first space and the second space occurs only through the gas passage portion.

[0013] The cap may include a gas vent portion configured to allow gas generated inside the housing to be discharged.

[0014] The battery may include a plug body configured to seal the gas vent portion.

[0015] The plug body may be integrally formed with the cap by welding the region where the gas vent portion is formed after a gas venting process for discharging gas generated inside the housing.

[0016] The battery may include a valve assembly configured to open the gas vent portion during a gas venting process for discharging gas generated inside the housing provided in the first space, and to close the gas vent portion after completion of the gas venting process.

[0017] The valve assembly may include a closure configured to be inserted from the first space into the gas vent portion, and an elastic member positioned between the closure and the frame and configured to elastically bias the closure toward the gas vent portion.

[0018] The cap may include a vent portion configured to break when the internal pressure of the housing increases.

[0019] The distance from the central portion of the cap to the joint portion between the frame and the cap may be configured to be further away than the distance from the central portion of the cap to the vent portion.

[0020] The frame may include an insulating layer formed on a first surface facing the electrode assembly.

[0021] The cap may be configured to have no polarity.

[0022] The battery may include a terminal electrically connected to the electrode assembly.

[0023] The battery may include a current collector configured to be coupled to one side of the electrode assembly to electrically connect the electrode assembly and the housing.

[0024] A battery pack according to an embodiment of the present invention for solving the above-described problems includes a battery according to an embodiment of the present invention.

[0025] A vehicle according to an embodiment of the present invention for solving the above-described problems includes a battery pack according to an embodiment of the present invention.

Advantages of the Invention

[0026] According to one aspect of the present invention, it is possible to suppress, as much as possible, the phenomenon in which the electrolytic solution adheres around the opening for the gas venting process during the manufacturing process.

[0027] However, the advantageous effects derived through the present invention are not limited to the above-described effects at all, and other advantageous effects not mentioned will be clearly understood by those of ordinary skill in the art from the description of the invention described below.

[0028] The drawings attached to this specification illustrate desirable embodiments of the present invention and are for the purpose of further understanding the technical idea of the present invention together with the content of the invention. Therefore, the present invention is not construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0029]

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Best Mode for Carrying Out the Invention

[0030] The terms and words used in this specification and the claims are not to be construed as being limited to their ordinary or dictionary meanings. Instead, in accordance with the principle that the inventor can appropriately define the concept of the terms in order to explain the invention in the best way, they are to be construed in meanings and concepts corresponding to the technical idea of the present invention. Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely preferred embodiments 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.

[0031] Referring to FIGS. 1 to 3, the structure of a battery according to an embodiment of the present invention will be described. FIG. 1 is a diagram showing a battery according to an embodiment of the present invention. FIG. 2 is a diagram showing a structure in which a gas vent portion for a gas venting process is formed in the battery shown in FIG. 1. FIG. 3 is a diagram showing the flow of gas discharge when the gas venting process of the battery of the present invention is performed.

[0032] Referring to FIGS. 1 to 3, a battery 1 according to an embodiment of the present invention may include an electrode assembly 10, a housing 20, a cap 30, and a frame 40. The battery 1 of the present invention may be a rechargeable secondary battery. The battery 1 may be, for example, a cylindrical battery.

[0033] The electrode assembly 10 may include a positive electrode, a negative electrode, and a separator sandwiched between the positive electrode and the negative electrode. The electrode assembly 10 may be, for example, a jelly roll type electrode assembly formed by winding a laminate including a positive electrode, a negative electrode, and a separator. The housing 20 may be configured to accommodate the electrode assembly 10 through an opening formed on one side. The housing 20 may include a conductive metal. An electrolytic solution may be accommodated in the housing 20 together with the electrode assembly 10. The cap 30 may be configured to cover the opening formed on one side of the housing 20. The cap 30 may include a metal.

[0034] The frame 40 may be coupled to the inner surface of the cap 30 in a state at least partially separated from the cap 30. When the frame 40 is coupled to the cap 30, a first space S1 may be formed between the cap 30 and the frame 40.

[0035] The frame 40 may include a gas passage portion 41. The gas passage portion 41 may be configured such that gas generated in a second space S2 in which the electrode assembly 10 is accommodated can flow into the first space. The gas passage portion 41 may be, for example, a through hole formed in the frame 40. The gas passage portion 41 may be provided as one or a plurality.

[0036] As described above, the battery 1 according to an embodiment of the present invention includes a frame 40 coupled to the inner surface of the cap 30, thereby suppressing, as much as possible, a phenomenon in which the electrolytic solution adheres to the inner surface of the cap 30 due to the flow of the electrolytic solution inside the housing 20 during the manufacturing process of the battery 1. Since the gas passage portion 41 is provided in the frame 40, gas generated inside the housing 20 can pass from the second space S2 to the first space S1. Therefore, the battery 1 of the present invention can be discharged through a gas vent portion 31 formed in the cap 30 at a position corresponding to the first space S1.

[0037] Thus, according to the battery 1 of the present invention, the gas generated inside through the activation process can be smoothly discharged to the outside (please refer to the gas discharge path along the arrow direction in FIG. 3), and moreover, in the process of discharging such gas, the phenomenon that the electrolytic solution leaks out together through the gas vent 31 can be prevented or suppressed as much as possible.

[0038] In the present invention, the gas vent 31 formed in the cap 30 may be formed in advance during the manufacture of the cap 30, or, alternatively, may be formed afterwards for the purpose of performing the gas venting process.

[0039] The frame 40 may be configured such that the communication between the first space S1 and the second space S2 is performed only through the gas passage portion 41. In this case, by adjusting the size of the gas passage portion 41, the gas generated in the second space S2 can smoothly pass through the gas passage portion 41, and the electrolytic solution can be prevented from smoothly passing through the gas passage portion 41. Thereby, when performing the manufacturing process of the battery 1, it is possible to suppress the electrolytic solution from approaching the gas vent 31 side of the cap 30 as the internal electrolytic solution flows.

[0040] The cap 30 may include a gas vent 31 configured to discharge the gas generated inside the housing 20. As described above, the gas vent 31 may be formed during the manufacture of the cap 30, or may be formed afterwards for the gas venting process. The gas vent 31 may be, for example, a through hole formed in the cap 30. The gas vent 31 may be formed at a position corresponding to the first space S1.

[0041] Next, with reference to FIGS. 4 and 5, the plug body 50 applied to the battery 1 of the present invention will be described.

[0042] FIG. 4 is a diagram showing a structure in which a plug body for closing the gas venting portion is applied after the gas venting process is completed in the battery shown in FIG. 2. FIG. 5 is a diagram showing a structure in which the gas venting portion is closed by welding after the gas venting process is completed in the battery shown in FIG. 2.

[0043] First, referring to FIG. 4, the battery 1 of the present invention may include a plug body 50 configured to seal the gas venting portion 31. The plug body 50 can seal the gas venting portion 31 by an interference fit method or a screwing (threaded connection) method, etc., by having a size corresponding to the gas venting portion 31. That is, the plug body 50 may be a component distinct from the cap 30.

[0044] In contrast, as shown in FIG. 5, the plug body 50 may be integrally formed with the cap 30 by being welded to the region where the gas venting portion 31 is formed after the gas venting process for discharging the gas generated inside the housing 20. Thus, when the plug body 50 is coupled to the gas venting portion 31 by welding, the sealing performance of the housing 20 can be enhanced.

[0045] Next, referring to FIGS. 6 to 8, the valve assembly 60 applied to the present invention will be described.

[0046] FIG. 6 is a diagram showing a structure in which a valve assembly for opening and closing the gas venting portion is applied in the battery shown in FIG. 2. FIG. 7 is a diagram showing the flow of gas discharge when the gas venting portion is opened in the battery shown in FIG. 6. FIG. 8 is a diagram showing the open state and closed state of the gas venting portion due to the operation of the valve assembly in the battery shown in FIG. 6.

[0047] First, referring to FIG. 6, the battery 1 may include a valve assembly 60. The valve assembly 60 can be applied in place of the plug body 50 described above.

[0048] The valve assembly 60 may be configured to open the gas venting portion 31 during the gas venting process of discharging the gas generated inside the housing 20 provided in the first space S1, and to close the gas venting portion 31 after the completion of the gas venting process.

[0049] The valve assembly 60 may include a closure 61 and an elastic member 62. The closure 61 may be configured to be inserted from the first space S1 into the gas venting portion 31. In this case, the width at the outer end of the gas venting portion 31 may be formed to be smaller than the maximum width of the closure 61 so that the closure 61 does not come off outside the battery 1. The closure 61 may be, for example, a spherical metal ball.

[0050] The elastic member 62 may be positioned between the closure 61 and the frame 40 and may be configured to elastically bias the closure 61 toward the gas venting portion 31. That is, the elastic member 62 may be interposed between the closure 61 and the frame 40 in a compressed state. The elastic member 62 may be, for example, a spring.

[0051] The valve assembly 60 may further include a fixing member 63 interposed between the closure 61 and the elastic member 62. One side of the fixing member 63 may be configured to support the closure 61, and the other side may be configured to be supported by the elastic member 62. One side of the fixing member 63 may be coupled to the closure 61. The other side of the fixing member 63 may be coupled to the elastic member 62.

[0052] Thus, when the battery 1 of the present invention includes the valve assembly 60, the gas vent 31 of the cap 30 can be opened by pressing the closure 61 in the direction of compressing the elastic member 62. When the gas vent 31 is opened in this way, as shown in FIG. 7, the internal gas can be discharged to the outside of the battery 1 along the arrow direction. That is, when performing the gas venting process, the gas vent 31 can be opened by pressing the closure 61 from the outside of the gas vent 31, and when a negative pressure is applied from the outside of the opened gas vent 31, the gas inside the battery 1 can be discharged to the outside.

[0053] Referring to FIG. 8, the closure 61 is pressed and the elastic member 62 is compressed, whereby the state in which the gas vent 31 is opened (see FIG. 8(a)) and the state in which the pressing on the closure 61 is released and the gas vent 31 is closed again by the closure 61 (see FIG. 8(b)) are shown. Thus, when the battery 1 of the present invention includes the valve assembly 60, the opening and closing of the gas vent 31 can be reversibly performed by the compression and extension of the elastic member 62. Therefore, an additional process for closing the gas vent 31 after the gas process can be omitted.

[0054] Next, referring to FIG. 9, the vent portion 32 of the present invention will be described. FIG. 9 is a diagram showing a structure in which a vent portion for venting is formed in a cap in a battery module according to an embodiment of the present invention.

[0055] Referring to FIG. 9, the cap 30 may include a vent portion 32. The vent portion 32 may be configured to break as the internal pressure of the housing 20 increases. The vent portion 32 may be a region configured to be more fragile than other regions around it in the cap 30. The vent portion 32 may be, for example, a region having a thinner thickness compared to the remaining regions of the cap 30. The vent portion 32 may be, for example, a region where one or both sides of the cap 30 are notched. The vent portion 32 may have a shape extending to draw a closed loop surrounding the central portion of the cap 30. The vent portion 32 may be formed continuously or discontinuously.

[0056] Thus, when the battery 1 of the present invention includes the vent portion 32, even if an abnormality occurs in the battery 1, it is possible to prevent the internal pressure of the battery 1 from increasing above a certain level.

[0057] Next, with reference to FIG. 10 in connection with FIG. 9, the position of the joint portion between the cap 30 and the frame 40 of the present invention will be described. FIG. 10 is a diagram for explaining the formation position of the vent portion and the joint position between the frame and the cap in the battery module shown in FIG. 9.

[0058] Referring to FIGS. 9 and 10, when the battery 1 of the present invention includes the vent portion 32, the distance D1 from the central portion of the cap 30 to the joint location between the frame 40 and the cap 30 may be formed to be further away than the distance D2 from the central portion of the cap 30 to the vent portion 32.

[0059] If the joint between the frame 40 and the cap 30 is located further inside than the vent portion 32, there is a risk that the weight of the frame 40 will prevent a part of the cap 30 from being removed due to the breakage of the vent portion 32. Thus, if the breakage of the vent portion 32 is prevented, there is a risk that gas cannot be discharged at an appropriate time. According to the configuration of the present invention as described above, when the internal pressure of the battery 1 abnormally increases, it is possible to prevent the breaking pressure of the vent portion 32 from becoming different from the design value due to the weight of the frame 40, thereby improving the safety in using the battery 1.

[0060] Next, with reference to FIG. 11, an insulation structure applied to the frame 40 of the present invention will be described. FIG. 11 is a diagram showing a structure in which an insulating layer is formed on the frame of the present invention.

[0061] Referring to FIG. 11, the frame 40 may include an insulating layer 42 formed on the first surface facing the electrode assembly 10. The cap 30 may contain metal to ensure rigidity. In this case, the frame 40 may also contain metal for welding connection with the cap 30, similar to the cap 30.

[0062] Thus, when the frame 40 contains metal and has conductivity, there is a risk of unnecessary electrical contact between the frame 40 and the electrode assembly 10 or unnecessary electrical contact between the frame 40 and other metal parts. When the frame 40 includes the insulating layer 42 as described above, such unnecessary electrical contact can be prevented. The insulating layer 42 can be formed, for example, by coating an insulating paint on the first surface of the frame 40.

[0063] On the one hand, in the battery 1 of the present invention, the cap 30 can be configured to have no polarity. For this purpose, the cap 30 can be electrically insulated from the housing 20 and can also be electrically insulated from the electrode assembly 10. Thus, when the cap 30 has no polarity, when performing the step of discharging the high-temperature gas through the gas vent 31 provided in the cap 30, and / or when the high-temperature gas is discharged due to the breakage of the vent portion 32, it is possible to prevent the occurrence and / or spread of a thermal event (thermal phenomenon) due to the contact between the high-temperature gas and the polar components.

[0064] Next, with reference to FIGS. 12 and 13, the electrical connection structure and the sealing structure of the battery 1 according to an embodiment of the present invention will be exemplarily described. FIG. 12 is a diagram showing the structure of the lower portion of a battery module according to an embodiment of the present invention. FIG. 13 is a diagram showing the structure of the upper portion of a battery module according to an embodiment of the present invention.

[0065] Referring to FIGS. 12 and 13, the battery 1 of the present invention may include a terminal T1 that is electrically connected to the electrode assembly 10. The terminal T1 can be electrically connected to, for example, the first plain portion 11 of the electrode assembly 10. The terminal T1 can be configured to be exposed outside the housing 20 through a closed portion formed on the opposite side of the open portion of the housing 20. The electrical connection between the terminal T1 and the electrode assembly 10 can be performed through the first current collector P1. The housing 20 can be electrically connected to the second plain portion 12 of the electrode assembly 10. The electrical connection between the housing 20 and the electrode assembly 10 can be performed through the second current collector P2.

[0066] An insulator IS for insulation may be interposed between the electrode assembly 10 and the closed portion of the housing 20, or between the first current collector P1 and the closed portion of the housing 20. A gasket for insulation and sealing may be interposed between the terminal T1 and the housing 20. A gasket G for insulation and sealing may be interposed between the cap 30 and the housing 20.

[0067] With such an electrical connection structure, the battery 1 of the present invention can utilize the terminal T1 as the first electrode terminal and the entire closed portion of the housing 20 as the second electrode terminal T2.

[0068] Next, referring to FIG. 14, a battery pack 3 according to an embodiment of the present invention will be described. FIG. 14 is a diagram showing a battery pack according to an embodiment of the present invention.

[0069] Referring to FIG. 14, the battery pack 3 according to an embodiment of the present invention may include at least one battery 1 as described above. The battery 1 may be housed in the pack housing 2. The battery pack 3 may include components for electrical connection between the batteries 1 and / or a battery management system (BMS) configured to control charging and discharging of the battery 1.

[0070] Next, referring to FIG. 15, an automobile 5 according to an embodiment of the present invention will be described. FIG. 15 is a diagram showing an automobile according to an embodiment of the present invention.

[0071] Referring to FIG. 15, the automobile 5 according to an embodiment of the present invention includes at least one battery pack 3. The automobile 5 may be configured to operate by receiving power supply from the battery pack 3. The automobile 5 may be, for example, a hybrid electric vehicle (HEV) or an electric vehicle (EV).

[0072] Although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations are possible within the equivalent scope of the technical idea and the claims of the present invention by those having ordinary knowledge in the technical field to which the present invention belongs.

Description of Reference Numerals

[0073] 1 Battery 2 Pack housing 3 Battery pack 5 Automobile 10 Electrode assembly 11 First plain part 12 Second plain part 20 Housing 30 Cap 31 Gas venting part 32 Vent part 40 Frame 41 Gas passage part 42 Insulation layer 50 Plug body 60 Valve assembly 61 Closure 62 Elastic member 63 Fixing member

Claims

1. An electrode assembly, A housing configured to accommodate the electrode assembly through an opening formed on one side, A cap configured to cover the opening, A frame including a gas passage portion that is coupled to an inner surface of the cap at least partially spaced apart therefrom to form a first space, and is configured such that gas generated in a second space in which the electrode assembly is accommodated can flow into the first space, A battery including the above components.

2. The frame, Is configured such that communication between the first space and the second space is performed only through the gas passage portion. The battery according to claim 1.

3. The cap, Is provided with a gas vent portion configured to allow gas generated inside the housing to be discharged. The battery according to claim 1.

4. The battery, Includes a plug body configured to seal the gas vent portion. The battery according to claim 3.

5. The plug body, Is integrally formed with the cap by welding a region where the gas vent portion is formed after a gas venting process of discharging gas generated inside the housing. The battery according to claim 4.

6. The battery, Includes a valve assembly configured to open the gas vent portion during a gas venting process of discharging gas generated inside the housing provided in the first space, and to close the gas vent portion after completion of the gas venting process. The battery according to claim 3.

7. The valve assembly, Includes a closure configured to be inserted from the first space into the gas vent portion, And an elastic member positioned between the closure and the frame and configured to elastically bias the closure toward the gas vent portion. The battery according to claim 6.

8. The cap, Is provided with a vent portion configured to break as the internal pressure of the housing increases. The battery according to claim 1.

9. The distance from the central portion of the cap to the connection point between the frame and the cap is further than the distance from the central portion of the cap to the vent portion. The battery according to claim 8.

10. The frame, Is provided with an insulating layer formed on a first surface facing the electrode assembly. The battery according to claim 1. ​

11. The cap is a battery according to claim 1, having no polarity.

12. The battery is a battery according to claim 1, including a terminal electrically connected to the electrode assembly.

13. The battery is a battery according to claim 12, including a current collector configured to be coupled to one side of the electrode assembly to electrically connect the electrode assembly and the housing.

14. A battery pack including the battery according to any one of claims 1 to 13.

15. An automobile including the battery pack according to claim 14.

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