Cylindrical battery, and battery pack and vehicle including same

Abstract

Disclosed in the present invention is a cylindrical battery configured to reduce deformation of an electrode assembly and intensity of a flame when a thermal event occurs inside a battery cell. A cylindrical battery according to one aspect of the present disclosure includes: an electrode assembly including a first electrode, a second electrode, and a separator therebetween, and having a center hole formed when a laminate including the first electrode, the second electrode, and the separator is wound around a winding axis; a battery case that accommodates the electrode assembly through an opening formed on one side thereof; and a flame retardant member, at least a portion of which is disposed inside the central hole.

Description

Technical Field

[0001] The present disclosure relates to cylindrical batteries, and battery packs and vehicles including the same, and more particularly, to cylindrical batteries configured to reduce deformation and flame intensity of an electrode assembly when a thermal event occurs therein, and battery packs and vehicles including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0068708 filed in Korea on May 26, 2023, the disclosure of which is incorporated herein by reference. Background Art

[0003] Secondary batteries, which are easily applicable depending on product groups and have electrical characteristics such as high energy density, are generally used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source, and are also used in portable devices.

[0004] These secondary batteries have attracted attention as new energy sources for improving eco-friendliness and energy efficiency due to a main advantage of significantly reducing the use of fossil fuels and another advantage of not generating byproducts due to energy use.

[0005] Currently widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of a unit secondary battery cell (i.e., a unit battery cell) is approximately 2.5V to 4.5V. Therefore, when an output voltage higher than this is required, a battery pack can be configured by connecting a plurality of battery cells in series. In addition, depending on the required charge / discharge capacity of the battery pack, the battery pack can be configured by connecting a plurality of batteries in parallel. Therefore, depending on the required output voltage or charge / discharge capacity, the number and electrical connection of the batteries included in the battery pack can be configured in various ways.

[0006] However, in the case where a large number of battery modules are densely provided in a small space, they may be susceptible to accidents such as fire or explosion. For example, in the case where a fire occurs due to a thermal event inside any one battery cell, the fire may be transferred to the outside, causing a cascade of thermal events in adjacent battery cells. Summary of the invention

[0007] Technical issues

[0008] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure aims to prevent deformation of an electrode assembly when a thermal event occurs inside a battery cell.

[0009] In another aspect, the present disclosure is directed to reducing the intensity of flames and gases when a thermal event occurs.

[0010] However, the technical problems that the present disclosure seeks to solve are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the description of the present invention described below.

[0011] Technical Solution

[0012] According to one aspect of the present disclosure, a cylindrical battery is provided, comprising: an electrode assembly comprising a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode, and the electrode assembly having a central hole formed by winding a laminate comprising the first electrode, the second electrode, and the separator around a winding axis; a battery case configured to accommodate the electrode assembly through an opening formed on one side thereof; and a flame retardant member at least partially received inside the central hole.

[0013] The flame retardant member may include a first portion received inside the central hole and a second portion located outside the central hole.

[0014] The first portion of the flame retardant member may have a shape corresponding to the central hole.

[0015] At least a portion of the second portion of the flame retardant member may be located on the electrode assembly.

[0016] The cylindrical battery may include an insulating member disposed between the flame retardant member and the electrode assembly.

[0017] The cylindrical battery may include a first collector including an electrode assembly coupling portion to be coupled to the electrode assembly and a case coupling portion to be coupled to a battery case.

[0018] The first collector may have a collector hole in a portion corresponding to the central hole.

[0019] At least a portion of the first portion of the flame retardant member may be located inside the collector hole.

[0020] The cylindrical battery may include an insulating member between the flame retardant member and the first current collector.

[0021] The flame retardant member may include porous metal.

[0022] The cylindrical battery may include a top cover configured to cover the opening.

[0023] The second portion of the flame retardant member may have a height corresponding to a distance between the electrode assembly and the top cover.

[0024] The cylindrical battery may include an insulating member disposed between the flame retardant member and the top cover.

[0025] The battery cell structure according to the present disclosure may include the cylindrical battery according to the present disclosure.

[0026] A vehicle according to the present disclosure may include the battery cell structure according to the present disclosure.

[0027] Beneficial Effects

[0028] According to one aspect of the present disclosure, when a thermal event occurs inside the battery, the electrode assembly can be prevented from being deformed due to the drag force generated along the outer circumference of the central hole. This is because the flame retardant member is inserted and fixed into the central hole, thereby preventing deformation caused by the drag force.

[0029] In addition, the flame retardant member may include porous metal. The flame retardant member may include a plurality of metal meshes. In this case, the flame retardant member can reduce the intensity of flames and gases. If flames or gases come into contact with the flame retardant member including porous metal, the flame retardant member may absorb heat. At the same time, the gas may be discharged through the porous flame retardant member. Therefore, the flame retardant member can reduce the temperature of flames and gases while allowing gas to be discharged.

[0030] According to another aspect of the present disclosure, if the flame retardant member fits tightly into the central hole, or if the diameter or size of the central hole becomes smaller due to expansion during battery use, the flame retardant member will be more firmly fixed to the center, thereby more effectively preventing deformation of the electrode assembly. In addition, the flame retardant member can be connected to the electrode assembly and / or the first collector to maximize the effect of reducing the intensity of flames and gases.

[0031] According to another aspect of the present disclosure, even if the separator is ruptured when the diameter or size of the central hole becomes smaller than a desired size due to expansion, a short circuit between the electrode assembly and the flame retardant member may be prevented.

[0032] According to another aspect of the present disclosure, unnecessary electrical connection between the flame-retardant member and the first current collector or a short circuit caused thereby may be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a diagram showing the appearance of a cylindrical battery according to the present disclosure.

[0034] Figure 2 is a diagram showing an electrode assembly before winding included in a cylindrical battery according to the present disclosure.

[0035] Figure 3 is a partial cross-sectional view of a cylindrical battery according to the present disclosure.

[0036] Figure 4 is a diagram showing deformation of an electrode assembly upon a thermal event inside a conventional cylindrical battery.

[0037] Figure 5 is a 3D diagram showing the deformation of an electrode assembly upon a thermal event inside a conventional cylindrical battery.

[0038] Figure 6 is a graph showing changes in internal pressure over time when a thermal event occurs inside a conventional cylindrical battery.

[0039] Figure 7 yes Figure 6 An enlarged view of a portion of the , showing the flow of pressure.

[0040] Figure 8 is a diagram illustrating a flame retardant member included in a cylindrical battery according to the present disclosure.

[0041] Fig. 9 is a partial cross-sectional view of a flame retardant member having an insulating surface included in a cylindrical battery according to the present disclosure.

[0042] Fig.10 is a diagram showing a first collector included in a cylindrical battery according to the present disclosure.

[0043] Fig.11 is included in the cylindrical battery according to the present disclosure and has Fig. 9 A partial cross-sectional view of a flame retardant member showing different insulating portions of the flame retardant member.

[0044] Fig.12 is a cross-sectional view of a cylindrical battery according to the present disclosure.

[0045] Fig.13 According to the present disclosure, Figure 3 Partial cross-sectional view of a cylindrical battery with different structures.

[0046] Fig.14 is a diagram showing a battery cell structure according to the present disclosure.

[0047] Fig.15 is a diagram showing a vehicle according to the present disclosure. DETAILED DESCRIPTION

[0048] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present disclosure and are used together with the detailed description of the present invention to provide a further understanding of the technical ideas of the present disclosure, and therefore, the present disclosure is not to be construed as being limited to the accompanying drawings. The same reference numerals denote the same elements. In addition, the thickness, proportions, and sizes of the elements in the accompanying drawings may be exaggerated to effectively illustrate the technical features of the present disclosure.

[0049] It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle allowing the inventor to appropriately define the terms in order to obtain the best interpretation.

[0050] Meanwhile, although terms indicating directions such as up, down, left, right, forward, and backward are used in this specification, it is obvious to those skilled in the art that these terms are for convenience of description only and may change depending on the position of the target object or the position of the observer.

[0051] Therefore, the configurations proposed in the embodiments of this specification and the drawings only indicate the best embodiments of the present disclosure, but do not represent all technical ideas of the present disclosure, and therefore it should be understood that various equivalents and modifications may be made thereto when the present application is filed.

[0052] Figure 1 is a diagram showing the appearance of a cylindrical battery according to the present disclosure. Figure 2 is a diagram showing an electrode assembly before winding included in a cylindrical battery according to the present disclosure. Figure 3 is a partial cross-sectional view of a cylindrical battery according to the present disclosure.

[0053] Reference Figures 1 to 3 , a cylindrical battery 10 according to the present disclosure may include an electrode assembly 100 , a battery case 200 , and a flame retardant member 300 .

[0054] The electrode assembly 100 may include a first electrode 110, a second electrode 120, and a separator 130 interposed therebetween. The electrode assembly 100 may have a central hole H1 formed by winding a laminate 100' including the first electrode 110, the second electrode 120, and the separator 130 around a winding axis. The first electrode 110, the second electrode 120, and the separator 130 interposed therebetween may be wound around the winding axis to provide the central hole H1. The first electrode 110 may be a negative electrode or a positive electrode, and the second electrode 120 may be an electrode having a polarity opposite to that of the first electrode 110. Figure 2 , the electrode assembly 100 may be manufactured by winding a laminate 100' formed by sequentially laminating a first electrode 110, a separator 130, a second electrode 120, and a separator 130 at least once. That is, the electrode assembly 100 applied to the present disclosure may be a roll-type electrode assembly 100. The electrode assembly 100 may have a central hole H1 formed at a substantial center of the electrode assembly 100 and extending in a height direction (parallel to the Z axis).

[0055] The battery case 200 can accommodate the electrode assembly 100 through an opening formed on one side (along the -Z axis direction). The battery case 200 is a substantially cylindrical container having an opening formed on one side thereof, and can be made of a conductive metal material. The battery case 200 can also accommodate an electrolyte through the opening. However, the battery case 200 in the present disclosure is not limited to the above-mentioned form.

[0056] The flame retardant member 300 may be at least partially received inside the central hole H1. At least a portion of the flame retardant member 300 may be inserted into the central hole H1.

[0057] Figure 4 is a diagram showing deformation of an electrode assembly upon a thermal event inside a conventional cylindrical battery. Figure 5 is a 3D diagram showing the deformation of an electrode assembly upon a thermal event inside a conventional cylindrical battery. Figure 6 is a graph showing changes in internal pressure over time when a thermal event occurs inside a conventional cylindrical battery. Figure 7 yes Figure 6 An enlarged view of a portion of the , showing the flow of pressure.

[0058] In the following, reference will be made to Figures 4 to 7 Problems caused in the case where a thermal event occurs inside a battery in the conventional invention are described in detail.

[0059] Reference Figure 4 and Figure 5 If flames and gases are discharged through the central hole due to a thermal event occurring inside the battery, the electrode assembly is deformed. In particular, a portion adjacent to the central hole of the electrode assembly is greatly deformed.

[0060] Reference Figure 6 and Figure 7 , deformation of the portion of the center hole adjacent to the above-mentioned electrode assembly may occur due to the drag force generated on the inner peripheral surface of the center hole (force acting along the core when a thermal event occurs). In addition, the lifting force that lifts the entire electrode assembly (force acting on the entire J / R when a thermal event occurs) may also be one of the causes of deformation of the electrode assembly.

[0061] However, when a thermal event occurs inside the battery, the cylindrical battery 10 of the present disclosure to which the flame retardant member 300 is applied can prevent the electrode assembly 100 from being deformed due to the drag force generated along the periphery of the central hole H1. This is because the flame retardant member 300 is inserted and fixed into the central hole H1, thereby preventing deformation caused by the drag force.

[0062] In addition, the flame retardant member 300 may include porous metal. The flame retardant member 300 may include a plurality of metal meshes. In this case, the flame retardant member 300 may reduce the intensity of the flame and gas. The high temperature gas and flame discharged from the central hole may contact the porous material while passing through the flame retardant member to dissipate its temperature and energy. When the flame and gas contact the flame retardant member 300 including the porous metal, the flame retardant member 300 may absorb heat. At the same time, the gas may be discharged through the porous flame retardant member 300. Therefore, the flame retardant member 300 may reduce the temperature of the flame and gas while allowing the gas to be discharged.

[0063] Figure 8 is a diagram illustrating a flame retardant member included in a cylindrical battery according to the present disclosure.

[0064] Reference Figure 8 , the flame retardant member 300 may include a first portion 310 and a second portion 320 .

[0065] The first part 310 may be received inside the center hole H1. The first part 310 may be inserted into the center hole H1. The first part 310 may have a shape corresponding to the center hole H1. The first part 310 may have a substantially cylindrical shape. The diameter of the first part 310 may be substantially equal to or smaller than the diameter of the center hole H1.

[0066] The second portion 320 may be located outside the central hole H1. At least a portion of the second portion 320 may be placed on the electrode assembly 100. The second portion 320 may be coupled to the electrode assembly 100 and / or the first electrode collector 400, which will be described later.

[0067] The first portion 310 may be formed to extend downward (in the -Z-axis direction) substantially from the center of the lower surface (surface oriented in the -Z-axis direction) of the second portion 320. The first portion 310 and the second portion 320 may be formed integrally with each other. Alternatively, the first portion 310 and the second portion 320 may be manufactured separately and then connected to each other by welding or bolting.

[0068] According to such configuration of the present disclosure, if the first portion 310 fits tightly into the center hole H1, or if the diameter or size of the center hole H1 becomes smaller due to expansion during battery use, the first portion 310 will naturally be more firmly fixed into the center hole H1, thereby more effectively preventing deformation of the electrode assembly 100. In addition, the second portion 320 may be coupled to the electrode assembly 100 and / or the first collector 400 to maximize the effect of reducing the intensity of flame and gas.

[0069] Fig. 9 is a partial cross-sectional view of a flame retardant member having an insulating surface included in a cylindrical battery according to the present disclosure.

[0070] Reference Fig. 9 and Figure 3 , the cylindrical battery 10 may have an insulating member C.

[0071] The insulating member C may be disposed between the flame retardant member 300 and the electrode assembly 100. For example, Fig. 9 As shown, the insulating member C may be disposed between the electrode assembly 100 and the flame retardant member 300 inside the central hole H1. In this case, at least a portion of the outer peripheral surface of the first portion 310 may be insulated. However, the surface of the portion of the flame retardant member 300 facing the electrode assembly 100 may be insulated without a separate member.

[0072] According to such configuration of the present disclosure, even if the separator 130 is broken when the diameter or size of the central hole H1 becomes smaller than a desired size due to expansion, a short circuit between the electrode assembly 100 and the flame retardant member 300 may be prevented.

[0073] Fig.10 is a diagram illustrating a first electrode collector 400 included in a cylindrical battery 10 according to the present disclosure.

[0074] Reference Fig.10 and Figure 3 , the cylindrical battery 10 may include a first electrode collector 400 .

[0075] The first collector 400 may include an electrode assembly coupling portion 410 and a housing coupling portion 420. The electrode assembly coupling portion 410 may be coupled to the first electrode 110. The electrode assembly coupling portion 410 may be formed to extend outwardly from a support portion 430 provided on the electrode assembly 100. The housing coupling portion 420 may be coupled to the battery housing 200. The housing coupling portion 420 may be formed to extend outwardly from a support portion 430 provided on the electrode assembly 100. At least a portion of the second portion 320 may be located in a region corresponding to the support portion 430 provided on the electrode assembly 100.

[0076] The first collector 400 may have a collector hole H2 in a portion corresponding to the central hole H1. The flame retardant member 300 may be inserted into the central hole H1 through the collector hole H2. The first portion 310 may be inserted into the central hole H1 through the collector hole H2. At least a portion of the flame retardant member 300 may be received inside the collector hole H2. At least a portion of the first portion 310 may be received inside the collector hole H2.

[0077] The collector hole H2 may be used as a passage for inserting a welding rod for welding between the battery terminal T and the second collector P (which will be described later), or for welding between the battery terminal T and the second electrode 120, or for irradiating a laser thereon. In addition, the collector hole H2 may also be used as a passage to ensure that the electrolyte is effectively impregnated into the electrode assembly 100 when the electrolyte is injected into the battery, and the first collector 400 may have an injection hole H3 on the electrode assembly coupling portion 410 to more effectively improve the impregnation performance.

[0078] Fig.11 is a partial cross-sectional view of a flame retardant member included in a cylindrical battery according to the present disclosure, which has Fig. 9 The flame retardant components shown are different insulating parts.

[0079] Reference Fig.11 and Figure 3 , the cylindrical battery 10 may have an insulating member C between the flame retardant member 300 and the first collector 400. However, the surface of the portion of the flame retardant member 300 facing the first collector 400 may be insulated without a separate member. Therefore, unnecessary electrical connection between the flame retardant member 300 and the first collector 400 or a short circuit caused thereby may be prevented.

[0080] Fig.12 is a cross-sectional view of a cylindrical battery according to the present disclosure.

[0081] Reference Fig.12 , the cylindrical battery 10 may include a top cover 500 , a battery terminal T, a second collector P, and an insulator I.

[0082] The battery terminal T may be electrically connected to the second electrode 120. The battery terminal T may pass through a closed portion of the battery case 200 disposed on the opposite side of the opening of the battery case 200 to be electrically connected to the second electrode 120. The battery terminal T may substantially penetrate the center of the closed portion of the battery case 200. The battery terminal T may be coupled to a second collector P, which will be described later, thereby establishing an electrical connection with the electrode assembly 100.

[0083] The second collector P may be electrically coupled to the second electrode 120 . The second collector P may be electrically coupled to the battery terminal T. The second collector P may have a terminal coupling portion to be coupled to the battery terminal T and a second coupling portion to be coupled to the second electrode 120 .

[0084] The top cover 500 may be configured to cover the opening. According to the cylindrical battery 10 of the present disclosure, since the first electrode 110 and the second electrode 120 are electrically connected through the terminal and the battery case 200 in the closed portion on which the terminal is provided, the top cover 500 provided in the opening on the opposite side of the closed portion may be configured to have polarity or non-polarity.

[0085] The top cover 500 may have a venting portion configured to be weaker than the surrounding area. The venting portion may have a smaller thickness than the surrounding area. The venting portion may be formed by grooving one or both sides of the top cover 500, thereby partially reducing the thickness of the top cover 500. According to this structure, if the internal pressure of the battery housing 200 rises to a predetermined level or higher due to an abnormality occurring in the battery, the venting portion may be ruptured, so that the gas may be discharged.

[0086] The insulator I may be positioned on the second electrode 120 to insulate the joint of the battery housing 200 and the second electrode 120. The insulator I may be interposed between the closed portion of the battery housing 200 and the electrode assembly 100 or between the closed portion of the battery housing 200 and the second collector P. The insulator I may include, for example, a resin material having insulating properties. The insulator I may have a hole approximately in the center so that the battery terminal T may be electrically connected to the second electrode 120.

[0087] Fig.13 According to the present disclosure, Figure 3 Partial cross-sectional view of a cylindrical battery with different structures.

[0088] Reference Fig.13 , the cylindrical battery 10 may have an insulating member C between the flame retardant member 300 and the top cover 500. However, the surface of the portion of the flame retardant member 300 facing the top cover 500 may be insulated without a separate member. Therefore, the cylindrical battery 10 can prevent unnecessary electrical connection between the flame retardant member 300 and the top cover 500 or a short circuit caused thereby.

[0089] Reference Fig.13 and Fig.12 , the flame retardant member 300 may be interposed between the electrode assembly 100 and the top cover 500. The second portion 320 of the flame retardant member 300 may have a height corresponding to the distance between the electrode assembly 100 and the top cover 500.

[0090] According to this configuration of the present disclosure, the flame retardant member 300 can effectively prevent the electrode assembly 100 from moving inside the battery case 200 due to the gap between the top cover 500 and the electrode assembly 100. In particular, referring to Figure 6 and Figure 7, the electrode assembly 100 can be prevented from being deformed due to the above lifting force. In addition, the flame retardant member 300 can prevent damage to the connection portion between the electrode assembly 100 and the first collector 400 and / or the connection portion between the first collector 400 and the battery case 200.

[0091] Fig.14 is a diagram showing a battery cell structure 2 according to the present disclosure.

[0092] Reference Fig.14 , the battery cell structure 2 according to the present disclosure may include a cylindrical battery 10. For example, the battery cell structure 2 may be a battery module or a battery pack. In addition to the cylindrical battery 10, the battery cell structure 2 may also include various elements of the battery module or battery pack, such as a BMS, a bus bar, a battery pack (or module) housing, a relay, a current sensor, etc., which are known at the time of filing the present disclosure.

[0093] Fig.15 2 is a diagram showing a vehicle 1 according to the present invention.

[0094] See also Fig.15 , the vehicle 1 according to the present disclosure may include a battery cell structure 2. The vehicle 1 may be a hybrid vehicle 1 or an electric vehicle 1. In addition to the battery cell structure 2, the vehicle 1 according to the present disclosure may further include various other components included in the vehicle 1. For example, in addition to the battery cell structure 2 according to the present disclosure, the vehicle 1 according to the present disclosure may further include a vehicle body, a motor, and a control device such as an ECU (Electronic Control Unit).

[0095] As described above, although the present disclosure has been described based on the preferred embodiments with reference to the accompanying drawings, it is obvious to those skilled in the art that various modifications can be made according to the description without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should be interpreted according to the claims including various modifications.

Claims

1. A cylindrical battery, comprising: an electrode assembly including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode, and having a central hole formed by winding a laminate including the first electrode, the second electrode, and the separator around a winding axis; a battery case configured to accommodate the electrode assembly through an opening formed on one side thereof; as well as A flame retardant member is at least partially received within the central aperture.

2. The cylindrical battery according to claim 1, in, The flame retardant component comprises: a first portion received within the central bore; and A second portion is located outside the central hole.

3. The cylindrical battery according to claim 2, in, The first portion of the flame retardant member has a shape corresponding to the central hole.

4. The cylindrical battery according to claim 2, in, At least a portion of the second portion of the flame retardant member is located on the electrode assembly.

5. The cylindrical battery according to claim 4, The cylindrical battery further includes an insulating member disposed between the flame retardant member and the electrode assembly.

6. The cylindrical battery according to claim 2, The cylindrical battery further includes a first collector including an electrode assembly coupling portion to be coupled to the electrode assembly and a case coupling portion to be coupled to the battery case.

7. The cylindrical battery according to claim 6, in, The first collector has a collector hole in a portion corresponding to the central hole.

8. The cylindrical battery according to claim 7, in, At least a portion of the first portion of the flame-retardant member is located inside the collector hole.

9. The cylindrical battery according to claim 6, The cylindrical battery further includes an insulating member located between the flame retardant member and the first current collector.

10. The cylindrical battery according to claim 1, in, The flame-retardant member includes a porous metal.

11. The cylindrical battery according to claim 2, The cylindrical battery further includes a top cover configured to cover the opening.

12. The cylindrical battery according to claim 11, in, The second portion of the flame retardant member has a height corresponding to a distance between the electrode assembly and the top cover.

13. The cylindrical battery according to claim 12, The cylindrical battery further includes an insulating member disposed between the flame retardant member and the top cover.

14. A battery cell structure comprising the cylindrical battery according to any one of claims 1 to 13.

15. A vehicle comprising the battery unit structure according to claim 14.

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