Cylindrical battery, battery unit structure including the same, and motor vehicle

Abstract

The present invention discloses a cylindrical battery configured to be able to reduce deformation of an electrode assembly and the intensity of a flame when a thermal event occurs inside a battery cell. A cylindrical battery according to one aspect of the present invention includes a first electrode, a second electrode, and a separator interposed therebetween, and an electrode assembly 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 housing that houses the electrode assembly through an opening formed on one side; and an anti-inflammatory member at least partially intervening inside the central hole.

Description

Technical Field

[0001] The present invention relates to a cylindrical battery, a battery pack including the same, and a motor vehicle, and more particularly, to a cylindrical battery configured to reduce deformation of an electrode assembly and the intensity of a flame when a thermal event occurs inside, a battery pack including the same, and a motor vehicle.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0068708 filed on May 26, 2023, and all of the content disclosed in the specification and drawings of the application is incorporated into this application.

Background Art

[0003] Secondary batteries, which are highly applicable to a wide range of products and have electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by an electric drive source.

[0004] Such secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency improvement because they not only have the primary advantage of significantly reducing the use of fossil fuels but also have the advantage of generating no by-products associated with energy use.

[0005] The types of secondary batteries currently widely used include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of such a single secondary battery cell is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, a plurality of batteries are connected in series to form a battery pack. Also, depending on the charge-discharge capacity required for the battery pack, a plurality of batteries may be connected in parallel to form a battery pack. Accordingly, the number of batteries included in the battery pack and the form of electrical connection can be variously set according to the required output voltage and / or charge-discharge capacity.

[0006] However, when a plurality of battery modules exist in a densely packed state in a narrow space in this way, they may be vulnerable to accidents such as fires and explosions. For example, when a flame occurs due to a thermal event inside a certain battery cell, if the flame propagates outside, there is a problem that a thermal event may occur chain-reaction in adjacent battery cells.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of the above problems, and an object thereof is to suppress deformation of the electrode assembly when a thermal event occurs inside the battery cell.

[0008] In another aspect, another object of the present invention is to reduce the intensity of flames and gases when a thermal event occurs.

[0009] However, the technical problems to be solved by the present invention are not limited to the above-described problems, 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

[0010] A cylindrical battery according to one aspect of the present invention for achieving the above object includes a first electrode, a second electrode, and a separator interposed therebetween, and an electrode assembly 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 housing that houses the electrode assembly through an opening formed on one side; and an anti-inflammatory member at least partially interposed inside the central hole.

[0011] The anti-inflammatory member may include a first portion interposed inside the central hole and a second portion located outside the central hole.

[0012] The anti-inflammatory member may have a shape in which the first portion corresponds to the central hole.

[0013] At least a part of the second portion of the anti-inflammatory member may be located on the electrode assembly.

[0014] The cylindrical battery may include an insulating member between the anti-inflammatory member and the electrode assembly.

[0015] The cylindrical battery may include a first current collector including an electrode assembly coupling portion that couples to the electrode assembly and a housing coupling portion that couples to the battery housing.

[0016] The first current collector may have a current collector hole in a portion corresponding to the central hole.

[0017] At least a part of the first portion of the anti-inflammatory member may be located inside the current collector hole.

[0018] The cylindrical battery may include an insulating member between the anti-inflammatory member and the first current collector.

[0019] The anti-inflammatory member may include a porous metal.

[0020] The cylindrical battery may include a top cap configured to cover the opening portion.

[0021] The flame extinguishing member may have a height such that the second portion corresponds to the distance between the electrode assembly and the top cap.

[0022] The cylindrical battery may include an insulating member between the flame extinguishing member and the top cap.

[0023] The battery unit structure according to an embodiment of the present invention may include a cylindrical battery according to an embodiment of the present invention.

[0024] An automobile according to an embodiment of the present invention may include a battery unit structure according to an embodiment of the present invention.

Advantages of the Invention

[0025] According to one aspect of the present invention, when a thermal event occurs inside the battery, deformation of the electrode assembly due to a drag force generated along the outer peripheral surface of the central hole can be suppressed. This is because the flame extinguishing member is inserted into and fixed to the central hole, suppressing deformation due to the drag force.

[0026] Also, the flame extinguishing member may include a porous metal. The flame extinguishing member may include a plurality of metal meshes. In such a case, the flame extinguishing member can reduce the intensity of the flame and gas. When the flame extinguishing member including the porous metal comes into contact with the flame and gas, the flame extinguishing member can absorb heat. At the same time, the gas can escape through the porous flame extinguishing member. Therefore, the flame extinguishing member can lower the temperature of the flame and gas by allowing the gas to escape.

[0027] According to another aspect of the present invention, when the anti-inflammatory member is snugly fitted into the central hole, or when the diameter or size of the central hole becomes smaller due to the swelling phenomenon during the use of the battery, the anti-inflammatory member is naturally better fixed within the central hole, thereby more effectively suppressing the deformation of the electrode assembly. Further, by combining the anti-inflammatory member with the electrode assembly and / or the first current collector, the effect of reducing the intensity of the flame and gas can be maximized.

[0028] According to still another aspect of the present invention, when the diameter or size of the central hole becomes smaller than necessary due to the swelling phenomenon, even if the separator is broken, it is possible to suppress a short circuit between the electrode assembly and the anti-inflammatory member.

[0029] According to still another aspect of the present invention, it is possible to suppress unnecessary electrical connection between the anti-inflammatory member and the first current collector and a short circuit resulting therefrom.

Brief Description of the Drawings

[0030]

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Embodiments for Carrying Out the Invention

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The drawings attached to this specification illustrate preferred embodiments of the present invention, and are for the purpose of further understanding the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention is not construed as being limited only to the matters described in such drawings. The same reference numerals refer to the same components. Also, in the drawings, the thickness, ratio, and dimensions of the components may be exaggerated for an effective explanation of the technical content.

[0032] The terms and words used in this specification and the claims are not to be construed as limited to their ordinary or dictionary meanings. In accordance with the principle that the inventor can appropriately define the concept of the terms in order to best explain the invention, they are to be construed in the meanings and concepts corresponding to the technical idea of the present invention.

[0033] In this specification, terms indicating directions such as up, down, left, right, front, and back are used. However, it is self-evident to those skilled in the art of the present invention that these terms are for convenience of explanation and may vary depending on the position of the object in question, the position of the observer, etc.

[0034] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical ideas of the present invention. Thus, there can be various equivalents and modified embodiments that can replace them at the time of this application.

[0035] FIG. 1 is a view showing the appearance of a cylindrical battery according to an embodiment of the present invention. FIG. 2 is a view showing the state before winding of the electrode assembly included in the cylindrical battery according to an embodiment of the present invention. FIG. 3 is a view showing a part of the cross-section of the cylindrical battery according to an embodiment of the present invention.

[0036] Referring to FIGS. 1 to 3, the cylindrical battery 10 according to an embodiment of the present invention may include an electrode assembly 100, a battery housing 200, and a flame-retardant member 300.

[0037] 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 include 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 include a central hole H1 formed by winding around a winding axis. Referring to FIG. 2, the electrode assembly 100 may be manufactured by winding a laminate 100' formed by laminating at least once the first electrode 110, the separator 130, the second electrode 120, and the separator 130 in this order. That is, the electrode assembly 100 applied to the embodiment of the present invention may be a jelly roll type electrode assembly 100. The electrode assembly 100 may include a central hole H1 formed at a substantially central portion thereof and extending along the height direction (direction parallel to the Z axis).

[0038] The battery housing 200 may accommodate the electrode assembly 100 through an opening formed on one side (negative direction of the Z axis). The battery housing 200 may be a substantially cylindrical container having an opening formed on one side and may be made of a conductive metal material. The battery housing 200 may also accommodate an electrolyte through the opening. However, the battery housing 200 according to the embodiment of the present invention is not limited to such a form.

[0039] The heat dissipation member 300 may have at least a part thereof interposed inside the central hole H1. At least a part of the heat dissipation member 300 may be inserted into the central hole H1.

[0040] FIG. 4 is a diagram showing the deformation of an electrode assembly when a thermal event occurs inside a conventional cylindrical battery. FIG. 5 is a 3D diagram showing the deformation of an electrode assembly when a thermal event occurs inside a conventional cylindrical battery. FIG. 6 is a diagram showing the internal pressure over time when a thermal event occurs inside a conventional cylindrical battery. FIG. 7 is an enlarged view of a part of FIG. 6 showing the flow of pressure.

[0041] Hereinafter, with reference to FIGS. 4 to 7, problems that occur when thermal events occur inside the battery in the case of the conventional invention will be described in detail.

[0042] Referring to FIGS. 4 and 5, when a thermal event occurs inside the battery and flames and gas are discharged from the central hole, the electrode assembly is deformed. In particular, a large deformation occurs in a portion adjacent to the central hole of the electrode assembly.

[0043] Referring to FIGS. 6 and 7, the deformation in the portion adjacent to the central hole of the electrode assembly described above is caused by the drag force (Drag force: the force flowing along the core portion when a thermal event occurs) generated on the inner peripheral surface of the central hole. In addition, the lift force (Lift force: the force acting on the entire J / R when a thermal event occurs) that lifts the electrode assembly as a whole is also one of the causes of the deformation of the electrode assembly.

[0044] However, the cylindrical battery 10 according to the embodiment of the present invention to which the anti-inflammatory member 300 is applied can suppress the deformation of the electrode assembly 100 due to the drag force generated along the outer peripheral surface of the central hole H1 when a thermal event occurs inside the battery. This is because the anti-inflammatory member 300 is inserted and fixed in the central hole H1, so that the deformation due to the drag force is suppressed.

[0045] In addition, the anti-inflammatory member 300 may include a porous metal. The anti-inflammatory member 300 may include a plurality of metal meshes. In such a case, the anti-inflammatory member 300 can reduce the intensity of the flames and gas. While the high-temperature gas and flames coming out of the central hole pass through the anti-inflammatory member, they can collide with the porous material to dissipate the temperature and energy. When the anti-inflammatory member 300 including the porous metal collides with the flames and gas, the anti-inflammatory member 300 can absorb heat. At the same time, the gas can pass through the porous anti-inflammatory member 300 and escape. Therefore, the anti-inflammatory member 300 can lower the temperature of the flames and gas by allowing the gas to escape.

[0046] FIG. 8 is a diagram showing an anti-inflammatory member included in a cylindrical battery according to an embodiment of the present invention.

[0047] Referring to FIG. 8, the anti-inflammatory member 300 may include a first portion 310 and a second portion 320.

[0048] The first portion 310 may be interposed inside the central hole H1. The first portion 310 may be inserted into the central hole H1. The first portion 310 may have a shape corresponding to the central hole H1. The first portion 310 may be substantially cylindrical. The first portion 310 may have a diameter substantially the same as or smaller than the diameter of the central hole H1.

[0049] The second portion 320 may be located outside the central hole H1. At least a part of the second portion 320 may be located on the electrode assembly 100. The second portion 320 may be coupled to the electrode assembly 100 and / or a first current collector 400 described later.

[0050] The first portion 310 may extend downward (in the negative Z-axis direction) from substantially the center of the lower surface (the surface located in the negative Z-axis direction) of the second portion 320. The first portion 310 and the second portion 320 may be integrally formed. Alternatively, the first portion 310 and the second portion 320 may be manufactured separately and then coupled to each other by welding or bolting.

[0051] According to such a configuration according to an embodiment of the present invention, when the first portion 310 fits exactly into the central hole H1, or when the diameter or size of the central hole H1 becomes smaller due to a swelling phenomenon during the use of the battery, the first portion 310 is naturally more firmly fixed in the central hole H1, thereby more effectively suppressing deformation of the electrode assembly 100. Further, the second portion 320 is coupled to the electrode assembly 100 and / or the first current collector 400, and the effect of reducing the intensity of the flame and gas can be maximized.

[0052] FIG. 9 is a partial cross-sectional view of an anti-inflammatory member included in the cylindrical battery according to an embodiment of the present invention, and shows an anti-inflammatory member having an insulating treatment on its surface.

[0053] Referring to FIG. 9 in combination with FIG. 3, the cylindrical battery 10 may include an insulating member C.

[0054] The insulating member C may be provided between the anti-inflammatory member 300 and the electrode assembly 100. For example, as shown in FIG. 9, the insulating member C may be provided between the anti-inflammatory member 300 and the electrode assembly 100 within the central hole H1. In this case, at least a part of the outer peripheral surface of the first portion 310 may be subjected to an insulating treatment. However, without a separate member, the surface of the portion of the anti-inflammatory member 300 facing the electrode assembly 100 may be subjected to an insulating treatment.

[0055] According to such a configuration according to an embodiment of the present invention, when the diameter or size of the central hole H1 becomes smaller than necessary due to the swelling phenomenon as described above, even if the separator 130 is broken, a short circuit between the electrode assembly 100 and the anti-inflammatory member 300 can be suppressed.

[0056] FIG. 10 is a view showing a first current collector 400 included in the cylindrical battery 10 according to an embodiment of the present invention.

[0057] Referring to FIG. 10 in combination with FIG. 3, the cylindrical battery 10 may include a first current collector 400.

[0058] The first current 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 outward from a support portion 430 disposed 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 outward from a support portion 430 disposed on the electrode assembly 100. At least a part of the second portion 320 may be located on a region corresponding to the support portion 430 disposed on the electrode assembly 100.

[0059] The first current collector 400 may be provided with a current collector hole H2 at a portion corresponding to the central hole H1. The anti-inflammatory member 300 may be inserted into the central hole H1 through the current collector hole H2. The first portion 310 may be inserted into the central hole H1 through the current collector hole H2. At least a part of the anti-inflammatory member 300 may be located within the current collector hole H2. At least a part of the first portion 310 may be located within the current collector hole H2.

[0060] The current collector hole H2 may function as a passage for inserting a welding rod or irradiating a laser for welding between the battery terminal T and the second current collector P, or between the battery terminal T and the second electrode 120, which will be described later. Also, when injecting an electrolytic solution into the battery, it can also function as a passage for smoothly impregnating the inside of the electrode assembly 100 with the electrolytic solution. In order to more effectively improve such an impregnation function, the first current collector 400 may be provided with a liquid injection hole H3 at the electrode assembly coupling portion 410.

[0061] FIG. 11 is a partial cross-sectional view of the anti-inflammatory member included in the cylindrical battery according to the embodiment of the present invention, and shows an anti-inflammatory member having an insulation treatment at a position different from the anti-inflammatory member shown in FIG. 9.

[0062] Referring to FIG. 11 together with FIG. 3, the cylindrical battery 10 may include an insulating member C between the anti-inflammatory member 300 and the first current collector 400. However, without a separate member, the surface of the portion of the anti-inflammatory member 300 facing the first current collector 400 may be subjected to an insulation treatment. Therefore, unnecessary electrical connection between the anti-inflammatory member 300 and the first current collector 400 and a short circuit caused thereby can be suppressed.

[0063] FIG. 12 is a cross-sectional view of the cylindrical battery according to the embodiment of the present invention.

[0064] Referring to FIG. 12, the cylindrical battery 10 may include a top cap 500, a terminal T, a second current collector P, and an insulator I.

[0065] The terminal T can be electrically connected to the second electrode 120. The terminal T can penetrate through the closed portion of the battery housing 200 provided on the opposite side of the open portion of the battery housing 200 and be electrically connected to the second electrode 120. The terminal T can penetrate through substantially the central portion of the closed portion of the battery housing 200. The terminal T can be electrically connected to the electrode assembly 100 by being coupled to a second current collector P described later.

[0066] The second current collector P can be electrically coupled to the second electrode 120. The second current collector P can be electrically coupled to the terminal T. The second current collector P can include a terminal coupling portion that couples to the terminal T and a second coupling portion that couples to the second electrode 120.

[0067] The top cap 500 can be configured to cover the open portion. According to the cylindrical battery 10 according to an embodiment of the present invention, in the closed portion provided with the terminal, the first electrode 110 and the second electrode 120 can be electrically connected via the terminal and the battery housing 200. Therefore, the top cap 500 provided in the open portion on the other side of the closed portion may be configured to have a polarity or may be configured not to have a polarity.

[0068] The top cap 500 can include a vent portion configured to be more fragile than the peripheral region. The vent portion can have a thickness thinner than that of the peripheral region. The vent portion can be formed by providing notches on one or both surfaces of the top cap 500 to partially reduce the thickness of the top cap 500. According to such a structure, when an abnormality occurs in the battery and the internal pressure of the battery housing 200 rises to a certain level, the vent portion can break and gas can be discharged.

[0069] The insulator I can be positioned on the second electrode 120 for insulation between the battery housing 200 and the tab of the second electrode 120. The insulator I can 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 current collector P. The insulator I can include, for example, a resin material having insulating properties. The insulator I can be provided with a hole substantially at the center so that the terminal T can be electrically connected to the second electrode 120.

[0070] FIG. 13 is a partial cross-sectional view of a cylindrical battery according to an embodiment of the present invention, and shows a cylindrical battery having a different structure as compared with FIG. 3.

[0071] Referring to FIG. 13, the cylindrical battery 10 can include an insulating member C between the flame retardant member 300 and the top cap 500. However, the surface of the portion of the flame retardant member 300 facing the top cap 500 can be subjected to insulation treatment without a separate member. Therefore, the cylindrical battery 10 can suppress unnecessary electrical connection between the flame retardant member 300 and the top cap 500 and a short circuit caused thereby.

[0072] Referring to FIG. 13 in conjunction with FIG. 12, the flame retardant member 300 can be interposed between the electrode assembly 100 and the top cap 500. The flame retardant member 300 can have a height in which the second portion 320 corresponds to the distance between the electrode assembly 100 and the top cap 500.

[0073] According to such a configuration according to an embodiment of the present invention, the anti-inflammatory member 300 can effectively suppress the movement of the electrode assembly 100 within the battery housing 200 by means of the play (clearance) formed between the top cap 500 and the electrode assembly 100. In particular, referring to FIGS. 6 and 7, deformation of the electrode assembly 100 due to the above-described lift force can be suppressed. Further, the anti-inflammatory member 300 can suppress damage from occurring at the joint portion between the electrode assembly 100 and the first current collector 400 and / or at the joint portion between the first current collector 400 and the battery housing 200.

[0074] FIG. 14 is a view showing a battery unit structure 2 according to an embodiment of the present invention.

[0075] Referring to FIG. 14, the battery unit structure 2 according to an embodiment of the present invention may include a cylindrical battery 10. For example, the battery unit structure 2 may be a battery module or a battery pack. In addition to the cylindrical battery 10, the battery unit structure 2 may further include various other components, such as components of a battery pack or a battery module that are known at the time of filing of the present invention, such as a battery management system (BMS), a bus bar, a pack (or module) case, a relay, a current sensor, and the like.

[0076] FIG. 15 is a view showing an automobile 1 according to an embodiment of the present invention.

[0077] Referring to FIG. 15, the vehicle 1 according to an embodiment of the present invention may include a battery unit structure 2. The vehicle 1 can be a hybrid vehicle 1 or an electric vehicle 1. In addition to such a battery unit structure 2, the vehicle 1 according to an embodiment of the present invention may further include various other components included in the vehicle 1. For example, in addition to the battery unit structure 2 according to an embodiment of the present invention, the vehicle 1 according to an embodiment of the present invention may further include a control device such as a vehicle body, a motor, and an electronic control unit (ECU).

[0078] As described above, the present invention has been described mainly with reference to the preferred embodiments with reference to the accompanying drawings. However, it is obvious to those skilled in the art that many diverse and obvious modifications can be made without departing from the scope of the present invention from such a description. Therefore, the scope of the present invention should be interpreted by the claims described to include such many modified embodiments.

Explanation of Reference Numerals

[0079] 10 Cylindrical battery 100 Electrode assembly 100’ Laminate 110 First electrode 120 Second electrode 130 Separator 200 Battery housing 300 Inflammation suppressing member 310 First part 320 Second part 400 First current collector 410 Electrode assembly coupling part 420 Housing coupling part 430 Support part 500 Top cap

Claims

1. An electrode assembly including a first electrode, a second electrode, and a separator interposed therebetween, wherein a laminate including the first electrode, the second electrode, and the separator is wound around a winding axis to form a central hole, and the electrode assembly having the central hole; A battery housing that houses the electrode assembly through an opening formed on one side; An anti-inflammatory member at least partially interposed inside the central hole; A cylindrical battery including the above.

2. The anti-inflammatory member A first portion interposed inside the central hole; A second portion located outside the central hole; The cylindrical battery according to Claim 1, including the above.

3. The cylindrical battery according to Claim 2, wherein the first portion of the anti-inflammatory member has a shape corresponding to the central hole.

4. The cylindrical battery according to Claim 2 or 3, wherein at least a part of the second portion of the anti-inflammatory member is located on the electrode assembly.

5. The cylindrical battery according to Claim 4, wherein the cylindrical battery includes an insulating member between the anti-inflammatory member and the electrode assembly.

6. The cylindrical battery according to Claim 2 or 3, including a first current collector including an electrode assembly coupling portion that couples with the electrode assembly and a housing coupling portion that couples with the battery housing.

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

8. The cylindrical battery according to Claim 7, wherein at least a part of the first portion of the anti-inflammatory member is located within the current collector hole.

9. The cylindrical battery according to Claim 6, wherein the cylindrical battery includes an insulating member between the anti-inflammatory member and the first current collector.

10. The cylindrical battery according to Claim 1, wherein the anti-inflammatory member includes a porous metal.

11. The cylindrical battery according to Claim 2 or 3, including a top cap configured to cover the opening.

12. The cylindrical battery according to Claim 11, wherein the second portion of the anti-inflammatory member has a height corresponding to the distance between the electrode assembly and the top cap.

13. The cylindrical battery according to Claim 12, wherein the cylindrical battery includes an insulating member between the anti-inflammatory member and the top cap.

14. A battery unit structure including the cylindrical battery according to claim 1.

15. An automobile including the battery unit structure according to claim 14.

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