Battery, battery pack containing the same, and automobile including battery pack

Abstract

A battery according to one embodiment of the present invention includes an electrode assembly, a battery housing configured to house the electrode assembly through an opening formed on one side, a battery terminal configured to be electrically connected to the electrode assembly through a closed portion provided on the opposite side of the opening of the battery housing, a current collector including a first coupling portion configured to be electrically coupled to the electrode assembly, and a second coupling portion configured to be electrically coupled to the battery terminal, with at least a portion of which a resistance-increasing region is formed.

Description

Technical Field

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

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0110068 filed on August 22, 2023, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] Currently, as fuse devices used in secondary batteries, there are PTC thermistors (positive temperature coefficient thermistors), TCOs (thermal cut-outs), etc. However, PTCs and TCOs have the disadvantage that when their operations are repeated, their own resistances increase, increasing the overall resistance in the circuit.

[0004] Also, all of the above elements operate by heat generation due to overcurrent. That is, the above elements are elements that operate to cut off the current flow only when an overcurrent occurs in the circuit current path due to overcharging or the like, and as a result, the temperature rises.

[0005] Therefore, in the case of the above elements, they can only operate to cut off the overcurrent after the situation where safety is threatened by heat generation, and cannot cut off the overcurrent immediately when the cause of the temperature rise occurs. Thus, if the overcurrent is not cut off at an appropriate time even when the internal pressure of the secondary battery increases due to an abnormal temperature rise inside the battery, there is a possibility of safety problems such as ignition and explosion.

[0006] Furthermore, the above-mentioned elements operate simply based on temperature, making them unsuitable for use in high-power secondary batteries such as those used in automobile battery packs. In other words, automobile battery packs require a high c-rate, which inevitably leads to high heat generation. Elements such as PTC thermistors (positive temperature coefficient thermistors), TCOs (thermal cut-outs), and thermal fuses have the problem of activating too early when exposed to such high-temperature environments.

[0007] Therefore, a secondary battery is needed that can be used in environments where high currents flow, and that has a structure that can preemptively shut off the current when an event causing the temperature rise (for example, an increase in the internal pressure of the secondary battery) occurs, before the temperature rises to a level where safety problems may arise. [Overview of the project] [Problems that the invention aims to solve]

[0008] This invention was made in consideration of the above-mentioned problems, and one of its objectives is to enable the rapid disconnection of electrical connections when an overcurrent exceeding a standard value occurs in the battery.

[0009] However, the technical problems that this invention aims to solve are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0010] A battery according to one embodiment of the present invention for solving the above problems includes an electrode assembly, a battery housing configured to house the electrode assembly through an open portion formed on one side, a battery terminal configured to be electrically connected to the electrode assembly through a closed portion provided on the opposite side of the open portion of the battery housing, a current collector including a first coupling portion configured to be electrically coupled to the electrode assembly, and a second coupling portion configured to be electrically coupled to the battery terminal, with at least a portion of which a resistance-increasing region is formed.

[0011] The resistance-increasing region may be configured to have an even smaller cross-sectional area compared to the remaining region of the second coupling.

[0012] The resistance-increasing region may be configured to have an even thinner thickness compared to the remaining region of the second coupling.

[0013] The resistance-increasing region may include grooves formed on one or both sides of the second coupling portion.

[0014] The groove may extend along the circumferential direction of the battery.

[0015] The resistance-increasing region may include a plurality of grooves formed on one or both sides of the second coupling portion. The plurality of grooves may be spaced apart from each other along the radial direction of the battery.

[0016] Multiple grooves may be arranged spaced apart from each other along the circumferential direction of the battery.

[0017] A welded portion may be provided in the region where the second coupling portion and the battery terminal are coupled. The welded portion may be provided in a region where the resistance-increasing region is not formed.

[0018] The resistance-increasing region may be configured to surround the welded portion.

[0019] The electrode assembly may have a structure in which a laminate including a first electrode, a second electrode, and a separation membrane interposed between the first electrode and the second electrode is wound. The resistance increase region may be provided at a position corresponding to the inside of a winding center hole formed by winding the electrode assembly.

[0020] The battery may include a protection member configured to cover an inner wall surface of the winding center hole on an inlet side of the winding center hole facing the current collector.

[0021] The first coupling portion and the second coupling portion of the current collector may be positioned apart from each other along the radial direction of the battery.

[0022] The current collector may include a rim portion located on an outer periphery of the first coupling portion and the second coupling portion, and a connection portion configured to connect the rim portion and the second coupling portion.

[0023] A battery pack according to an embodiment of the present invention for solving the above problems includes a battery according to an embodiment of the present invention.

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

Advantages of the Invention

[0025] According to one aspect of the present invention, when an overcurrent equal to or greater than a reference value occurs in the battery, an electrical connection can be quickly interrupted, thereby ensuring safety in battery use.

[0026] However, the advantageous effects derived through the present invention are not limited to the above effects, and other advantageous effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0027] The following drawings attached to this specification illustrate desirable embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention. Therefore, the present invention should not be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0028] [Figure 1] It is a diagram showing the upper portion structure of a battery according to an embodiment of the present invention. [Figure 2] It is a diagram showing a resistance increasing region provided in a current collector (first current collector) according to an embodiment of the present invention. [Figure 3] It is a diagram showing a cross-section cut along A-A' of FIG. 2. [Figure 4] It is a diagram showing an exemplary form of a resistance increasing region according to an embodiment of the present invention. [Figure 5] It is a diagram showing an exemplary form of a resistance increasing region according to an embodiment of the present invention. [Figure 6] It is a diagram showing the positional relationship between a resistance increasing region provided in a current collector (first current collector) according to an embodiment of the present invention and a welded portion formed on the current collector. [Figure 7] It is a diagram showing the positional relationship between a resistance increasing region provided in a current collector (first current collector) according to an embodiment of the present invention and a welded portion formed on the current collector. [Figure 8] It is a diagram for explaining the formation position of a resistance increasing region according to an embodiment of the present invention. [Figure 9] It is a diagram showing a battery to which a protection member according to an embodiment of the present invention is applied. [Figure 10] It is a diagram showing an exemplary form of a current collector (first current collector) according to an embodiment of the present invention. [Figure 11] It is a diagram showing the lower portion structure of a battery according to an embodiment of the present invention. [Figure 12] It is a diagram showing a battery pack according to an embodiment of the present invention. [Figure 13]This is a diagram showing an automobile relating to one embodiment of the present invention. [Modes for carrying out the invention]

[0029] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims are not to be interpreted in their usual and dictionary sense, but rather in accordance with the technical ideas of the present invention, in accordance with the principle that the inventor himself may appropriately define the concepts of terms in order to best describe the invention. Therefore, it should be understood that the configurations shown in the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entirety of the technical ideas of the present invention, and that there may be a variety of equivalents and modifications that can be substituted for them at the time of this application.

[0030] First, a battery 1 according to one embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a diagram showing the upper portion structure of a battery according to one embodiment of the present invention. Figure 2 is a diagram showing a resistance-increasing region provided in a current collector (first current collector) according to one embodiment of the present invention. Figure 3 is a diagram showing a cross-section taken along line A-A' in Figure 2.

[0031] Referring to Figures 1 to 3, a battery 1 according to one embodiment of the present invention may include an electrode assembly 10, a battery housing 20, battery terminals 30, and a current collector (first current collector) 40. The battery 1 may be a rechargeable battery configured to be chargeable and dischargeable. The battery 1 may be, for example, a cylindrical battery.

[0032] The electrode assembly 10 may include a first electrode having a first polarity, a second electrode having a second polarity opposite to the first polarity, and a separation membrane interposed between the first electrode and the second electrode. The electrode assembly 10 may have a shape in which a laminate including the first electrode, the second electrode, and the separation membrane is wound in one direction. When the electrode assembly 10 has such a wound shape, a winding center hole 10a may be formed in the region that is the winding center.

[0033] The first electrode may include a first blank portion 11, which is a region not coated with electrode active material. The first blank portion 11 may extend from one end of the first electrode along the winding direction of the electrode assembly 10. Thus, the first blank portion 11 may be provided on a first surface substantially perpendicular to the outer circumferential surface of the electrode assembly 10.

[0034] The second electrode may include a second blank area 12, which is a region not coated with electrode active material (see Figure 11). The second blank area 12 may extend from one end of the second electrode along the winding direction of the electrode assembly 10. Thus, the second blank area 12 may be provided on a second surface (a surface opposite to the first surface) substantially perpendicular to the outer circumferential surface of the electrode assembly 10.

[0035] Although not specifically shown in the drawings, the first blank section 11 and / or the second blank section 12 may include a plurality of segments formed by dividing the electrode assembly 10 along the winding direction. Such segments may be formed by cutting out the first blank section 11 and / or the second blank section 12 to a predetermined depth. The plurality of segments may be bent along the substantially radial direction of the electrode assembly 10. In this case, some of the segments adjacent to each other along the radial direction may overlap each other.

[0036] The battery housing 20 may be configured to house the electrode assembly 10 through an opening formed on one side thereof. The battery housing 20 may have a closed portion formed on the opposite side of the opening. The battery housing 20 may contain a conductive metal. The battery housing 20 may be electrically connected to the second electrode of the electrode assembly 10.

[0037] The battery terminal 30 may be configured to be electrically connected to the electrode assembly 10 via a closed portion provided on the opposite side of the open portion of the battery housing 20. The battery terminal 30 may be electrically connected, for example, to the first electrode of the electrode assembly 10. In this case, the battery terminal 30 can function as the first terminal of the battery 1. The battery terminal 30 and the battery housing 20 have opposite polarities, and in this case, a first sealing member G1 may be provided between the battery housing 20 and the battery terminal 30 to prevent contact between these parts and to ensure the airtightness of the battery housing 20.

[0038] The battery terminal 30 may include a first portion 31 and a second portion 32. The first portion 31 may be configured to be electrically coupled to the current collector 40 inside the battery housing 20. The first portion 31 may be located in a position corresponding to the winding center hole 10a of the electrode assembly 10. The second portion 32 may be exposed to the outside of the battery housing 20. The second portion 32 may be located approximately in the center of the closure of the battery housing 20. The battery terminal 30 may include a third portion 33 located outside the first portion 31. The third portion 33 may be riveted toward the closure of the battery housing 20 to secure the battery terminal 30 to the battery housing 20.

[0039] The current collector 40 may be configured to electrically connect the battery terminal 30 and the electrode assembly 10. The current collector 40 may be electrically connected to the first electrode of the electrode assembly 10. To prevent contact between the battery housing 20 and the current collector 40, which have opposite polarities, an insulator IS may be interposed between the current collector 40 and the inner surface of the closing portion of the battery housing 20.

[0040] The current collector 40 may be positioned on the first surface of the electrode assembly 10. The current collector 40 may include a first coupling portion 41 and a second coupling portion 42. The first coupling portion 41 may be configured to be electrically coupled to the electrode assembly 10. The first coupling portion 41 may be coupled to a first blank portion 11 of the electrode assembly 10. The first coupling portion 41 may be coupled to a coupling surface formed by the bending of the first blank portion 11. At least a portion of the first coupling portion 41 may be coupled to the first blank portion 11 in a region where the number of overlapping layers of the divided pieces of the first blank portion 11 is maximized. The second coupling portion 42 may be electrically coupled to the battery terminal 30. The second coupling portion 42 may be electrically coupled to a first portion 31 of the battery terminal 30. The second joint 42 can be welded to the first portion 31 of the battery terminal 30 by a welding tool inserted through the winding central hole 10a of the electrode assembly 10 or by a laser irradiated through the winding central hole 10a.

[0041] On the other hand, the second coupling portion 42 may have a resistance-increasing region 40a formed in at least a part thereof. The resistance-increasing region 40a may be located in the area where the battery terminal 30 and the current collector 40 are in contact with each other, at least a part of it. The resistance-increasing region 40a may be configured to have an even smaller cross-sectional area compared to the rest of the second coupling portion 42. The resistance-increasing region 40a may be configured to have an even thinner thickness compared to the rest of the second coupling portion 42, for example, as shown in Figure 3.

[0042] Thus, the battery 1 according to one embodiment of the present invention is configured to have a region on the current collector 40 in which the resistance is partially increased, so that when an overcurrent occurs due to a malfunction of the battery 1, the overcurrent can be quickly interrupted by the breakage of the current collector 40 itself and / or damage to the connection between the current collector 40 and the battery terminal 30.

[0043] Next, various embodiments of the resistance-increasing region 40a according to one embodiment of the present invention will be described with reference to Figures 1 to 3, as well as Figures 4 and 5. Figures 4 and 5 are diagrams showing a resistance-increasing region provided in a current collector (first current collector) according to one embodiment of one invention, and are diagrams showing various embodiments of the groove lines constituting the resistance-increasing region.

[0044] Referring to Figures 4 and 5 in conjunction with Figures 1 to 3, the resistance-increasing region 40a may include grooves L formed on one or both sides of the second coupling portion 42 of the current collector 40. The grooves L may be formed to a predetermined depth on one or both sides of the second coupling portion 42. The grooves L may extend along the circumferential direction of the battery 1. The grooves L may be provided in a substantially closed loop shape. The resistance region 40a may also include a plurality of grooves L. The plurality of grooves L may be spaced apart from each other along the circumferential direction of the battery. The plurality of grooves L may be spaced apart from each other along the radial direction of the battery 1.

[0045] Next, with reference to Figures 1 to 3, as well as Figures 6 and 7, the positional relationship between the resistance-increasing region 40a and the welded portion W according to one embodiment of the present invention will be explained. Figures 6 and 7 show the positional relationship between the resistance-increasing region provided on the current collector (first current collector) according to one embodiment of the present invention and the welded portion formed on the current collector.

[0046] Referring to Figures 1 to 3, as well as Figures 6 and 7, a welded portion W may be provided in the region where the second coupling portion 42 of the current collector 40 according to one embodiment of the present invention is coupled to the battery terminal 30. The welded portion W may be provided in a region where the resistance-increasing region 40a is not formed. With this configuration, when welding to couple the battery terminal 30 and the current collector 40, it is possible to prevent the groove line L constituting the resistance-increasing region 40a from melting and the cross-sectional area reduction region from being removed.

[0047] The resistance-increasing region 40a may be configured to surround the weld W. For example, if the resistance-increasing region 40a includes a substantially closed-loop groove L, the weld W may be located within the space surrounded by the groove L. In another embodiment, the weld W may be located between mutually separated and adjacent grooves L, as shown in Figure 7. When the weld W and the resistance-increasing region 40a are arranged in this manner, the current flowing from the battery terminal 30 to the electrode assembly 10 via the current collector 40 will pass through the resistance-increasing region 40a in the current collector 40. Therefore, when an overcurrent occurs, rapid rupture will occur in the resistance-increasing region 40a, thereby improving the safety of the battery 1 during use.

[0048] Next, with reference to Figure 8, the relative positional relationship between the resistance-increasing region 40a and the electrode assembly 10 according to one embodiment of the present invention will be explained. Figure 8 is a diagram illustrating the formation position of the resistance-increasing region according to one embodiment of the present invention.

[0049] Referring to Figure 8, the resistance-increasing region 40a according to one embodiment of the present invention may be located within a region corresponding to the inside of the winding central hole 10a formed by the winding of the electrode assembly 10. That is, the resistance-increasing region 40a may be located within the region indicated by the arrow in Figure 8. With this configuration, even if an overcurrent occurs during the use of the battery 1, causing a fracture in the resistance-increasing region 40a, the foreign matter from the fracture will fall through the winding central hole 10a, thereby minimizing the possibility of it flowing into the interior of the electrode assembly 10.

[0050] Next, with reference to Figure 9, a protective member 50 according to one embodiment of the present invention will be described. Figure 9 is a diagram showing a battery to which a protective member according to one embodiment of the present invention is applied.

[0051] Referring to Figure 9, the battery 1 according to one embodiment of the present invention may include a protective member 50 configured to cover the inner wall surface of the winding central hole 10a on the inlet side of the winding central hole 10a facing the current collector 40. When the battery 1 according to one embodiment of the present invention has such a protective member 50, the risk of damage to the separation membrane located on the inner wall surface of the winding central hole 10a by foreign matter generated when the resistance-increasing region 40a breaks, as described above, flows into the winding central hole 10a can be reduced.

[0052] The protective member 50 may be configured to cover only a portion of the entire inner wall surface of the winding center hole 10a. Alternatively, the protective member 50 may be configured to cover only the area adjacent to the current collector 40 of the entire inner wall surface of the winding center hole 10a. Such a configuration minimizes the phenomenon of impaired impregnation of the electrolyte through the inner wall surface of the winding center hole 10a.

[0053] Next, with reference to Figure 10, an exemplary embodiment of the current collector 40 according to one embodiment of the present invention will be described. Figure 10 is a diagram showing an exemplary embodiment of the current collector (first current collector) according to one embodiment of the present invention.

[0054] Referring to Figure 10, the current collector 40 according to one embodiment of the present invention may have a structure in which the first coupling portion 41 and the second coupling portion 42 are spaced apart from each other in the radial direction. The current collector 40 according to one embodiment of the present invention may include a rim portion 43 located on the outer circumference of the first coupling portion 41 and the second coupling portion 42. The current collector 40 may include a connecting portion 44 configured to connect the rim portion 43 and the second coupling portion 42. In this way, when the first coupling portion 41 and the second coupling portion 42 are connected indirectly via the rim portion 43 rather than directly to each other, the impact applied to the battery 1 can be dispersed. That is, the transmission of impact applied to the weld portion of the first coupling portion 41 to the weld portion of the second coupling portion 42 can be minimized, and the transmission of impact applied to the weld portion of the second coupling portion 42 to the first coupling portion 41 can also be minimized.

[0055] Next, with reference to Figure 11, the lower structure of the battery 1 according to one embodiment of the present invention will be described. Figure 11 is a diagram showing the lower portion structure of the battery according to one embodiment of the present invention.

[0056] Referring to Figure 11, a battery 1 according to one embodiment of the present invention may include a current collector (second current collector) 60. The current collector 60 may be configured to electrically connect the electrode assembly 10 and the battery housing 20. The current collector 60 may be electrically connected to the second electrode of the electrode assembly 10. The current collector 60 may be electrically coupled to a second blank portion 12 provided on the second surface of the electrode assembly 10. The current collector 60 may be electrically coupled to the inner surface of the battery housing 20. The current collector 60 may be electrically coupled to a beading portion 21 formed by press-fitting around the outer circumferential surface of the battery housing 20.

[0057] The battery 1 may include a cap 70. The cap 70 may be configured to close the opening of the battery housing 20. The cap 70 may be secured by a crimping portion 22 that extends from the beading portion 21 of the battery housing 20, bends, and surrounds the edge of the cap 70. A sealing member (second sealing member) G2 may be interposed between the cap 70 and the inner surface of the battery housing 20. The cap 70 may include a vent portion 71 that is configured to be weaker than the rest of the area. The vent portion 71 may be configured to partially reduce the thickness of the cap 70. The vent portion 71 may be configured to rupture when the internal pressure of the battery 1 increases and exceeds a predetermined pressure.

[0058] Next, with reference to Figure 12, a battery pack 3 according to one embodiment of the present invention will be described. Figure 12 is a diagram showing a battery pack according to one embodiment of the present invention.

[0059] Referring to Figure 12 in conjunction with Figures 1 and 11, a battery pack 3 according to one embodiment of the present invention may include a battery 1 according to one embodiment of the present invention and a pack housing 2 that houses the battery 1. Multiple batteries 1 may be provided, and the multiple batteries 1 may be electrically connected to each other. In one embodiment of the present invention, the battery terminals 30 and the closing portion of the battery housing 20 may be configured to function as a first electrode terminal and a second electrode terminal, respectively. Therefore, when arranging multiple batteries 1 in the pack housing 2, by arranging the terminals 30 of all batteries 1 facing upward, electrical connections can be made at the top of the batteries 1.

[0060] Next, with reference to Figure 13, an automobile 5 according to one embodiment of the present invention will be described. Figure 13 is a diagram showing an automobile according to one embodiment of the present invention.

[0061] Referring to Figure 13, an automobile 5 according to one embodiment of the present invention may include a battery pack 3 according to one embodiment of the present invention. The automobile 5 may be configured to operate by being powered by the battery pack 3. The automobile 5 may be, for example, an electric vehicle or a hybrid vehicle.

[0062] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and various modifications and variations are possible within the equivalent scope of the technical idea of ​​the present invention and the claims described below by persons with ordinary skill in the art to which the present invention pertains. [Explanation of Symbols]

[0063] 1: Battery 2: Pack Housing 3: Battery pack 5: Automobile 10: Electrode assembly 20: Battery Housing 30: Battery terminals 40: Current collector (first current collector) 40a: Resistance increase region L: Groove line 50: Protective component 60: Current collector (second current collector)

Claims

1. Electrode assembly and A battery housing configured to accommodate the electrode assembly through an opening formed on one side, A battery terminal configured to be electrically connected to the electrode assembly via a closed portion provided on the opposite side of the open portion of the battery housing, A current collector comprising: a first coupling portion configured to be electrically coupled to the electrode assembly; and a second coupling portion configured to be electrically coupled to the battery terminal, with at least a portion thereof having a resistance-increasing region formed therein. Includes a battery.

2. The aforementioned resistance increase region is, The battery according to claim 1, configured to have a smaller cross-sectional area compared to the remaining area of ​​the second coupling portion.

3. The aforementioned resistance increase region is, The battery according to claim 1 or 2, configured to have a thinner thickness compared to the remaining area of ​​the second coupling portion.

4. The aforementioned resistance increase region is, The battery according to claim 1 or 2, comprising grooves formed on one or both sides of the second coupling portion.

5. The groove line is, The battery according to claim 4, which extends along the circumferential direction of the battery.

6. The resistance-increasing region includes a plurality of grooves formed on one or both sides of the second coupling portion. The battery according to claim 1 or 2, wherein the plurality of grooves are arranged spaced apart from each other along the radial direction of the battery.

7. The resistance-increasing region includes a plurality of grooves formed on one or both sides of the second coupling portion. The battery according to claim 1 or 2, wherein the plurality of grooves are arranged spaced apart from each other along the circumferential direction of the battery.

8. A welded portion is provided in the region where the second coupling portion and the battery terminal are coupled. The battery according to claim 1 or 2, wherein the welded portion is provided in a region where the resistance-increasing region is not formed.

9. A welded portion is provided in the region where the second coupling portion and the battery terminal are coupled. The battery according to claim 1 or 2, wherein the resistance-increasing region is configured to surround the welded portion.

10. The electrode assembly has a structure in which a laminate including a first electrode, a second electrode, and a separation membrane interposed between the first electrode and the second electrode is wound around it. The battery according to claim 1 or 2, wherein the resistance-increasing region is provided at a position corresponding to the inside of the winding center hole formed by the winding of the electrode assembly.

11. The aforementioned battery is The battery according to claim 10, further comprising a protective member configured to cover the inner wall surface of the winding central hole on the entrance side of the winding central hole facing the current collector.

12. The battery according to claim 1 or 2, wherein the first coupling portion and the second coupling portion of the current collector are located apart from each other along the radial direction of the battery.

13. The aforementioned current collector is The rim portion located on the outer circumference of the first joint and the second joint, A connecting portion configured to connect the rim portion and the second connecting portion, The battery according to claim 11, including the following:

14. A battery pack comprising the battery described in claim 1 or 2.

15. An automobile comprising the battery pack described in claim 14.

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