Batteries, battery packs containing the same, and automobiles

Abstract

A battery according to one embodiment of the present invention includes an electrode assembly having a central winding hole formed by winding a laminate including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; a housing configured to receive the electrode assembly via an opening formed on one side thereof; and a current collector having a diameter larger than that of the central winding hole, the current collector having a current collector hole formed at a position corresponding to the central winding hole, and coupled to one surface of the electrode assembly on the open side of the housing.

Description

[Technical Field]

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

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0089125, filed on July 19, 2022, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0003] Secondary batteries are generally designed to release internal gas to reduce the internal pressure if a problem occurs and the internal pressure rises. In this way, if venting (gas release) is performed smoothly when the internal pressure rises above a certain level, accidents such as explosions caused by a continuous rise in internal pressure can be prevented.

[0004] However, if there is a factor that prevents venting from being performed in a timely manner, or if the structure collapses due to an increase in internal pressure, causing a short circuit, a thermal event may spread, which may significantly compromise the safety of the secondary battery in use.

[0005] In a thermal runaway test to eliminate this risk, there is a risk of a short circuit, such as when part of the electrode assembly is ejected outside the housing after venting occurs.

[0006] In the case of thermal runaway, the electrode assembly may be ejected from the housing too quickly, which may cause a short circuit inside the secondary battery or an external short circuit due to debris from the ejected electrode assembly and / or other metal parts.

[0007] Additionally, if the internal pressure inside the housing increases and / or the electrode assembly ejects too quickly due to a thermal event, there is a concern that a partial rupture of the housing could cause the ejected portion of the electrode assembly to block the vent path for the internal gas before venting occurs, preventing smooth venting. This obstruction of venting could lead to a significant increase in internal pressure and potentially a major explosion.

[0008] Therefore, there is a strong demand for the development of a secondary battery structure that can prevent or delay as much as possible the structural collapse of the electrode assembly when the internal pressure increases due to an abnormality in the secondary battery. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in view of the above problems, and its purpose is to prevent or delay as much as possible structural collapse of the electrode assembly when an internal pressure rise and / or a thermal event occurs due to an abnormality in the battery.

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

[0011] In order to solve the above-mentioned problems, a battery according to one embodiment of the present invention includes an electrode assembly having a winding center hole formed by winding a laminate including a first electrode, a second electrode, and a separator (separation membrane) interposed between the first electrode and the second electrode; a housing configured to receive the electrode assembly through an opening formed on one side thereof; and a current collector having a diameter larger than that of the winding center hole, the current collector having a current collector hole formed at a position corresponding to the winding center hole, and coupled to one surface of the electrode assembly on the open side of the housing.

[0012] The winding center hole may be located inside the current collector hole.

[0013] The difference between the diameter of the current collector hole and the diameter of the winding center hole divided by the diameter of the winding center hole may be 0.015 or more and less than 0.4.

[0014] The diameter of the winding center hole may be equal to or greater than 5.0 mm and less than 7.0 mm.

[0015] The difference between the diameter of the current collector hole and the diameter of the winding center hole may be 0.1 mm or more and less than 2.0 mm.

[0016] The current collector may be electrically connected to the housing.

[0017] The battery may include a cap configured to cover the opening.

[0018] The cap may include a vent portion configured to be weaker than the surrounding area so that it can rupture when internal pressure increases.

[0019] Meanwhile, a battery pack according to an embodiment of the present invention for solving the above-mentioned problems includes a battery according to an embodiment of the present invention.

[0020] In order to solve the above-mentioned problems, a vehicle according to an embodiment of the present invention includes a battery pack according to an embodiment of the present invention. [Effects of the Invention]

[0021] According to one aspect of the present invention, when an internal pressure rise and / or a thermal event occurs due to an abnormality in the battery, structural collapse of the electrode assembly can be prevented or delayed to the greatest extent possible.

[0022] However, the advantageous effects obtained by the present invention are not limited to those described above, and other advantageous effects not mentioned will be clearly understood by those skilled in the art from the following description of the invention.

[0023] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical concepts of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a view showing an upper portion of a battery according to an embodiment of the present invention being opened; [Figure 2] 1 is a plan view showing a combination of an electrode assembly and a current collector according to the present invention; [Figure 3] 10A and 10B are diagrams illustrating an increase in normal force due to a decrease in the diameter of the winding center hole of the electrode assembly. [Figure 4] 10A and 10B are diagrams illustrating an increase in frictional force due to an increase in normal force acting on a core of an electrode assembly. [Figure 5] 10 is a CT image showing the change in discharge rate of an electrode assembly depending on the diameter of the winding center hole of the electrode assembly. [Figure 6] 10 is a CT image showing the change in discharge rate of an electrode assembly depending on the diameter of the winding center hole of the electrode assembly. [Figure 7] 10 is a CT image showing the change in discharge rate of an electrode assembly depending on the diameter of the winding center hole of the electrode assembly. [Figure 8] 1 is a diagram showing an upper structure of a battery according to an embodiment of the present invention; [Figure 9] FIG. 2 is a plan view showing a vent portion formed in the cap of the present invention. [Figure 10] FIG. 2 is a diagram showing the structure of the lower portion of a battery according to one embodiment of the present invention. [Figure 11] 1 illustrates a battery pack according to one embodiment of the present invention. [Figure 12] 1 illustrates a vehicle according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present invention, based on the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical ideas of the present invention, and therefore, various equivalent and modified embodiments may be available as of the time of filing this application.

[0026] First, a battery 1 according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a view showing an upper portion of a battery according to an embodiment of the present invention with the upper portion opened. Figure 2 is a plan view showing a combination of an electrode assembly and a current collector according to the present invention.

[0027] 1 and 2, a battery 1 according to an embodiment of the present invention may be a cylindrical battery. The battery 1 may include an electrode assembly 10, a housing 20, and a current collector (first current collector) 30.

[0028] The electrode assembly 10 may have a central winding hole 10a formed by winding a laminate including a first electrode, a second electrode, and a separator interposed therebetween. The first electrode may have a first uncoated portion 11 formed at one end along the winding direction. In this case, the first uncoated portion 11 may be disposed on one surface of the electrode assembly 10.

[0029] The housing 20 may be configured to receive the electrode assembly 10 through an opening formed on one side. Although not shown in FIG. 1, a closing portion may be provided on the opposite side of the opening. The housing 20 may include a conductive metal. Although FIG. 1 of the present invention shows one side of the housing 20 open, the opening may also be closed by a separate part.

[0030] The current collector 30 may be disposed on one surface of the electrode assembly 10 on the open side of the housing 20. The current collector 30 may be electrically coupled to, for example, the first uncoated portion 11 of the electrode assembly 10. The first uncoated portion 11 may be formed at one end of the first electrode constituting the electrode assembly 10. The first uncoated portion 11 may extend along the winding direction of the electrode assembly 10. The first uncoated portion 11 may be provided on one surface of the electrode assembly 10, for example, may extend above the electrode assembly 10. Meanwhile, although not shown in FIG. 1 of the present invention, the current collector 30 may be configured to electrically connect the first electrode of the electrode assembly 10 and the housing 20.

[0031] The current collector 30 may have a current collector hole 30a. The current collector hole 30a may be formed at a position corresponding to the winding center hole 10a of the electrode assembly 10. The current collector hole 30a may have a diameter R2 that is larger than the diameter R1 of the winding center hole 10a of the electrode assembly 10.

[0032] 2, the winding center hole 10a of the electrode assembly 10 may be located inside the current collector hole 30a. That is, the current collector 30 may be disposed so as not to cover the winding center hole 10a of the electrode assembly 10 even partially.

[0033] According to this configuration of the present invention, when an electrolyte is poured into an assembly in which the electrode assembly 10 and the current collector 30 are combined and housed in the housing 20, the electrolyte can be smoothly circulated through the winding central hole 10a. In another aspect, according to this configuration of the present invention, a process of welding components such as terminals provided on the closed portion opposite the open portion of the housing 20 can be easily performed by irradiating a welding laser or inserting a welding device through the winding central hole 10a.

[0034] If the current collector 30 covers even a part of the winding central hole 10a of the electrode assembly 10, there is a risk that the electrolyte will not flow and circulate smoothly during the electrolyte injection step as described above. In another aspect, if the current collector 30 covers even a part of the winding central hole 10a of the electrode assembly 10, there is a risk that the welding step through the winding central hole 10a will not be carried out smoothly and / or that the inner wall surface of the winding central hole 10a will be damaged during the welding step.

[0035] Next, referring to Figures 3 to 7 in addition to Figures 1 and 2, we will explain the difference in the degree of deformation of the core portion of the electrode assembly 10 depending on the change in the diameter of the winding center hole 10a of the electrode assembly 10. Figure 3 is a diagram for explaining the increase in normal force as the diameter of the winding center hole of the electrode assembly decreases, and Figure 4 is a diagram for explaining the increase in frictional force as the normal force formed on the core of the electrode assembly increases. Figures 5 to 7 are CT images showing the change in the discharge rate of the electrode assembly depending on the diameter of the winding center hole of the electrode assembly.

[0036] The core exposure ratio A, which is the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a of the electrode assembly 10 divided by the diameter R1 of the winding center hole 10a, may be about 0.015 to 0.5. The core exposure ratio A may be about 0.015 or more and less than 0.4. The core exposure ratio A may be about 0.072 or more and less than 0.3. The core exposure ratio A may be about 0.016 to 0.5. The core exposure ratio A may be about 0.016 or more and less than 0.4. The core exposure ratio A may be about 0.077 or more and less than 0.3. The core exposure ratio A may be about 0.016 to 0.416. The core exposure ratio A may be about 0.016 to 0.333. The core exposure ratio A may be about 0.077 or more and less than 0.25.

[0037] The diameter R1 of the winding center hole 10a may be approximately 5.0 mm or more and less than 7.0 mm. The diameter R1 of the winding center hole 10a may be approximately 5.0 mm or more and less than 6.5 mm. The diameter R1 of the winding center hole 10a may be approximately 6.0 mm or more and less than 6.5 mm.

[0038] The difference R2-R1 between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a may be approximately 0.1 mm to 2.5 mm. The difference R2-R1 between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a may be approximately 0.1 mm or more and less than 2.0 mm. The difference R2-R1 between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a may be approximately 0.5 mm or more and less than 1.5 mm.

[0039] This range of values takes into consideration all of the following: suppression of deformation of the core of the electrode assembly 10, ensuring smooth circulation of the electrolyte, ensuring ease of the welding process, and ensuring ease of alignment of the current collector 30 and the electrode assembly 10. The influence of the diameter R1 of the winding center hole 10a and the diameter R2 of the current collector hole 30a on the resistance force that suppresses discharge from the core portion of the electrode assembly 10 will be described in detail below.

[0040] 1 and 2, as the diameter of the winding center hole 10a decreases, the normal force acting outward from the core of the electrode assembly 10 increases. This is because as the winding center hole 10a of the electrode assembly 10 becomes smaller, the curvature of the electrode assembly 10 increases, and as a result, the tension due to the restoring force of the wound laminate including the first electrode, the second electrode, and the separator increases.

[0041] 1 and 2, the increase in normal force due to the decrease in diameter R1 of the winding center hole 10a increases the resistance to the upward discharge force of the core portion of the electrode assembly 10. This is because the frictional force between adjacent layers of the laminate including the first electrode, the second electrode, and the separator increases with the increase in normal force applied outward from the core portion of the electrode assembly 10.

[0042] The frictional force between the layers of the laminate may act as a resistance force against the ejection force of the core portion of the electrode assembly 10 that occurs due to an increase in the internal pressure of the battery 1. Therefore, such an increase in frictional force may suppress the ejection of the core portion of the electrode assembly 10.

[0043] 5 to 7 in addition to FIGS. 1 and 2, when an increase in the internal pressure of the battery 1 causes the core portion of the electrode assembly 10 to be ejected, the smaller the central winding hole 10a of the electrode assembly 10, the shorter the length of the core portion of the electrode assembly 10 ejected toward the opening of the housing 20. FIG. 5 shows a case where the diameter R1 of the central winding hole 10a is approximately 6 mm, FIG. 6 shows a case where the diameter R1 of the central winding hole 10a is approximately 7 mm, and FIG. 7 shows a case where the diameter R1 of the central winding hole 10a is approximately 8 mm. In FIGS. 6 and 7, the core portion of the electrode assembly 10 is ejected upward due to a thermal event in the battery 1, but the ejected portion is not exposed to the outside of the battery 1. In particular, FIG. 5 shows that the ejected length of the core portion of the electrode assembly 10 is very short. However, FIG. 7 shows that the ejected length of the core portion of the electrode assembly 10 is very long, ejected upward to a position far away from the core portion of the electrode assembly 10.

[0044] Thus, if the discharge rate of the core portion of the electrode assembly 10 is high, there is a possibility that a further thermal event will occur due to a short circuit caused by unnecessary electrical contact and / or that the discharge portion will prevent the internal gas from being discharged. Therefore, in order to keep the discharge rate of the core portion of the electrode assembly 10 below a certain level, it is necessary to adjust the diameter R1 of the winding center hole 10a of the electrode assembly 10 to the level proposed in the present invention.

[0045] Meanwhile, the value obtained by dividing the diameter R1 of the winding central hole 10a by the diameter of the electrode assembly 10 may be approximately 0.109 to 0.159. The value obtained by dividing the diameter R1 of the winding central hole 10a by the diameter of the electrode assembly 10 may be approximately 0.109 to 0.147. The value obtained by dividing the diameter R1 of the winding central hole 10a by the diameter of the electrode assembly 10 may be approximately 0.130 to 0.147.

[0046] Meanwhile, the value obtained by dividing the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a by the diameter of the electrode assembly 10 may be approximately 0.002 to 0.056. The value obtained by dividing the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a by the diameter of the electrode assembly 10 may be approximately 0.002 to 0.045. The value obtained by dividing the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a by the diameter of the electrode assembly 10 may be approximately 0.011 to 0.034.

[0047] The resistance force that suppresses the discharge of the core portion of the electrode assembly 10 may be affected not only by the absolute values of the diameter R1 of the winding center hole 10a of the electrode assembly 10 and the diameter R2 of the current collector hole 30a, but also by the ratio of the diameter R1 of the winding center hole 10a to the overall diameter of the electrode assembly 10.

[0048] The diameter of the electrode assembly 10 of the present invention may be, for example, about 44 mm to 46 mm.

[0049] As described above, if the diameter R1 of the winding central hole 10a is excessively large, there is a risk that the discharge of the core portion of the electrode assembly 10 may not be sufficiently suppressed when a thermal event occurs. Therefore, it is necessary to set an upper limit value for the diameter R1 of the winding central hole 10a taking this into consideration.

[0050] Conversely, if the diameter R1 of the central winding hole 10a is too small, problems may occur such as the electrolyte not circulating smoothly through the central winding hole 10a and / or the process of welding components located on the opposite side of the open portion of the housing 20 through the central winding hole 10a not being carried out smoothly. In particular, when welding is performed by irradiating a laser through the central winding hole 10a, it is necessary to ensure sufficient space so that the laser can stably enter the central winding hole 10a. Therefore, the lower limit of the diameter R1 of the central winding hole 10a must be set taking this into consideration.

[0051] Meanwhile, the diameter R2 of the current collector hole 30a formed in the current collector 30 may also have an effect on determining the resistance force that suppresses the discharge from the core portion of the electrode assembly 10.

[0052] If the diameter R2 of the current collector hole 30a is formed excessively large, the effect of suppressing the ejection of the core portion of the electrode assembly 10 decreases. Therefore, taking this into consideration, it is necessary to set an upper limit for the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a.

[0053] Conversely, if the diameter R2 of the current collector hole 30a is formed too small, it may become difficult to align the winding center hole 10a within the current collector hole 30a. If the winding center hole 10a is not accurately positioned within the current collector hole 30a, the winding center hole 10a may be partially hidden by the current collector 30. This may interfere with the injection / circulation of electrolyte through the winding center hole 10a and may also interfere with the welding process performed through the winding center hole 10a. Therefore, taking this into consideration, it is necessary to set a lower limit for the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a.

[0054] [Table 1]

[0055] Referring to Table 1 above in conjunction with the previously referenced drawings, it can be seen that generally good results are obtained when the diameter of the winding center hole 10a of the electrode assembly 10 is less than about 7 mm. In other words, it can be seen that when the diameter of the winding center hole 10a is less than about 7 mm, deformation of the core portion of the electrode assembly 10 is suppressed even if a thermal event occurs inside the battery 1.

[0056] On the other hand, the experimental results shown in Table 1 indicate that the core deformation suppression force is also affected by the difference between the diameter R2 of the current collector hole 30a and the diameter R1 of the winding center hole 10a. It can be seen that a sufficient core deformation suppression force is obtained when R2 - R1 is approximately 2.5 mm or less while maintaining R1 below 7 mm.

[0057] However, when R1 is 6.5 mm or more, even if R2 - R1 is 2.5 mm or less, deformation of the core may occur, as shown in TEST 5 and TEST 7. Taking this into consideration, measures can be taken to limit R1 to less than approximately 6.5 mm, and / or to limit R2 - R1 to less than approximately 2.0 mm, and / or to limit R2 - R1 to less than approximately 1.5 mm, which can further improve the effect of suppressing core deformation.

[0058] Next, the overall structure of a battery 1 according to one embodiment of the present invention will be described with reference to Figures 8 to 10. Figure 8 is a diagram showing the upper structure of a battery according to one embodiment of the present invention. Figure 9 is a plan view showing a vent portion formed in a cap of the present invention. Figure 10 is a diagram showing the lower portion structure of a battery according to one embodiment of the present invention.

[0059] 8 and 9, the current collector 30 may be configured to be electrically connected to the housing 20. For example, the current collector 30 may be electrically connected to a beading portion having a structure in which the outer circumferential surface of the housing 20 is pressed inward.

[0060] The battery 1 may include a cap 40 configured to cover an opening formed on one side of the housing 20. The cap 40 may be configured to be electrically insulated from the electrode assembly 10 and the housing 20 and to have no polarity. For example, a first insulating member G1 may be interposed between the cap 40 and the housing 20.

[0061] The cap 40 may include a vent portion 40a configured to be rupturable when the internal pressure of the battery 1 increases. The vent portion 40a may be configured to be weaker than the surrounding area. For example, the vent portion 40a may correspond to an area having a smaller thickness than other areas of the cap 40. The vent portion 40a may extend to form a closed loop within the cap 40, as shown in FIG. 8.

[0062] As described above, when the battery 1 of the present invention includes the cap 40 and the cap 40 is provided with the vent portion 40a, it is even more important to ensure the discharge suppression force of the core portion of the electrode assembly 10, as described above. If the discharge suppression force of the core portion is not ensured, a phenomenon may occur in which the discharged core portion of the electrode assembly 10 fills the space formed between the cap 40 and the current collector 30 before the internal gas is discharged due to the rupture of the vent portion 40a formed in the cap 40. In this case, even if the vent portion 40a is broken, smooth gas discharge may not be achieved, which may lead to the diffusion of a thermal event.

[0063] Referring to FIG. 10 , the battery 1 may include a first terminal T1. The first terminal T1 may be electrically coupled to the second uncoated portion 12 of the electrode assembly 10. Similar to the first uncoated portion 11 described above, the second uncoated portion 12 may be formed at one end of the second electrode. The second uncoated portion 12 may extend along the winding direction of the electrode assembly 10. The second uncoated portion 12 may be provided on one of the two surfaces of the electrode assembly 10 opposite the surface on which the first uncoated portion 11 is provided, and may extend downward, for example. The first terminal T1 may be partially inserted into the housing 20, for example, through a closing portion of the housing 20. The first terminal T1 may be configured to be insulated from the housing 20. For example, a second insulating member G2 may be interposed between the first terminal T1 and the housing 20. In this way, when the first terminal T1 is provided on the closed portion side of the housing 20, the outer surface of the closed portion of the housing 20 can function as the second terminal T2.

[0064] The battery 1 may include a current collector (second current collector) P configured to electrically connect the first terminal T1 and the electrode assembly 10. The current collector P may be electrically coupled to the first terminal T1. For example, the current collector P may be welded to the first terminal T1 by irradiating a laser or inserting a welding tool through the winding center hole 10a of the electrode assembly 10 from the open side of the housing 20.

[0065] When the battery 1 of the present invention includes a current collector P, an insulator IS may be interposed between the current collector P and the closure of the housing 20. The insulator IS can prevent contact between the current collector P and the housing 20, which are configured to have opposite polarities.

[0066] Next, a battery pack 3 according to one embodiment of the present invention will be described with reference to Fig. 11. Fig. 11 is a diagram showing a battery pack according to one embodiment of the present invention.

[0067] 11 , a battery pack 3 according to one embodiment of the present invention may include at least one battery 1 of the present invention as described above. The battery 1 may be housed in a pack housing 2. The battery pack 3 may include components for electrical connection of the battery 1 and / or a battery management system (BMS) configured to control charging and discharging of the battery 1.

[0068] Next, a vehicle 5 according to an embodiment of the present invention will be described with reference to Figure 12. Figure 12 is a diagram showing a vehicle according to an embodiment of the present invention.

[0069] 12, an automobile 5 according to one embodiment of the present invention includes at least one battery pack 3. The automobile 5 may be configured to operate by being powered by the battery pack 3. The automobile 5 may be, for example, a hybrid electric vehicle (HEV) or an electric vehicle (EV).

[0070] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the appended claims. [Explanation of symbols]

[0071] 1 battery 2-pack housing 3 Battery Pack 5. Automobiles 10 Electrode assembly 11 First plain area 12 Second plain area 10a Winding center hole 20. Housing 30 Current collector (first current collector) 30a Current collector hole 40 Cap 40a vent T1 First terminal T2 Second terminal P current collector (second current collector) IS insulator

Claims

1. an electrode assembly having a winding center hole formed by winding a laminate including a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; a housing configured to receive the electrode assembly through an opening formed on one side thereof; a current collector having a diameter larger than the diameter of the winding center hole, the current collector having a current collector hole formed at a position corresponding to the winding center hole, the current collector being coupled to one surface of the electrode assembly on the open portion side of the housing; Including the battery.

2. The winding center hole is The battery of claim 1 , located inside the current collector hole.

3. 2. The battery according to claim 1, wherein a value obtained by dividing the difference between the diameter of the current collector hole and the diameter of the winding center hole by the diameter of the winding center hole is 0.015 or more and less than 0.

4.

4. The battery according to claim 1 , wherein the diameter of the winding center hole is equal to or greater than 5.0 mm and less than 7.0 mm.

5. 2. The battery according to claim 1, wherein the difference between the diameter of the current collector hole and the diameter of the winding center hole is 0.1 mm or more and less than 2.0 mm.

6. The current collector is The battery of claim 1 in electrical communication with the housing.

7. The battery The battery of claim 1 , including a cap configured to cover the opening.

8. The cap is The battery of claim 7 , further comprising a vent portion configured to be weaker than the surrounding area so as to be able to rupture when internal pressure increases.

9. A battery pack comprising the battery of any one of claims 1 to 8.

10. A motor vehicle comprising the battery pack of claim 9.

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