Battery and battery pack and vehicle

Abstract

Battery containing: an electrode assembly defining a core and an outer periphery by winding a first electrode, a second electrode, and a separator disposed therebetween around a winding center, each of the first electrode and the second electrode having a first uncoated portion and a second uncoated portion, to which no active material layer is applied, along the winding direction; a battery case that receives the electrode assembly through an opening formed on one side thereof; a cap having a vent portion configured to have a thinner thickness compared to a surrounding area, covering the opening, and electrically connected to the battery case and the first uncoated portion; and a battery terminal electrically connected to the second uncoated portion.

Description

TITLE OF THE INVENTION BATTERY AND BATTERY PACK AND VEHICLE TECHNICAL FIELD

[0001] The present disclosure relates to a battery and a battery pack, as well as a vehicle. More particularly, the present disclosure relates to a battery having a structure in which a cap covering an opening on one side of a battery case can simultaneously function as a venting device and a current interrupting device (CID), as well as to a battery pack and a vehicle.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0022877 filed on February 19, 2021, Korean Patent Application No. 10-2021-0022894 filed on February 19, 2021, Korean Patent Application No. 10-2021-0024424 filed on February 23, 2021, Korean Patent Application No. 10-2021-0131215 filed on October 1, 2021, and Korean Patent Application No. 10-2021-0154307 filed on November 10, 2021 in the Republic of Korea. STATE OF THE ART

[0003] In general, when a battery pack is manufactured using a cylindrical battery, a plurality of cylindrical batteries are usually arranged upright within a casing, and the plurality of cylindrical batteries are electrically connected to each other by using an upper end and a lower end of the cylindrical battery as a positive electrode terminal and a negative electrode terminal, respectively.

[0004] This is because, in a cylindrical battery, an uncoated portion of a negative electrode of an electrode assembly housed in the battery case extends downward to be electrically connected to a bottom surface of the battery case, and an uncoated portion of a positive electrode extends upward to be electrically connected to a cap. That is, in the cylindrical battery, it is common for the bottom surface of the battery case to be used as a negative electrode terminal, and the cap covering an upper opening of the battery case to be used as a positive electrode terminal.

[0005] However, if the positive electrode terminal and the negative electrode terminal of the cylindrical battery are located on opposite sides, an electrical connection component, such as a bus bar for electrically connecting the multiple cylindrical batteries, should be attached to both the upper and lower portions of the cylindrical battery. This complicates the electrical connection structure of the battery pack.

[0006] In addition, since in this structure, an insulation component and a waterproof component should be individually attached to the upper and lower portions of the battery pack, the number of attached components is increased and the structure is further complicated.

[0007] Therefore, in order to simplify the electrical connection structure of the plurality of cylindrical batteries, there is a need to develop a cylindrical battery having a structure in which a positive electrode terminal and a negative electrode terminal are arranged in the same direction. Furthermore, in the cylindrical battery having such a structure, multiple components can be concentrated in a direction in which the positive electrode terminal and the negative electrode terminal are formed to form the positive electrode terminal and the negative electrode terminal. Therefore, a structure for venting when the internal pressure increases and a structure for blocking a current when an overcurrent occurs must be formed on the side opposite to the direction in which the positive electrode terminal and the negative electrode terminal are formed. RevelationTechnical task

[0008] The present disclosure is designed to solve the problems of the prior art and is directed to enabling a cap covering an opening of a battery case to function simultaneously as a venting device and a current interrupting device (CID).

[0009] Furthermore, the present disclosure is directed to simplifying an electrical connection structure of a plurality of batteries.

[0010] Furthermore, the present disclosure aims to ensure a coupling area between an electrical connection component and a battery sufficient to electrically connect multiple batteries. However, technical problems to be solved by the present disclosure are not limited to the problems described above, and other problems not mentioned here can be clearly understood by those skilled in the art from the following description of the present disclosure. Technical solution

[0011] In one aspect of the present disclosure, a battery is provided, comprising: an electrode assembly defining a core and an outer periphery by winding a first electrode, a second electrode, and a separator disposed therebetween around a winding center, each of the first electrode and the second electrode including a first uncoated portion and a second uncoated portion, to which no active material layer is applied, along the winding direction; a battery case accommodating the electrode assembly through an opening formed on one side thereof; a cap including a vent portion configured to have a thinner thickness compared to a surrounding area, covering the opening and electrically connected to the battery case and the first uncoated portion;and a battery terminal electrically connected to the second uncoated portion;

[0012] The battery casing may be electrically connected to the first uncoated portion through the cap.

[0013] The cap may include a connecting portion for electrical connection to the first uncoated portion.

[0014] The venting portion may be continuous, forming a closed loop, and the connecting portion may be arranged in the closed loop.

[0015] The vent portion may have a groove shape formed on at least one of an outer surface and an inner surface of the cap.

[0016] The battery terminal may be exposed to the outside of the battery housing through a closed portion of the battery housing located on a side of the battery housing opposite the opening.

[0017] The battery terminal may penetrate a central portion of the closed section.

[0018] The battery terminal may be electrically insulated from the battery casing.

[0019] The battery may further include a first current collector coupled to the first uncoated portion.

[0020] The first current collector may be electrically connected to the cap.

[0021] The first current collector and the cap may be electrically connected by a terminal lug.

[0022] The terminal lug may have a length that is longer than a distance between the first current collector and the cap.

[0023] The battery may further include a second current collector coupled to the second uncoated portion.

[0024] The second current collector can be connected to the battery terminal.

[0025] The battery may further include a seal disposed between the cap and the battery housing.

[0026] The battery case may include a bead portion formed by pressing in an outer periphery thereof; and a crimp portion extending and bent such that an end defining the opening under the bead portion surrounds an edge of the cap.

[0027] The seal may be arranged in a region other than a contact region between the cap and the battery case in a region where the crimping portion is formed.

[0028] The battery case may include a bead portion formed by pressing in an outer periphery thereof; and a crimp portion extending and bent such that an end defining the opening under the bead portion surrounds an edge of the cap.

[0029] An edge of the first pantograph may be supported by the bead portion.

[0030] An insulating layer may be disposed between the edge of the first current collector and the bead portion of the battery case, which face each other.

[0031] The insulating layer may be an insulating coating layer formed on a surface of the first current collector or the bead portion.

[0032] The battery may further include an insulator covering a lower surface of the electrode assembly facing the cap.

[0033] The insulator may include a hole formed at a position corresponding to a hole formed at a winding center of the electrode assembly.

[0034] The first current collector and the cap may be electrically connected by a terminal lug, and the insulator may include a hole through which the terminal lug passes.

[0035] At least a portion of the first uncoated portion may include a plurality of segment parts divided along a winding direction of the electrode assembly, and the plurality of segment parts may be bent along a radial direction of the electrode assembly.

[0036] The plurality of bent segment parts may be overlapped in multiple layers along the radial direction.

[0037] The electrode assembly may include a welding target region, which is a region in which the number of overlapping segment parts of the first uncoated portion remains constant along a radial direction of the electrode assembly, and the first current collector may be coupled to the first uncoated portion in the welding target region.

[0038] At least a portion of the second uncoated portion may include a plurality of segment parts divided along a winding direction of the electrode assembly, and the plurality of segment parts may be bent along a radial direction of the electrode assembly.

[0039] The plurality of bent segment parts may be overlapped in multiple layers along the radial direction.

[0040] The electrode assembly may include a welding target region, which is a region in which the number of overlapping segment parts of the second uncoated portion remains constant along a radial direction of the electrode assembly, and the second current collector may be coupled to the second uncoated portion in the welding target region.

[0041] The resistance measured between the positive electrode and the negative electrode may be 4 milliohms or less.

[0042] The ratio of the form factor obtained by dividing the diameter of the battery by the height can be greater than 0.4.

[0043] In another aspect of the present disclosure, a battery pack is provided that includes a plurality of batteries according to the present disclosure as described above.

[0044] The plurality of batteries may be arranged in a predetermined number of columns, and the battery terminal of each battery and the outer surface of the closed portion of the battery case may be arranged to face upward.

[0045] The battery pack may include a plurality of bus bars connecting the plurality of batteries in series and parallel, wherein the plurality of bus bars may be arranged on the plurality of batteries. In this case, each of the bus bars may have a body portion extending between battery terminals of adjacent batteries; a plurality of first bus bar terminals extending in one direction of the body portion and electrically coupled to the battery terminal of the battery located in one direction described above; and a plurality of second bus bar terminals extending in the other direction of the body portion and electrically coupled to the outer surface of the closed portion of the battery case of the battery located in the other direction described above.

[0046] In another aspect of the present disclosure, a vehicle is provided that includes a battery pack according to the present disclosure as described above. Beneficial effects

[0047] According to the present disclosure, the cap covering the opening of the battery case can simultaneously function as a venting device and a current interruption device (CID).

[0048] Furthermore, according to the present disclosure, it is possible that a plurality of batteries are electrically connected on one side in the longitudinal direction of the batteries, and thereby the electrical connection structure can be simplified.

[0049] Furthermore, according to the present disclosure, a coupling area between an electrical connection component and a battery can be sufficiently secured, thereby reducing electrical resistance and sufficiently securing coupling strength.

[0050] However, effects to be achieved by the present disclosure are not limited to the effects described above, and other effects not mentioned here can be clearly understood by those skilled in the art from the following description of the present disclosure. DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the above disclosure, serve to provide a further understanding of the technical features of the present disclosure, and thus, the present disclosure is not to be construed as limited to the drawings. Fig. 1 is a view illustrating an appearance of a cylindrical battery according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view illustrating an internal structure of a cylindrical battery according to an embodiment of the present disclosure. Fig. 3 is a cross-sectional view illustrating a lower structure of a battery, and is a view for describing a problem that may occur when a first current collector comes into contact with a battery case in the battery of the present disclosure. Fig. 3a and Fig. 3b are partial cross-sectional views illustrating a bottom structure of a cylindrical battery according to an embodiment of the present disclosure. Fig. 4 is a view illustrating a bottom surface of a cylindrical battery according to an embodiment of the present disclosure. Fig. 5 is a conceptual view for describing a positional relationship of a connecting portion and a vent portion provided on a cap of the present disclosure, and a shape of a vent portion. Fig. 6 is a partial cross-sectional view illustrating an upper structure of a cylindrical battery according to an embodiment of the present disclosure. Fig. 7 is a view illustrating an electrode assembly in which segment parts are formed. Fig. 8 and Fig. 9 are views illustrating a coupling structure between a current collector and an uncoated portion of an electrode assembly applied to the present disclosure. Fig. 10 is a plan view illustrating a state in which a plurality of cylindrical batteries according to an embodiment of the present disclosure are connected in series and parallel using bus bars. Fig. 11 is a schematic view illustrating a battery pack according to an embodiment of the present disclosure. Fig. 12 is a conceptual view illustrating a vehicle according to an embodiment of the present disclosure. EMBODIMENTS

[0052] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before proceeding, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to generic and dictionary-like meanings, but should be interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure, based on the principle that the inventor is permitted to define terms appropriately for the best explanation.

[0053] Therefore, the description proposed herein is only a preferred example for purposes of illustration only and is not intended to limit the scope of the disclosure, so that it is understood that other equivalents and modifications could be made thereto without departing from the scope of the disclosure.

[0054] Furthermore, to facilitate understanding of the present disclosure, the accompanying drawings are not drawn to scale; rather, the dimensions of some components may be exaggerated. Furthermore, the same component may be assigned the same reference numeral in different embodiments.

[0055] A statement that two comparison objects are identical means "essentially identical." Therefore, "essentially identical" may include deviations that are technically considered small, for example, deviations within 5%. Furthermore, the uniformity of a particular parameter within a predetermined range may mean that it is uniform with respect to an average.

[0056] Although the first, second, and the like are used to describe various components, these components are, of course, not limited by these terms. These terms are used only to distinguish one component from another, and unless otherwise noted, it is understood that the first component can be the second component.

[0057] As used herein, each component may be singular or plural unless otherwise noted.

[0058] Placing any component on the "top (or bottom)" of a component or the "top (or bottom)" of a component may mean that any component is placed in contact with the top (or bottom) surface of the component, and may also mean that other components may be placed between the component and any component placed on (or below) the component.

[0059] Additionally, when a component is described as being "linked," "coupled," or "connected" to another component, the components may be directly linked or connected to each other, but it is understood that another component may be "interposed" between each component, or each component may be "linked," "coupled," or "connected" by yet another component.

[0060] As used herein, the term "A and / or B" means "A, B or both" unless expressly stated to the contrary, and the term "C to D" means "C or more and D or less" unless expressly stated to the contrary.

[0061] With reference to the Fig. 1 to Fig. 3b and Fig. 6, a battery 1 according to an embodiment of the present disclosure may, for example, be a cylindrical battery. The cylindrical battery 1 includes an electrode assembly 10, a battery case 20, a cap 30, and a battery terminal 40. The cylindrical battery 1 may further include a first current collector 50, a gasket 60, an insulating gasket 70, a second current collector 80, and / or an insulator (a first insulator) 90 in addition to the components described above. The present disclosure is not limited by the type of battery and may be applied to a battery of other types, for example, a prismatic battery.

[0062] The electrode assembly 10 has a first uncoated portion 11 and a second uncoated portion 12. The electrode assembly 10 includes a first electrode with a first polarity, a second electrode with a second polarity, and a separator disposed between the first electrode and the second electrode. The first electrode is a negative electrode or a positive electrode, and the second electrode corresponds to an electrode with a polarity opposite to that of the first electrode.

[0063] The electrode assembly 10 may, for example, have a jelly-roll shape (wound roll shape). That is, the electrode assembly 10 may be manufactured by winding a stack formed by sequentially stacking the first electrode, the separator, and the second electrode at least once. The jelly-roll electrode assembly 10 may include a winding center hole formed at the winding center C and extending along the height direction (direction parallel to the Z-axis). Meanwhile, an additional separator may be provided on the outer periphery of the electrode assembly 10 for insulation from the housing 20.

[0064] The first electrode includes a first conductive substrate and a first electrode active material layer formed by applying it to one or both surfaces of the first conductive substrate. A first uncoated electrode portion, to which the first electrode active material is not applied, is provided at one end of the first conductive substrate in a width direction (direction parallel to the Z axis). The first uncoated electrode portion has a shape that extends from one end to the other end along the longitudinal direction of the first electrode when viewed with the first electrode unfolded. The first uncoated electrode portion 11 can function as a first electrode tab. The first uncoated portion 11 is provided on one surface of the electrode assembly 10.More specifically, the first uncoated portion 11 is provided on a lower surface of the electrode assembly 10 accommodated in the casing 20 in the height direction (direction parallel to the Z-axis).

[0065] The second electrode includes a second conductive substrate and a second electrode active material layer formed by applying it to one or both surfaces of the second conductive substrate. A second uncoated electrode portion, to which the second electrode active material is not applied, is provided at the other end of the second conductive substrate in a width direction (direction parallel to the Z axis). The second uncoated electrode portion has a shape extending from one end to the other end along the longitudinal direction of the second electrode when viewed in a state where the second electrode is unfolded. The second uncoated electrode portion 12 can function as a second electrode tab. The second uncoated portion 12 is provided on the other surface of the electrode assembly 10.More specifically, the second uncoated portion 12 is provided on the top surface of the electrode assembly 10 accommodated in the casing 20 in the height direction (direction parallel to the Z-axis).

[0066] That is, the first uncoated portion 11 and the second uncoated portion 12 extend and protrude in the height direction (direction parallel to the Z-axis) of the electrode assembly 10, that is, in opposite directions along the height direction of the cylindrical battery 1, and are exposed to the outside of the separator.

[0067] With reference to Fig. 7, at least a portion of the first uncoated portion 11 and / or the second uncoated portion 12 may include a plurality of segment parts F that are divided from each other along a winding direction of the electrode assembly 10. In this case, the plurality of segment parts may be bent along a radial direction of the electrode assembly 10. The plurality of bent segment parts may be overlapped into multiple layers. In this case, the first current collector 50 and / or the second current collector 80, which will be described later, may be coupled to a region where the plurality of segment parts F are overlapped into multiple layers.

[0068] Here, the electrode assembly 10 may have a welding target region, which is a region in which the number of overlapping layers of the segment parts F of the first uncoated portion 11 and / or the second uncoated portion 12 remains constant along a radial direction of the electrode assembly 10. Since the number of overlapping layers of the segment parts F is kept approximately at a maximum in this welding target region, it may be advantageous for welding the first current collector 50 and the first uncoated portion 11 and / or welding the second current collector 80 and the second uncoated portion 12 in the welding target region.This is intended, for example, to prevent the laser beam penetrating the first uncoated portion 11 and / or the second uncoated portion 12 from damaging the electrode assembly 10 when the laser power is increased to improve the weld quality when using laser welding. This is also intended to effectively prevent foreign matter, such as weld spatter, from being introduced into the electrode assembly 10.

[0069] With reference to the Fig. 1 to Fig. 3b, the battery case 20 is a substantially cylindrical container with an opening formed at its lower portion and is made of a conductive metal material. The side and upper surfaces of the battery case 20 may be integrally formed. The upper surface of the battery case 20, that is, the outer surface of the closed portion of the battery case 20, has a substantially flat shape. The battery case 20 accommodates the electrode assembly 10 through an opening formed on one side of the battery case 20 in the height direction (direction parallel to the Z-axis) and also accommodates an electrolyte.

[0070] The battery case 20 may have an open lower end in the height direction (direction parallel to the Z-axis) and a closed upper end. The battery case 20 may include a bead portion 21 and a crimp portion 22 formed at a lower end thereof. The bead portion 21 is formed below the electrode assembly 10. The bead portion 21 may be formed by pressing in the outer periphery of the battery case 20. For example, the bead portion 21 may function as a support portion on which the cap 30 is fitted by preventing the electrode assembly 10, which has a size corresponding to the width (diameter) of the battery case 20, from coming out through the opening formed on a bottom side of the battery case 20. In another aspect, the bead portion 21 may also function as a support portion on which the first current collector 50 is fitted.That is, the edge of the first current collector 50 can be supported by the bead portion 21.

[0071] The crimping portion 22 is formed below the beading portion 21. The crimping portion 22 may have a shape that extends and is bent such that an end defining an opening of the battery case 20 below the beading portion 21 surrounds the edge of the cap 30.

[0072] However, according to the present disclosure, it is also possible that the battery case 20 does not have the bead portion 21 and / or the crimp portion 22.

[0073] In this case, the fastening of the electrode assembly 10 and / or the fastening of the cap 30 and / or the sealing of the battery housing 20 can be realized, for example, by additionally attaching components that can act as a stopper for the electrode assembly 10, and / or by additionally attaching a structure on which the cap 30 can sit, and / or by welding between the battery housing 20 and the cap 30.

[0074] Meanwhile, the battery case 20 has the same polarity as that of the first uncoated portion 11 extending downward. The battery case 20 is electrically connected to the first uncoated portion 11 through the cap 30. The polarity of the battery case 20 will be described in more detail later along with the description of the cap 30.

[0075] With reference to the Fig. 2 to Fig. 5, the cap 30 covers an opening formed at the bottom of the battery case 20 and is electrically connected to the battery case 20 and the first uncoated portion 11. The cap 30 is a component made of a conductive metal material. The cap 30 includes a vent portion 31 that is ruptured to release internal gas when the internal pressure increases, and a connection portion P for electrically connecting to the first uncoated portion 11. In the cylindrical battery 1 of the present disclosure, the cap 30 functions as a vent member when the internal pressure increases due to an abnormal occurrence of the battery, and also functions as a current blocking member when an overcurrent occurs.

[0076] The cap 30 may be coupled to an opening formed at the bottom of the battery case 20 by welding. Alternatively, the cap 30 may be secured by a gasket 60 in the crimping portion 22 of the battery case 20, which will be described later. Of course, even if the gasket 60 is applied, the fastening may be performed by welding in parallel to improve the fastening force and reduce electrical resistance.

[0077] The cap 30 is electrically connected to the first uncoated portion 11 of the electrode assembly 10. The first uncoated portion 11 of the electrode assembly 10 may be directly coupled to the connecting portion P of the cap 30. Alternatively, the first uncoated portion 11 of the electrode assembly 10 may be coupled to the connecting portion P of the cap 30 by a first current collector 50 and / or a terminal lug L, which will be described later.

[0078] The vent portion 31 corresponds to a weaker region in terms of rigidity compared to the surrounding region of the cap 30. When the vent portion 31 is formed by adjusting the thickness of the cap 30, the vent portion 31 corresponds to a region of the cap 30 that has a thinner thickness compared to the surrounding region of the cap 30. For example, the vent portion 31 may have a groove shape formed on the outer surface and / or the inner surface of the cap 30. When the cap 30 is made of the same material as a whole and the thickness of a specific region is thinner, and when the internal pressure of the battery case 20 abnormally and significantly increases, a region formed with a thinner thickness is ruptured, and the gas generated therein may be discharged through the ruptured portion.Of course, it is alternatively also possible to form the venting section 31 by applying a weaker material in terms of strength and / or melting point compared to the surrounding area.

[0079] The cylindrical battery 1 according to an embodiment of the present disclosure has a structure in which a battery terminal 40 is provided at the upper portion in the height direction (direction parallel to the Z axis), which will be described later, and this makes the upper structure more complex than the lower structure. Therefore, the vent portion 31 may be formed in the cap 30 forming the bottom surface of the cylindrical battery 1 to discharge the internal gas through the vent.

[0080] Furthermore, the vent portion 31 is continuously formed, forming a closed loop, and the connecting portion P is disposed within the closed loop. That is, the current traveling from the first uncoated portion 11 of the electrode assembly 10 through the cap 30 to the battery case 20 should flow through the vent portion 31. This is intended to enable the cap 30 to function not only as a vent element as described above, but also as a current blocking element when an overcurrent occurs. If the connecting portion P is disposed outside the closed loop of the vent portion 31, the current will not flow through the vent portion 31, and thus the vent portion 31 cannot function as a current blocking element.In addition, the current transmitted from the electrode assembly 10 to the cap 30 flows through the open area, and thereby the vent portion 31 cannot function as a current blocking member even if the connecting portion P is disposed in the loop formed by the vent portion 31 and the loop does not form a closed loop as shown in FIG. Fig. 5, but is open in one section.

[0081] With reference to the Fig. 1, Fig. 2 and Fig. 6, the battery terminal 40 may penetrate the closed portion located on the opposite side of the opening formed on one side of the battery case 20. The battery terminal 40 is electrically connected to the second uncoated portion 12 of the electrode assembly 10 in the battery case 20. The battery terminal 40 may be directly coupled to the second uncoated portion 12 through a second current collector 80, or may be electrically connected to the electrode assembly 10, which will be described later. The battery terminal 40 is a component made of a conductive metal material. The battery terminal 40 is electrically insulated from the battery case 20.

[0082] The insulation between the battery terminal 40 and the battery housing 20 can be implemented in various ways. For example, the insulation can be implemented by applying an insulating gasket 70. As another example, the insulation can be implemented by coating at least a portion of the battery terminal 40 and / or the battery housing 20 for insulation. As yet another example, the insulation can be implemented by firmly securing the battery terminal 40 such that the state of separation between the battery terminal 40 and the battery housing 20 is maintained without treatment, such as coating for insulation or attaching a separate component.

[0083] The battery terminal 40 may penetrate a substantially central portion of the upper surface (surface parallel to the XY plane) of the battery case 20. At least a portion of the battery terminal 40 that is partially inserted into the battery case 20 may be coupled to the second uncoated portion 12 of the electrode assembly 10 or the second electrode current collector 80 by welding or the like. Furthermore, at least a portion of the battery terminal 40 that is partially inserted into the battery case 20 may be bent toward the upper surface of the battery case 20 to be riveted. That is, the battery terminal 40 of the present disclosure may be a rivet-like terminal that penetrates the battery case 20 and is coupled to the inner surface of the battery case 20 by riveting.

[0084] As described above, in the cylindrical battery 1 of the present disclosure, the upper surface of the battery case 20, which has the same polarity as the first uncoated portion 11, that is, the outer surface of the closed portion, can function as the first electrode terminal T1, and the battery terminal 40, which has the same polarity as the second uncoated portion 12, can function as the second electrode terminal T2. Therefore, the cylindrical battery 1 of the present disclosure has a structure in which a pair of electrode terminals T1, T2 are both provided on one side in the height direction, and thereby all electrical connection components can be concentrated in one direction when the plurality of cylindrical batteries 1 are electrically connected. This structure can lead to structural simplification in the manufacture of the battery pack, thereby improving productivity and energy density.

[0085] Furthermore, the cylindrical battery 1 of the present disclosure can utilize the entire remaining area, except for the area occupied by the battery terminal 40, under the substantially flat upper surface of the battery case 20 as the first electrode terminal T1. Therefore, it is possible to ensure a sufficient coupling area when an electrical connection component, such as a bus bar, is coupled to the first electrode terminal T1. Therefore, even when a large-area bus bar is applied, easy coupling is possible, and the electrical resistance at a coupling portion can be reduced.

[0086] With reference to Fig. 2 to Fig. 3b, the first current collector 50 may be coupled to the lower end of the electrode assembly 10 in the height direction (direction parallel to the Z-axis). The first current collector 50 may be coupled to the first uncoated portion 11. The first current collector 50 is electrically connected to the cap 30. That is, when the cylindrical battery 1 includes the first current collector 50, the first uncoated portion 11 of the electrode assembly 10 is electrically connected to the cap 30 through the first current collector 50. The first current collector 50 may be electrically connected to the cap 30, for example, through a terminal lug L. The terminal lug L may be a component formed integrally with the first current collector 50 or may be provided separately such that one side thereof is coupled to the first current collector 50 and the other side is coupled to the cap 30. Referring to Fig. 5 together with Fig. 2 and Fig. 3, the first current collector 50 or the terminal tab L is coupled to the connecting portion P of the cap 30, and the connecting portion P is arranged in the closed loop formed by the vent portion 31. This is to ensure that the current flowing between the first current collector 50 and the battery case 20 should flow through the vent portion 31, thereby quickly blocking the overcurrent through the vent portion 31 when an overcurrent occurs.

[0087] Preferably, the terminal tab L may be configured to have a length longer than the distance between the first current collector 50 and the cap 30. This is to prevent the breaking pressure of the vent portion 31 due to the terminal tab L from being greater than a design value when the extension length of the terminal tab L is insufficient.

[0088] Meanwhile, the first current collector 50 may include a current collector hole 50a formed at a position corresponding to the hole formed in the winding center C of the electrode assembly 10. The current collector hole 50a communicates with a hole formed in the winding center C of the electrode assembly 10, and thus, a tool is inserted or a laser beam is passed through the winding center hole of the electrode assembly 10, thereby welding the second current collector 80 positioned opposite the first current collector 50 and the battery terminal 40. The current collector hole 50a may also function as a passage for injecting an electrolyte.

[0089] With reference to Fig. 2 to Fig. 3b, the gasket 60 is a component applied to improve the sealing properties of the cap 30 covering the opening at the bottom of the battery case 20 in the height direction (direction parallel to the Z axis). Considering this function, a material having elasticity can be applied as a material of the gasket 60. The gasket 60 is partially disposed between the battery case 20 and the cap 30. As described above, the battery case 20 should be in contact with the cap 30 to be electrically connected. Therefore, the gasket 60 should not completely block the contact between the battery case 20 and the cap 30.For this purpose, the seal 60 is arranged between the cap 30 and the battery case 20 in a region where the crimping portion 22 of the battery case 20 is formed, and may be arranged in the remaining region except for a contact region between the cap 30 and the battery case 20.

[0090] With reference to the Fig. 1, Fig. 2 and Fig. 6, the insulating gasket 70 may be disposed between the battery case 20 and the battery terminal 40 to prevent the battery case 20 and the battery terminal 40, which have opposite polarities, from contacting each other. Furthermore, the insulating gasket 70 can prevent the sealing properties of the battery case 20 from deteriorating due to the application of the battery terminal 40. Considering this function, a material having insulating properties and elasticity may be applied as the material of the insulating gasket 70. A portion of the insulating gasket 70 may be bent toward the inner surface of the closed portion of the battery case 20 together with the flange portion of the battery terminal 40 during riveting of the battery terminal 40.Therefore, a portion of the insulating gasket 70 may be disposed between the flange portion of the battery terminal 40 and the inner surface of the closed portion of the battery case 20.

[0091] With reference to Fig. 6, the second current collector 80 is coupled to the upper end of the electrode assembly 10 in the height direction (direction parallel to the Z-axis). Thus, the second current collector 80 is coupled to the second uncoated portion 12. The second current collector 80 is electrically connected to the battery terminal 40. That is, when the cylindrical battery 1 includes the second current collector 80, the second uncoated portion 12 of the electrode assembly 10 is electrically connected to the battery terminal 40 through the second current collector 80. The second current collector 80 may be directly coupled to the battery terminal 40. Alternatively, the second current collector 80 may be connected to the battery terminal 40 through a separate component, such as a terminal lug (not shown), which is provided with the above-described first current collector 50 (see Fig. 3), be electrically connected to the battery terminal 40. In this case, the terminal tab may be a component formed integrally with the second current collector 80, or may be provided separately from the second current collector 80 such that one side thereof is coupled to the second current collector 80 and the other side may be coupled to the battery terminal 40.

[0092] With reference to Fig. 8 and Fig. 9 illustrates a coupling structure between the current collectors 50, 80 and the electrode assembly 10 that is applied to the present disclosure.

[0093] First, with reference to Fig. 8, the second current collector 80 may be coupled to a coupling surface formed by bending one end of the second uncoated portion 12 in a direction substantially parallel to the second current collector 80. The coupling between the second uncoated portion 12 and the second electrode current collector 80 may be performed, for example, by laser welding. The laser welding may be performed by partially melting the base material of the second current collector 80 or in a state where solder for welding is disposed between the second current collector 80 and the second uncoated portion 12. In this case, it is preferable that the solder has a lower melting point compared to the second current collector 80 and the second uncoated portion 12.

[0094] With reference to Fig. 9, the first current collector 50 may be coupled to a coupling surface formed by bending one end of the first uncoated portion 11 in a direction parallel to the first current collector 50. The bending direction of the first uncoated portion 11 may, for example, be a direction toward the winding center C of the electrode assembly 10.

[0095] When the first uncoated portion 11 and / or the second uncoated portion 12 have such a curved shape, a space occupied by the first uncoated portion 11 and / or the second uncoated portion 12 is reduced along the height direction (direction parallel to the Z-axis) of the electrode assembly 10, that is, the height (length of the Z-axis direction) of the electrode assembly 10 is reduced, thereby improving the energy density.

[0096] With reference to Fig. 6, the insulator 90 is disposed between the upper end of the electrode assembly 10 and the inner surface of the battery case 20, or between the second current collector 80 coupled to the upper portion of the electrode assembly 10 and the inner surface of the battery case 20. The insulator 90 may have a shape that extends to further cover the side of the electrode assembly 10. The insulator 90 prevents contact between the second uncoated portion 12 and the battery case 20, or between the second current collector 80 and the battery case 20.

[0097] When the cylindrical battery 1 of the present disclosure includes the insulator 90 disposed on top of the electrode assembly 10, the battery terminal 40 penetrates the insulator 90 inside the battery case 20 to be coupled to the second current collector 80 or the second uncoated portion 12.

[0098] However, if the first current collector 50 and the battery case 20 are in direct contact with each other, as in Fig. 3 of the present disclosure, the cap 30 of the present disclosure may not function as an overcurrent blocking element. For the cap 30 to function as an overcurrent blocking element, an electrical connection should be established between the first current collector 50 and the battery case 20 through the cap 30. This is because the current transmitted from the first current collector 50 should flow through the vent portion 31 formed in the cap 30, whereby the vent portion 31, which is configured to have a thinner thickness than the circumference, is broken by the overcurrent to block an overcurrent.

[0099] With reference to the Fig. 3a and Fig. 3b, an insulating layer CL and / or an insulator (second insulator) IS may be arranged between the first current collector 50 and the battery case 20 to prevent the first current collector 50 from directly contacting the battery case 20.

[0100] The insulating layer CL may be disposed between the edge of the first current collector 50 and the bead portion 21 of the battery case 20, which face each other. The insulating layer CL may, for example, be an insulating coating layer formed on the surface of the first current collector 50 and / or the bead portion 21.

[0101] The insulator (second insulator) IS may cover a lower surface of the electrode assembly 10 facing the cap 30. The insulator IS may have a shape extending so as to be disposed between the first uncoated portion 11 and the inner surface of the sidewall portion of the battery case 20, both of which face each other, to ensure insulation. The insulator IS may include a hole formed at a position corresponding to the hole formed in the winding center C of the electrode assembly 10. This hole may function as a passage for injecting an electrolyte and / or a passage for inserting a tool or guiding a laser beam for welding the second current collector 80 and the battery terminal 40. Meanwhile, the insulator IS may include a hole through which the terminal tab L, which electrically connects the first current collector 50 and the cap 30, passes.

[0102] The above-described cylindrical battery 1 of the present disclosure has a structure in which resistance is minimized by expanding a welding area due to the formation of a coupling surface formed by bending the uncoated portions 11, 12, by expanding a welding area by coupling bus bars using the outer surface of the closed portion of the battery case 20, and the like. The AC resistance of the cylindrical battery 1, measured with an ohmmeter between the positive electrode and the negative electrode between the battery terminals 40, T2 and the substantially flat surface T1 around them, can be about 0.5-4 milliohms, preferably about 1-4 milliohms, which is suitable for rapid charging.

[0103] Preferably, the cylindrical battery may, for example, be a cylindrical battery in which the ratio of the shape factor (a value obtained by dividing a diameter of the cylindrical battery by a height, ie, the ratio of the diameter Φ to the height H) is greater than about 0.4.

[0104] Here, the shape factor refers to a value indicating the diameter and height of the cylindrical battery. Preferably, the diameter of the cylindrical battery may be about 40-50 mm, and the height may be about 60-130 mm. The cylindrical battery according to an embodiment of the present disclosure may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, and a 4680 battery. In the numbers representing the shape factor, the first two digits represent the diameter of the battery, and the remaining digits represent the height of the battery.

[0105] When an electrode assembly having a tabless structure is applied to a cylindrical battery with an aspect ratio of more than 0.4, the uncoated portion is easily torn due to a large stress applied in the radial direction when the uncoated portion is bent. Furthermore, when welding the current collector to the bent surface portion of the uncoated portion, it is necessary to sufficiently increase the number of stacks of the uncoated portion in the bent surface portion to sufficiently ensure welding strength and lower resistance. This requirement can be achieved by the electrode and electrode assembly according to embodiments (modified examples) of the present disclosure.

[0106] The battery according to an embodiment of the present disclosure is a substantially cylindrical battery and may have a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of about 0.418.

[0107] The battery according to another embodiment is a substantially cylindrical battery and may have a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of about 0.640.

[0108] The battery according to yet another embodiment is a substantially cylindrical battery and may have a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of about 0.418.

[0109] The battery according to yet another embodiment is a substantially cylindrical battery and may have a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of about 0.600.

[0110] The battery according to yet another embodiment is a substantially cylindrical battery and may have a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of about 0.575.

[0111] Conventionally, batteries with a form factor ratio of about 0.4 or less were used. For example, an 1865 battery, a 2170 battery, and the like were conventionally used. In the case of the 1865 battery, its diameter is about 18 mm, its height is about 65 mm, and the form factor ratio is about 0.277. In the case of the 2170 battery, its diameter is about 21 mm, its height is about 70 mm, and the form factor ratio is about 0.300.

[0112] With reference to Fig. 10, a plurality of cylindrical batteries 1 may be connected in series and parallel at the top of the cylindrical battery 1 using busbars 150. The number of cylindrical batteries 1 may be increased or decreased depending on the capacity of the battery pack.

[0113] In each cylindrical battery 1, the battery terminals 40, T2 can have a positive polarity, and the outer surface T1 of the closed portion of the battery housing 20 can have a negative polarity. Of course, a reverse configuration is also conceivable.

[0114] Preferably, the plurality of cylindrical batteries 1 may be arranged in a plurality of columns and rows. Columns are located in the vertical direction relative to the floor, and rows are located in the horizontal direction relative to the floor. To maximize space efficiency, the cylindrical batteries 1 may also be arranged in a closest packing structure. The closest packing structure is formed when an equilateral triangle is formed if the centers of the battery terminals 40 exposed to the outside of the battery case 20 are connected to each other. Preferably, the bus bars 150 may be arranged on the plurality of cylindrical batteries 1, preferably between adjacent columns. Alternatively, the bus bars 150 may be arranged between adjacent rows.

[0115] Preferably, the bus bar 150 connects the batteries 1 arranged in the same column in parallel and the cylindrical batteries 1 arranged in two adjacent columns in series.

[0116] Preferably, the busbar 150 may include a body portion 151, a plurality of first busbar terminals 152, and a plurality of second busbar terminals 153 for serial and parallel connection.

[0117] The body portion 151 may extend between the battery terminals 40 of adjacent cylindrical batteries 1, preferably between columns of the cylindrical batteries 1. Alternatively, the body portion 151 may extend along the columns of the cylindrical batteries 1 and be regularly bent like a zigzag shape.

[0118] The plurality of first bus bar terminals 152 may protrude and extend from one side of the body portion 151 to the battery terminal 40 of each cylindrical battery 1 and may be electrically coupled to the battery terminal 40. The electrical coupling between the first bus bar terminal 152 and the battery terminal 40 may be performed by laser welding, ultrasonic welding, or the like. Furthermore, the plurality of second bus bar terminals 153 may be electrically coupled to the outer surface T1 of the closed portion of the battery case 20 of each cylindrical battery 1 from the other side of the body portion 151. The electrical coupling between the second bus bar terminal 153 and the outer surface T1 may be performed by laser welding, ultrasonic welding, or the like.

[0119] Preferably, the body portion 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 may be formed from a conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but the present disclosure is not limited thereto. In a modified example, the body portion 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 may be manufactured as separate parts and then coupled together by welding or the like.

[0120] In the cylindrical battery 1 according to the present disclosure, since the battery terminal 40 having a positive polarity and the outer surface T1 of the closed portion of the case 20 having a negative polarity are located in the same direction, it is possible to easily implement the electrical connection of the cylindrical batteries 1 by using the bus bar 150.

[0121] In addition, since the battery terminal 40 of the cylindrical battery 1 and the outer surface T1 of the closed portion of the battery case 20 have a large area, it is possible to sufficiently ensure the coupling area of the bus bar 150 and sufficiently reduce the resistance of the battery pack including the cylindrical battery 1.

[0122] With reference to Fig. 11, a battery pack 3 according to an embodiment of the present disclosure includes a battery assembly in which a plurality of cylindrical batteries 1 according to an embodiment of the present disclosure are electrically connected as described above, and a pack case 2 that accommodates them. The electrical connection structure of the plurality of batteries 1 by the bus bar was described above with reference to Fig. 10 is described by way of example, and other components such as a cooling unit, a power terminal, and the like are omitted for simplicity of illustration.

[0123] With reference to Fig.12, a vehicle 5 according to an embodiment of the present disclosure may, for example, be an electric vehicle and include the battery pack 3 according to an embodiment of the present disclosure. The vehicle 5 is operated by receiving power from the battery pack 3 according to an embodiment of the present disclosure.

[0124] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the disclosure, are given for illustrative purposes only, since various changes and modifications within the scope of the disclosure will become apparent to those skilled in the art from this detailed description. [Reference symbol] 5 vehicle 3 battery packs 2 packing housings 1 battery 10 Electrode arrangement C Wrap center 11 first uncoated section 12 second uncoated section F Segment parts 20 battery cases T1 first electrode connection 21 Bead section 22 Crimping section 30 cap 31 Ventilation section 40 Battery connection T2 second electrode connection 50 first pantograph L connection tab 60 Seal 70 insulating seal 80 second pantograph 90 Insulator (first insulator) IS Isolator (second insulator) CL insulation layer QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 10-2021-0022877

[0002] KR 10-2021-0022894

[0002] KR 10-2021-0024424

[0002] KR 10-2021-0131215

[0002] KR 10-2021-0154307

[0002]

Claims

[1] Battery containing: an electrode assembly defining a core and an outer periphery by winding a first electrode, a second electrode, and a separator disposed therebetween around a winding center, each of the first electrode and the second electrode having a first uncoated portion and a second uncoated portion, to which no active material layer is applied, along the winding direction; a battery case that receives the electrode assembly through an opening formed on one side thereof; a cap having a vent portion configured to have a thinner thickness compared to a surrounding area, covering the opening, and electrically connected to the battery case and the first uncoated portion; and a battery terminal electrically connected to the second uncoated portion. [2] The battery of claim 1, wherein the battery case is electrically connected to the first uncoated portion through the cap. [3] The battery of claim 1, wherein the cap has a connecting portion for electrical connection to the first uncoated portion. [4] The battery according to claim 3, wherein the venting portion is continuously formed to form a closed loop, and the connecting portion is arranged in the closed loop. [5] The battery according to claim 1, wherein the vent portion has a groove shape formed on at least one of an outer surface and an inner surface of the cap. [6] The battery according to claim 1, wherein the battery terminal is exposed to the outside of the battery case through a closed portion of the battery case located on a side of the battery case opposite to the opening. [7] The battery of claim 6, wherein the battery terminal penetrates a central portion of the closed portion. [8] The battery of claim 1, wherein the battery terminal is electrically insulated from the battery case. [9] The battery of claim 1, further comprising a first current collector coupled to the first uncoated portion. [10] The battery of claim 9, wherein the first current collector is electrically connected to the cap. [11] The battery of claim 10, wherein the first current collector and the cap are electrically connected to each other by a terminal tab. [12] The battery of claim 10, wherein the terminal tab has a length longer than a distance between the first current collector and the cap. [13] The battery of claim 1, further comprising a second current collector coupled to the second uncoated portion. [14] The battery of claim 13, wherein the second current collector is coupled to the battery terminal. [15] The battery of claim 1, further comprising a seal disposed between the cap and the battery case. [16] A battery according to claim 15, wherein the battery case comprises: a bead portion formed by pressing in an outer periphery thereof; and a crimp portion extending and bent such that an end defining the opening below the crimp portion surrounds an edge of the cap. [17] The battery according to claim 16, wherein the seal is arranged in a region other than a contact region between the cap and the battery case in a region where the crimping portion is formed. [18] A battery according to claim 9, wherein the battery case comprises: a bead portion formed by pressing in an outer periphery thereof; and a crimping portion extending and bent such that an end defining the opening under the crimping portion surrounds an edge of the cap, and wherein an edge of the first current collector is supported by the bead portion. [19] The battery according to claim 18, wherein an insulating layer is disposed between the edge of the first current collector and the bead portion of the battery case facing each other. [20] The battery according to claim 19, wherein the insulating layer is an insulating coating layer formed on a surface of the first current collector or the bead portion. [21] The battery of claim 18, further comprising an insulator covering a lower surface of the electrode assembly facing the cap. [22] The battery according to claim 21, wherein the insulator has a hole formed at a position corresponding to a hole formed at a winding center of the electrode assembly. [23] The battery of claim 21, wherein the first current collector and the cap are electrically connected by a terminal tab, and the insulator has a hole through which the terminal tab passes. [24] Battery according to claim 9, wherein at least a portion of the first uncoated portion has a plurality of segment parts divided along a winding direction of the electrode assembly, and the plurality of segment parts are bent along a radial direction of the electrode arrangement. [25] The battery according to claim 24, wherein the plurality of bent segment parts are overlapped in multiple layers along the radial direction. [26] Battery according to claim 25, wherein the electrode assembly has a welding target area which is an area in which the number of overlapping segment parts of the first uncoated portion remains constant along a radial direction of the electrode assembly, and the first current collector is coupled to the first uncoated portion in the welding target area. [27] Battery according to claim 13, wherein at least a portion of the second uncoated portion comprises a plurality of segment parts divided along a winding direction of the electrode assembly, and the plurality of segment parts are bent along a radial direction of the electrode arrangement. [28] The battery according to claim 27, wherein the plurality of bent segment parts are overlapped in multiple layers along the radial direction. [29] Battery according to claim 28, wherein the electrode assembly has a welding target region which is a region in which the number of overlapping segment parts of the second uncoated portion remains constant along a radial direction of the electrode assembly, and the second current collector is coupled to the second uncoated portion in the welding target area. [30] The battery of claim 1, wherein the resistance measured between the positive electrode and the negative electrode is 4 milliohms or less. [31] The battery of claim 1, wherein the ratio of the shape factor obtained by dividing the diameter of the battery by the height is greater than 0.

4. [32] Battery pack comprising a plurality of batteries according to one of claims 1 to 31. [33] Battery pack according to claim 32, wherein the plurality of batteries are arranged in a predetermined number of columns, and the battery terminal of each battery and the outer surface of the closed portion of the battery case are arranged to face upward. [34] Battery pack according to claim 32, which has several busbars connecting the several batteries in series and parallel, wherein the plurality of busbars are arranged on the plurality of batteries, each of the busbars comprising: a body portion extending between battery terminals of adjacent batteries; a plurality of first bus bar terminals extending in a direction of the body portion and electrically coupled to the battery terminal of the battery located in a direction described above; and a plurality of second bus bar terminals extending in the other direction of the body portion and electrically coupled to the outer surface of the closed portion of the battery case of the battery located in the other direction described above. [35] A vehicle comprising a battery pack according to claim 32.

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