Vibration-adaptable current collecting plate and cylindrical battery cell using same

Abstract

Disclosed is a current collecting plate applicable to a cylindrical battery cell and adaptable to vibration. The current collecting plate includes a plate body having a first surface and a second surface facing each other. In the plate body, the first surface includes a first region of the plate body, including a terminal bonding portion that is bonded to a cap, a can bottom, or an electrode terminal, and the second surface includes a second region of the plate body surrounding the first region and including an electrode bonding portion that is bonded to an electrode tab of an electrode assembly. The current collecting plate includes a first notch provided on the first surface and a second notch provided on the second surface in a boundary region between the first region and the second region.

Description

Vibration-adaptive current collector and cylindrical battery cell using the same

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0052346, dated April 18, 2024, and Korean Patent Application No. 10-2024-0151192, dated October 30, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a current collector plate, and more particularly, to a current collector plate applicable to a cylindrical battery cell and capable of responding to vibration.

[0003] The process of manufacturing a battery cell using a cylindrical can includes the steps of deep drawing a metal sheet to form a circular bottom portion and a circular tubular side wall member connected thereto, accommodating an electrode assembly therein, and then closing the open end of the side wall member with a cap.

[0004] Referring to FIGS. 1 and 2, before accommodating the electrode assembly (20) in the can (10), a current collector (30) may be joined to the axial lower portion of the electrode assembly (20). When inserting the electrode assembly (20) into the can (10), the current collector (30) faces the bottom member (12) of the cylindrical can.

[0005] An electrode terminal (13) is installed in the central portion of the above-described bottom member (12). The electrode terminal (13) is sealed, insulated, and fixed to the bottom member (12) with a gasket (14) interposed therebetween. In a state where the electrode assembly (20) is accommodated in the can (10), an insulator (19) is interposed between the current collector (30) and the bottom member (12) to electrically insulate the current collector (30) of the electrode assembly (20) from the bottom member (12). In this state, the central portion of the current collector (30) is joined to the electrode terminal (13).

[0006] Referring to FIGS. 3 and 4, the peripheral portion of the current collector plate (30) has an electrode joint portion (33) joined to the electrode tab (27) of the electrode assembly (20), and the central portion of the current collector plate (30) has a terminal joint portion (32) joined to the electrode terminal (13). When the electrode assembly (20) moves relative to the can (10) while the current collector plate (30) is joined to the electrode tab (27) and the terminal joint portion (32), the relative positions of the electrode joint portion (33) and the terminal joint portion (32) tend to change, and thus, there is a concern that stress may be concentrated on the electrode joint portion (33) and the terminal joint portion (32). In particular, when the battery cell is used in an environment where there is a lot of vibration, such as in a power tool or a vehicle, there is a risk that the electrode joint (33) and the terminal joint (32) may be damaged due to the relative displacement between the electrode joint (33) and the terminal joint (32).

[0007] In consideration of this, the current collector plate (30) is formed with a penetration portion (34) that allows elastic deformation of the current collector plate (30) when the relative positions of the electrode joint portion (33) and the terminal joint portion (32) are about to change. However, due to the penetration portion (34), even though the straight-line distance between the electrode joint portion (33) and the terminal joint portion (32) is close, the shortest current path (P) formed in the current collector plate (30) between the electrode joint portion (33) and the terminal joint portion (32) becomes very long.

[0008] That is, the conventional collector plate had a problem in that the penetration portion (34) formed to adapt to vibration increased the internal resistance by bypassing the current path.

[0009] The present invention has been derived to solve the above-described problem, and its purpose is to provide a current collector plate that can adapt to vibration without bypassing the current path between the electrode joint and the terminal joint, and a battery cell using the same.

[0010] The purpose of the present invention is to provide a current collector plate capable of simply implementing a structure that can adapt to vibration, and a battery cell using the same.

[0011] The present invention aims to provide a current collector plate capable of improving impregnation properties and reducing self-weight by minimizing a closed area in the current collector plate, and a battery cell using the same.

[0012] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0013] In order to solve the above-described problem, the present invention implements a notch in the plate body so as to provide flexibility without blocking the current path when manufacturing a current collector with a plate body having a predetermined thickness.

[0014] The above plate body has a first surface and a second surface that are opposite to each other.

[0015] The above plate body, when viewed in the thickness direction, has a first region and a second region.

[0016] The above second area surrounds the above first area.

[0017] In the first region, a terminal joint is provided where the first surface is joined to a cap, can bottom, or electrode terminal of a battery cell.

[0018] In some examples, the cap may be a component that covers the open end of the can and seals the can.

[0019] In some examples, the can bottom may be a bottom portion connected to the side wall of the can. The can bottom may be molded integrally with the side wall, or may be manufactured as a separate part and then connected to the side wall.

[0020] In some examples, the electrode terminal may be provided on the cap.

[0021] In some examples, the electrode terminal may be provided on the can. Specifically, the electrode terminal may be provided on the bottom of the can.

[0022] In the second region, an electrode joint is provided where the second surface is joined to an electrode tab of the electrode assembly.

[0023] There is a boundary area between the first and second areas.

[0024] In the above boundary area, a first notch formed on the first surface and a second notch formed on the second surface are provided.

[0025] The above first notch may extend in a substantially closed loop shape to surround the first region.

[0026] The second notch may extend substantially in a closed loop shape to surround the first region.

[0027] Each of the first notch and the second notch may be provided in one or more forms.

[0028] At least one of the first notch and the second notch may be provided in multiple numbers.

[0029] Both the first notch and the second notch may be provided in multiple numbers.

[0030] The first notch and the second notch may be arranged alternately along an approach direction, which is a direction in which one of the first and second regions approaches the other region. For example, the approach direction may be a direction corresponding to the radial direction of the plate body.

[0031] Optionally or additionally, the widthwise center of the first notch and the widthwise center of the second notch may be arranged alternately along the approach direction.

[0032] Optionally or additionally, the deepest recessed floor in the first notch and the deepest recessed floor in the second notch may be arranged alternately along the approach direction.

[0033] The shortest distance between the first inner surface and the second inner surface, which define the first notch and the second notch adjacent to each other in the above approach direction, may be smaller than the thickness of the plate body.

[0034] Optionally or additionally, when viewed in the thickness direction of the plate body, the first and second notches adjacent to each other in the approach direction may partially overlap.

[0035] The width of the first notch may gradually decrease in the depth direction.

[0036] The cross-sectional shape of the first inner surface viewed in the extension direction of the first notch may be substantially triangular, trapezoidal, semicircular, or round.

[0037] The width of the second notch may gradually decrease in the depth direction.

[0038] The cross-sectional shape of the second inner surface viewed in the extension direction of the second notch may be substantially triangular, trapezoidal, semicircular, or round.

[0039] The above first notch and the above second notch can be arranged concentrically.

[0040] The above plate body is substantially circular, and the first region can be provided at the center of the plate body.

[0041] The first notch and the second notch may each surround the first region in a circular shape.

[0042] In the second region, a penetration portion penetrating the plate body in the thickness direction may be provided.

[0043] The above penetration portion can extend radially.

[0044] The shortest current path between the terminal junction and the electrode junction can be configured in a direction approaching from one of the first and second regions to the other region.

[0045] The shortest current path between the terminal junction and the electrode junction may not have a section extending away from one of the first and second regions in the direction of the other region.

[0046] The present invention provides a battery cell including the above-described current collector plate.

[0047] The can of the above battery cell has a bottom member and a side wall member.

[0048] The above battery cell includes an electrode assembly accommodated in the can.

[0049] The above battery cell includes a cap that covers the open end of the can while the electrode assembly is accommodated in the can.

[0050] The above battery cell includes an electrode terminal.

[0051] The above current collector plate is connected to the first surface of the cap, the bottom member of the can, or the electrode terminal.

[0052] The above joining may be accomplished by welding. The welding may be resistance welding. However, the joining method is not necessarily limited to this.

[0053] The above current collector plate is electrically connected to an electrode tab provided on one axial side of the electrode assembly.

[0054] The above electrode joint can be joined to the electrode tab of the electrode assembly. The joining can be accomplished by welding. For example, the welding can be laser welding. However, the joining method is not necessarily limited thereto.

[0055] Other joining methods, such as soldering or brazing, may be applied.

[0056] The above battery cell may be cylindrical.

[0057] The above electrode terminal can be insulated and fixed to the floor member.

[0058] Optionally, the electrode terminal may be provided on the cap.

[0059] The current collector plate according to the present invention provides flexibility by first and second notches provided at the boundary between the first and second regions. Accordingly, even when vibration or impact occurs, tension or stress applied to the joint portion and the current collector plate portion connected thereto can be minimized.

[0060] The current collector plate according to the present invention is provided with flexibility by the first and second notches provided between the electrode connection portion and the terminal connection portion, preventing cracking or fatigue failure even when subjected to continuous impact or vibration. Accordingly, stability can be maintained even with continuous, long-term use.

[0061] The current collector plate according to the present invention is capable of adapting to vibration without bypassing the current path between the electrode joint and the terminal joint by providing flexibility in a notch-forming manner rather than a fractured portion.

[0062] The collector plate according to the present invention can simply implement a structure that can adapt to vibration by forming notches in a specific pattern.

[0063] According to the present invention, by forming a first notch and a second notch on the first surface and the second surface of a plate body having a predetermined thickness, respectively, it is possible to minimize the space occupied by the current collector plate in the axial direction of the battery cell while providing sufficient flexibility to absorb vibration.

[0064] According to the present invention, by forming a penetration portion but not allowing the penetration portion to block the gap between the electrode joint and the terminal joint, the current path between the electrode joint and the terminal joint is not bypassed, while minimizing the closed area in the current collector plate, thereby improving impregnation properties and reducing self-weight.

[0065] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0066] Figure 1 is a cross-sectional view showing the process of inserting an electrode assembly into a can of a battery cell of a comparative example.

[0067] Fig. 2 is a cross-sectional view showing a state in which an electrode assembly is accommodated in the can of Fig. 1.

[0068] Figure 3 is a perspective view of a current collector connecting the electrode assembly of Figure 1 and the bottom member of the can.

[0069] Figure 4 is an enlarged cross-sectional view of a current collector plate each joined to the electrode terminal and electrode assembly of Figure 1.

[0070] Figure 5 is a plan view of a current collector plate according to an embodiment of the present invention.

[0071] Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5.

[0072] Figure 7 is an enlarged view of part VII of Figure 6.

[0073] Figure 8 is an enlarged view of part VIII of Figure 7.

[0074] Figure 9 is an exploded perspective view of a laminate of electrode assemblies accommodated inside a can according to an embodiment of the present invention.

[0075] Fig. 10 is a perspective view of an assembled cylindrical jelly-roll-shaped electrode assembly by winding up the laminate of Fig. 9.

[0076] Figure 11 is a perspective view showing a state in which a first collector plate is joined to an electrode tab provided on one axial end of an electrode assembly facing the bottom of a can.

[0077] Fig. 12 is a cross-sectional view showing a state in which the electrode assembly of Fig. 11 is inserted into a can of the first embodiment and the electrode terminals on the bottom of the can are joined.

[0078] Fig. 13 is a cross-sectional view showing a state in which the electrode tab provided at the axial end of the electrode assembly inserted into the can of the first embodiment and the can are connected to the second collector plate, and the open end of the can is sealed with a cap assembly.

[0079] Fig. 14 is a cross-sectional view showing the state in which the electrode assembly of Fig. 11 is inserted into the can of the second embodiment and the first collector plate and the bottom of the can are joined.

[0080] Fig. 15 is a cross-sectional view showing a state in which the electrode tab provided on the axial end of the electrode assembly inserted into the can of the second embodiment and the cap assembly are connected to the second collector plate, and the open end of the can is sealed with the cap assembly.

[0081] [Explanation of symbols]

[0082] 10: Can 11: Side wall member 113: Beading part 115: Crimping part 12: Bottom member, bottom surface, bottom 13: First electrode terminal 14: Gasket 15: Second electrode terminal 16: Cap assembly 161: Electrode terminal 163: Vent 165: Current interrupting disk (CID) 167: Gasket 168: Insulating spacer 17: Cap 19: Insulator 20: Electrode assembly 21: First electrode 22: Second electrode 23: Metal foil 24: Active material layer 25: Supporting part 26: Non-coated part 27: Electrode tab (notched tab) 28: Separator 29: Hollow part 30: First current collector (bottom current collector) 31: Plate body 311: First region 312: Second region 315: Boundary area 317: First side 318: Second side 32: Terminal joint 33: Electrode joint 34: Penetration 35: First notch 36: Second notch P: Current path 40: Second collector plate (open end collector plate) 41: Inner ring 42: Hole 43: Electrode connection 44: Can connection

[0083] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0084] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0085] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0086] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0087] Additionally, when it is described that a component is "connected," "coupled," or "contacted" with another component, it should be understood that the components may be directly connected or in contact with each other, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "contacted" through other components.

[0088] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0089] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C through D", this means C or more and D or less, unless otherwise stated.

[0090] In describing the embodiment, the axial direction refers to the direction in which the axis forming the winding center of the jelly-roll type electrode assembly extends, the radial direction refers to the direction closer to or farther from the axis, and the circumferential direction refers to the direction surrounding the axis.

[0091] [Collector board]

[0092] Referring to FIGS. 5 to 8, the collector plate (30) of the embodiment according to the present invention is manufactured as a plate body (31) having a predetermined thickness.

[0093] The above plate body (31) can be manufactured from a metal sheet or metal plate having a predetermined thickness. The metal sheet can be manufactured from copper or an alloy containing copper, or aluminum or an alloy containing aluminum.

[0094] The above plate body (31) is in the form of a plate having a predetermined thickness and has a substantially circular flat plate shape.

[0095] The above plate body (31) has a first surface (317) and a second surface (318) that are opposite to each other. The first surface (317) faces the electrode terminal (13) to be described later, and the second surface (318) faces the electrode assembly (20) to be described later.

[0096] The above plate body (31) has a first region (311) and a second region (312) that do not overlap each other when viewed in the thickness direction.

[0097] Preferably, the first region (311) may be provided at the center of the plate body (31). However, the first region (311) does not necessarily have to be placed at the center of the plate body (31).

[0098] The above first region (311) can be understood as a region having a circular outer perimeter. However, the outer perimeter of the first region (311) does not necessarily have to be circular.

[0099] The above second region (312) surrounds the above first region (311).

[0100] The second region (312) may be understood as a ring-shaped region having a circular inner perimeter and a circular outer perimeter. However, the inner perimeter and outer perimeter of the second region (312) do not necessarily have to be circular.

[0101] Preferably, the first region (311) and the second region (312) may be arranged concentrically. However, they do not necessarily have to be arranged concentrically.

[0102] In the first region (311), a terminal joint (32) is provided to be joined to the first surface (317) of the battery cell to be described later, the bottom member (12) of the can (10), or the electrode terminal (13).

[0103] In the second region (312), an electrode joint (33) is provided to which the second surface (318) is joined to the electrode tab (27) of the electrode assembly (20) to be described later.

[0104] A boundary region (315) exists between the first region (311) and the second region (312). The embodiment is implemented in a form in which a boundary region (315) exists between the first region (311) and the second region (312) in a radial direction with respect to the first region (311).

[0105] It can be understood that the outer perimeter of the above boundary region (315) corresponds to the inner perimeter of the second region (312), and the inner perimeter of the above boundary region (315) corresponds to the outer perimeter of the first region (311).

[0106] In the above boundary area (315), a first notch (35) formed on the first surface (317) and a second notch (36) formed on the second surface (318) are provided.

[0107] The first notch (35) and the second notch (36) can be provided with a shape in which the surface is etched and sunken in the thickness direction on the first surface (317) and the second surface (318), respectively.

[0108] The first notch (35) and the second notch (36) may be formed to extend in a closed loop shape to surround the first region (311).

[0109] The above closed loop may be circular.

[0110] The above first notch (35) and second notch (36) may each be provided one or more times. In the embodiment, a form in which the first notch (35) and second notch (36) are each provided three times is exemplified. However, the number of these is not limited thereto.

[0111] The diameters of the plurality of above notches (35, 36) may be different from each other.

[0112] The plurality of above notches (35, 36) may be concentric. However, they do not necessarily have to be concentric.

[0113] The first notch (35) and second notch (36) may have a shape in which the width gradually decreases as the depth increases.

[0114] The cross-sectional shape of the first inner surface (35I) defining the first notch (35) as viewed in the circumferential direction may be substantially triangular, trapezoidal, semicircular, or round. This may also be the case with the second inner surface (36I) of the second notch (36).

[0115] The first notch (35) and the second notch (36) may be arranged alternately along the radial direction, which is the direction in which one of the first region (311) and the second region (312) approaches the other region.

[0116] The widthwise center (35C) of each of the first notches (35) and the widthwise center (36C) of each of the second notches (36) can be alternately arranged along the radial direction.

[0117] The deepest recessed bottom (35B) in the first notch (35) and the deepest recessed bottom (36B) in the second notch (36) can be arranged alternately along the radial direction.

[0118] The shortest distance (d) between the first inner surface (35I) and the second inner surface (36I) of the first notch (35) and the second notch (36) adjacent in the radial direction may be smaller than the thickness (t) of the plate body (31) defined as the distance between the first surface (317) and the second surface (318).

[0119] When viewed in the thickness direction of the above plate body (31), the first notch (35) and the second notch (36) adjacent in the radial direction may partially overlap (OL).

[0120] According to the embodiment, when manufacturing the current collector plate (30), a notch is implemented in the plate body (31) as described above so as to provide flexibility without blocking the current path (P).

[0121] In one example, the notch can be formed by pressing it into a mold. In another example, the notch can be formed using a laser scanning method. However, as long as the forming process is simple and flexibility can be imparted through the notches as described above, the forming method of the notch need not be limited to this.

[0122] The shortest current path (P) between the terminal junction (32) and the electrode junction (33) is configured in a radial direction approaching from one of the first region (311) and the second region (312) to the other region.

[0123] That is, the shortest current path (P) can be provided between the terminal joint (32) and the electrode joint (33) in a radial direction with respect to the terminal joint (32).

[0124] The shortest current path (P) between the terminal junction (32) and the electrode junction (33) may extend in a direction in which either the straight-line distance to the terminal junction (32) or the straight-line distance to the electrode junction (33) decreases and the other increases. In other words, the shortest current path (P) may not extend in a direction in which both the straight-line distance to the terminal junction (32) and the straight-line distance to the electrode junction (33) increase or decrease.

[0125] The above shortest current path (P) may not exist radially outside the electrode joint (33).

[0126] In the second region (312), a penetration portion (34) is provided that penetrates the plate body (31) in the thickness direction. The penetration portion (34) may extend in the radial direction. The penetration portion (34) prevents the current collector (30) from covering the electrode assembly (20) in the axial direction, thereby improving the impregnation property of the electrolyte.

[0127] In the embodiment, the penetration portion (34) is exemplified as extending radially, but having both the radially inner and outer sides blocked. However, alternatively, the penetration portion (34) may be open radially outward.

[0128] The above penetration portions (34) can be arranged in multiple pieces spaced apart along the circumferential direction.

[0129] The two circumferentially adjacent penetration portions (34) are not interconnected in the circumferential direction between the terminal joint portion (32) and the electrode joint portion (33) in the radial direction. Accordingly, the penetration portions (34) do not block the shortest current path (P).

[0130] [Battery Cell - First Embodiment]

[0131] Referring to FIGS. 9 to 13, the battery cell of the first embodiment includes an electrode assembly (20), a current collector (30, 40) electrically connected to the electrode assembly (20), and a can (10) that accommodates the electrode assembly (20) and the current collector (30, 40).

[0132] The above electrode assembly (20) is manufactured in a jelly-roll shape by stacking a first electrode (21), a second electrode (22), and a separator (28) that extend in the longitudinal direction with a predetermined width in the order of the first electrode (21), the separator (28), the second electrode (22), and the separator (28) and winding them around a core shaft.

[0133] The above first electrode (21) may be an anode, and the above second electrode (22) may be a cathode. Of course, the opposite may also be the case.

[0134] The above first electrode (21) and second electrode (22) are manufactured in the form of sheets. The electrode sheet is manufactured in the form of an active material layer (24) applied to the surface of a metal foil (23). The electrode sheet has a holding portion (25) region where the active material layer (24) is applied, and a non-coated portion (26) region where the active material layer (24) is not applied. The positive electrode sheet has a non-coated portion (26) region on one side in the width direction, and the negative electrode sheet has a non-coated portion (26) region on the other side in the width direction.

[0135] The non-conductive portion (26) is exposed or protrudes in the width direction of the laminate. The non-conductive portion (26) itself functions as an electrode tab (27).

[0136] In the above-mentioned blank portion (26), notches can be formed at a predetermined interval to form flag-shaped notching tabs (27).

[0137] In the embodiment, the above-described notching tabs (27) are exemplified as having an equilateral trapezoidal shape. However, their shapes may be various, such as a semicircle, a semi-ellipse, a triangle, a rectangle, a parallelogram, etc.

[0138] In addition, in the embodiment, a form in which the notching tabs (27) arranged along the longitudinal direction have the same width is exemplified. However, the width of the notching tabs may be gradually or stepwise widened from the core side to the outer periphery side.

[0139] In addition, in the embodiment, a form in which the height of the notching tabs (27) gradually increases from the core side to the outer circumference side is exemplified. However, the height of these notching tabs may be implemented in a form in which they are constant or gradually decrease.

[0140] In addition, in the embodiment, a structure is exemplified in which a notching tab (27) is deleted in a predetermined section of the centrifugal end of the above-mentioned plain portion (26) and a predetermined section of the centrifugal end. However, it goes without saying that the notching tab may not be deleted in the centrifugal end of the plain portion, and the notching tab may not be deleted in the centrifugal end of the plain portion.

[0141] In the jelly roll-shaped electrode assembly (20), the notched tab (27) can be bent radially and flattened as illustrated in FIG. 10. The notched tab (27) can be bent radially inward or outward. In the embodiment, a structure in which the notched tab (27) is bent radially inward is exemplified.

[0142] The above-mentioned notched tabs (27) can be bent one by one during the process of forming a jelly roll-shaped electrode assembly (20) by winding the laminate. Alternatively, the above-mentioned notched tabs (27) can be bent all at once after the laminate is wound to form a jelly roll-shaped electrode assembly.

[0143] The notching tabs (27) of the first electrode (21) and the notching tabs (27) of the second electrode (22), which are bent and overlapped in the radial direction in this way, can provide a plane that is substantially perpendicular to the axial direction at each of the axial ends of the electrode assembly (20).

[0144] A substantially flat surface provided by bending the notched tab (27) exposed at the axial end of the electrode assembly (20) may be joined to a current collector plate (30, 40) as shown in FIGS. 11 to 15.

[0145] The first collector plate (30) is joined to one axial end of the electrode assembly (20), i.e., the bottom side. This joining can be achieved, for example, by irradiating the surface of the first collector plate (30) with a laser to weld the back surface of the first collector plate (30) and the electrode tab (27).

[0146] The above first collector plate (30) can be electrically connected to the first electrode by being joined to the electrode tab (27) of the first electrode (21) of the electrode assembly (20).

[0147] In the embodiment, the first collector plate (30) is exemplified as being a positive collector plate. However, the first collector plate (30) may also be a negative collector plate.

[0148] In the embodiment, the first collector plate (30) is exemplified as being made of aluminum. However, the first collector plate (30) may also be made of copper. In other words, the material of the collector plate need not be limited thereto.

[0149] The above second collector plate (40) is joined to the axial other end of the electrode assembly (20), i.e., the upper side. This joining can be achieved, for example, by irradiating the surface of the second collector plate (40) with a laser to weld the back surface of the second collector plate (40) and the electrode tab (27).

[0150] The above second collector plate (40) can be electrically connected to the second electrode by being joined to the electrode tab (27) of the second electrode (22) of the electrode assembly (20).

[0151] In the embodiment, the second collector plate (40) is exemplified as a negative collector plate. However, the second collector plate (40) may also be a positive collector plate.

[0152] In the embodiment, the second collector plate (40) is exemplified as being made of copper. However, the second collector plate (40) may also be made of aluminum. In other words, the material of the collector plate need not be limited thereto.

[0153] The above-mentioned collector plate (30, 40) can be manufactured by punching, trimming, piercing, and bending a metal sheet.

[0154] The can (10) includes a bottom member (12), a side wall member (11) connected to the bottom member (12) and extending in the axial direction, and a cap (17) covering an open end of the side wall member (11).

[0155] The above floor member (12) may have a disc shape, and the side wall member (11) may have a circular tube shape.

[0156] The above-mentioned bottom member (12) and side wall member (11) can be manufactured by forming a metal sheet with a nickel plated surface using a deep drawing process, and trimming the front end of the side wall member (11) with a punch while holding it with a blank holder. Of course, the material of the can (10) is not limited to this.

[0157] The above floor member (12) has a disc shape with a hole formed in the center.

[0158] A first electrode terminal (13) can be fitted into the hole. The first electrode terminal (13) can be fixed by riveting to the bottom member (12) with a gasket (14) interposed therebetween. The gasket (14) is interposed between the first electrode terminal (13) and the bottom member (12), sealing the inside and outside of the can (10) to prevent leakage of the electrolyte, and electrically insulating the first electrode terminal (13) and the bottom member (12).

[0159] However, the method of connecting the first electrode terminal (13) and the bottom member (12) is not limited to this. For example, if there is a structure that can seal between the first electrode terminal (13) and the bottom member (12) and electrically insulate the first electrode terminal (13) and the bottom member (12), various other fixing methods, such as a bolt-nut joint method, a glass seal method, or a chrome coating & PP-MAH thermal bonding method, can also be applied.

[0160] The first electrode terminal (13) above may have a first polarity, and the can (10) may have a second polarity. That is, the bottom member (12) of the can (10) and the side wall member (11) connected thereto may both have a second polarity.

[0161] Accordingly, the battery cell may have both the first electrode terminal (13) and the second electrode terminal (15) positioned at the axial end, i.e., the closed end, provided with the bottom member (12), as illustrated in Fig. 13. Then, the battery cell may have both the bus bar connected to the first electrode terminal (13) and the bus bar connected to the second electrode terminal (15) positioned at the upper portion of the battery cell.

[0162] In one example, the first electrode terminal (13) may be a positive terminal and the second electrode terminal (15) may be a negative terminal. Of course, the opposite may also be true.

[0163] Referring to Fig. 12, the first collector plate (30) can be placed so as to face the bottom (12) of the can (10), and the electrode assembly (20) can be accommodated in the can (10). The electrode assembly (20) is accommodated in the can (10) in a state where the first collector plate (30) is aligned so as to face the bottom member (12) of the can (10). Then, the first region (311) of the first collector plate (30) faces and contacts the first electrode terminal (13) installed in the bottom member (12). Meanwhile, an insulator (19) is interposed between the second region (312) of the first collector plate (30) and the bottom member (12) of the can (10), so as to electrically insulate the first collector plate (30) and the bottom member (12).

[0164] The terminal joint (31) of the first region (311) of the first collector plate (30) is joined to the first electrode terminal (13) fixed to the bottom (12) by resistance welding, ultrasonic welding, laser welding, or the like. The welding device for welding the first collector plate (30) and the first electrode terminal (13) can approach the back surface of the center of the terminal joint (31) of the first collector plate (30) through the core hollow portion (29) of the electrode assembly (20) from the open end of the can (10) to perform welding. Of course, in addition to this, the first collector plate (30) and the first electrode terminal (13) can also be joined by brazing or soldering. In other words, various methods can be applied to the first collector plate (30) and the first electrode terminal (13) as long as they are joined electrically and fixed to each other.

[0165] Referring to FIG. 13, the second collector plate (40) defines a hole (42) corresponding to the core hollow portion (29) of the electrode assembly (20), and includes an inner portion (41) provided in a form surrounding the core hollow portion, an electrode connection portion (43) extending radially from the inner portion (41), and a can connection portion (44) positioned on the centrifugal side relative to the electrode tab connection portion (43) and connected to the inner portion (41).

[0166] In FIGS. 12 and 13, the electrode assembly (20) is inserted into the can (10) in a state where the second collector plate (40) is not bonded to the electrode assembly (20). However, it is of course also possible to insert the electrode assembly (20) into the can (10) in a state where the second collector plate (40) is first bonded to the electrode assembly (20).

[0167] In a state where the electrode assembly (20) is accommodated inside the can (10), the electrode tab (27) of the second electrode (22) and the second current collector (40) are arranged to face the open end of the side wall member (11).

[0168] With the electrode assembly (20) housed inside the can (10), the end of the side wall member (11) of the can (10) can be molded inward to form a beading portion (113). Then, welding of these can be performed with the can connection portion (44) of the second collector plate (40) in contact with the beading portion (113).

[0169] After the electrolyte is injected into the can (10), a cap (17) having a vent structure is placed on the beading portion (113), and the upper end of the side wall member (11) is crimped radially inward to press the edge of the cap (17), thereby covering the open end of the can (10). At this time, a gasket (167) is interposed between the beading portion (113) and crimping portion (115) of the side wall member (11) and the cap (17), so that insulation sealing can be achieved. Accordingly, the cap (17) may be non-polar.

[0170] The above first collector plate (30) may be a bottom collector plate facing the bottom (12) of the can (10), and the second collector plate (40) may be an open end collector plate facing the open end of the can (10).

[0171] [Battery Cell - Second Embodiment]

[0172] The first collector plate (30) described above can be applied not only to the battery cell of the first embodiment, but also to the battery cell of the second embodiment described later.

[0173] Referring to FIGS. 14 and 15 below, a second embodiment of a cylindrical battery cell of the present invention will be described. In describing this, any explanation that overlaps with the first embodiment will be omitted.

[0174] In the second embodiment, the bottom member (12) of the can (10) itself constitutes a second electrode terminal (15), and the first electrode terminal (13) is constituted by a cap assembly (16).

[0175] The above first collector plate (30) can be electrically connected to the first electrode by being joined to the electrode tab (27) of the first electrode (21) of the electrode assembly (20).

[0176] In the embodiment, it is exemplified that the first electrode is a cathode and the first collector plate (30) is a cathode collector plate. However, the first electrode may be a cathode and the first collector plate (30) may be a cathode collector plate.

[0177] In the embodiment, the first collector plate (30) is exemplified as being made of copper. However, the first collector plate (30) may also be made of aluminum. In other words, the material of the collector plate need not be limited thereto.

[0178] The above second collector plate (40) can be electrically connected to the second electrode by being joined to the electrode tab (27) of the second electrode (22) of the electrode assembly (20).

[0179] In the embodiment, the second electrode is exemplified as being a positive electrode and the second collector plate (40) is a positive collector plate. However, the second electrode may be a negative electrode and the second collector plate (40) may be a negative collector plate.

[0180] In the embodiment, the second collector plate (40) is exemplified as being made of aluminum. However, the second collector plate (40) may also be made of copper. In other words, the material of the collector plate need not be limited thereto.

[0181] Referring to Fig. 14, the first collector plate (30) faces the bottom (12) of the can (10), and the electrode assembly (20) can be accommodated in the can (10). The electrode assembly (20) is accommodated in the can (10) in a state where the first collector plate (30) is aligned to face the bottom member (12) of the can (10). Then, the first region (311) of the first collector plate (30) faces and contacts the central portion of the bottom member (12).

[0182] The first region (311) of the first collector plate (30) and the bottom member (12) can be welded. The welding can be a laser welding method in which a laser is irradiated from the outside of the bottom member (12) of the can or a laser is irradiated to the second surface (318) of the first region (311) of the first collector plate (30). In addition to this, various other welding methods such as resistance welding or ultrasonic welding can also be applied.

[0183] Referring to Fig. 15, after welding of the first collector plate (30) and the can (10), a beading portion (113) can be formed at the end of the side wall member (11). The other axial end of the electrode assembly (20) and the cap assembly (16) can be electrically connected through the second collector plate (40). Accordingly, the second electrode (22) of the electrode assembly (20) can be electrically connected to the electrode terminal (161) of the cap assembly (16) through the second collector plate (40).

[0184] Preferably, the cap assembly (16) may further include a current interrupting disc (CID) (165). One end of the second collector plate (40) may be joined to the electrode tab (27) of the electrode assembly (20), and the other end may be joined to the current interrupting disc (165) of the cap assembly (16).

[0185] Preferably, the cap assembly (16) may further include a vent (163) whose central portion is electrically connected to the current blocking disk (165).

[0186] Preferably, the cap assembly (16) may further include an insulating spacer (168) that insulates and separates the periphery of the current blocking disk (165) and the vent (163).

[0187] The edge of the vent (163) and the edge of the electrode terminal (161) are axially overlapped and placed on the beading portion (113). The edge of the vent (163) and the edge of the electrode terminal (161) are sealed and fixed by the beading portion (113) and the crimping portion (115).

[0188] The edge of the vent (163) and the edge of the electrode terminal (161) are sealed and fixed with a gasket (167) interposed therebetween, and the can (10) and the cap assembly (16) are electrically insulated from each other by the gasket (167).

[0189] Referring to FIG. 15, the can (10) of the cylindrical battery cell has a first polarity corresponding to the first electrode (21) of the electrode assembly (20), and the electrode terminal (161) is positioned at the upper center of the cylindrical battery cell and has a second polarity corresponding to the second electrode (22) of the electrode assembly (20).

[0190] The notches (35, 36) provided in the boundary area (315) of the first collector plate (30) of the embodiment described above allow for changes in the relative axial position and radial position of the terminal joint (31) with respect to the electrode joint (33).

[0191] The above boundary region (315) is positioned in a path where vibration or external impact applied to the can (10) is transmitted to the electrode joint (33) through the terminal joint (31). This boundary region is naturally elastically deformed in response to the vibration or impact by the notches (35, 36). Accordingly, the magnitude of tensile stress or compressive stress repeatedly and continuously applied to the connection portion between the terminal joint (31) and the electrode joint (33) can be minimized.

[0192] In the embodiment, the battery cell is exemplified as being cylindrical. However, the battery cell does not necessarily have to be cylindrical.

[0193] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0194] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A plate body having a first surface and a second surface that are opposite to each other; A first area of ​​the plate body including a terminal joint that is joined to the first surface of the cap, the bottom of the can, or the electrode terminal; A second area of ​​the plate body surrounding the first area, the second area including an electrode joint that is joined to the electrode tab of the electrode assembly; and A current collector plate including a first notch provided on the first surface and a second notch provided on the second surface, in a boundary region between the first region and the second region.

2. In claim 1, the first notch is extended in a closed loop shape to surround the first region, the current collector plate.

3. In claim 1, The second notch is a collector plate that extends in a closed loop shape to surround the first region.

4. In claim 1, the first notch and the second notch are arranged alternately along an approach direction, which is a direction in which one of the first and second regions approaches the other region.

5. In claim 1, a current collector plate in which the widthwise center of the first notch and the widthwise center of the second notch are alternately arranged along an approach direction, which is a direction in which one of the first and second regions approaches the other region.

6. In claim 1, the deepest recessed bottom in the first notch and the deepest recessed bottom in the second notch are arranged alternately along an approach direction, which is a direction in which one of the first and second regions approaches the other region.

7. A current collector plate according to any one of claims 4 to 6, wherein the shortest distance between the first inner surface and the second inner surface, which define the first notch and the second notch, respectively, adjacent in the approach direction, is smaller than the thickness of the plate body.

8. A current collector plate according to any one of claims 4 to 6, wherein, when viewed in the thickness direction of the plate body, the first notch and the second notch, which are adjacent in the approaching direction, partially overlap each other.

9. A current collector plate according to claim 1, wherein the cross-sectional shape of the first inner surface defining the first notch when viewed in the extension direction of the first notch is substantially triangular, trapezoidal, semicircular, or round.

10. A current collector plate according to claim 1, wherein the cross-sectional shape of the second inner surface defining the second notch when viewed in the extension direction of the second notch is substantially triangular, trapezoidal, semicircular, or round.

11. A collector plate according to claim 1, wherein the width of the first notch gradually decreases in the depth direction.

12. A collector plate according to claim 1, wherein the width of the second notch gradually decreases in the depth direction.

13. A current collector plate according to claim 1, wherein the first notch and the second notch are arranged concentrically.

14. In claim 1, the plate body is substantially circular, The above first region is a current collector plate provided at the center of the plate body.

15. In claim 1, the first notch and the second notch each surround the first region in a circular shape, the current collector plate.

16. In claim 1, a current collector plate having a through-hole formed in the second region that penetrates the plate body in the thickness direction.

17. A current collector plate according to claim 1, wherein the shortest current path between the terminal joint and the electrode joint is configured in a direction approaching from one of the first and second regions to the other region.

18. A current collector plate according to claim 1, wherein the shortest current path between the terminal junction and the electrode junction does not have a section extending in a direction away from one of the first and second regions.

19. A can having a bottom member and a side wall member; An electrode assembly accommodated in the above can; A cap covering the open end of the can while the electrode assembly is accommodated in the can; electrode terminals; and A battery cell comprising a current collector plate according to any one of claims 1 to 18, wherein a first side is bonded to the cap, the bottom member of the can, or the electrode terminal, and a second side is electrically connected to an electrode tab provided on one axial side of the electrode assembly.

20. A battery cell according to claim 19, wherein the battery cell is cylindrical.

21. In claim 19, the electrode terminal is provided in the cap, a battery cell.

22. In claim 19, the electrode terminal is insulated and fixed to the bottom member, the battery cell.

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