Battery cell, and battery pack and device containing same

Abstract

A battery cell according to one aspect of the present invention comprises: a housing which has a sidewall member extending in the axial direction, an opening provided at a first end, in the axial direction, of the sidewall member, and a bottom member connected to a second end, in the axial direction, of the sidewall member; an electrode assembly which has a first electrode and a second electrode and is accommodated in the housing; a cap, the edge of which is electrically connected to the first end of the sidewall member, and which covers the opening of the housing; a first electrode terminal which is electrically insulated from the cap and installed so as to penetrate through a hole formed in the center of the cap; and a sealing member which seals a through hole formed in the bottom member of the housing, wherein the first electrode is electrically connected to the first electrode terminal, and the second electrode is electrically connected to the housing.

Description

Battery cells and battery packs and devices containing the same

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

[0002] This application claims priority to Korean Application No. 10-2024-0104088, filed on August 5, 2024, the entire disclosure of which is incorporated herein by reference.

[0003] Cylindrical battery cells house a jelly-roll-shaped electrode assembly within a cylindrical metal housing, making them more robust against mechanical shock and temperature changes than pouch-type batteries. For this reason, demand for cylindrical battery cells with metal housings, particularly for use in vehicle battery packs, is steadily increasing.

[0004] The manufacturing process for a cylindrical battery cell involves deep drawing a metal sheet to form a circular bottom member and a cylindrical side wall member extending from the bottom member, accommodating the electrode assembly within the bottom member, and then sealing the opening of the side wall member with a cap. Next, an electrolyte is injected into the housing, and the opening is covered with a cap, which is then secured by seam welding or crimping.

[0005] However, when welding is performed after electrolyte injection, the high temperature heat or plasma generated during welding may come into contact with the electrolyte vapor inside the housing, posing a risk of deterioration or ignition. This is a major safety consideration.

[0006] In addition, due to the structural characteristics of conventional cylindrical housings, the air gap formed between the cap and the electrode assembly acts as a kind of insulating layer, so when the battery cell is mounted in the pack case in an upright position, there is a problem in that bottom cooling through the bottom member does not occur smoothly.

[0007] In addition, since the top and bottom of conventional cylindrical battery cells function as different electrode terminals, there is also a problem in that bottom cooling through the bottom member is impossible.

[0008] Accordingly, conventional cylindrical battery cells have mainly adopted a side cooling method through side wall members, but this limits the freedom of pack design and has the problem of reduced thermal control efficiency during high-output operation.

[0009] The present invention aims to address the above-mentioned problems and provides a battery capable of bottom cooling. Furthermore, it aims to provide a battery that is less susceptible to weld defects or ignition due to electrolyte gas when sealing the electrolyte penetration hole of the bottom member.

[0010] In addition, the present invention aims to provide a battery pack including the battery cell and a device including the battery pack.

[0011] The present invention provides battery cells, battery packs and devices of the following implementation examples.

[0012] The battery cell according to the first embodiment,

[0013] A housing comprising a side wall member extending in an axial direction, an opening provided in the axial first end of the side wall member, and a bottom member connected to the axial second end of the side wall member; an electrode assembly having a first electrode and a second electrode and accommodated in the housing; a cap having an edge electrically connected to the first end of the side wall member and blocking the opening of the housing; a first electrode terminal electrically insulated from the cap and installed penetrating into a hole formed in the center of the cap; and a sealing member sealing a through hole formed in the bottom member of the housing; wherein the first electrode is electrically connected to the first electrode terminal, and the second electrode is electrically connected to the housing.

[0014] The second embodiment is, in the first embodiment,

[0015] The first electrode is electrically connected to the first electrode terminal through the first collector plate,

[0016] The first collector plate has a first electrode connection portion joined to the first electrode, and a first terminal connection portion joined to the first electrode terminal, and the first electrode protrudes axially outward from the axial first end of the electrode assembly and is bent radially to provide a first surface whose surface faces the axial outer side, and the first electrode connection portion of the first collector plate is joined to the first surface to be electrically connected.

[0017] The third embodiment is, in the first embodiment or the second embodiment,

[0018] The second electrode is electrically connected to the bottom member through a second collector plate, and the second collector plate has a second electrode connection portion joined to the second electrode and a second terminal connection portion joined to the bottom member of the can, and the second electrode protrudes axially outward from an axial second end of the electrode assembly and is bent radially to provide a second surface whose surface faces the axial outer side, and the second electrode connection portion of the second collector plate is joined to the second surface to be electrically connected.

[0019] The fourth embodiment is, in any one of the first to third embodiments,

[0020] The second electrode protrudes axially outward from the axial second end of the electrode assembly and is bent radially to provide a second surface facing axially outward, and the second surface can be electrically connected to the bottom member by being joined thereto.

[0021] The fifth embodiment is, in any one of the first to fourth embodiments,

[0022] The surface of the above electrode assembly facing the bottom member can be supported by the bottom member.

[0023] The sixth embodiment is, in any one of the first to fifth embodiments,

[0024] There may be no separate insulating layer between the electrode assembly and the floor member.

[0025] The seventh embodiment is, in any one of the first to sixth embodiments,

[0026] There may be no separate insulating layer between the electrode assembly and the cap.

[0027] The eighth embodiment is, in any one of the first to seventh embodiments,

[0028] An electrically insulating insulator is interposed between the cap and the electrode assembly,

[0029] The upper surface of the insulator can support the cap, and the lower surface of the insulator can support the electrode assembly.

[0030] The ninth embodiment is, in any one of the first to eighth embodiments,

[0031] The second electrode may be electrically connected to the housing and the cap.

[0032] The tenth embodiment is, in any one of the first to ninth embodiments,

[0033] At least one of the above cap and the above bottom member may include at least one vent notch.

[0034] The eleventh embodiment is any one of the first to tenth embodiments,

[0035] The above sealing member may include any one of a ball type, a plug type, a plate type, and a type in which a ball and a plate are applied together.

[0036] The 12th embodiment is, in any one of the 1st to 11th embodiments,

[0037] The above sealing member can be riveted, fitted or screwed into the through hole of the floor member.

[0038] The 13th embodiment is, in any one of the first to twelfth embodiments,

[0039] The above electrode assembly may have a structure in which a separator is interposed between the first electrode and the second electrode and is wound around a core hollow portion extending in the axial direction.

[0040] The 14th embodiment is, in any one of the 1st to 13th embodiments,

[0041] The above electrode assembly may have a structure wound around a core portion extending in the axial direction, with a separator interposed between the first electrode and the second electrode.

[0042] The battery pack according to the 15th embodiment,

[0043] A battery cell according to any one of the first to fourteenth embodiments; and a pack case accommodating the battery cell may be provided.

[0044] The 16th implementation example is, in the 15th implementation example,

[0045] The battery cell may be accommodated in the pack case such that the bottom member is in contact with the bottom of the pack case and the cap faces upward.

[0046] The 17th embodiment is, in the 15th embodiment or the 16th embodiment,

[0047] A cooling structure for cooling the battery cell through the bottom member of the battery cell may be provided on the bottom of the pack case.

[0048] The device according to the 18th embodiment,

[0049] A battery pack according to any one of the 15th to 17th embodiments is mounted and can be driven by power from the battery pack.

[0050] A battery cell according to one aspect of the present invention may have a structure in which a first electrode terminal and a second electrode terminal may be arranged on the upper side of the battery cell in the cap, thereby enabling bottom cooling.

[0051] According to one aspect of the present invention, a battery cell can efficiently cool heat through the bottom member because there is no separate insulating layer between the electrode assembly and the bottom member of the housing.

[0052] A battery cell according to one aspect of the present invention can efficiently dissipate heat because there is no separate insulating layer between the electrode assembly and the cap.

[0053] According to one aspect of the present invention, a battery cell can inject electrolyte through a through hole in a bottom member, so there is less possibility of defects or ignition due to electrolyte gas.

[0054] A battery pack according to one aspect of the present invention may apply a lower cooling structure.

[0055] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in these drawings. Meanwhile, the shape, size, scale, or ratio of elements in the drawings included in this specification may be exaggerated to emphasize a clearer explanation.

[0056] Figure 1 is a diagram illustrating a vertical cross-section of a cylindrical battery according to the prior art.

[0057] Figure 2 is an exploded perspective view of an electrode assembly before winding according to one embodiment of the present invention.

[0058] Figure 3 is a perspective view of a pre-wound laminated state of an electrode assembly according to one embodiment of the present invention.

[0059] FIG. 4 is a perspective view of an electrode assembly assembled into a cylindrical jelly-roll shape by winding a pre-rolled laminate of an electrode assembly according to one embodiment of the present invention.

[0060] FIG. 5A is a perspective view showing a state in which a first current collector plate is joined to an electrode tab provided at an axial first end of an electrode assembly facing an opening of a can according to one embodiment of the present invention.

[0061] FIG. 5b is a perspective view showing a state in which a first current collector plate is joined to an electrode tab provided at an axial first end of an electrode assembly facing an opening of a can according to one embodiment of the present invention.

[0062] FIG. 6A is a perspective view showing a state in which a second collector plate is joined to an electrode tab provided on an axial second end of an electrode assembly facing a bottom member of a can according to one embodiment of the present invention.

[0063] FIG. 6b is a perspective view showing a state in which a second collector plate is joined to an electrode tab provided on a second axial end of an electrode assembly facing a bottom member of a can according to one embodiment of the present invention.

[0064] FIG. 7 is a cross-sectional view showing a state in which an electrode assembly is inserted into a can so that the second collector plate is in contact with the bottom member and the first collector plate is positioned toward the opening according to one embodiment of the present invention.

[0065] Figure 8 is a cross-sectional view showing a vertical cross-section of an electrode assembly according to one embodiment of the present invention.

[0066] FIG. 9a is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0067] FIG. 9b is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0068] FIG. 9c is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0069] FIG. 10a is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0070] FIG. 10b is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0071] FIG. 11a is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0072] FIG. 11b is a diagram illustrating a sealing member covering a through hole of a floor member according to one embodiment of the present invention.

[0073] FIG. 12 is a drawing showing a battery pack having battery cells built into a pack housing according to one embodiment of the present invention.

[0074] FIG. 13 is a drawing showing a vehicle equipped with a battery pack according to one embodiment of the present invention.

[0075] Hereinafter, the present invention will be described in detail with reference to the drawings. Terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention, they should be interpreted in the sense and concept consistent with the technical spirit of the present invention.

[0076] Accordingly, the embodiments described in this specification and the configurations described in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0077] Additionally, throughout the specification, whenever a part is said to “include,” “comprise,” “have,” or “have” a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0078] In addition, the terms 'about', 'substantially', etc. used throughout this specification are used in the sense of or near to the numerical values ​​when manufacturing and material tolerances inherent to the meanings stated are presented, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure where exact or absolute values ​​are mentioned to aid understanding of this specification.

[0079] Throughout this specification, references to 'A and / or B' mean 'A or B or both.'

[0080] Throughout this specification, terms such as "upper," "lower," "left," "right," "inner," and "outer" refer to positions or directions within the referenced drawings and should not be limiting. The terms "inner" and "outer" refer to directions toward or away from the geometric center of the designated device, system, or its components, respectively. These terms include the words listed above, their derivatives, and words of similar meaning.

[0081] In this specification, when it is said that a member is located “on” another member, this includes not only cases where a member is in contact with another member, but also cases where another member exists between the two members.

[0082]

[0083] Figure 1 is a diagram illustrating a vertical cross-section of a cylindrical battery cell according to the prior art.

[0084] Referring to Fig. 1, a battery housing (10) of a conventional cylindrical battery cell has a bottom member (12) positioned at the top and an opening formed at the lower end of a side wall member (11). A first electrode terminal (17) is sealedly installed in the center of the bottom member (12) with a terminal gasket (170) interposed therebetween.

[0085] In a state where the electrode assembly (20) is accommodated inside the battery housing (10), the first current collector (30) bonded to the first electrode of the electrode assembly (20) is electrically connected by being bonded to the first electrode terminal (17), and the second current collector (40) bonded to the second electrode of the electrode assembly (20) is electrically connected by being bonded to the beading portion (113) formed at the lower end of the side wall member (11) of the battery housing (10). Accordingly, the bottom member (12) and the side wall member (11) can form a second electrode terminal (14).

[0086] A cap (16) is attached to the lower end of the side wall member (11) to close the opening of the battery housing (10). The edge of the cap (16) is installed by compression between the beading portion (113) and the crimping portion (115) of the side wall member (11) with the cap gasket (15) interposed therebetween. The cap (16) may be non-polarized due to the cap gasket (15).

[0087] However, since the cap (16) of the battery is positioned at the lower end of the battery housing (10) and the air gap between the cap (16) and the electrode assembly (20) acts as a kind of insulating layer, it is impossible to perform bottom cooling of the battery when the battery is installed in a battery pack in an upright position.

[0088] Accordingly, the battery structure described above cannot avoid side cooling via the sidewall member (11). This limitation in the battery cooling method significantly limits the design freedom of the battery pack. For example, it prevents the application of a battery pack structure capable of bottom cooling.

[0089]

[0090] A first aspect of the present invention relates to a battery cell.

[0091] A battery cell according to one aspect of the present invention,

[0092] A housing comprising a side wall member extending in an axial direction, an opening provided in the axial first end of the side wall member, and a bottom member connected to the axial second end of the side wall member; an electrode assembly having a first electrode and a second electrode and accommodated in the housing; a cap having an edge electrically connected to the first end of the side wall member and blocking the opening of the housing; a first electrode terminal electrically insulated from the cap and installed penetrating into a hole formed in the center of the cap; and a sealing member sealing a through hole formed in the bottom member of the housing; wherein the first electrode is electrically connected to the first electrode terminal, and the second electrode is electrically connected to the housing.

[0093]

[0094] Fig. 2 is an exploded perspective view of an electrode assembly accommodated inside a housing before being wound, and Fig. 3 is a perspective view of the electrode assembly in a laminated state before being wound. Fig. 4 is a perspective view of an electrode assembly assembled into a cylindrical jelly-roll shape by winding the laminated body of the electrode assembly before being wound.

[0095] The electrode assembly (20) is manufactured in the form of a jelly-roll by preparing a first electrode (21), a second electrode (22), and a separator (28) that extend in the longitudinal direction with a predetermined width as shown in FIG. 2, and then forming a laminate by stacking the first electrode (21), the separator (28), the second electrode (22), and the separator (28) in that order as shown in FIG. 3, and then winding this around a core shaft as shown in FIG. 4.

[0096] The electrode assembly (20) is manufactured in the form of a jelly-roll by preparing the first electrode (21), the second electrode (22), and the separator (28) that extend in the longitudinal direction with a predetermined width as shown in FIG. 2, and then forming a laminate by stacking the first electrode (21), the separator (28), the second electrode (22), and the separator (28) in that order as shown in FIG. 3, and then winding this around a core shaft as shown in FIG. 4.

[0097] The center of the above electrode assembly (20) may be a core hollow portion (29), but may also include a separate center pin core portion. The center pin core portion may include ceramic, metal, or polymer resin, and may perform roles such as securing the winding stability of the electrode assembly (20), mechanical support, heat conduction, or electrical insulation.

[0098] 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.

[0099] The first electrode (21) and the second electrode (22) are manufactured in the form of sheets. The electrode sheet is manufactured in the form in which an active material layer (24) is 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 the non-coated portion (26) region on one side in the width direction, and the negative electrode sheet has the non-coated portion (26) region on the other side in the width direction.

[0100] The above-mentioned non-woven portion (26) is exposed or protrudes in the width direction of the laminate. The above-mentioned non-woven portion (26) itself functions as an electrode tab (27).

[0101] The above-described plain portion (26) may be provided with notches at predetermined intervals to form flag-shaped notching tabs (27). The notching tabs (27) may be in the form of an equilateral trapezoid as illustrated in the drawing, but may also be in various forms such as a semicircle, a semi-ellipse, a triangle, a rectangle, or a parallelogram. In addition, the drawing exemplifies a form in which the notching tabs (27) arranged along the longitudinal direction have the same width. However, the width of the notching tabs may also be gradually or stepwise widened from the core side toward the outer periphery side. In addition, the drawing exemplifies a form in which the height of the notching tabs (27) gradually increases from the core side toward the outer periphery side. However, the height of the notching tabs may be implemented in a constant or gradually decreasing form. In addition, the drawing exemplifies a structure in which the notching tabs (27) are deleted in a predetermined section of the centripetal end of the above-described plain portion (26) and a predetermined section of the centrifugal end. However, it goes without saying that the notching tab may not be deleted from the centripetal end of the above-mentioned non-conductive portion, and that the notching tab may not be deleted from the centrifugal end of the above-mentioned non-conductive portion.

[0102] Referring to Fig. 4, in the jelly roll-shaped electrode assembly (20), the notched tab (27) can be bent radially and flattened. The notched tab (27) can be bent radially inward as shown in Fig. 4. In addition, unlike as shown in Fig. 4, the notched tab (27) can be bent radially outward.

[0103] 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.

[0104] The notched tabs (27) of the first electrode (21) and the notched tabs (27) of the second electrode (22), which are bent and overlapped in the radial direction in this way, can provide a first plane and a second plane that are substantially perpendicular to the axial direction at the axially opposite ends of the electrode assembly (20), respectively.

[0105] The first and second collector plates (30) and the second collector plate (40) may be joined to the substantially flat first and second surfaces provided by bending the notched tabs (27) exposed at both axial ends of the electrode assembly (20), respectively. However, the first collector plate (30) may be joined to the first surface, and the second collector plate (40) may not be joined to the second surface. Conversely, the first collector plate (30) may not be joined to the first surface, and the second collector plate (40) may be joined to the second surface. In addition, the first collector plate (30) may not be joined to the first surface, and the second collector plate (40) may not be joined to the second surface.

[0106]

[0107] In one embodiment of the present invention, the first electrode can be electrically connected to a first electrode terminal through a first collector plate. The first collector plate has a first electrode connection portion joined to the first electrode, and a first terminal connection portion joined to the first electrode terminal, and the first electrode protrudes axially outward from an axial first end of the electrode assembly and is bent radially to provide a first surface facing axially outward, and the first electrode connection portion of the first collector plate can be joined to the first surface to be electrically connected.

[0108]

[0109] In one embodiment of the present invention, the second electrode can be electrically connected to the bottom member through a second collector plate. The second collector plate has a second electrode connection portion joined to the second electrode and a second terminal connection portion joined to the bottom member of the can, and the second electrode protrudes axially outward from the axial second end of the electrode assembly and is bent radially to provide a second surface whose surface faces the axial outer side, and the second electrode connection portion of the second collector plate can be joined to the second surface to be electrically connected.

[0110]

[0111] In one embodiment of the present invention, the second electrode protrudes axially outward from the axial second end of the electrode assembly and is bent radially to provide a second surface facing axially outward, and the second surface can be electrically connected to the bottom member by being joined to the bottom member. That is, the second electrode can be directly joined to the bottom member without going through the second collector plate. At this time, the surface of the electrode assembly facing the bottom member can be supported by the bottom member.

[0112]

[0113] Hereinafter, with reference to FIGS. 5a to 6b, an electrode assembly to which a first collector plate or a second collector plate is connected according to one embodiment of the present invention will be described in detail.

[0114] Figures 5a and 5b are perspective views illustrating a state in which a first current collector (30) is joined to an electrode tab provided at an axial first end of an electrode assembly (20) that faces the opening of a battery housing (10). Figures 6a and 6b are perspective views illustrating a state in which a second current collector (40) is joined to an electrode tab provided at an axial second end of an electrode assembly (20) that faces the bottom member (12) of the battery housing.

[0115] The first collector plate (30) may be a positive collector plate, and the second collector plate (40) may be a negative collector plate. However, the first collector plate (30) may be a negative collector plate, and the second collector plate (40) may be a positive collector plate. The second collector plate (40) may include a copper material, and the first collector plate (30) may include an aluminum material. However, the materials are not limited thereto. The collector plates (30, 40) may be manufactured by punching, trimming, piercing, and bending a metal sheet.

[0116]

[0117] Referring to FIG. 5a, the first current collector plate (30) may include a first terminal connection portion (32) provided at a portion corresponding to a core hollow portion (not shown) of the electrode assembly (20), and a first electrode connection portion (31) provided in a form surrounding the first terminal connection portion (32). The first current collector plate (30) may have a reinforcing rib (33) provided radially between the first electrode connection portion (31) and the first terminal connection portion (32). The reinforcing rib (33) may be in the form of a short circular tube extending axially from the first electrode connection portion (31) so that the first terminal connection portion (32) is offset outward in the axial direction. The above reinforcing rib (33) reinforces the first terminal connection portion (32) so that it does not sag axially inwardly relative to the first electrode connection portion (31) when the first terminal connection portion (32) receives an axial load. A hole may be provided in the center of the first terminal connection portion (32). Accordingly, welding between the second current collector plate (40) and the bottom member (12), which will be described later, can be performed more smoothly.

[0118] The above first electrode connection portion (31) can be joined to the notched tab (27) of the first electrode (21) of the electrode assembly (20) by laser welding or the like before the electrode assembly (20) is accommodated in the battery housing (10). The welding line of the laser can extend radially.

[0119] Alternatively, the first electrode connecting portion (31) may be joined to the notched tab (27) of the first electrode (21) of the electrode assembly (20) by laser welding or the like after the electrode assembly (20) is accommodated in the battery housing (10). Accordingly, the welding of the second current collector (40) and the bottom member (12) can be performed more smoothly.

[0120]

[0121] Referring to FIG. 5b, the first current collector plate (30) may include a first terminal connection portion (32) provided at a portion corresponding to the core cavity (not shown) of the electrode assembly (20), and a first electrode connection portion (31) provided around the first terminal connection portion (32). The first electrode connection portion (31) is arranged at the center of the first current collector plate (30) and is provided in a form that covers at least a portion of the core cavity of the electrode assembly (20) in the axial direction. The first electrode connection portion (31) may be spaced apart from the first terminal connection portion (32) in the radial direction and may be arranged in a radially extended form. A plurality of first electrode connection portions (31) are arranged spaced apart from each other along the circumferential direction. The first terminal connection portion (32) and the first electrode connection portion (31) may be physically and electrically connected to each other through a conductive portion (33). The conductive portion (33) includes a radial extension portion (331) extending radially from the first electrode connection portion (31), and a circumferential extension portion (332) extending circumferentially from the centrifugal end of the radial extension portion. The radial extension portion (331) is spaced apart from the first electrode connection portion (31) in a circumferential direction and alternately arranged. The circumferential extension portion (332) is connected to the centrifugal end of the first electrode connection portion (31).

[0122] The above first electrode connection portion (31) can be joined to the notched tab (27) of the first electrode (21) of the electrode assembly (20) by laser welding or the like before the electrode assembly (20) is accommodated in the battery housing (10). The welding line of the laser can extend radially.

[0123] Alternatively, the first electrode connecting portion (31) may be joined to the notched tab (27) of the first electrode (21) of the electrode assembly (20) by laser welding or the like after the electrode assembly (20) is accommodated in the battery housing (10). Accordingly, the welding of the second current collector (40) and the bottom member (12) can be performed more smoothly.

[0124]

[0125] Referring to Fig. 6a, the second collector plate (40) has a second terminal connection portion (42) extending radially from the center, and a second electrode connection portion (41) connected to the second terminal connection portion (42) through a ring portion that connects the centrifugal edge of the second terminal connection portion (42) in the circumferential direction. The second electrode connection portion (41) is arranged alternately with the second terminal connection portion (42) along the circumferential direction and extends radially inward from the ring portion. The radially inner end of the second electrode connection portion (41) is not connected to the second terminal connection portion (42). The center portion of the second terminal connection portion (42) can cover at least a portion of the core hollow portion (29) of the electrode assembly (20).

[0126] The second electrode connection portion (41) may be joined to the notched tab (27) of the second electrode (22) of the electrode assembly (20) by laser welding or the like before the electrode assembly (20) is placed in the battery housing (10). The welding line of the laser may extend radially.

[0127]

[0128] Referring to FIG. 6b, the second collector plate (40) has a second electrode connection portion (41) including a ring-shaped ring portion (410) having a hole formed in the center, and an extension portion (411) extending radially outward from the ring portion (410). In addition, the second collector plate (40) has a bridge (43) having a central end connected to the ring portion (410) and extending radially from the ring portion, and a second terminal connection portion (42) in the shape of an outer ring connected to a centrifugal end of the bridge (43). The second electrode (22) and the second collector plate (40) are electrically connected by being joined to each other through a laser welding line extending radially along the extension portion (411) and the ring portion (410).

[0129] The above bridge (43) is arranged between the above extensions (411) in the circumferential direction. The above bridge (43) may have a stepped portion (430) so that at least a portion of the above bridge (43) and the above second terminal connection portion (42) are offset axially outward.

[0130] The above second terminal connection portion (42) may have a ring shape in the form of an “L” cross section that extends radially outward and then extends axially again from its end.

[0131] The second electrode connection portion (41) may be joined to the notched tab (27) of the second electrode (22) of the electrode assembly (20) by laser welding or the like before the electrode assembly (20) is accommodated in the battery housing (10). The welding line of the laser may extend radially.

[0132]

[0133] Hereinafter, a battery cell according to an embodiment of the present invention will be described in detail with reference to FIGS. 7 and 8. FIG. 7 is a cross-sectional view showing a state in which an electrode assembly (20) in which a first collector plate (30) and a second collector plate (40) are joined is inserted into a housing (11). FIG. 8 is a cross-sectional view showing a state in which an opening of the housing (10) is covered with a cap (16), a first electrode terminal (17) is joined to the first collector plate (30), and an edge portion (166) of the cap (16) is joined to a side wall member (11).

[0134]

[0135] Referring to Fig. 7, the housing (10) includes a side wall member (11) extending axially between a first end and a second end, and a bottom member (12) connected to the second end of the side wall member (11) and extending radially. The first end of the side wall member (11) is open to define an opening of the battery housing (10).

[0136] The above opening is sealed by covering it with a cap (16) after accommodating the electrode assembly (20) in the battery housing (10).

[0137] The above-mentioned bottom member (12) may have a disc shape, and the side wall member (11) may have a circular tube shape. The above-mentioned bottom member (12) includes a through hole through which an electrolyte can be injected.

[0138] The above floor member (12) may include at least one vent notch.

[0139] The above-mentioned bottom member (12) and the side wall member (11) can be manufactured by forming a metal sheet with a nickel plated surface of steel 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 housing (10) is not limited to this.

[0140] The electrode assembly (20) may be accommodated in the housing (10) in a state where the second collector plate (40) is aligned so as to face the bottom member (12) of the housing (10). Accordingly, both surfaces of the flat second collector plate (40) may be interposed between the bottom member (12) and the second surface of the second electrode (22), respectively. In this case, the second collector plate (40) may be in surface contact with the second surface of the second electrode (22) and may also be in surface contact with the bottom member (12).

[0141] For example, the second terminal connection portion (42) of the second current collector plate (40) may be joined to the bottom member (12) of the battery housing (10). The joining may be thermal joining. The thermal joining may be, for example, welding, and specifically, ultrasonic welding or laser welding. In a state where the electrode assembly (20) is accommodated inside the battery housing (10), the electrode tab (27) of the first electrode (21) and the first current collector plate (30) may be arranged to face the opening of the side wall member (11).

[0142] In one embodiment, unlike that illustrated in FIG. 7, the electrode assembly (20) may be supported directly by contacting the bottom member (12) without passing through the second collector plate (20). For example, the second electrode of the electrode assembly (20) may protrude axially outward from the axial second end of the electrode assembly and be bent radially to provide a second surface facing axially outward, and the second surface may be electrically connected to the bottom member by being joined thereto.

[0143] In this way, in the present invention, since the electrode assembly (20) and the bottom member (12) are in direct contact or in contact through the second current collector (40), no separate insulating layer exists between the electrode assembly (20) and the bottom member (12). Therefore, heat inside the battery cell can be easily discharged through the bottom member (12), and the battery cell can also be cooled through the bottom member (12).

[0144] In addition, in the present invention, the electrodes of the electrode assembly (20) and the bottom member (12) are in direct contact or are in contact through a current collector. That is, since no separate lead member is included between the electrode assembly (20) and the bottom member (12), the resistance is small and less heat generation can occur.

[0145]

[0146] Referring to Fig. 8, the cap (16) may include a cap body (160) having a hole formed in the center thereof, and an edge portion (166) connected to the radially outer side of the cap body (160). The cap body (160) may be formed to be thicker than the edge portion (166).

[0147] The cap (16) may include at least one vent notch (163). For example, the cap body (160) and the edge portion (166) may be interconnected through the vent notch (163) interposed therebetween in the radial direction. Alternatively, a vent notch (163) may be provided near the edge portion (166) of the cap (16) to reduce the thickness of the cap (16) and thereby weaken its strength. Accordingly, when the pressure inside the battery exceeds a predetermined dangerous pressure level, the vent notch (163) is damaged, causing the cap body (160) to tear from the edge portion (166).

[0148] The first electrode terminal (17) can be inserted into the hole, and specifically, can be fitted or riveted. The first electrode terminal (17) can be fixed by being riveted to the cap body (160) with a terminal gasket (170) interposed therebetween. The terminal gasket (170) is interposed between the first electrode terminal (17) and the cap body (160), sealing the inside and the outside with the cap (16) as the boundary to prevent leakage of the electrolyte, and electrically insulating the first electrode terminal (17) and the cap (16).

[0149] However, the method of connecting the first electrode terminal (17) and the cap (16) is not limited to this. For example, if there is a structure that can seal between the first electrode terminal (17) and the cap (16) and electrically insulate the first electrode terminal (17) and the cap (16), 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.

[0150] A first collector plate (30) may be interposed between the first electrode terminal (17) and the electrode assembly (20). Accordingly, both flat surfaces of the first collector plate (30) may be interposed between the first electrode terminal (17) and the first surface of the first electrode (21), respectively. That is, the first collector plate (30) may be in surface contact with the first electrode terminal (17) and may also be in surface contact with the first surface of the first electrode (21). Alternatively, without using the first collector plate (30), the first surface of the first electrode (21) may be in direct surface contact with the first electrode terminal (17). When the first electrode (21) is directly electrically connected to the first electrode terminal (17), a separate lead member is not used, so the resistance is low and the heat generation may be low. In addition, when the first electrode (21) and the first electrode terminal (17) are directly connected, a separate insulating layer may not be formed between the first electrode (21) and the first electrode terminal (17).

[0151] The first electrode terminal (17) may have a first polarity, and the cap (16) may have a second polarity. The edge portion (166) of the cap (16) is fixed to and electrically connected to the first end portion of the side wall member (11) of the housing (10). Accordingly, the cap (16), the side wall member (11) of the battery housing (10), and the bottom member (12) connected thereto may all have a second polarity. The edge portion (166) may be coupled to the inner surface of the first end portion of the side wall member (11), or may be coupled to the edge end portion of the first end portion of the side wall member (11).

[0152] Accordingly, both the first electrode terminal (17) and the second electrode terminal (14) can be placed at the first end of the battery where the cap (16) is placed. Accordingly, both the bus bar connected to the first electrode terminal (17) of the battery and the bus bar connected to the second electrode terminal (14) can be positioned at the top of the battery.

[0153] The above first electrode terminal (17) may be a positive terminal, and the above second electrode terminal (14) may be a negative terminal. Of course, the opposite may also be true.

[0154] The first electrode terminal (17) of the cap (16) can be fixed and electrically connected to the surface of the first terminal connection portion (32) of the first current collector (30) by a thermal bonding method such as resistance welding, ultrasonic welding, or laser welding. The first electrode terminal (17) and the first terminal connection portion (32) of the cap (16) can be connected after the electrode assembly (20) is placed in the battery housing (10).

[0155] The edge portion (166) of the cap (16) may be welded to the axial end portion of the side wall member (11). Through seam welding in which a laser is irradiated along the circumferential direction to the abutting portion of the side wall member (11) and the cap (16), a weld portion (18) may be formed at the abutting portion of the side wall member (11) and the cap (16). By the weld portion (18), the cap (16) and the side wall member (11) are sealed and electrically connected. At this time, the welding may be ultrasonic welding or laser welding.

[0156] An insulator (19) made of an electrically insulating material may be positioned between the cap (16) and the electrode assembly (20). When the cap (16) is fixed to the side wall member (11), the cap (16) can axially support the insulator (19). Accordingly, due to the elasticity of the insulator (19), the second current collector (40) is elastically pressed in the axial direction between the electrode assembly (20) and the bottom member (12). That is, the upper surface of the insulator (19) can support the cap (16), and the lower surface of the insulator can support the electrode assembly (20).

[0157] In addition, a separate insulating layer may not exist between the electrode assembly (20) and the cap (16). Specifically, a separate insulating layer may not exist between the cap (16), the insulator (19), and the electrode assembly (20). Accordingly, heat within the battery cell can be efficiently discharged to the outside.

[0158] The above-mentioned bottom member (12) may include a through hole (120), and the through hole (120) may be sealed by a sealing member (121). An electrolyte may be injected through the through hole (120).

[0159]

[0160] Referring to FIGS. 9A to 11B, a sealing member (121) according to one embodiment of the present invention will be described. In one embodiment of the present invention, the through hole (120) and the through hole formed in the bottom member (12) can be sealed by the sealing member (121).

[0161] A through hole (120) for electrolyte injection is formed in the above-mentioned bottom member (12). In addition, a sealing member (121) may be configured to cover the through hole. At least a portion of the sealing member (121) may be pressed into the inside of the through hole (120). For example, the press-fitting load of the sealing member (121) may be approximately 150 kgf or less.

[0162] The sealing member (121) is a plug that covers the through hole (120) and may include, for example, one of a ball type, a plug type, a plate type, and a type that applies both a ball and a plate. The sealing member (121) may include at least one of low-carbon steel and copper (Cu).

[0163] The above sealing member (121) can be applied to various types in addition to the above type, and can be riveted, fitted, or screw-connected to the through hole (120) of the bottom member (12).

[0164]

[0165] Figures 9a to 9c are schematic diagrams showing that the sealing member (121) is a plug type.

[0166] When the sealing member (121) is of a plug type, it may include an insertion portion (121b) configured to be inserted into the through hole (120) as shown in FIG. 9a, and a joint portion positioned on the insertion portion (121b). The insertion portion (121b) and the joint portion may have columnar shapes with different diameters. The maximum outer diameter of the insertion portion (121b) of the sealing member (121) may be larger than the minimum inner diameter of the through hole (120). That is, the insertion portion (121b) may be forcibly fitted into the through hole (120). For example, the through hole (120) may form a pipe portion having a constant diameter. It may be characterized in that the width (inner diameter) of the through hole (120) is a first width, and the width (diameter) of at least a portion of the insertion portion (121b) is a second width that is wider than the first width. That is, the width of the insertion portion (121b) of the sealing member (121) may be relatively wider than the width of the through hole (120). In other words, the width of the insertion portion (121b) may have an outer diameter tolerance greater than the width of the through hole (120). By forming the width of the insertion portion (121b) of the sealing member (121) wider than the width of the through hole (120), the insertion portion (121b) can be forcibly inserted into the through hole (120) using physical force, and the electrolyte formed inside can be prevented from flowing out of the through hole (120). In other words, by forcibly pressing the sealing member (121), the electrolyte vapor can be prevented from leaking out, and welding defects and ignition can be prevented during laser welding. The insertion portion (121b) can be forcibly pressed into the through hole (120) to enable physical sealing. The joint portion can be joined to the bottom member (12) by welding, etc.

[0167] Fig. 9b is a schematic diagram illustrating the formation of screws in the sealing member (121) and the through hole (120). Referring to this, a male screw may be formed in the insertion portion (121b) of the sealing member (121), and a female screw corresponding to the male screw may be formed on the inside of the through hole (120). When screws are formed in the sealing member (121) and the through hole (120), the sealing force can be further strengthened.

[0168] Fig. 9c is a schematic diagram illustrating a sealing member (121) in which an insertion portion (121c) is further formed. That is, the sealing member (121) may include an insertion portion (121b) configured to be inserted into a through hole, a joining portion located above the insertion portion (121b), and an insertion portion (121c) located below the insertion portion (121b). The insertion portion (121c) passes through the bottom member (12) and is inserted into the housing (10), so that the sealing member (121) can be riveted to the bottom member (121).

[0169]

[0170] Figures 10a and 10b are schematic diagrams showing that the sealing member (121) is of a ball type.

[0171] When the above sealing member (121) is of a ball type, the ball may have a spherical shape. The maximum outer diameter of the spherical shape may be larger than the minimum inner diameter of the through hole (120). That is, the spherical shape may be forcibly fitted into the through hole (120). After the spherical ball is inserted into the through hole (120), the sealing property may be further enhanced by welding or applying epoxy or the like to the portion where the ball and the through hole (120) come into contact.

[0172] By making the maximum outer diameter of the above spherical shape larger than the minimum inner diameter of the through hole (120), when the spherical shape is forcibly inserted into the through hole (120) by physical force, the injected electrolyte formed inside can be prevented from flowing out of the through hole (120). In other words, by forcibly inserting the sealing member (121), the electrolyte vapor can be prevented from leaking out, and welding defects and ignition can be prevented during laser welding.

[0173] As shown in Fig. 10b, the inner surface of the through hole (120) further includes a groove formed in the radial direction of the bottom member (12), and a ball-type sealing member (121) can be fitted into the groove. The groove can be formed in a shape corresponding to the ball-type sealing member (121). In this case, the sealing member (121) can be strongly fastened to the bottom member (12).

[0174]

[0175] Figure 11a is a diagram illustrating that the sealing member (121) is of a plate type.

[0176] When the sealing member (121) is of a plate type, the sealing member (121) may be in a pillar shape, and the maximum outer diameter may be larger than the minimum inner diameter of the through hole (120). That is, the sealing member (121) may be forcibly fitted into the through hole (120). After the pillar-shaped plate-type sealing member (121) is inserted into the through hole (120), the sealing property may be further strengthened by welding or applying epoxy or the like to the portion where the through hole (120) and the sealing member (121) come into contact.

[0177] Unlike the above drawing 11a, the plate type sealing member (121) may not be inserted into the through hole (120), but may be joined to the outer surface of the bottom member (121) so as to cover the through hole (120).

[0178]

[0179] Fig. 11b is a schematic diagram of a type in which the sealing member (121) is applied with both a plate and a ball. When the sealing member (121) is a type in which both a ball and a plate are applied, the ball is first inserted into the through hole (120), and the through hole (120) can be finally sealed with a plate. As described above, when the ball is inserted into the through hole (120), a plate can be positioned in the opening of the through hole (120), and the portion where the bottom member (12) and the plate come into contact can be welded. The plate and ball are as described above.

[0180]

[0181] A battery pack according to one aspect of the present invention may include a battery cell according to the present invention described above and a pack case housing the same. The battery cell may be accommodated in the pack case such that it contacts the bottom of the pack case and the cap faces upward. In addition, a cooling structure for cooling the battery cell through the bottom member of the battery cell may be provided on the bottom of the pack case.

[0182]

[0183] Fig. 12 is a drawing showing a battery pack having a battery cell according to the present invention built into a pack housing. Referring to Fig. 12, the battery cell (72) can be accommodated in the pack housing (71) of the battery pack. The battery pack can be configured using a battery module, which is an intermediate form of assembly, or, as shown, the battery pack (70) can be configured directly without a battery module.

[0184] Since the battery cell (72) described above has a large volume in itself, there is no particular difficulty in implementing a battery pack (70) even without using an intermediate structure called a battery module. In addition, the battery cell (72) has low internal resistance, low heat generation, and a higher energy density. Accordingly, the energy density of a battery pack (70) equipped with the battery cell (72) can be implemented even higher.

[0185]

[0186] A device according to one aspect of the present invention can be equipped with the battery pack and driven by power from the battery pack. For example, the device can be an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an e-bike, an electric scooter, a drone, a robot, an energy storage system (ESS), a portable electronic device, or an industrial power supply.

[0187] The battery pack of the present invention provides excellent mechanical stability and thermal management performance even in high-power driving and high-speed charge / discharge environments, and thus can be stably applied to various application devices as described above.

[0188]

[0189] Figure 13 is a drawing of a vehicle equipped with the battery pack of Figure 12. A battery pack (70) with increased energy density can store the same amount of energy while reducing its volume and weight. Therefore, if a battery pack (70) equipped with such battery cells (72) is installed in a vehicle such as a vehicle (80) that uses electricity as its energy source, as shown in Figure 13, the vehicle's mileage relative to its energy consumption can be further increased.

[0190] Even if the above battery cell (72) generates heat in the electrode assembly (20), this heat is quickly dissipated downwards through the second electrode (22), the second collector plate (40), and the bottom member (12). Accordingly, if a cooling structure is implemented in the bottom of the battery pack (70), the cooling of the battery cell (72) can be achieved very smoothly.

[0191]

[0192] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0193] <Explanation of symbols>

[0194] 10: Housing

[0195] 11: Side wall member

[0196] 113: Bidding Department

[0197] 115: Crimping section

[0198] 12: Flooring

[0199] 120: Penetration

[0200] 121: Sealing member

[0201] 15: Cap gasket

[0202] 14: Second electrode terminal

[0203] 16: Cap

[0204] 160: Cap body

[0205] 163: Vent notch

[0206] 166: Edge

[0207] 17: First electrode terminal

[0208] 170: Terminal gasket

[0209] 18: Welding

[0210] 19: Insulator

[0211] 20: Electrode assembly

[0212] 21: First electrode

[0213] 22: Second electrode

[0214] 23: Metal foil

[0215] 24: Active material layer

[0216] 25: Maintenance Department

[0217] 26: Ministry of Immigration

[0218] 27: Electrode tab

[0219] 28: Membrane

[0220] 29: Hollow core

[0221] 30: First collector plate

[0222] 31: First electrode connection

[0223] 32: First terminal connection

[0224] 33: Reinforcing rib

[0225] 40: Second collector plate

[0226] 41: Second electrode connection

[0227] 410: Ringbu

[0228] 411: Extension

[0229] 42: Second terminal connection

[0230] 43: Bridge

[0231] 430: Step section

Claims

1. A housing having a side wall member extending in an axial direction, an opening provided at the first axial end of the side wall member, and a bottom member connected to the second axial end of the side wall member; An electrode assembly having a first electrode and a second electrode and accommodated in the housing; A cap having an edge portion electrically connected to the first end of the side wall member and blocking the opening of the housing; A first electrode terminal electrically insulated from the cap and installed through a hole formed in the center of the cap; and A sealing member that seals a through hole formed in the bottom member of the housing; A battery cell, wherein the first electrode is electrically connected to the first electrode terminal, and the second electrode is electrically connected to the housing.

2. In paragraph 1, The first electrode is electrically connected to the first electrode terminal through the first collector plate, The above first collector plate has a first electrode connecting portion connected to the first electrode, and a first terminal connecting portion connected to the first electrode terminal. The first electrode protrudes axially outward from the axial first end of the electrode assembly and is bent radially to provide a first surface facing axially outward, A battery cell in which the first electrode connecting portion of the first collector plate is bonded to the first surface and electrically connected.

3. In paragraph 1, The second electrode is electrically connected to the floor member through the second collector plate, The second collector plate has a second electrode connection portion connected to the second electrode and a second terminal connection portion connected to the bottom member of the can. The second electrode protrudes axially outward from the axial second end of the electrode assembly and is bent radially to provide a second surface whose surface faces axially outward, A battery cell in which the second electrode connecting portion of the second collector plate is bonded to the second surface and electrically connected.

4. In paragraph 1, The second electrode protrudes axially outward from the axial second end of the electrode assembly and is bent radially to provide a second surface whose surface faces axially outward, A battery cell in which the second surface is electrically connected to the bottom member by bonding.

5. In paragraph 1, A battery cell in which the surface of the electrode assembly facing the bottom member is supported by the bottom member.

6. In paragraph 1, A battery cell in which there is no separate insulating layer between the electrode assembly and the bottom member.

7. In paragraph 1, A battery cell in which there is no separate insulating layer between the electrode assembly and the cap.

8. In paragraph 1, An electrically insulating insulator is interposed between the cap and the electrode assembly, The upper surface of the above insulator supports the cap, The lower surface of the above insulator supports the above electrode assembly, a battery cell.

9. In paragraph 1, The second electrode is electrically connected to the housing and the cap, the battery cell.

10. In paragraph 1, A battery cell, wherein at least one of the cap and the bottom member includes at least one vent notch.

11. In paragraph 1, A battery cell, wherein the sealing member comprises any one of a ball type, a plug type, a plate type, and a type in which a ball and a plate are applied together.

12. In paragraph 1, A battery cell, wherein the sealing member is riveted, fitted or screwed into the through hole of the bottom member.

13. In paragraph 1, A battery cell having a structure in which the electrode assembly is wound around a core hollow portion extending in the axial direction, with a separator interposed between the first electrode and the second electrode.

14. In paragraph 1, A battery cell having a structure in which the electrode assembly is wound around a core portion extending in the axial direction, with a separator interposed between the first electrode and the second electrode.

15. A battery cell according to any one of claims 1 to 14; and A battery pack comprising a pack case that accommodates the above battery cells.

16. In paragraph 15, A battery pack, wherein the battery cell is accommodated in the pack case such that the bottom member is in contact with the bottom of the pack case and the cap faces upward.

17. In paragraph 16, A battery pack, wherein a cooling structure for cooling the battery cell through the bottom member of the battery cell is provided on the bottom of the pack case.

18. A device equipped with a battery pack according to any one of claims 15 to 17 and powered by the power of the battery pack.

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