Battery cell and battery device comprising same

Abstract

The invention provides a battery cell which comprises an electrode assembly, a plurality of electrode plates and a plurality of diaphragms which are stacked along a first direction, and the electrode plates comprise a plurality of electrode tabs; the battery core shell is used for accommodating the electrode assembly; the cover plate assembly covers the end part of the opening of the battery cell shell and comprises an electrode terminal; and a current collection member electrically connecting the plurality of electrode tabs and the electrode terminal, the plurality of electrode tabs including bent portions having a bent shape, each bent portion being layered in the first direction, the current collection member being welded to the plurality of bent portions in a state of being disposed in a second direction crossing the first direction.

Description

Technical Field

[0001] The present disclosure relates to a battery cell (secondary battery cell) capable of being charged and discharged, and a battery device including the battery cell. Background Art

[0002] Unlike primary batteries, secondary batteries (battery cells) can be easily charged and discharged, and therefore have attracted much attention as a power source for various mobile devices, electric vehicles, energy storage devices, etc.

[0003] Secondary batteries can be manufactured as pouch-type or can-type cells. Pouch-type cells have an electrode assembly housed within a flexible pouch casing. Can-type cells have an electrode assembly housed within a rigid casing and can be cylindrical or prismatic. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] A battery cell may include an electrode assembly (also known as a jelly jelly jelly jelly jelly) and a cell housing that houses the electrode assembly. The electrode assembly may have a structure with a separator disposed between electrode plates. The electrode plates include portions coated with active material and exposed portions uncoated with active material. The exposed portions may serve as electrode tabs. The electrode tabs on the multiple electrode plates may be welded to current collectors, which may be electrically connected to electrode terminals provided on the cell housing.

[0006] To weld multiple electrode tabs to a current collector, a process can be performed to aggregate the ends of the multiple electrode tabs or portions adjacent to the ends of the multiple electrode tabs into one or more pieces. However, during this process, the electrode assembly may tilt to one side, causing misalignment of the electrode assembly.

[0007] In addition, if the ends of the electrode tabs gathered on one side are bent or folded toward one side, the electrode assembly may be tilted, and the alignment of the electrode assembly may be misaligned.

[0008] In addition, when the end of the electrode tab is bent or folded to one side, if a portion of the electrode tab is exposed too much to the outside in the thickness direction of the electrode assembly, the collector may also protrude to the outside in the thickness direction of the electrode assembly, thereby reducing the energy density of the battery cell.

[0009] Alternatively, multiple electrode tabs and current collector components can be welded using ultrasonic or laser welding. Laser welding involves irradiating the current collector component with the electrode tabs and current collector component positioned. If there is space between the electrode tabs when viewed from the direction of the laser beam, the laser beam could pass through the space between the tabs and enter the interior of the electrode assembly. In this case, the electrode assembly could be damaged or deformed by the laser beam.

[0010] According to one aspect of the present disclosure, a battery cell and a battery device including the battery cell may be provided, which may prevent or limit damage to an electrode assembly during welding of an electrode tab and a current collecting member.

[0011] According to one aspect of the present disclosure, a battery cell and a battery device including the battery cell can be provided, wherein the battery cell can reduce the tilting phenomenon of the electrode assembly. In addition, according to one aspect of the present disclosure, a battery cell and a battery device including the battery cell can be provided, wherein the battery cell can stably maintain the alignment of the electrode assembly.

[0012] According to one aspect of the present disclosure, a battery cell and a battery device including the battery cell may be provided, wherein the battery cell may improve the energy density of the battery cell.

[0013] The disclosed battery cells and battery devices including these cells can be widely used in electric vehicles, battery charging stations, and other green technology fields such as solar power generation and wind power generation using batteries. Furthermore, the disclosed battery cells and battery devices including these cells can be used in eco-friendly electric vehicles and hybrid vehicles, which aim to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0014] (2) Technical solution

[0015] According to the present disclosure, the battery cell may include: an electrode assembly, in which a plurality of electrode plates and a plurality of separators are stacked along a first direction, the electrode plates including a plurality of electrode tabs; a battery cell shell, which accommodates the electrode assembly; a cover plate assembly, which covers the open end of the battery cell shell and includes an electrode terminal; and a current collector, which electrically connects the plurality of electrode tabs and the electrode terminals, the plurality of electrode tabs may include a bent portion having a bent shape, each bent portion may be arranged in layers along the first direction, and the current collector may be welded to the plurality of bent portions in a state of being arranged toward a second direction intersecting the first direction.

[0016] According to one embodiment, the electrode assembly may be formed by arranging a plurality of electrode plates having the bent portions formed thereon along the first direction.

[0017] According to one embodiment, when viewed from the second direction, the bent portions may have an overlapping shape.

[0018] According to one embodiment, the bent portion may have a zigzag bent or folded shape.

[0019] According to one embodiment, the bent portion may have a shape that is bent or folded two or more times.

[0020] According to one embodiment, the bending portion may have a plurality of bent parts, and the sum of the bending angles of the plurality of parts may be greater than 180 degrees.

[0021] According to one embodiment, the bent portion may have a unidirectionally wound shape.

[0022] According to one embodiment, the bent portion may have a shape in which the end portion of the electrode tab is wound more than 270 degrees.

[0023] According to one embodiment, the second direction is a direction perpendicular to the first direction.

[0024] According to one embodiment, the electrode assembly may include a first portion coated with an active material and a second portion provided with the electrode tab. The electrode assembly may be configured such that a thickness of the first portion in the first direction is equal to or less than a maximum thickness of the second portion in the first direction.

[0025] According to one embodiment, a portion of the second portion that protrudes further than the thickness of the first portion in the first direction may be bent toward an inner side of the electrode assembly.

[0026] According to one embodiment, the current collecting member may be welded in a state of being in contact with a bent portion provided on each electrode plate.

[0027] According to one embodiment, the current collecting member and the plurality of bent portions may be joined by laser welding.

[0028] According to one embodiment, the welding line formed on the current collecting component may be parallel to the first direction or inclined at an angle of 30 degrees or less to the first direction.

[0029] According to one embodiment, the width of the welding line in the first direction is less than or equal to the width of the current collecting component in the first direction.

[0030] According to one embodiment, the second direction may be perpendicular to the first direction, the battery cell housing may have a shape open in a third direction perpendicular to the first and second directions, and the electrode tabs may be respectively arranged at both ends of the electrode assembly in the second direction.

[0031] According to one embodiment, the battery cell case may have a shape open in the second direction, and the electrode tabs may include a positive electrode tab and a negative electrode tab disposed at one end portion of the electrode assembly in the second direction.

[0032] According to another aspect of the present disclosure, a battery cell may include: an electrode assembly, in which a plurality of electrode plates and a plurality of separators are stacked along a first direction, the electrode plates including a plurality of electrode tabs; a battery cell shell, which accommodates the electrode assembly; a cover plate assembly, which covers the open end of the battery cell shell and includes an electrode terminal; and a current collector, which electrically connects the plurality of electrode tabs and the electrode terminals, the plurality of electrode tabs may include a bent portion having a bent shape, and the plurality of electrode plates may be arranged in layers along the first direction in a state in which the bent portion is formed.

[0033] According to another aspect of the present disclosure, a battery device may include: a plurality of battery cells; and a casing for accommodating the plurality of battery cells, each battery cell may include: an electrode assembly, wherein a plurality of electrode plates and a plurality of separators are stacked along a first direction, the electrode plates including a plurality of electrode tabs; a battery cell shell for accommodating the electrode assembly; a cover assembly covering an open end of the battery cell shell and including an electrode terminal; and a current collector for electrically connecting the plurality of electrode tabs and the electrode terminals, the plurality of electrode tabs may include a bent portion having a bent shape, each bent portion may be arranged in layers along the first direction, and the current collector may be welded to the plurality of bent portions in a state of being arranged toward a second direction intersecting the first direction.

[0034] (3) Beneficial effects

[0035] According to one embodiment of the present disclosure, it is possible to prevent or limit damage to the electrode assembly during welding of the electrode tab and the current collecting component.

[0036] According to one embodiment of the present disclosure, due to the layered arrangement of the bent portions, the tilting phenomenon of the electrode assembly can be reduced, thereby stably maintaining the alignment of the electrode assembly.

[0037] According to one embodiment of the present disclosure, the extent to which the bent portion protrudes outward in the thickness direction of the electrode assembly can be limited, thereby improving the energy density of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a perspective view of a battery cell according to one embodiment.

[0039] Figure 2 yes Figure 1 An exploded perspective view of the battery cell is shown.

[0040] Figure 3 It shows Figure 1 A three-dimensional diagram showing the state in which the electrode tab and the current collecting component are combined in the battery cell.

[0041] Figure 4 It is a plan view showing the arrangement of electrode tabs and current collecting members.

[0042] Figure 5 is a plan view of an electrode tab according to one embodiment.

[0043] Figures 6a to 6f Schematic diagrams sequentially illustrating a manufacturing process of a battery cell according to an embodiment.

[0044] Figure 7 It is a schematic diagram showing a state where the electrode tab portion protruding outward is subjected to subsequent processing.

[0045] Figure 8 is a plan view showing the arrangement of electrode tabs and current collecting members according to another embodiment.

[0046] Figure 9 (a) to (e) are sequentially shown for Figure 8 Schematic diagram of the process for processing the electrode tab shown.

[0047] Figure 10 is a plan view showing the arrangement of electrode tabs and current collecting members according to still another embodiment.

[0048] Figure 11 (a) to (e) are sequentially shown for Figure 10 Schematic diagram of the process for processing the electrode tab shown.

[0049] Figure 12 is a perspective view of a battery cell according to yet another embodiment.

[0050] Figure 13 is a plan view of a battery device according to one embodiment.

[0051] Description of reference numerals:

[0052] 100: Battery cell 110: Battery cell shell

[0053] 120: Cover assembly 121: Cover

[0054] 122: Electrode terminal 122a: Positive terminal

[0055] 122b: Negative terminal 125: Exhaust port

[0056] 126: injection hole plug 130: electrode assembly

[0057] 131: Electrode plate 131a: Positive electrode plate

[0058] 131b: Negative plate 132: Foil

[0059] 133: electrode tab 133b: negative electrode tab

[0060] 134: Bend portion 135: Flat portion

[0061] 136: Active substances 137: Part I

[0062] 138: Part II 139: Diaphragm

[0063] 140: Current collecting component 150: Insulating component

[0064] 200: Battery device 210: Housing DETAILED DESCRIPTION

[0065] The same reference numerals or symbols in the various figures accompanying this specification represent components or assemblies that perform substantially the same functions. For ease of description and understanding, the same reference numerals or symbols may be used in different embodiments. That is, even if components with the same reference numerals are shown in multiple figures, the multiple figures do not necessarily represent the same embodiment.

[0066] In the following description, unless the context clearly indicates otherwise, singular expressions include plural expressions. Terms such as "including" or "comprising" should be understood as intending to specify the presence of the features, numbers, steps, operations, components, parts, or their combination recorded in the specification, rather than excluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or their combination in advance.

[0067] In addition, it should be noted that in the following description, expressions such as upper side, upper part, lower side, lower part, side, front part, and rear part are based on the directions shown in the figures. If the direction of the corresponding object changes, it can be expressed in different ways.

[0068] Additionally, in this specification and claims, terms including ordinal numbers such as "first" and "second" may be used to distinguish components. These ordinal numbers are used to distinguish identical or similar components and should not be construed as limiting the meaning of the terms. For example, the order in which components are used or arranged in conjunction with these ordinal numbers should not be construed as limiting. These ordinal numbers can be used interchangeably as needed.

[0069] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings, but this is merely an example, and the present disclosure is not limited to the specific embodiments described exemplarily.

[0070] Figure 1 is a perspective view of a battery cell 100 according to an embodiment. Figure 2 yes Figure 1 An exploded perspective view of the battery cell 100 is shown.

[0071] Reference Figure 1 and Figure 2 According to one embodiment, the battery cell 100 may include a battery cell case 110, a cap assembly 120, an electrode assembly 130, and a current collecting component 140. Figure 1 and Figure 2 The illustrated battery cell 100 is a prismatic battery cell having a hexahedral shape, but the shape of the battery cell 100 of the present disclosure is not limited thereto.

[0072] The cell case 110 has a storage space formed therein, and the cell case 110 may be open at one end. One end (e.g., the upper side) of the cell case 110 in the third direction Z may be open. The storage space of the cell case 110 may accommodate the electrode assembly 130. The electrode assembly 130 may be accommodated within the cell case 110 through the open end.

[0073] The cell case 110 may have a flat and prismatic hexahedron shape, but the shape thereof is not limited thereto. The cell case 110 may be formed of aluminum or a material including aluminum, but the material of the cell case 110 is not limited thereto.

[0074] The cap plate assembly 120 may cover the open end of the cell case 110. The cap plate assembly 120 may include a cap plate 121 and an electrode terminal 122. The cap plate 121 may cover the open end of the cell case 110. The cap plate 121 may be combined with the cell case 110 to form a space for accommodating the electrode assembly 130. The cap plate 121 may be formed of aluminum or a material containing aluminum, but the material of the cap plate 121 is not limited thereto.

[0075] The electrode terminal 122 may be provided on the cap plate 121. The electrode terminal 122 may be electrically connected to the electrode plate 131. The electrode terminal 122 may include a positive terminal 122a electrically connected to the positive electrode plate 131a and a negative terminal 122b electrically connected to the negative electrode plate 131b.

[0076] A vent 125 may be provided in at least one of the cell housing 110 and the cover plate assembly 120. For example, the vent 125 may be provided on the cover plate 121. The vent 125 may be secured to the cover plate 121 by laser welding or the like. The vent 125 may be configured to discharge gas, etc., generated within the accommodation space of the cell housing 110. For example, when the internal pressure of the cell housing 110 increases due to gas, etc., the vent 125 may rupture. The location and number of the vent 125 may vary. For example, the vent 125 may be provided on the cell housing 110.

[0077] The cap plate assembly 120 may include an injection hole plug 126 for closing the electrolyte injection port after the electrolyte is injected into the interior space of the battery cell case 110 . The electrolyte injection port and the injection hole plug 126 may be provided on the cap plate 121 .

[0078] Also refer to Figure 1 、 Figure 2 and Figure 4 The electrode assembly 130 may include a plurality of electrode plates 131 and a plurality of separators 139. The electrode plates 131 may include a positive electrode plate 131a and a negative electrode plate 131b. The separator 139 may be formed of an insulator interposed between the positive electrode plate 131a and the negative electrode plate 131b. The electrode assembly 130 may be configured in a stacked manner, with the positive electrode plates 131a and the negative electrode plates 131b alternately stacked with the separator 139 interposed therebetween. As an example, the positive electrode plates 131a, the separator 139, and the negative electrode plates 131b may be stacked along a first direction X. In this specification and claims, the first direction X is defined as the direction in which the positive electrode plates 131a, the separator 139, and the negative electrode plates 131b are stacked.

[0079] In contrast, the electrode assembly 130 may be configured as a jelly roll in which the negative electrode plate 131 b , the separator 139 , and the positive electrode plate 131 a are stacked and wound together. However, the method of configuring the electrode assembly 130 is not limited thereto and may be variously modified.

[0080] The electrode plate 131 may include an electrode tab 133. The electrode tab 133 may have a shape extending from the electrode plate 131. The electrode tab 133 may include a positive tab 133a provided on the positive plate 131a and a negative tab 133b provided on the negative plate 131b. The electrode tabs 133 may be respectively arranged at both ends of the second direction Y of the electrode assembly 130. As an example, the positive tab 133a may be arranged on one side of the second direction Y of the electrode assembly 130, and the negative tab 133b may be arranged on the other side of the second direction Y of the electrode assembly 130. However, the setting position of the electrode tab 133 is not limited thereto. For example, Figure 12 As shown, the electrode tab 133 can be disposed at one end of the electrode assembly 130 .

[0081] The current collecting component 140 can electrically connect the plurality of electrode tabs 133 to the electrode terminal 122. The current collecting component 140 can include a positive current collecting component 140a electrically connected to the positive electrode tab 133a and a negative current collecting component 140b electrically connected to the negative electrode tab 133b. The positive current collecting component 140a can electrically connect the positive electrode tab 133a to the positive electrode terminal 122a, and the negative current collecting component 140b can electrically connect the negative electrode tab 133b to the negative electrode terminal 122b. The current collecting component 140 can be respectively connected to the electrode terminal 122 and the electrode tab 133 using known connecting methods such as welding. The current collecting component 140 and the electrode terminal 122 can be connected using laser welding, ultrasonic welding, screws, bolts, rivets, assembly, etc., but the connecting methods are not limited to these.

[0082] When the cell case 110 has a shape that is open in a third direction Z perpendicular to the first direction X and the second direction Y, and the electrode tabs 133 are respectively provided at both ends of the electrode assembly 130 in the second direction Y, the current collecting component 140 can be electrically connected to the electrode tabs 133 that are opposite to each other in the second direction Y, and to the electrode terminals 122 that are opposite to each other in the third direction Z. In this case, the current collecting component 140 can have a shape that is bent in an "L" shape.

[0083] The battery cell 100 may include an insulating member 150 to electrically insulate the battery cell 100 from external components. The insulating member 150 may be disposed between the current collecting member 140 and the inner side surface of the battery cell case 110 to electrically insulate the current collecting member 140 from the battery cell case 110 .

[0084] Figure 3 It shows Figure 1 and Figure 2 FIG. 1 is a perspective view of a battery cell 100 in which the electrode tab 133 and the current collecting component 140 are combined.

[0085] The current collecting component 140 can be coupled to the electrode assembly 130 by welding. The current collecting component 140 can be welded to the electrode tab 133 while being positioned toward the electrode tab 133. The current collecting component 140 can be welded to the plurality of electrode tabs 133 while being positioned toward the second direction Y. The first direction X can be defined as the direction in which the electrode plates 131 are layered, and the second direction Y can be defined as a direction intersecting the first direction X. The second direction Y can be defined as the direction in which the current collecting component 140 faces the electrode tab 133. As an example, the second direction Y can be a direction perpendicular to the first direction X.

[0086] The electrode tabs 133 may be disposed at both ends of the electrode assembly 130 in the second direction Y. The current collector 140 may be welded to the electrode tab 133 while being disposed in the second direction Y so as to face the electrode tab 133. The current collector 140 and the electrode tab 133 may be joined by laser welding, but is not limited thereto. For example, the current collector 140 and the electrode tab 133 may be joined by other welding methods such as ultrasonic welding.

[0087] The weld line W formed on the current collecting component 140 can be parallel to the first direction X or inclined at a predetermined angle or less to the first direction X. For example, the weld line W can be parallel to the first direction X or inclined at a predetermined angle or less to the first direction X. The width of the weld line W in the first direction X can be less than or equal to the width of the current collecting component 140 in the first direction X. The width of the current collecting component 140 in the first direction X can correspond to the width of the electrode tab 133 in the first direction X.

[0088] Figure 4 1 is a plan view showing the arrangement of the electrode tabs 133 and the current collecting member 140 .

[0089] The electrode assembly 130 may have a shape in which a plurality of electrode plates 131 and a plurality of separators 139 are stacked in the first direction X. That is, the electrode assembly 130 may be alternately stacked by positive electrode plates 131 a and negative electrode plates 131 b with separators 139 interposed therebetween.

[0090] The electrode plate 131 may have a structure in which an active material 136 is coated on a foil 132. The positive electrode plate 131a may have a positive electrode active material coated on the foil 132, while the negative electrode plate 131b may have a negative electrode active material coated on the foil 132. For example, the negative electrode plate 131b may be formed by coating graphite or the like on a copper or nickel foil, while the positive electrode plate 131a may be formed by coating a transition metal oxide active material on an aluminum foil.

[0091] The electrode plate 131 may include an electrode tab 133. The electrode tab 133 may include an exposed portion that is not coated with an active material 136. The positive electrode plate 131a may be equipped with a positive electrode tab ( Figure 2133a), the negative plate 131b can be equipped with a negative electrode tab ( Figure 2 Although the following description takes the case where the electrode tab 133 is the negative electrode tab 133b as an example, the following description can also be applied to the positive electrode tab 133a.

[0092] The plurality of electrode tabs 133 may include a flat portion 135 extending from the electrode plate 131 and a bent portion 134 connected to the flat portion 135 and having a bent shape. In the electrode assembly 130 , each bent portion 134 may be arranged in layers along the first direction X.

[0093] The electrode assembly 130 may be formed by arranging a plurality of electrode plates 131 having bent portions 134 in a first direction X. For example, the electrode assembly 130 may have a structure in which the electrode plates 131 having bent portions 134 and the separator 139 are stacked in the first direction X.

[0094] The plurality of electrode plates 131 may be arranged in layers along the first direction X with the bent portions 134 formed thereon.

[0095] The bending portion 134 may be bent or folded in a zigzag shape. The bending portion 134 may be bent or folded twice or more. In another embodiment, the bending portion 134 may be unidirectionally wound.

[0096] The current collecting member 140 may be welded to the plurality of bent portions 134 while being disposed in a second direction Y intersecting the first direction X. The current collecting member 140 may be welded while being in contact with the bent portions 134 of the plurality of electrode plates 131 .

[0097] When viewed from the second direction Y, the bent portion 134 may have an overlapping shape. When viewed from the second direction Y, the area of the bent portion 134 having the overlapping shape may be greater than 90% of the thickness of the electrode assembly 130 in the first direction X. For example, the area of the bent portion 134 having the overlapping shape may be greater than 92%, greater than 95%, greater than 97%, greater than 99%, or even greater than 100% of the thickness of the electrode assembly 130 in the first direction X. In other words, the range of the overlapping shape of the bent portion 134 may include a situation where it is slightly smaller than the thickness of the electrode assembly 130 in the first direction X.

[0098] Electrode assembly 130 may include a first portion 137 coated with active material 136 and a second portion 138 provided with electrode tab 133. Electrode assembly 130 may be configured such that a thickness T1 of first portion 137 in a first direction X is equal to or less than a maximum thickness T2 of second portion 138 in the first direction X. For example, because electrode tab 133 is provided with a bend 134, a portion of the outer bend 134 may protrude further outward than the thickness of electrode assembly 130. In other words, a portion of second portion 138 provided with electrode tab 133 may have a shape that protrudes further than the thickness of first portion 137 in the first direction X.

[0099] The current collector 140 can be welded while facing and contacting the bent portion 134 of the electrode tab 133. The current collector 140 and the electrode tab 133 can be joined by laser welding. Laser welding is a non-contact welding method using a laser beam, which has the advantage of not generating burrs or slag. Laser welding utilizes a high-density heat source, allowing heat to be transferred to a localized weld area.

[0100] The current collecting component 140 and the electrode tab 133 may be welded by irradiating a laser beam to the current collecting component 140 while the current collecting component 140 and the electrode tab 133 are arranged opposite to each other in the second direction Y.

[0101] When viewed from the second direction Y, the bent portions 134 of the electrode tabs 133 have overlapping shapes. Therefore, in the laser beam irradiation direction LD, the bent portions 134 may also have overlapping shapes. The overlapping bent portions 134 can block or limit the laser beam from penetrating into the first portion 137 of the electrode assembly 130. Therefore, according to embodiments, damage to the electrode assembly 130 during welding of the electrode tabs 133 and the current collecting component 140 can be prevented or limited.

[0102] Furthermore, to limit the laser beam from penetrating the first portion 137 of the electrode assembly 130, the weld line W formed on the current collecting member 140 may be parallel to the first direction X or inclined at an angle of 30 degrees or less to the first direction X. Since the end of the bent portion 134 has a shape extending along the third direction Z, forming the weld line W in the first direction X or a similar direction perpendicular to the third direction Z can limit the laser beam from moving inwardly toward the electrode assembly 130. However, the direction of the weld line W is not limited to the first direction X or a similar direction.

[0103] In addition, according to the embodiment, the bending portions 134 are arranged in layers, so that the tilting phenomenon of the electrode assembly 130 can be reduced, and thus the alignment state of the electrode assembly 130 can be stably maintained.

[0104] Figure 5is a plan view of an electrode tab 133 according to one embodiment.

[0105] The electrode plate 131 may include a portion on which an active material 136 is coated on a foil 132 and an electrode tab 133. The electrode tab 133 may include a portion on which the active material 136 is not coated. The electrode tab 133 may include a flat portion 135 extending from the electrode plate 131 and a bent portion 134 having a bent shape. The bent portion 134 may have a shape that is bent or folded in a zigzag shape. The bent portion 134 may have a shape that is bent or folded twice or more. For example, Figure 5 As shown, the bent portion 134 may have a shape that is folded three times, but the number of bends or folds may vary.

[0106] The bent portion 134 may include a plurality of bent portions. Figure 5 The bent portion 134 may include a first portion 134a bent from the flat portion 135 at a first angle θ1, a second portion 134b bent from the first portion 134a at a second angle θ2, and a third portion 134c bent from the second portion 134b at a third angle θ3. The bending angles are relative to the second direction Y and are defined when no external force is applied. The sum of the bending angles of the multiple portions may be greater than 180 degrees.

[0107] The lengths of the first portion 134a, the second portion 134b, and the third portion 134c may have different values. For example, the lengths of the first portion 134a, the second portion 134b, and the third portion 134c may be configured to gradually increase. In this case, not only can the plurality of bends 134 be easily arranged along the first direction X, but the laser beam can also be smoothly blocked from moving inwardly toward the electrode assembly 130.

[0108] Figures 6a to 6f 1 is a schematic diagram sequentially illustrating a manufacturing process of a battery cell 100 according to an embodiment.

[0109] first, Figures 6a to 6c The steps of preparing the electrode plate 131 are shown. Figure 6a shows an electrode plate 131 coated with an active material 136, Figure 6a The upper figure is a plan view, and the lower figure is a side view. The electrode tab 133 is in the shape before the bent portion 134 is formed.

[0110] Figure 6b The figure shows the process of forming a bend 134 on the electrode tab 133. While one side of the electrode plate 131 is held down by the clamp 11, the forming machine 12 applies pressure to the electrode tab 133. The forming machine 12 has a shape corresponding to the bend 134, so the forming machine 12 can form the bend 134 on the electrode tab 133.

[0111] Figure 6c The electrode plate 131 is shown with a bent portion 134 formed thereon. Figure 6c The top figure is a plan view, and the bottom figure is a side view. Electrode tab 133 includes a flat portion 135 and a bent portion 134. Bend portion 134 can be bent into multiple sections 134a, 134b, and 134c. In the plan view, L1, L2, and L3 represent bending lines.

[0112] Next, if Figure 6d As shown, a plurality of electrode plates 131 having bent portions 134 may be arranged along a first direction X to form an electrode assembly 130. The electrode assembly 130 may have a structure in which positive electrode plates 131a and negative electrode plates 131b are stacked along the first direction X with a separator 139 interposed therebetween.

[0113] Figure 6e The electrode assembly 130 is shown in a stacked state. The electrode assembly 130 may have a bent portion 134 with electrode tabs 133 provided on both sides.

[0114] like Figure 6f As shown, the laser beam can be irradiated onto the current collecting component 140 while it is in contact with the bent portion 134 of the electrode tab 133. To bring the current collecting component 140 into contact with the bent portion 134, the current collecting component 140 can be pressed against the bent portion 134. In the laser beam irradiation direction LD, or in a second direction Y relative to the current collecting component 140 and the electrode tab 133, the bent portion 134 of the electrode tab 133 can have an overlapping shape. The overlapping bent portion 134 can prevent the laser beam from affecting the inner side of the electrode assembly 130.

[0115] Figure 7 This is a schematic diagram showing a state where the electrode tab 133 portion protruding outward is subjected to subsequent processing.

[0116] Refer to it together Figure 7 and Figure 4 When the electrode tab 133 is provided with a bent portion 134, a portion of the outer bent portion 134 may form a protrusion 134p that protrudes outward further than the thickness T1 of the electrode assembly 130 in the first direction X. In other words, a portion of the second portion 138 where the electrode tab 133 is provided may have a shape that protrudes further than the thickness of the first portion 137 coated with the active material 136 in the first direction X.

[0117] If the protrusion 134p protrudes slightly (e.g., less than 0.5 mm), the electrode assembly 130 can maintain the bent portion 134 protruding. On the other hand, if the protrusion 134p protrudes significantly (e.g., greater than 0.5 mm), the protrusion 134p can be subjected to subsequent processing. The protrusion 134p can be bent inward of the electrode assembly 130 by subsequent processing using a roller 21 or the like. As an example, the subsequent processing may include moving the roller 21 toward the protrusion 134p (e.g., outward) while pressing the protrusion 134p. This subsequent processing can reduce the protrusion 134p's protrusion.

[0118] Figure 8 is a plan view showing the arrangement of electrode tabs 133 and current collecting members 140 according to another embodiment.

[0119] Figure 8 Another embodiment of a bend 134 formed on an electrode tab 133 is shown. The bend 134 of the electrode tab 133 may have a unidirectionally wound shape. The shape of the bend 134 may include a quadrilateral. The bend 134 may have a shape in which the end of the electrode tab 133 is wound more than 270 degrees. For example, the bend 134 may have a shape in which the end of the electrode tab 133 is wound more than 360 degrees. The electrode assembly 130 may be formed by stacking electrode tabs 133 having bends 134 in a unidirectionally wound shape.

[0120] Even if the bent portion 134 of the electrode tab 133 has a coiled shape, the bent portion 134 may have an overlapping shape when viewed from the second direction Y. Furthermore, in the laser beam irradiation direction LD, the coiled bent portion 134 may have an overlapping shape. Therefore, the overlapping bent portion 134 may block or limit the laser beam from penetrating into the inner portion of the electrode assembly 130.

[0121] Figure 9 (a) to (e) are sequentially shown for Figure 8 FIG. 1 is a schematic diagram of a process for processing the electrode tab 133 shown.

[0122] Figure 9 (a) shows an electrode plate 131 coated with an active material 136 , Figure 9 (a) shows the shape of the electrode tab 133 before the bent portion 134 is formed.

[0123] like Figure 9 As shown in (b) to (d), the end portion of the electrode tab 133 can be processed into a first shape S1, a second shape S2 and a third shape S3 in sequence by a mold.

[0124] Finally, the bent portion 134 of the electrode tab 133 may have Figure 9 The shape shown in (e). If Figure 9 The electrode plates 131 shown in (e) are stacked to form Figure 8 The electrode assembly 130 is shown.

[0125] Figure 10 is a plan view showing the arrangement of electrode tabs 133 and current collecting members 140 according to yet another embodiment.

[0126] Figure 10 Another embodiment of forming a bend 134 on the electrode tab 133 is shown. The bend 134 of the electrode tab 133 can have a unidirectionally wound shape. The shape of the bend 134 can include a circle. The bend 134 can have a shape in which the end of the electrode tab 133 is wound more than 270 degrees. For example, the bend 134 can have a shape in which the end of the electrode tab 133 is wound more than 360 degrees. The electrode assembly 130 can be formed by stacking the electrode tabs 133 having the bend 134 in the unidirectionally wound shape.

[0127] Even if the bent portion 134 of the electrode tab 133 has a coiled shape, the bent portion 134 may have an overlapping shape when viewed from the second direction Y. Furthermore, in the laser beam irradiation direction LD, the coiled bent portion 134 may have an overlapping shape. Therefore, the overlapping bent portion 134 may block or limit the laser beam from penetrating into the inner portion of the electrode assembly 130.

[0128] Figure 11 (a) to (e) are sequentially shown for Figure 10 FIG. 1 is a schematic diagram of a process for processing the electrode tab 133 shown.

[0129] Figure 11 (a) shows an electrode plate 131 coated with an active material 136 , Figure 11 (a) shows the shape of the electrode tab 133 before the bent portion 134 is formed.

[0130] like Figure 11 As shown in (b), in order to form the bent portion 134 wound in a circular shape, a rotary forming mechanism 31 such as a mandrel can be installed at the end portion of the electrode tab 133. Figure 11 (c) shows a rotary molding mechanism 31, which can mold Figure 11 If the rotary molding mechanism 31 is further rotated, the bent portion 134 of the electrode tab 133 may have a first shape S1 as shown in (d). Figure 11 The shape shown in (e). If stacked Figure 11 The electrode plate 131 shown in (e) can be formed Figure 10 The electrode assembly 130 is shown.

[0131] Figure 12 is a perspective view of a battery cell 100 according to another embodiment.

[0132] Figure 12 The illustrated battery cell 100 a may include a battery cell case 110 , a cap plate assembly 120 , an electrode assembly 130 , and a current collecting component 140 .

[0133] Figure 12 The battery cell 100a shown is Figures 1 to 3 The battery cell 100 shown is different in that the electrode tab 133 is disposed on the upper surface of the electrode assembly 130 , and the current collecting component 140 is coupled to the electrode tab 133 on the upper surface of the electrode assembly 130 .

[0134] and Figure 3 The same as the embodiment, in Figure 12 In the embodiment, the first direction X can be defined as the direction in which the electrode plates 131 are layered, and the second direction Z can be defined as the direction in which the current collecting component 140 faces the electrode tab 133 .

[0135] The electrode plates 131 of the electrode assembly 130 are arranged along the first direction X, and the electrode tabs 133 may include a positive electrode tab 133a and a negative electrode tab 133b disposed at one end of the electrode assembly 130 in the second direction Z. Figure 12 In the illustrated embodiment, the cell case 110 may have a shape with one side (upper side) in the second direction Z being open.

[0136] The current collecting member 140 can electrically connect the plurality of electrode tabs 133 and the electrode terminal 122. The current collecting member 140 can include a positive current collecting member 140a electrically connected to the positive electrode tab 133a and a negative current collecting member 140b electrically connected to the negative electrode tab 133b.

[0137] When the cell case 110 has a shape with one side open in the second direction Z and the electrode tab 133 is disposed at one end of the electrode assembly 130 in the second direction Z, the current collecting component 140 may be disposed between the electrode terminal 122 and the electrode tab 133 in the second direction Z.

[0138] Figure 13 is a plan view of a battery device according to one embodiment.

[0139] According to one embodiment, the battery device 200 may include a plurality of battery cells 100 and a housing 210. The housing may include an inner space for accommodating the plurality of battery cells 100. The battery cells 100 may include a Figures 1 to 12 The battery cells 100 and 100a are shown.

[0140] The battery device 200 may include a battery module or a battery pack including a plurality of battery cells 100 .

[0141] The present disclosure is described using a prismatic battery cell as an example, but the battery cell of the present disclosure can also be applied to a pouch-type battery cell, a cylindrical battery cell, a coin-shaped battery cell, and the like.

[0142] The above content is only an example of applying the principles of the present disclosure, and other configurations may also be included without departing from the scope of the present invention. In addition, some components in the above embodiments may be deleted or various embodiments may be combined to implement the present invention.

Claims

1. A battery cell comprising: An electrode assembly, comprising a plurality of electrode plates and a plurality of separators stacked along a first direction, wherein the electrode plates include a plurality of electrode tabs; A battery cell shell, accommodating the electrode assembly; a cap assembly covering an end portion of the opening of the cell case and including an electrode terminal; and a current collecting component electrically connecting the plurality of electrode tabs and the electrode terminals, The plurality of electrode tabs include a bent portion having a bent shape, Each bending portion is arranged in layers along the first direction, The current collecting member is welded to the plurality of bent portions while being disposed in a second direction intersecting the first direction.

2. The battery cell according to claim 1, wherein: The electrode assembly is formed by arranging a plurality of electrode plates having the bent portions formed therein along the first direction.

3. The battery cell according to claim 1, wherein: When viewed from the second direction, the bent portions have an overlapping shape.

4. The battery cell according to any one of claims 1 to 3, wherein The bending portion has a zigzag bent or folded shape.

5. The battery cell according to claim 4, wherein: The bending portion has a shape that is bent or folded twice or more.

6. The battery cell according to claim 4, wherein: The bending portion has a plurality of bent parts, The sum of the bending angles of the multiple parts is greater than 180 degrees.

7. The battery cell according to any one of claims 1 to 3, wherein: The bent portion has a unidirectionally wound shape.

8. The battery cell according to claim 7, wherein: The bent portion has a shape in which the end portion of the electrode tab is wound at more than 270 degrees.

9. The battery cell according to any one of claims 1 to 3, wherein: The electrode assembly includes a first portion coated with an active material and a second portion provided with the electrode tab. The electrode assembly is configured such that a thickness of the first portion in the first direction is equal to or smaller than a maximum thickness of the second portion in the first direction.

10. The battery cell according to any one of claims 1 to 3, wherein: The electrode assembly includes a first portion coated with an active material and a second portion provided with the electrode tab. A portion of the second portion that protrudes further than the thickness of the first portion in the first direction is bent toward an inner side of the electrode assembly.

11. The battery cell according to any one of claims 1 to 3, wherein: The current collecting member and the plurality of bent portions are joined by laser welding, and a welding line formed on the current collecting member is parallel to the first direction or inclined at an angle of 30 degrees or less to the first direction.

12. The battery cell according to any one of claims 1 to 3, wherein: The second direction is perpendicular to the first direction, The cell case has a shape that is open in a third direction perpendicular to the first direction and the second direction. The electrode tabs are respectively arranged at both ends of the electrode assembly in the second direction.

13. The battery cell according to any one of claims 1 to 3, wherein: The second direction is perpendicular to the first direction, The cell case has a shape that is open in the second direction, The electrode tabs include a positive electrode tab and a negative electrode tab disposed at one end portion of the electrode assembly in the second direction.

14. A battery cell comprising: An electrode assembly, comprising a plurality of electrode plates and a plurality of separators stacked along a first direction, wherein the electrode plates include a plurality of electrode tabs; A battery cell shell, accommodating the electrode assembly; a cap assembly covering an end portion of the opening of the cell case and including an electrode terminal; and a current collecting component electrically connecting the plurality of electrode tabs and the electrode terminals, The plurality of electrode tabs include a bent portion having a bent shape, The plurality of electrode plates are arranged in layers along a first direction with the bent portions formed thereon.

15. A battery device comprising: Multiple battery cells; as well as a housing for accommodating the plurality of battery cells, Each battery cell includes: An electrode assembly, comprising a plurality of electrode plates and a plurality of separators stacked along a first direction, wherein the electrode plates include a plurality of electrode tabs; A battery cell shell, accommodating the electrode assembly; a cap assembly covering an end portion of the opening of the cell case and including an electrode terminal; and a current collecting component electrically connecting the plurality of electrode tabs and the electrode terminals, The plurality of electrode tabs include a bent portion having a bent shape, Each bending portion is arranged in layers along the first direction, The current collecting member is welded to the plurality of bent portions while being disposed in a second direction intersecting the first direction.

Images