Cylindrical battery cell, battery pack including same, and automobile

Abstract

A cylindrical battery cell according to one embodiment of the present invention includes: an electrode assembly having a first electrode tab and a second electrode tab; a battery can that houses the electrode assembly and is electrically connected to the second electrode tab; a top cap that covers an upper opening of the battery can, is electrically connected to the first electrode tab, and is electrically insulated from the battery can; and a terminal extension member that is coupled to the upper end of the battery can and is electrically insulated from the top cap.

Description

[Technical field]

[0001] The present invention relates to a cylindrical battery cell having a structure in which a positive terminal and a negative terminal are formed in the same direction, a battery pack including the same, and an automobile. More specifically, the present invention relates to a cylindrical battery cell having a structure in which a positive terminal and a negative terminal are both disposed adjacent to one side of the cylindrical battery cell without significantly modifying the structure of a conventional cylindrical battery cell, and a battery pack and an automobile including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2020-0186476 filed on December 29, 2020, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0003] When manufacturing a battery pack using cylindrical battery cells, a plurality of cylindrical battery cells are typically arranged upright in a housing, and the upper and lower ends of the cylindrical battery cells are used as positive and negative terminals, respectively, to electrically connect the plurality of cylindrical battery cells to each other.

[0004] This is because, in a cylindrical battery cell, the negative electrode uncoated portion of the electrode assembly housed inside the battery can extends downward to be electrically connected to the bottom surface of the battery can, and the positive electrode uncoated portion extends upward to be electrically connected to the top cap. That is, in a cylindrical battery cell, the bottom surface of the battery can is generally used as the negative electrode terminal, and the top cap covering the upper opening of the battery can is generally used as the positive electrode terminal.

[0005] However, when the positive and negative terminals of the cylindrical battery cells are located on opposite sides of each other in this manner, electrical connection components such as bus bars for electrically connecting the multiple cylindrical battery cells must be applied to both the upper and lower parts of the cylindrical battery cells, making the electrical connection structure of the battery pack complicated.

[0006] Furthermore, in such a structure, components for insulation and components for ensuring waterproofing must be applied to the upper and lower parts of the battery pack, respectively, resulting in an increase in the number of components to be applied and a complicated structure.

[0007] Therefore, there is a need to develop a cylindrical battery cell having a structure in which the positive and negative terminals are applied in the same direction so as to simplify the electrical connection structure of a plurality of cylindrical battery cells. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a cylindrical battery cell structure in which a positive terminal and a negative terminal are applied in the same direction.

[0009] Another object of the present invention is to provide a cylindrical battery cell in which negative terminals applied in the same direction have a sufficient area to be welded to electrical connection parts such as bus bars for manufacturing a battery pack.

[0010] It is yet another object of the present invention to provide a cylindrical battery cell in which the volume occupied by the electrode assembly inside the battery can is minimized.

[0011] The technical problem that the present invention is to solve is not limited to the above-mentioned problem, and other problems will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0012] In order to achieve the above object, a cylindrical battery cell according to one embodiment of the present invention includes an electrode assembly having a first electrode tab and a second electrode tab, a battery can that accommodates the electrode assembly and is electrically connected to the second electrode tab, a top cap that covers an upper opening of the battery can, is electrically connected to the first electrode tab, and is electrically insulated from the battery can, and a terminal extension member that is coupled to an upper end of the battery can and is electrically insulated from the top cap.

[0013] The terminal extension member may extend inward from an upper end of the battery can along a radial direction of the cylindrical battery cell.

[0014] The terminal extension member may have a width greater than that of a flat portion formed on an upper end of the battery can.

[0015] The battery can may include a crimping portion extending inwardly from an upper periphery of the battery can along a radial direction of the cylindrical battery cell.

[0016] The terminal extension member may be coupled to an upper surface of the crimping portion.

[0017] The crimping portion may have a flat portion on an upper surface thereof, and the terminal portion extension member may be coupled onto the flat portion of the crimping portion.

[0018] The terminal extension member may have a width greater than a width of the flat portion of the crimping portion.

[0019] The terminal portion expanding member may be in the form of a washer having a hole formed in the center.

[0020] The top cap may include a protrusion protruding upward from a center portion thereof, and the protrusion may be provided at a position corresponding to a hole formed in the center portion of the terminal portion extension member.

[0021] The projection may project upwardly above an upper surface of the terminal extension member.

[0022] The cylindrical battery cell may further include a terminal insulating member interposed between the top cap and the terminal extension member to electrically insulate the top cap and the terminal extension member.

[0023] The terminal insulating member may be in the form of a washer having a hole formed in the center.

[0024] The top cap may have a protrusion protruding upward from the center, and the terminal portion insulating member may include a first portion interposed between the lower surface of the terminal portion extension member and the upper surface of other areas of the top cap excluding the protrusion, and a second portion protruding upward from the first portion and interposed between the inner surface of a hole formed in the center of the terminal portion extension member and the protrusion.

[0025] The battery can may include a crimping portion extending inward from an upper edge of the battery can along a radial direction of the cylindrical battery cell, and an upper surface of the first portion may be located at the same height as an upper surface of the crimping portion.

[0026] The second portion may have an inner diameter corresponding to an outer diameter of the protrusion.

[0027] The protrusion may have an outer diameter that gradually decreases upward, and the inner diameter of the second portion may correspond to the outer diameter of a lower end of the protrusion.

[0028] The terminal extension member may have an inner diameter corresponding to an outer diameter of the second portion.

[0029] The terminal portion insulating member may include a first portion interposed between the lower surface of the terminal portion extension member and the upper surface of other areas of the top cap excluding the protrusion, and a second portion protruding upward from the first portion and interposed between the inner surface of a hole formed in the center of the terminal portion extension member and the protrusion.

[0030] The terminal extension member may have an inner diameter corresponding to an outer diameter of the second portion.

[0031] The thickness of the crimped portion in the area where the flat portion is provided may be greater than in other areas of the crimped portion.

[0032] The second portion may have an extended shape so as to cover a portion of an upper surface of the top cap.

[0033] The terminal extension member and the terminal insulation member may be a combined body formed by insert injection.

[0034] An upper surface of the crimping portion may be provided with an insertion protrusion or an insertion groove, and a lower surface of the crimping portion may be provided with an insertion groove that is coupled with the insertion protrusion formed on the crimping portion or an insertion protrusion that is coupled with the insertion groove formed on the crimping portion.

[0035] The terminal insulating member includes a resin material and can be joined to the terminal extension member and the top cap by thermal fusion.

[0036] The electrode assembly may have a jelly roll structure in which a laminate having a first electrode, a second electrode and a separator interposed therebetween is wound in one direction.

[0037] The first electrode tab may be a first uncoated portion at an upper end of the first electrode where an electrode active material is not coated, and the second electrode tab may be a second uncoated portion at a lower end of the second electrode where an electrode active material is not coated.

[0038] At least a portion of the first electrode tab may include a plurality of first segments divided along a winding direction of the electrode assembly.

[0039] The plurality of first segments may be bent along a radial direction of the electrode assembly.

[0040] The cylindrical battery cell may further include a first current collecting plate coupled to an upper portion of the electrode assembly and electrically connected to the top cap, and the first current collecting plate may be coupled onto a coupling surface formed by bending the plurality of first segment pieces.

[0041] The plurality of first segments are overlapped in multiple layers, the first electrode tab includes a welding target area in which the number of overlapping layers of the plurality of first segments is maintained constant along a radial direction of the electrode assembly, and the first current collecting plate may be coupled to the first electrode tab within the welding target area.

[0042] At least a portion of the second electrode tab may include a plurality of second divided pieces divided along the winding direction of the electrode assembly.

[0043] The plurality of second segments may be bent along a radial direction of the electrode assembly.

[0044] The cylindrical battery cell may further include a second current collecting plate coupled to a lower portion of the electrode assembly and electrically connected to the battery can, and the second current collecting plate may be coupled onto a coupling surface formed by bending the plurality of second pieces.

[0045] The plurality of second segments are overlapped in a multiplicity, and the second electrode tab includes a welding target area in which the number of overlapping layers of the plurality of second segments is maintained constant along a radial direction of the electrode assembly, and the second current collecting plate may be coupled to the second electrode tab within the welding target area.

[0046] The cylindrical battery cell may further include a first current collecting plate coupled to an upper portion of the electrode assembly and electrically connected to the top cap.

[0047] The first current collecting plate may include a plurality of tab connectors extending radially from the central portion.

[0048] The first current collecting plate may further include a lead disposed between adjacent tab coupling portions and electrically connecting the first current collecting plate and the top cap.

[0049] The battery can may include a beading portion having a shape pressed along an outer periphery thereof, and the first current collecting plate may be located between the electrode assembly and the beading portion.

[0050] The maximum outer diameter of the first current collecting plate may be equal to or smaller than the inner diameter of the battery can at the height where the beading portion is formed.

[0051] The first current collecting plate may include a first current collecting plate hole formed at a position corresponding to a hole formed in a winding center portion of the electrode assembly.

[0052] The diameter of the hole in the first current collector plate may be the same as or larger than the diameter of the hole formed in the winding center of the electrode assembly.

[0053] The battery can may include a closing portion formed at a lower end opposite the opening, and the closing portion may include a venting portion that breaks when the internal pressure of the battery can increases above a reference value.

[0054] The venting portion may be configured to have a thinner thickness than a surrounding area of ​​the closure portion.

[0055] The venting portion may be formed by notching one or both sides of the closing portion.

[0056] The cylindrical battery cell may further include an insulator disposed between the beading portion and the first current collecting plate.

[0057] The insulator may be interposed between a first electrode tab of the electrode assembly and an inner circumferential surface of the battery can.

[0058] In order to achieve the above object, a battery pack according to another aspect of the present invention includes a plurality of the cylindrical battery cells of the present invention described above.

[0059] The cylindrical battery cells may be arranged in a predetermined number of rows, and the top cap and the terminal extension member provided on each of the cylindrical battery cells may be disposed toward an upward direction.

[0060] The battery pack may include a plurality of bus bars connecting the cylindrical battery cells in series and in parallel, the plurality of bus bars being disposed on upper portions of the plurality of cylindrical battery cells, and each of the plurality of bus bars may include a body portion extending between cell terminals of adjacent cylindrical battery cells, a plurality of first bus bar terminals extending to one side of the body portion and electrically coupled to the top caps of the cylindrical battery cells located on the one side, and a plurality of second bus bar terminals extending to the other side of the body portion and electrically coupled to the terminal portion extension members of battery cans of the cylindrical battery cells located on the other side.

[0061] Also, a vehicle according to yet another aspect of the present invention includes at least one battery pack according to an aspect of the present invention. Effect of the Invention

[0062] According to one aspect of the present invention, a cylindrical battery cell having a structure in which a positive electrode terminal and a negative electrode terminal are applied in the same direction is provided, which not only simplifies an electrical connection structure of a plurality of cylindrical battery cells but also minimizes the volume of a battery pack when the battery pack is constructed, thereby improving the energy density of the battery pack.

[0063] In addition, according to one aspect of the present invention, the negative terminal of the cylindrical battery cell has a sufficient area for welding to an electrical connection part such as a bus bar, thereby ensuring sufficient joint strength between the negative terminal and the electrical connection part, and reducing the resistance at the joint between the electrical connection part and the negative terminal to a desired level.

[0064] Furthermore, according to one aspect of the present invention, the volume occupied by the electrode assembly in the battery can can be minimized, thereby improving the energy density of the cylindrical battery cell.

[0065] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in the drawings. [Brief description of the drawings]

[0066] [Figure 1] FIG. 2 is a diagram showing the external appearance of a cylindrical battery cell according to one embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view showing an internal structure of a cylindrical battery cell according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a partial cross-sectional view showing an upper structure of a cylindrical battery cell according to an embodiment of the present invention. [Figure 4] FIG. 2 is a partial cross-sectional view showing an upper structure of a cylindrical battery cell according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a partial cross-sectional view showing an upper structure of a cylindrical battery cell according to an embodiment of the present invention. [Figure 6] FIG. 2 is a diagram showing a first current collecting plate applied to the present invention. [Figure 7] FIG. 2 is a diagram showing a first current collecting plate applied to the present invention. [Figure 8] 4 is a cross-sectional view showing a coupling structure between a first current collecting plate and an electrode assembly applied to the present invention. FIG. [Figure 9]4 is a cross-sectional view showing a coupling structure between a first current collecting plate and an electrode assembly applied to the present invention. FIG. [Figure 10] FIG. 2 is a partial cross-sectional view showing a lower structure of a cylindrical battery cell according to an embodiment of the present invention. [Figure 11] FIG. 2 illustrates a bottom view of a cylindrical battery cell according to an embodiment of the present invention. [Figure 12] 1 is a view showing an electrode assembly in which a non-coating portion is folded according to an embodiment of the present invention; [Figure 13] FIG. 2 is a top view illustrating a state in which a plurality of cylindrical battery cells are connected in series and in parallel using a bus bar according to an embodiment of the present invention. [Figure 14] 1 is a schematic diagram showing a battery pack according to an embodiment of the present invention; [Figure 15] 1 is a conceptual diagram showing a vehicle according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings, but should be interpreted as being in accordance with the meaning and concept of the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of the term in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely one most preferred embodiment of the present invention, and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0068] 1 to 3, a cylindrical battery cell 1 according to an embodiment of the present invention includes an electrode assembly 10, a battery can 20, a top cap 30, and a terminal extension member 40. In addition to the above-mentioned components, the cylindrical battery cell 1 may further include a sealing gasket 50 and / or a terminal insulating member 60 and / or a first current collecting plate 70 and / or a second current collecting plate 70′ and / or an insulator 80 and / or a connection plate 90.

[0069] 1 to 4, the electrode assembly 10 includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first and second electrodes. The electrode assembly 10 may have a jelly-roll structure. That is, the electrode assembly 10 may be manufactured by stacking the sheet-shaped first and second electrodes at least once with a separator interposed therebetween, and winding the stack in one direction based on a winding center C. In this case, an additional separator may be provided on the outer periphery of the electrode assembly 10 for insulation from the battery can 20. Any jelly-roll structure known in the art may be applied to the present invention without limitation. The first electrode corresponds to a positive electrode or a negative electrode, and the second electrode corresponds to an electrode having the opposite polarity to the first electrode.

[0070] The first electrode includes a first electrode collector and a first electrode active material coated on one or both sides of the first electrode collector. The first electrode includes a plain portion (first plain portion) on which the electrode active material is not coated at an upper end. That is, the plain portion (first plain portion) on which the first electrode active material is not coated is present at one end of the width direction (direction parallel to the Z axis) of the first electrode collector. The plain portion itself can function as a first electrode tab 11. The first electrode tab 11 is provided at an upper portion in a height direction (direction parallel to the Z axis) of the electrode assembly 10 accommodated in the battery can 20. That is, the first electrode collector includes a first plain portion on which the active material layer is not coated at a long side end and the separator is exposed to the outside, and at least a portion of the first plain portion itself is used as an electrode tab. The first electrode tab can be, for example, a positive electrode tab.

[0071] Meanwhile, referring to FIG. 12, a structure of an electrode assembly 10 according to an embodiment of the present invention is shown. Referring to FIG. 12, a part of the first electrode tab 11, i.e., at least a part of the first uncoated portion, may include a plurality of first divided segments 11a divided along the winding direction of the electrode assembly 10. The first divided segments 11a are bent along the radial direction of the electrode assembly 10, and in this case, the plurality of first divided segments 11a may overlap in multiple. In this case, a first current collecting plate 70 described later may be bonded to a region where the plurality of first divided segments 11a overlap in multiple. Meanwhile, the electrode assembly 10 may include a welding target region, which is a region where the number of overlapping layers of the first divided segments 11a is maintained constant along the radial direction of the electrode assembly 10. In this region, the number of overlapping layers is maintained at a maximum, so that it is advantageous to perform welding between the first current collecting plate 70 described later and the first electrode tab 11 in this region.

[0072] This is to prevent the laser beam from penetrating the first electrode tab 11 and damaging the electrode assembly 10 when the laser output is increased to improve welding quality when laser welding is applied, for example. Also, this is to effectively prevent foreign matter such as welding spatter from entering the inside of the electrode assembly 10.

[0073] Referring to FIG. 12, the second electrode includes a second electrode collector and a second electrode active material coated on one or both sides of the second electrode collector. The second electrode includes a plain portion (second plain portion) on which the electrode active material is not coated at a lower end. That is, the plain portion on which the second electrode active material is not coated exists at the other end of the second electrode collector in the width direction (direction parallel to the Z axis). The plain portion itself can function as the second electrode tab 12. The second electrode tab 12 is provided at the lower part of the electrode assembly 10 in the height direction (direction parallel to the Z axis) accommodated in the battery can 20. That is, the second electrode collector includes a second plain portion on which the active material layer is not coated at a long side end and the separator is exposed to the outside, and at least a portion of the second plain portion itself is used as an electrode tab. The second electrode tab 12 can be, for example, a negative electrode tab.

[0074] Meanwhile, although FIG. 12 shows only a structure in which the first electrode tab 11 has a divided segment, such a divided segment may also be formed on the second electrode tab 12. That is, a part of the second electrode tab 12, i.e., at least a part of the second uncoated portion, may include a plurality of second divided segments (not shown) divided along the winding direction of the electrode assembly 10. The second divided segments are bent along the radial direction of the electrode assembly 10, and in this case, the plurality of second divided segments may overlap in multiple layers. In this case, a second current collecting plate 70' described later may be bonded to a region where the plurality of second divided segments overlap in multiple layers. Meanwhile, the electrode assembly 10 may include a welding target region, which is a region where the number of overlapping layers of the second divided segments is maintained constant along the radial direction of the electrode assembly 10. In this region, the number of overlapping layers is maintained at a maximum, so that it is advantageous to perform welding between the second current collecting plate 70' described later and the second electrode tab 12 in this region.

[0075] This is to prevent the laser beam from penetrating the second electrode tab 12 and damaging the electrode assembly 10 when the laser output is increased to improve welding quality when laser welding is applied, for example. Also, this is to effectively prevent foreign matter such as welding spatter from entering the inside of the electrode assembly 10.

[0076] The first electrode tab 11 and the second electrode tab 12 may extend in opposite directions along a height direction (parallel to the Z-axis) of the cylindrical battery cell 1. In this case, the first electrode tab 11 extends toward an opening formed at an upper end of the battery can 20, and the second electrode tab 12 extends toward a closing portion formed at a lower end of the battery can 20.

[0077] 1 to 4, the battery can 20 is a substantially cylindrical container having an opening at the top, and is made of a conductive metal material. The battery can 20 accommodates the electrode assembly 10 through the upper opening, and also accommodates an electrolyte. The side wall portion and a closing portion formed at the bottom of the battery can 20 may be integrally formed, or may be formed separately and joined to each other by welding, etc.

[0078] The battery can 20 is electrically connected to the second electrode tab 12 of the electrode assembly 10. Thus, the battery can 20 has the same second polarity as the second electrode tab 12. The electrical connection between the electrode assembly 10 and the battery can 20 may be made, for example, through a second current collecting plate 70′.

[0079] The battery can 20 may include a beading portion 21 and / or a crimping portion 22 formed at an upper end thereof. The beading portion 21 is formed adjacent to an upper opening of the battery can 20. The beading portion 21 has a shape pressed along the periphery of the outer periphery of the battery can 20. That is, the beading portion 21 is formed by pressing the periphery of the battery can 20. Thus, the beading portion 21 has a shape recessed by a predetermined depth along a radial direction from the outer periphery of the battery can 20 and extends along a circumferential direction of the battery can 20. The beading portion 21 prevents the electrode assembly 10, which has a size corresponding to the width of the battery can 20, from slipping out of the upper opening of the battery can 20, and may function as a support on which the top cap 30 is placed.

[0080] The crimping part 22 may be formed at the upper end of the battery can 20. The crimping part 22 may have a shape extending inward from the upper edge of the battery can 20 along the radial direction of the cylindrical battery cell 1. The crimping part 22 is provided in a region corresponding to the periphery of the upper surface of the top cap 30 to fix the top cap 30, thereby preventing the top cap 30 from being removed upward. If the battery can 20 has a beading part 21, the crimping part 22 is formed on the upper part of the beading part 21. The crimping part 22 extends from the beading part 21 and has a shape that is bent so as to surround the outer circumferential surface of the top cap 30 and a part of the upper surface of the top cap 30 disposed on the beading part 21. The upper end of the crimping part 22 may extend inward a predetermined distance along the radial direction of the cylindrical battery cell 1 to cover a part of the upper surface of the top cap 30. As a result, the crimping part 22 fixes the periphery of the upper surface of the top cap 30. That is, the peripheral region of the top cap 30 is fixed to the battery can 20 between the upper end of the crimping portion 22 and the beading portion 21 , and covers the opening of the battery can 20 .

[0081] 10 and 11, the battery can 20 may further include a venting portion 23 formed to prevent the internal pressure caused by gas generated inside the battery can 20 from increasing beyond a preset value. The venting portion 23 may be provided in a closed portion formed at the lower end of the battery can 20. The venting portion 23 corresponds to a region of the closed portion formed at the lower end of the battery can 20 that is weaker in rigidity than the surrounding region. The venting portion 23 may be configured to have a thinner thickness than other regions of the closed portion, for example. Therefore, if an abnormality occurs in the cylindrical battery cell 1 and the internal pressure increases above a certain level, the venting portion 23 is broken to discharge the gas generated inside the battery can 20. The cylindrical battery cell 1 according to the present invention has a structure in which both a positive electrode terminal and a negative electrode terminal are provided on the upper side, as described below. Therefore, by providing the venting portion 23 in the closed portion of the battery can 20 located on the opposite side to the positive electrode terminal and the negative electrode terminal, safety can be further improved. That is, according to the structure of the cylindrical battery cell 1 of the present invention, when the venting gas is ejected due to the breakage of the venting part 23, the gas can be ejected in the opposite direction to the part where the electrical connection parts such as the bus bar are provided. As a result, the cylindrical battery cell 1 of the present invention can reduce problems such as diffusion of events that occur when the hot venting gas directly hits the electrical connection parts such as the bus bar during venting. In addition, since the cylindrical battery cell 1 according to one embodiment of the present invention has a structure in which the positive electrode terminal and the negative electrode terminal are all present at the upper part, the structure of the upper part is more complicated than the structure of the lower part. Therefore, in order to smoothly exhaust the gas generated inside the battery can 20, it is advantageous to provide the venting part 23 on the closed surface side of the lower end of the battery can 20.

[0082] Although the drawings only show a case in which the venting portion 23 is continuously formed in a circular shape on the closed portion of the battery can 20, the present invention is not limited thereto. The venting portion 23 may be discontinuously formed, and its shape may be a straight line and / or a curved line and / or an ellipse and / or any other geometric shape.

[0083] Meanwhile, the venting portion 23 may have a shape in which the thickness is partially reduced by notching the inner surface and / or the outer surface of the closing portion provided at the lower end of the battery can 20. That is, the venting portion 23 may be formed by notching on one side or on both sides.

[0084] 1 to 4, the top cap 30 is a part made of a conductive metal material and covers the upper opening of the battery can 20. The top cap 30 is electrically connected to the first electrode tab 11 of the electrode assembly 10 and is electrically insulated from the battery can 20. Thus, the top cap 30 has the same first polarity as the first electrode tab 11 of the electrode assembly 10 and can function as a first electrode terminal of the cylindrical battery cell 1. The electrical connection between the first electrode tab 11 and the top cap 30 may be made by, for example, a first current collecting plate 70 and / or a lead 72.

[0085] The top cap 30 may be placed on a beading portion 21 formed on the battery can 20. The top cap 30 may be fixed by a crimping portion 22. That is, the periphery of the lower surface of the top cap 30 may be supported by the upper surface of the beading portion 21, and the periphery of the upper surface of the top cap 30 may be fixed by bending the upper end of the crimping portion 22. Meanwhile, a sealing gasket 50 for sealing the upper end opening of the battery can 20 and electrically insulating the battery can 20 from the top cap 30 may be interposed between the top cap 30 and the crimping portion 22 of the battery can 20. The sealing gasket 50 may include a material having insulating properties and elasticity. The sealing gasket 50 may include, for example, a polymer resin. The sealing gasket 50 may be folded together along the folded shape of the crimping portion 22 of the battery can 20. When the battery can 20 includes a beading portion 21, the sealing gasket 50 may be interposed between the upper surface of the beading portion 21 and the upper end of the crimping portion 22. The top cap 30 may include a protrusion 31 protruding upward from approximately its center. The protrusion 31 may be provided at a position corresponding to a hole formed at approximately the center of the terminal extension member 40. The protrusion 31 may protrude upward higher than the upper surface of the terminal extension member 40 through a hole in the terminal extension member 40 described later so as to easily contact an electrical connection part such as a bus bar. However, the present invention is not limited thereto, and the top cap 30 may be formed flat overall. Also, even when the top cap 30 includes the protrusion 31, the upper surface of the protrusion 31 may be located at approximately the same height as or lower than the upper surface of the terminal extension member 40.

[0086] 1 to 5, the terminal extension member 40 is made of a conductive metal material. The terminal extension member 40 may be, for example, substantially disk-shaped with a hole formed at its center. That is, the terminal extension member 40 may be in the form of a washer with a hole formed at its center. The terminal extension member 40 is coupled to the upper end of the battery can 20. The terminal extension member 40 extends inward from the upper end of the battery can 20 along the radial direction of the cylindrical battery cell 1. Thus, the terminal extension member 40 has a width greater than that of a flat portion formed at the upper end of the battery can 20. That is, the length of the terminal extension member 40 extending from the upper end of the battery can 20 along the radial direction of the cylindrical battery cell 1 is longer than the length of the flat portion formed at the upper end of the battery can 20 along the radial direction of the cylindrical battery cell 1. The flat portion formed at the upper end of the battery can 20 may be substantially parallel to the lower surface of the battery can 20. When the crimping portion 22 is formed at the upper end of the battery can 20, the terminal extension member 40 is coupled to the upper end of the crimping portion 22. Preferably, the upper end of the crimping portion 22 may have a flat portion that is approximately parallel to the closed portion of the battery can 20. In this case, the terminal extension member 40 may be coupled to the flat portion formed at the upper end of the crimping portion 22. The coupling between the terminal extension member 40 and the crimping portion 22 may be performed, for example, by laser welding. Referring to FIG. 3a, the flat portion of the crimping portion 22 that is coupled to the terminal extension member 40 may be configured to be thicker than other areas of the crimping portion 22. In this case, in the process of fixing the terminal extension member 40 to the upper end of the crimping portion 22 by laser welding, even if the laser output is sufficiently increased for firm fixation, the risk of the crimping portion 22 being pierced is reduced. In addition, by making the thickness of the crimping portion 22 partially thick in this manner, when the internal pressure of the cylindrical battery cell 1 increases, the sealing force on the open side of the battery can 20 decreases before the venting portion 23 breaks, preventing a phenomenon in which the venting portion 23 cannot function normally.

[0087] The terminal extension member 40 is electrically insulated from the top cap 30. The top cap 30 is exposed through a hole formed in the center of the terminal extension member 40, and the terminal extension member 40 and the top cap 30 are spaced apart from each other.

[0088] When the top cap 30 includes the protrusion 31, the protrusion 31 may be exposed through a hole formed in the approximate center of the terminal extension member 40. In this case, the protrusion 31 is spaced apart from the inner surface of the hole formed in the terminal extension member 40, and the other parts of the top cap 30 except for the protrusion 31 are spaced apart from the terminal extension member 40 in the vertical direction. Therefore, the terminal extension member 40 has the same second polarity as the second electrode tab 12 of the electrode assembly 10 and the battery can 20, and can thus function as the second electrode terminal of the cylindrical battery cell 1. That is, the cylindrical battery cell 1 according to an embodiment of the present invention has a structure in which a first electrode terminal having a first polarity and a second electrode terminal having a second polarity are both arranged in the same direction.

[0089] Referring to FIG. 3, the width D2 of the terminal extension member 40 is wider than the width D1 of the flat portion formed on the upper surface of the crimping portion 22 of the battery can 20. Thus, the terminal extension member 40 extends from the upper surface of the crimping portion 22 toward the center of the cylindrical battery cell 1 in the radial direction. When the protrusion 31 is provided, the terminal extension member 40 extends from the upper surface of the crimping portion 22 toward the protrusion 31 of the top cap 30. This is to ensure a sufficient coupling area for coupling an electrical connection component to the upper end of the battery can 20 having the second polarity so that the coupling of the connection components for the electrical connection of the plurality of cylindrical battery cells 1 is performed on one side of the cylindrical battery cell 1. In this way, the application of the terminal extension member 40 ensures a sufficient area to be coupled with the electrical connection components, thereby making it possible to smoothly perform the welding process, improve the fastening force between the two components, and reduce the electrical resistance at the coupling site.

[0090] 5, the battery can 20 may have an insertion groove 22a formed on an upper surface of the crimping portion 22, and the terminal expansion member 40 may have an insertion protrusion 41 on a lower surface thereof having a shape corresponding to the insertion groove 22a and being coupled with the insertion groove 22a. Conversely, the battery can 20 may have an insertion protrusion formed on an upper surface of the crimping portion 22, and the terminal expansion member 40 may have an insertion groove having a shape corresponding to the insertion protrusion and being coupled with the insertion protrusion.

[0091] The insertion groove 22a and the insertion protrusion 41 can increase the contact area between the terminal expansion member 40 and the crimping portion 22, thereby improving the fastening force and reducing the electrical resistance at the joining portion. In addition, the insertion groove 22a and the insertion protrusion 41 can prevent the terminal expansion member 40 from contacting the protrusion 31 of the top cap 30 by guiding the placement position when the terminal expansion member 40 is placed on the crimping portion 22. In addition, the insertion groove 22a and the insertion protrusion 41 can improve processability by preventing the terminal expansion member 40 from moving on the crimping portion 22 during the welding process.

[0092] 2 and 3, the terminal insulating member 60 is interposed between the top cap 30 and the terminal expansion member 40. The terminal insulating member 60 is made of an insulating material. The terminal insulating member 60 may be in the form of a washer having a hole formed in approximately its center.

[0093] In the cylindrical battery cell 1 according to an embodiment of the present invention, the top cap 30 functions as a first electrode terminal having a first polarity, and the terminal extension member 40 functions as a second electrode terminal having a second polarity opposite to the first polarity, so that an electrical insulated state must be maintained between the top cap 30 and the terminal extension member 40. Therefore, in order to stably maintain such an insulating state, it is advantageous to apply a terminal insulating member 60.

[0094] The terminal insulating member 60 is interposed between the lower surface of the terminal expansion member 40 and the top cap 30. As described above, the terminal expansion member 40 has a width D2 wider than the width D1 of the upper surface of the crimping portion 22, and extends from the crimping portion 22 toward the protrusion 31 of the top cap 30. Therefore, the terminal insulating member 60 may extend to cover the inner surface of a hole formed in the center of the terminal expansion member 40 so that the inner surface of the hole formed in the center of the terminal expansion member 40 and the protrusion 31 of the top cap 30 do not come into contact with each other.

[0095] For example, the terminal insulating member 60 may include a first portion 61 interposed between the lower surface of the terminal extension member 40 and the upper surface of the top cap 30 (if the top cap 30 has a protrusion 31, the upper surface of the other portion excluding the protrusion 31), and a second portion 62 interposed between the inner surface of a hole formed in the approximate center of the terminal extension member 40 and the protrusion 31 of the top cap 30 by protruding upward from the first portion 61. In this case, the second portion 62 may have an inner diameter corresponding to the outer diameter of the protrusion 31 of the top cap 30. This is for fixing the terminal extension member 40 on the top cap 30 without any movement. The protrusion 31 may have a shape in which the outer diameter gradually decreases toward the upper side, for example. In this case, the inner diameter of the second portion 62 is made to correspond to the outer diameter of the lower end of the protrusion 31, so that the terminal insulating member 60 can be naturally inserted into the protrusion 31.

[0096] Meanwhile, the hole formed at the approximate center of the terminal expansion member 40 may have an inner diameter corresponding to the outer diameter of the second portion 62 of the terminal insulating member 60. This is to fix the terminal expansion member 40 firmly on the terminal insulating member 60 without any movement. When the terminal expansion member 40 is firmly fixed on the terminal insulating member 60, the welding process between the terminal expansion member 40 and the crimping portion 22 can be easily performed. Meanwhile, the upper surface (the upper surface of the first portion 61) of the terminal insulating member 60 may be located at approximately the same height as the upper surface of the crimping portion 22 formed on the upper end of the battery can 20. In this case, when the terminal expansion member 40 is placed on the terminal insulating member 60, the lower surface of the terminal expansion member 40 and the upper surface of the crimping portion 22 naturally come into contact with each other.

[0097] When the terminal insulating member 60 is made of a resin material, the terminal insulating member 60 can be joined to the terminal expansion member 40 and the top cap 30 by thermal fusion. In this case, the airtightness at the joining interface between the terminal insulating member 60 and the terminal expansion member 40 and the joining interface between the terminal insulating member 60 and the top cap 30 is strengthened.

[0098] 4, the terminal insulating member 60 may have an extended shape so as to cover a part of the upper surface of the terminal expanding member 40. That is, the second portion 62 (see FIG. 3) of the terminal insulating member 60 may have a shape that extends further so as to cover not only the inner peripheral surface of the terminal expanding member 40 but also the periphery of the upper surface of the terminal expanding member 40. In this case, the effect of preventing contact between the terminal expanding member 40 and the top cap 30 is further improved.

[0099] When the terminal insulating member 60 has such a form that it extends to the edge region of the upper surface of the terminal expanding member 40, the process of placing the terminal expanding member 40 on the crimping unit 22 can be performed more accurately and quickly. After the terminal insulating member 60 is inserted through a hole formed in the center of the terminal expanding member 40 and fixed to the terminal expanding member 40, the combined body consisting of the terminal expanding member 40 and the terminal insulating member 60 is placed on the crimping unit 22 and the top cap 30, so that the terminal expanding member 40 is naturally placed in the correct position. At this time, the protrusion 31 of the top cap 30 can be exposed upward through a hole formed in the approximate center of the terminal insulating member 60.

[0100] 4 may be manufactured by insert injection. That is, the terminal insulating member 60 and the terminal expansion member 40 can be manufactured by insert injection so that the terminal expansion member 40 made of a metal material is inserted / fixed into the terminal insulating member 60 made of a resin material, and the combined member can be arranged on the crimping portion 22 and the top cap 30 to achieve a natural alignment effect.

[0101] Meanwhile, in the present invention, insulation between the terminal extension member 40 and the top cap 30 can be achieved not only by applying the terminal insulating member 60 but also by other methods. For example, an insulating coating layer may be formed on the area of ​​the terminal extension member 40 facing the top cap 30. Conversely, an insulating coating layer may be formed on the area of ​​the top cap 30 facing the terminal extension member 40. In addition, it is also possible to ensure insulation by sufficiently separating the terminal extension member 40 and the top cap 30 so that they do not come into contact with each other.

[0102] 2 to 4, the first current collecting plate 70 is coupled to an upper portion of the electrode assembly 10. The first current collecting plate 70 may be located between the electrode assembly 10 and the beading portion 21. The first current collecting plate 70 is made of a conductive metal material and is coupled to a first electrode tab 11. The first current collecting plate 70 is electrically connected to the top cap 30. A lead 72 is connected to the first current collecting plate 70, and the lead 72 may extend upward and be directly coupled to the top cap 30 or may be coupled to a connection plate 90 coupled to a lower surface of the top cap 30. Thus, the top cap 30 has the same first polarity as the first electrode tab 11 and may function as a first electrode terminal.

[0103] 6 and 7, the first current collecting plate 70 may include a plurality of tab coupling parts 71 extending radially from a center portion. A space between adjacent tab coupling parts 71 is utilized as a space for injecting an electrolyte. The first current collecting plate 70 and the lead 72 may be integrally formed. In this case, the lead 72 may have an elongated plate shape extending outward from the center portion of the first current collecting plate 70, similar to the tab coupling parts 71. The lead 72 may be provided, for example, between adjacent tab coupling parts 71. However, the structure of the first current collecting plate 70 of the present invention is not limited thereto, and the first current collecting plate 70 may have a shape corresponding to the upper surface of the electrode assembly 10 so as to entirely cover the upper portion of the first electrode tab 11.

[0104] The first current collecting plate 70 may have a first current collecting plate hole H1 formed at approximately its center. The first current collecting plate hole H1 may be provided at a position corresponding to a hole formed at the winding center C of the electrode assembly 10. The first current collecting plate hole H1 may be utilized as a space for injecting an electrolyte, a space for irradiating a laser for welding between the second current collecting plate 70′ and the bottom surface of the battery can 20, or a space for inserting a tool for ultrasonic welding. In consideration of such a function of the first current collecting plate hole H1, the diameter of the first current collecting plate hole H1 may be formed to be approximately the same as or larger than the diameter of the hole formed at the winding center C of the electrode assembly 10.

[0105] The maximum outer diameter of the first current collecting plate 70 (twice the distance from the center to the end of the tab coupling portion 71) may be formed to be approximately the same as or smaller than the minimum inner diameter of the battery can 20 (the inner diameter of the battery can 20 at the position where the beading portion 21 is formed). In this case, it is possible to prevent the electrode assembly 10 from being directly pressed by the beading portion 21 or from being pressed by the first current collecting plate 70 and being damaged during a sizing process for adjusting the total height of the cylindrical battery cell 1.

[0106] Meanwhile, although not shown, the first current collecting plate 70 may have a plurality of projections and recesses formed radially on its lower surface. When projections and recesses are formed, the first current collecting plate 70 may be pressed against the electrode tabs 11 and 12.

[0107] 8, the first current collecting plate 70 is coupled to an end of the first electrode tab 11. The first electrode tab 11 and the first current collecting plate 70 may be coupled to each other by, for example, laser welding. The laser welding may be performed by partially melting a base material of the first current collecting plate 70, or may be performed with solder for welding interposed between the first current collecting plate 70 and the first electrode tab 11. In this case, the solder may have a lower melting point than the first current collecting plate 70 and the first electrode tab 11.

[0108] Referring to FIG. 9, the first current collecting plate 70 may be coupled to a coupling surface formed by bending an end of the first electrode tab 11 in a direction parallel to the first current collecting plate 70. The bending direction of the first electrode tab 11 may be, for example, a direction toward the winding center of the electrode assembly 10. When the first electrode tab 11 has such a folded shape, the space occupied by the first electrode tab 11 is reduced, and the energy density can be improved. Specifically, as described above with reference to FIG. 12, the first electrode tab 11 of the present invention may have a plurality of first divided segments 11a. The plurality of first divided segments 11a may have a folded shape along the radial direction of the electrode assembly 10. The plurality of first divided segments 11a folded in one direction may overlap each other in a plurality of layers. There is a section in which the number of overlapping layers of the first divided segments 11a is maximum and maintained approximately constant along a direction from the outer circumferential surface of the electrode assembly 10 toward the winding center C or the opposite direction. That is, the first electrode tab 11 includes a region in which the number of overlapping layers is maintained substantially constant by bending the first divided piece 11a. The first current collecting plate 70 may be coupled to the first electrode tab 11 within the welding target region, which is the section in which the number of overlapping layers is maintained constant.

[0109] 10, the second current collecting plate 70' may be coupled to the lower surface of the electrode assembly 10. The second current collecting plate 70' may be electrically connected to the second electrode tab 12 of the electrode assembly 10 and the battery can 20. One surface of the second current collecting plate 70' may be coupled to the second electrode tab 12 of the electrode assembly 10, for example, by welding, and the other surface of the second current collecting plate 70' may be coupled to the inner bottom surface of the battery can 20, i.e., the inner surface of the closure, for example, by welding. The coupling structure between the second current collecting plate 70' and the second electrode tab 12 coupled to the lower surface of the electrode assembly 10 may be substantially the same as the coupling structure between the first current collecting plate 70 and the first electrode tab 11 described above.

[0110] Although not shown, like the first electrode tab 11, the second electrode tab 12 also includes a plurality of second segments (not shown), and the second segments may also have a shape bent along the radial direction of the electrode assembly 10. In this case, there is a welding target area in which the number of overlapping layers of the second segments is approximately maximum and maintained constant along the radial direction of the electrode assembly 10. The second current collecting plate 70' may be coupled to the second electrode tab 12 within the welding target area.

[0111] Meanwhile, the second current collecting plate 70' may have a second current collecting plate hole H2 formed at approximately its center. In this case, the second current collecting plate hole H2 may be formed at a position corresponding to a hole formed at the winding center C of the electrode assembly 10. It is preferable that the second current collecting plate hole H2 has a diameter that is approximately the same as or smaller than that of the hole formed at the winding center C of the electrode assembly 10. This is because the second current collecting plate 70' is welded to the bottom surface of the battery can 20 by irradiating a laser or inserting a welding rod from above the electrode assembly 10.

[0112] The insulator 80 is disposed between the upper end of the electrode assembly 10 and the beading portion 21, or between a first current collecting plate 70 coupled to the upper portion of the electrode assembly 10 and the beading portion 21, to prevent contact between the first electrode tab 11 and the battery can 20 or between the first current collecting plate 70 and the battery can 20. The insulator 80 may also be disposed between the first electrode tab 11 of the electrode assembly 10 and an inner peripheral surface of the battery can 20.

[0113] The insulator 80 has a lead hole 81 through which a lead 72 extending upward from the first current collecting plate 70 or the first electrode tab 11 is drawn out. The lead 72 is drawn upward through the lead hole 81 and coupled to the lower surface of the connecting plate 90 or the lower surface of the top cap 30.

[0114] As described above, the cylindrical battery cell 1 according to an embodiment of the present invention has a structure in which the top cap 30 and the terminal extension member 40 provided on one side of the longitudinal direction (direction parallel to the Z axis in FIG. 2) of the battery can 20 can be used as a first electrode terminal and a second electrode terminal, respectively. Therefore, when a plurality of cylindrical battery cells 1 according to an embodiment of the present invention are electrically connected, electrical connection parts such as a bus bar can be disposed only on one side of the cylindrical battery cell 1, thereby simplifying the structure and improving the energy density.

[0115] 13, a plurality of cylindrical battery cells 1 may be connected in series, in parallel, or in a mixed form of series and parallel using a bus bar 150 at the top of the cylindrical battery cells 1. FIG 13 exemplarily illustrates a structure in which a plurality of cylindrical battery cells 1 are connected in a mixed form of series and parallel. The number of cylindrical battery cells 1 may be increased or decreased in consideration of the capacity of the battery pack.

[0116] In each cylindrical battery cell 1, the top cap 30 functioning as the first electrode terminal may have a positive polarity, and the terminal extension member 40 functioning as the second electrode terminal may have a negative polarity. Of course, the opposite is also possible.

[0117] Preferably, the cylindrical battery cells 1 may be arranged in a plurality of columns and rows. The columns are in the up-down direction with reference to FIG. 13, and the rows are in the left-right direction with reference to FIG. 13. In addition, in order to maximize space efficiency, the cylindrical battery cells 1 may be arranged in a closest packing structure. The closest packing structure is formed when an equilateral triangle is drawn when the centers of the top caps 30 are connected to each other. Preferably, the bus bar 150 may be arranged on top of the cylindrical battery cells 1, more preferably between adjacent columns. Alternatively, the bus bar 150 may be arranged between adjacent rows.

[0118] Preferably, the bus bar 150 may connect the cylindrical battery cells 1 arranged in the same row in parallel to each other, and may connect the cylindrical battery cells 1 arranged in two adjacent rows in series to each other.

[0119] Preferably, the bus bar 150 may include a body portion 151, a plurality of first bus bar terminals 152, and a plurality of second bus bar terminals 153 for series and parallel connection. The body portion 151 may extend between centers of the top caps 30 of adjacent cylindrical battery cells 1, preferably between rows of cylindrical battery cells 1. Alternatively, the body portion 151 may extend along the rows of cylindrical battery cells 1, but may be regularly folded, such as in a zigzag shape.

[0120] The plurality of first bus bar terminals 152 may protrude and extend from one side of the body portion 151 toward the top cap 30 of each cylindrical battery cell 1, and may be electrically coupled to a center of the top cap 30 exposed from the center of the terminal part extension member 40. The electrical coupling between the first bus bar terminals 152 and the top cap 30 may be performed by laser welding, ultrasonic welding, etc. In addition, the plurality of second bus bar terminals 153 may protrude and extend from the other side of the body portion 151 toward the terminal part extension member 40 of each cylindrical battery cell 1, and may be electrically coupled to the terminal part extension member 40. The electrical coupling between the second bus bar terminals 153 and the terminal part extension member 40 may be performed by laser welding, ultrasonic welding, etc.

[0121] Preferably, the body portion 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 may be formed of a single conductive metal plate. The metal plate may be, for example, an aluminum plate or a copper plate, but the present invention is not limited thereto. Alternatively, the body portion 151, the plurality of first busbar terminals 152, and the plurality of second busbar terminals 153 may be manufactured as separate pieces and then joined by welding or the like.

[0122] In the cylindrical battery cell 1 according to the present invention, the top cap 30 having a first polarity and the terminal extension member 40 having a second polarity are located in the same direction (above the Z axis with respect to the drawing), so that electrical connection between the cylindrical battery cells 1 can be easily implemented using the bus bar 150.

[0123] In addition, since the area of ​​the top cap 30 and the terminal extension member 40 of the cylindrical battery cell 1 is large, the bonding area of ​​the bus bar 150 can be sufficiently secured to increase the bonding strength of the bus bar 150, and the resistance of the battery pack including the cylindrical battery cell 1 can be sufficiently reduced.

[0124] 14, a battery pack 3 according to an embodiment of the present invention includes a battery cell assembly in which a plurality of cylindrical battery cells 1 according to an embodiment of the present invention are electrically connected as described above, and a pack housing 2 that accommodates the battery cell assembly. For convenience of illustration, components such as bus bars and power terminals for electrical connection are omitted from the drawings. The electrical connection structure between the battery cells 1 for manufacturing the battery pack 3 is exemplarily as described above with reference to FIG.

[0125] 15, an automobile 5 according to an embodiment of the present invention may be, for example, an electric vehicle, and includes a battery pack 3 according to an embodiment of the present invention. The automobile 5 operates by receiving power from the battery pack 3 according to an embodiment of the present invention.

[0126] As described above, the present invention has been described using limited embodiments and drawings. However, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention belongs within the technical spirit of the present invention and the equivalent scope of the claims. [Item 1] an electrode assembly including a first electrode tab and a second electrode tab; a battery can housing the electrode assembly and electrically connected to the second electrode tab; a top cap that covers an upper end opening of the battery can, is electrically connected to the first electrode tab, and is electrically insulated from the battery can; a terminal extension member coupled to an upper end of the battery can and electrically insulated from the top cap. [Item 2] The terminal portion expansion member is 2. The cylindrical battery cell according to item 1, having a shape extending inward along a radial direction of the cylindrical battery cell from an upper end of the battery can. [Item 3] The terminal portion expansion member is 3. The cylindrical battery cell according to item 2, having a width greater than the flat portion formed at the upper end of the battery can. [Item 4] The battery can is 2. The cylindrical battery cell according to item 1, comprising a crimping portion having a shape extending inward along a radial direction of the cylindrical battery cell from an upper peripheral edge of the battery can. [Item 5] The terminal portion expansion member is Item 5. The cylindrical battery cell according to item 4, bonded to an upper surface of the crimping portion. [Item 6] A flat portion is provided on the upper surface of the crimping portion, 5. The cylindrical battery cell according to item 4, wherein the terminal extension member is bonded onto a flat portion of the crimping portion. [Item 7] The terminal portion expansion member is 7. The cylindrical battery cell according to item 6, having a width greater than a width of a flat portion of the crimping portion. [Item 8] The terminal portion expansion member is 2. The cylindrical battery cell according to item 1, which is in the form of a washer with a hole formed in the center. [Item 9] The top cap has a protrusion protruding upward from a center portion, 9. The cylindrical battery cell according to item 8, wherein the protrusion is provided at a position corresponding to a hole formed in the center of the terminal extension member. [Item 10] The protrusion is 10. The cylindrical battery cell of item 9, wherein the terminal extension member protrudes upwardly above an upper surface of the terminal extension member. [Item 11] The cylindrical battery cell comprises: 2. The cylindrical battery cell according to item 1, further comprising a terminal insulating member interposed between the top cap and the terminal extension member to electrically insulate the top cap and the terminal extension member. [Item 12] The terminal insulating member is Item 12. The cylindrical battery cell according to item 11, which is in the form of a washer with a hole formed in the center. [Item 13] The top cap has a protrusion protruding upward from a center portion, The terminal insulating member is a first portion interposed between a lower surface of the terminal extension member and an upper surface of a region of the top cap other than the protruding portion; Item 13. The cylindrical battery cell according to item 12, further comprising: a second portion protruding upward from the first portion and interposed between the protruding portion and an inner surface of a hole formed in the center of the terminal extension member. [Item 14] The battery can is a crimping portion extending inward from an upper peripheral edge of the battery can along a radial direction of the cylindrical battery cell, The top surface of the first portion is Item 14. The cylindrical battery cell according to item 13, wherein the upper surface of the crimping portion is located at the same height. [Item 15] The second portion is Item 14. The cylindrical battery cell of item 13, having an inner diameter corresponding to an outer diameter of the protrusion. [Item 16] The protrusion has an outer diameter that gradually decreases upward, Item 16. The cylindrical battery cell according to item 15, wherein an inner diameter of the second portion corresponds to an outer diameter of a lower end of the protrusion. [Item 17] The terminal portion expansion member is Item 14. The cylindrical battery cell of item 13, having an inner diameter corresponding to an outer diameter of the second portion. [Item 18] The terminal insulating member is a first portion interposed between a lower surface of the terminal extension member and an upper surface of a region of the top cap other than the protruding portion; Item 14. The cylindrical battery cell according to item 13, further comprising: a second portion protruding upward from the first portion and interposed between the protruding portion and an inner surface of a hole formed in the center of the terminal extension member. [Item 19] The terminal portion expansion member is Item 19. The cylindrical battery cell of item 18, having an inner diameter corresponding to an outer diameter of the second portion. [Item 20] The thickness of the crimping portion in the region where the flat portion is provided is Item 7. The cylindrical battery cell of item 6, wherein the crimping portion is thicker than other areas. [Item 21] The second portion is Item 19. The cylindrical battery cell of item 18, having an extended configuration covering a portion of an upper surface of the top cap. [Item 22] The terminal portion expanding member and the terminal portion insulating member are 22. The cylindrical battery cell according to item 21, wherein the battery cell is a combination formed by insert injection. [Item 23] The crimping portion has an upper surface provided with an insertion protrusion or an insertion groove, 5. The cylindrical battery cell according to item 4, wherein a lower surface of the crimping portion is provided with an insertion groove that is coupled to an insertion protrusion formed on the crimping portion or an insertion protrusion that is coupled to an insertion groove formed on the crimping portion. [Item 24] The terminal insulating member is Item 12. The cylindrical battery cell according to item 11, comprising a resin material and coupled with the terminal extension member and the top cap by heat sealing. [Item 25] The electrode assembly includes: Item 2. A cylindrical battery cell according to item 1, having a jelly roll structure in which a laminate having a separator interposed between a first electrode and a second electrode is wound in one direction. [Item 26] The first electrode tab is a first uncoated portion that is not coated with an electrode active material at an upper end of the first electrode, 26. The cylindrical battery cell according to item 25, wherein the second electrode tab is a second uncoated portion at a lower end of the second electrode that is not coated with an electrode active material. [Item 27] At least a portion of the first electrode tab Item 27. The cylindrical battery cell according to item 26, comprising a plurality of first sections divided along the winding direction of the electrode assembly. [Item 28] The plurality of first sections include Item 28. The cylindrical battery cell according to item 27, wherein the electrode assembly is folded along a radial direction. [Item 29] The cylindrical battery cell comprises: a first current collecting plate coupled to an upper portion of the electrode assembly and electrically connected to the top cap, The first current collecting plate is Item 29. The cylindrical battery cell according to item 28, bonded on a bonding surface formed by bending the plurality of first sections. [Item 30] The plurality of first sections are overlapped with each other, the first electrode tab includes a welding target area in which a number of overlapping layers of the plurality of first segments is maintained constant along a radial direction of the electrode assembly; 30. The cylindrical battery cell of claim 29, wherein the first current collecting plate is bonded to the first electrode tab within the weld target area. [Item 31] At least a portion of the second electrode tab is 27. The cylindrical battery cell according to item 26, comprising a plurality of second sections divided along the winding direction of the electrode assembly. [Item 32] The plurality of second sections include Item 32. The cylindrical battery cell according to item 31, wherein the electrode assembly is folded along a radial direction. [Item 33] The cylindrical battery cell comprises: a second current collecting plate coupled to a lower portion of the electrode assembly and electrically connected to the battery can, The second current collecting plate is Item 33. The cylindrical battery cell according to item 32, bonded on a bonding surface formed by bending the plurality of second sections. [Item 34] The plurality of second sections are overlapped in a multiplicity, the second electrode tab includes a welding target area in which a number of overlapping layers of the plurality of second segments is maintained constant along a radial direction of the electrode assembly; Item 34. The cylindrical battery cell of item 33, wherein the second current collecting plate is bonded to the second electrode tab within the weld target area. [Item 35] The cylindrical battery cell comprises: 2. The cylindrical battery cell according to item 1, further comprising a first current collecting plate coupled to an upper portion of the electrode assembly and electrically connected to the top cap. [Item 36] The first current collecting plate is 36. The cylindrical battery cell of item 35, including a plurality of tab bonds extending radially from a center portion thereof. [Item 37] The first current collecting plate is Item 37. The cylindrical battery cell according to item 36, further comprising a lead disposed between adjacent tab bonds and electrically connecting between the first current collecting plate and the top cap. [Item 38] the battery can has a beading portion that is pressed along the outer circumferential surface of the battery can, Item 36. The cylindrical battery cell according to item 35, wherein the first current collecting plate is located between the electrode assembly and a beading portion. [Item 39] The maximum outer diameter of the first current collecting plate is Item 39. The cylindrical battery cell according to item 38, wherein the inner diameter of the battery can at the height where the beading portion is formed is equal to or smaller than the inner diameter of the battery can. [Item 40] The first current collecting plate is Item 36. The cylindrical battery cell according to item 35, further comprising a first current collector hole formed at a position corresponding to a hole formed in the winding center of the electrode assembly. [Item 41] The diameter of the first current collecting plate hole is Item 41. The cylindrical battery cell according to item 40, wherein the diameter of the hole formed in the winding center of the electrode assembly is equal to or larger than the diameter of the hole. [Item 42] The battery can is A closing portion is formed at a lower end opposite the upper end opening, 2. The cylindrical battery cell according to item 1, wherein the closing portion is provided with a venting portion that ruptures when the internal pressure of the battery can increases above a reference value. [Item 43] Item 43. The cylindrical battery cell of item 42, wherein the venting portion is configured to have a smaller thickness than a surrounding area of ​​the closure portion. [Item 44] The venting portion is Item 44. The cylindrical battery cell according to item 43, wherein one or both sides of the closure are formed by notching. [Item 45] The cylindrical battery cell comprises: Item 39. The cylindrical battery cell of item 38, further comprising an insulator disposed between the beading portion and the first current collecting plate. [Item 46] The insulator is Item 46. The cylindrical battery cell according to item 45, interposed between a first electrode tab of the electrode assembly and an inner peripheral surface of the battery can. [Item 47] A battery pack comprising a plurality of cylindrical battery cells according to any one of items 1 to 46. [Item 48] The cylindrical battery cells are arranged in a predetermined number of rows; Item 48. The battery pack according to item 47, wherein the top cap and the terminal extension member of each of the cylindrical battery cells are arranged toward an upward direction. [Item 49] The battery pack includes a plurality of bus bars connecting the cylindrical battery cells in series and in parallel, The bus bars are disposed on top of the cylindrical battery cells, Each of the plurality of bus bars comprises: a body portion extending between cell terminals of adjacent cylindrical battery cells; a plurality of first bus bar terminals extending to one side of the body portion and electrically coupled to the top caps of cylindrical battery cells located on the one side; and a plurality of second bus bar terminals extending to the other side of the body portion and electrically coupled to the terminal extension members of the battery cans of the cylindrical battery cells located on the other side. [Item 50] 50. A motor vehicle comprising at least one battery pack according to any one of items 47 to 49.

Claims

1. A cylindrical battery cell, an electrode assembly including a first electrode tab and a second electrode tab; a battery can housing the electrode assembly and electrically connected to the second electrode tab; a top cap that covers an upper end opening of the battery can, is electrically connected to the first electrode tab, and is electrically insulated from the battery can; a terminal extension member coupled to an upper end of the battery can and electrically insulated from the top cap, the battery can includes a crimping portion extending inward from an upper peripheral edge of the battery can along a radial direction of the cylindrical battery cell, the crimping portion fixing a peripheral region of an upper surface of the top cap; The crimping portion has an upper surface provided with a flat portion, the terminal extension member is coupled onto the flat portion of the crimping portion; The terminal portion expansion member is A cylindrical battery cell having a shape extending inward along a radial direction so as to have a width greater than that of the flat portion, and configured not to protrude outward beyond the battery can along the radial direction.

2. The terminal portion expansion member is The cylindrical battery cell according to claim 1 , wherein the crimping portion has a width greater than a width of a flat portion.

3. The terminal portion expansion member is 10. The cylindrical battery cell of claim 1, in the form of a washer having a hole formed in the center.

4. The top cap has a protrusion protruding upward from a center portion, The cylindrical battery cell according to claim 3 , wherein the protrusion is provided at a position corresponding to a hole formed in the center of the terminal extension member.

5. The protrusion is The cylindrical battery cell of claim 4 , wherein the terminal extension member protrudes upwardly above a top surface of the terminal extension member.

6. The cylindrical battery cell comprises:

2. The cylindrical battery cell according to claim 1, further comprising a terminal insulating member interposed between the top cap and the terminal extension member to electrically insulate the top cap and the terminal extension member.

7. The terminal insulating member is 7. The cylindrical battery cell of claim 6, in the form of a washer having a hole formed in the center.

8. The top cap has a protrusion protruding upward from a center portion, The terminal insulating member is a first portion interposed between a lower surface of the terminal extension member and an upper surface of a region of the top cap other than the protruding portion; 8. The cylindrical battery cell according to claim 7, further comprising: a second portion protruding upward from the first portion and interposed between the protruding portion and an inner surface of a hole formed in the center of the terminal extension member.

9. The battery can is a crimping portion extending inward from an upper peripheral edge of the battery can along a radial direction of the cylindrical battery cell, The top surface of the first portion is The cylindrical battery cell according to claim 8 , which is flush with an upper surface of the crimping portion.

10. The second portion is The cylindrical battery cell of claim 8 , having an inner diameter corresponding to an outer diameter of the protrusion.

11. The protrusion has an outer diameter that gradually decreases upward, The cylindrical battery cell according to claim 10 , wherein an inner diameter of the second portion corresponds to an outer diameter of a lower end of the protrusion.

12. The terminal portion expansion member is The cylindrical battery cell of claim 8 having an inner diameter corresponding to an outer diameter of the second portion.

13. The thickness of the crimping portion in the region where the flat portion is provided is The cylindrical battery cell of claim 1 , wherein the crimping portion is thicker than other areas of the crimping portion.

14. The second portion is The cylindrical battery cell according to claim 8 , having an extended configuration covering a portion of an upper surface of the top cap.

15. The terminal portion expanding member and the terminal portion insulating member are 15. The cylindrical battery cell of claim 14, wherein the assembly is formed by insert injection.

16. The crimping portion has an upper surface provided with an insertion protrusion or an insertion groove, 2. The cylindrical battery cell of claim 1, wherein a lower surface of the terminal portion expansion member is provided with an insertion groove coupled to an insertion protrusion formed on the crimping portion or an insertion protrusion coupled to an insertion groove formed on the crimping portion.

17. The terminal insulating member is The cylindrical battery cell according to claim 6 , comprising a resin material and coupled with the terminal extension member and the top cap by heat sealing.

18. The electrode assembly includes:

2. The cylindrical battery cell according to claim 1, having a jelly roll structure in which a laminate having a separator interposed between a first electrode and a second electrode is wound in one direction.

19. The first electrode tab is a first uncoated portion that is not coated with an electrode active material at an upper end of the first electrode, The cylindrical battery cell of claim 18 , wherein the second electrode tab is a second uncoated portion that is not coated with an electrode active material at a lower end of the second electrode.

20. At least a portion of the first electrode tab The cylindrical battery cell according to claim 19 , comprising a plurality of first sections divided along a winding direction of the electrode assembly.

21. The plurality of first sections include The cylindrical battery cell according to claim 20 , wherein the electrode assembly is folded along a radial direction.

22. The cylindrical battery cell comprises: a first current collecting plate coupled to an upper portion of the electrode assembly and electrically connected to the top cap, The first current collecting plate is The cylindrical battery cell according to claim 21 , wherein the cylindrical battery cell is bonded on a bonding surface formed by bending the plurality of first sections.

23. The plurality of first sections overlap each other in a multiplicity, the first electrode tab includes a welding target area in which a number of overlapping layers of the plurality of first segments is maintained constant along a radial direction of the electrode assembly; 23. The cylindrical battery cell according to claim 22, wherein the first current collecting plate is coupled to the first electrode tab within the weld target area.

24. At least a portion of the second electrode tab The cylindrical battery cell according to claim 19 , comprising a plurality of second segments divided along a winding direction of the electrode assembly.

25. The plurality of second sections include The cylindrical battery cell according to claim 24 , wherein the electrode assembly is folded along a radial direction.

26. The cylindrical battery cell comprises: a second current collecting plate coupled to a lower portion of the electrode assembly and electrically connected to the battery can, The second current collecting plate is The cylindrical battery cell according to claim 25 , wherein the cylindrical battery cell is bonded on a bonding surface formed by bending the plurality of second sections.

27. The plurality of second sections overlap each other in a multiplicity, the second electrode tab includes a welding target area where a number of overlapping layers of the plurality of second segments is maintained constant along a radial direction of the electrode assembly; 27. The cylindrical battery cell of claim 26, wherein the second current collecting plate is coupled to the second electrode tab within the weld target area.

28. The cylindrical battery cell comprises: The cylindrical battery cell of claim 1 , further comprising a first current collecting plate coupled to an upper portion of the electrode assembly and electrically connected to the top cap.

29. The first current collecting plate is 30. The cylindrical battery cell of claim 28, comprising a plurality of tab bonds extending radially from a central portion thereof.

30. The first current collecting plate is 30. The cylindrical battery cell of claim 29, further comprising a lead disposed between adjacent tab bonds and electrically connecting between the first current collecting plate and the top cap.

31. the battery can has a beading portion that is pressed along the outer circumferential surface of the battery can, 30. The cylindrical battery cell according to claim 28, wherein the first current collecting plate is located between the electrode assembly and a beading portion.

32. The maximum outer diameter of the first current collecting plate is 32. The cylindrical battery cell according to claim 31, wherein the inner diameter of the battery can at the height where the beading portion is formed is equal to or smaller than the inner diameter of the battery can.

33. The first current collecting plate is The cylindrical battery cell according to claim 28 , further comprising a first current collector hole formed at a position corresponding to a hole formed in the winding center of the electrode assembly.

34. The diameter of the first current collecting plate hole is 34. The cylindrical battery cell according to claim 33, wherein the diameter of the hole formed in the winding center of the electrode assembly is equal to or larger than the diameter of the hole.

35. The battery can is A closing portion is formed at a lower end opposite the upper end opening, The cylindrical battery cell according to claim 1 , wherein the closing portion is provided with a venting portion that breaks when the internal pressure of the battery can increases to or exceeds a reference value.

36. 36. The cylindrical battery cell of claim 35, wherein the venting portion is configured to have a thinner thickness than a peripheral area of ​​the closure portion.

37. The venting portion is 37. The cylindrical battery cell of claim 36, wherein one or both sides of the closure are formed by notching.

38. The cylindrical battery cell comprises:

32. The cylindrical battery cell of claim 31, further comprising an insulator disposed between the beading portion and the first current collecting plate.

39. The insulator is The cylindrical battery cell according to claim 38 , wherein the electrode assembly is interposed between a first electrode tab of the electrode assembly and an inner circumferential surface of the battery can.

40. A battery pack comprising a plurality of cylindrical battery cells according to any one of claims 1 to 39.

41. The cylindrical battery cells are arranged in a predetermined number of rows; The battery pack of claim 40 , wherein the top cap and the terminal extension member of each of the cylindrical battery cells are arranged toward an upward direction.

42. The battery pack includes a plurality of bus bars connecting the cylindrical battery cells in series and in parallel, the bus bars are disposed on top of the cylindrical battery cells, Each of the plurality of bus bars is a body portion extending between cell terminals of adjacent cylindrical battery cells; a plurality of first bus bar terminals extending to one side of the body portion and electrically coupled to the top caps of cylindrical battery cells located at the one side; and a plurality of second bus bar terminals extending to another side of the body portion and electrically coupling to the terminal extension members of the battery cans of cylindrical battery cells located on the other side.

43. 43. A motor vehicle comprising at least one battery pack according to any one of claims 40 to 42.

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