Electrode assembly, battery cell

Abstract

An electrode assembly, a battery cell. In a state where a first electrode (2), a first separator (3), a second electrode (4), and a second separator (3) are laminated, the assembly is wound into a cylindrical electrode assembly (1) by being wound around a winding center in a lengthwise direction, both surfaces of the first electrode (2) are coated with an active material, constituting a first electrode coated portion, one side end portion of the first electrode (2) in an axial direction constitutes a first electrode uncoated portion (21), both surfaces of the second electrode (4) are coated with an active material, constituting a second electrode coated portion (42), the other side end portion of the second electrode (4) in the axial direction constitutes a second electrode uncoated portion (41), a prescribed interval from a boundary portion of the second electrode coated portion (42) and the second electrode uncoated portion (41) toward an end portion of the second electrode uncoated portion (41) is coated with an insulating material, forming an insulating coating (45).

Description

Technical Field

[0001] This invention relates to electrode assemblies and battery cells. Background Technology

[0002] In cylindrical secondary batteries, in order to maximize the current collection efficiency, a gel roll type electrode assembly can be used, which has a battery canister with positive and negative electrode tabs extending vertically along the height direction.

[0003] like Figure 1 As shown, the electrode assembly, which is a gel roll wound around the center, has an uncoated portion 21 of the first electrode exposed on one side along its axial direction, and an uncoated portion 41 of the second electrode exposed on the other side. Here, we assume that the first electrode 2 is the positive electrode and the second electrode 4 is the negative electrode. However, the opposite scenario can also be applied.

[0004] Recently, such as Figure 2 This shows the uncoated portion exposed at the end being bent radially to form a flat surface, and as shown... Figure 3 The battery structure is shown with current collector 6 welded onto multiple uncoated sections that are bent.

[0005] However, during the pressure application process for welding the second electrode current collector 6 onto the multiple uncoated portions 41 of the bent second electrodes, such as Figure 4 As shown, there is a concern that the base end of the uncoated portion 41 of the second electrode may be bent. Therefore, even if the separation membrane 3 is sandwiched between the first electrode 2 and the second electrode 4, there is still a possibility that the uncoated portion 41 of the second electrode may come into contact with the adjacent first electrode 2 due to this bending, causing a short circuit.

[0006] Meanwhile, during the process of welding the uncoated portion 41 of the second electrode to the current collector plate 6 of the second electrode, the heat generated by welding reaches the separation membrane of the electrode assembly, which raises concerns about causing deformation of the separation membrane.

[0007] In the operating environment, the cylindrical secondary battery is used with the centrally protruding positive terminal facing upwards and the can serving as the negative terminal. Therefore, in the gel roll electrode assembly, the positive electrode tab connected to the axial end is continuously oriented upwards, both in a simple flow environment and under operating conditions.

[0008] Conversely, it can be said that the other end in the axial direction always faces the bottom. Therefore, apart from the pressure applied during the welding of the multiple uncoated portions 41 of the second electrodes, the multiple uncoated portions 41 of the second electrodes continuously receive axial loads in the operating environment. In particular, the axial loads received in the operating environment act on the bent welding portions 41 of the second electrodes, so the portion of the second electrode uncoated portion 41 located inside the bending portion and extending along the axial direction becomes more prone to deformation due to bending.

[0009] Moreover, regardless of whether the connection method on the positive side is to bend and weld the uncoated part 21 of the first electrode or to use the electrode tab 7, there is a risk of bending. Summary of the Invention

[0010] Technical problems to be solved

[0011] The present invention was made to solve the above-mentioned problems, and its object is to provide an electrode assembly that ensures the hardness of the base end of the uncoated portion and avoids bending of the base end of the uncoated portion during the process of applying pressure to the uncoated portion in the axial direction using a current collector, and a battery cell using the same.

[0012] The purpose of this invention is to provide an electrode assembly that prevents deformation of the separation membrane even when the base end of the uncoated portion is bent during the axial pressing of the uncoated portion using a current collector, and a battery cell using the same.

[0013] The purpose of this invention is to provide an electrode assembly and a battery cell that can prevent short circuits when the base end of the uncoated portion is bent during the axial pressing of the uncoated portion using a current collector and when the bent uncoated portion comes into contact with electrodes of different polarities.

[0014] The object of the present invention is to provide an electrode assembly that is resistant to bending under pressure and continuously subjected to loads due to the weight of the uncoated portion of the battery cell, and a battery cell using the same.

[0015] The purpose of this invention is to provide an electrode assembly and a battery cell that can prevent the separation membrane from being damaged or deformed by heat generated during welding of the uncoated portion.

[0016] The technical problem addressed by this invention is not limited to the objectives described above. Other objectives and advantages of this invention not mentioned will be understood through the following description, and will be further clearly understood through embodiments of this invention. Furthermore, it will be readily understood that the objectives and advantages of this invention can be achieved through the means and combinations thereof shown in the claims.

[0017] means of solving technical problems

[0018] The present invention can be applied to an electrode assembly 1 in which a separation membrane 3 is wound up while the first electrode 2 and the second electrode 4 are sandwiched between them. The first electrode 2 may have a region on the surface of the first electrode foil 20 coated with a first active material 23, i.e., a first electrode coating portion 22, and the second electrode 4 may have a region on the surface of the second electrode foil 40 coated with a second active material 46, i.e., a second electrode coating portion 42.

[0019] The second electrode coating portion 42 may have a wider width in the axial direction than the first electrode coating portion 22. Therefore, the two ends of the second electrode coating portion 42 in the axial direction may be positioned to extend further outward in the axial direction than the two ends of the first electrode coating portion 22 in the axial direction.

[0020] The second electrode 4 may have an uncoated area, i.e., the uncoated portion 41 of the second electrode, on one end in the axial direction (width direction). The boundary between the coated portion 42 and the uncoated portion 41 of the second electrode may be located further inside the axial end of the separation membrane 3.

[0021] The thickness of the second electrode 4 can be thinner than the thickness of the first electrode 2.

[0022] The rigidity of the material of the second electrode 4 can be lower than that of the material of the first electrode 2.

[0023] The first electrode 2 can form a positive electrode, and the second electrode 4 can form a negative electrode.

[0024] The first electrode 2 may have an uncoated active material region at the other end in the axial direction, namely the uncoated portion 21 of the first electrode.

[0025] The bending resistance of the uncoated portion 41 of the second electrode can be lower than that of the uncoated portion 21 of the first electrode.

[0026] The axial length of the uncoated portion 41 of the second electrode can be longer than the axial length of the uncoated portion 21 of the first electrode.

[0027] The first electrode 2 may have an electrode tab 7, which is welded to the area not coated with the first active material 23 and protrudes to the other side in the axial direction of the first electrode 2.

[0028] In order to solve the above-mentioned technical problems, the second electrode 4 of the present invention has an insulating coating 45, which is coated with an insulating material in a predetermined range from the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41 toward the end of the second electrode uncoated portion 41.

[0029] The aforementioned insulating coating 45 can be provided by applying an insulating liquid or by attaching insulating tape.

[0030] The insulating coating 45 may extend further outward in the axial direction than the axial end of the separation membrane 3.

[0031] The insulating coating 45 can be thinner than the second electrode coating 42. Therefore, unlike the case where the second electrode coating 42 is in close contact with the separation membrane 3, the insulating coating 45 can be lightly in contact with or separate from the separation membrane 3.

[0032] When the insulating coating 45 covers the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41, it can also cover the micro-area 43 at the end of the second electrode coated portion 42.

[0033] The thickness of the insulating coating 45 applied in the axial direction can be uniform.

[0034] In a certain section along the axial direction, the thickness of the insulating coating 45 may be uneven.

[0035] The second electrode coated portion 42, adjacent to the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41, may have a sliding portion whose thickness gradually decreases towards the boundary portion. Complementarily, the insulating coating 45 coated on the sliding portion may gradually thicken towards the boundary portion.

[0036] The uncoated portion 41 of the second electrode can be bent in the radial direction of the electrode assembly 1 at a predetermined position F. The bending position F is located further outward in the axial direction than the end of the separation membrane 3.

[0037] The insulating coating 45 can cover at least a portion of the area from the boundary between the coated portion 42 and the uncoated portion 41 of the second electrode to the bending position F of the uncoated portion 41 of the second electrode.

[0038] The aforementioned insulating coating 45 can be applied from the aforementioned bending position F along the axial direction without covering the uncoated portion 41 of the second electrode, which is equivalent to a specified gap G.

[0039] The uncoated portion 41 of the second electrode may have a cut-out portion N formed from its end toward the inner side in the axial direction, and a plurality of such cut-out portions N are arranged separately from each other along the periphery direction (length direction) of the second electrode 4.

[0040] The uncoated portion of the second electrode, located between two adjacent cut-out portions N in the perimeter direction, can be designated as having a cut-out tab T.

[0041] The circumferential length of the multiple aforementioned cut-off tabs T can be uniform. In contrast, the circumferential length of the multiple aforementioned cut-off tabs T can gradually increase or increase in stages from the core side toward the outer periphery.

[0042] In the aforementioned second electrode uncoated portion 41, the tab T may not be cut off within a specified range on the core end side and / or on the outer peripheral end side.

[0043] The shape of the aforementioned cut-off tab T can be a trapezoidal shape in which the width narrows from the base end toward the anterior end. In contrast, the aforementioned cut-off tab T can have various shapes such as triangle, semicircle, semi-ellipse, parallelogram, etc.

[0044] The aforementioned bending position F can be located at the base end of the aforementioned cut-off tab T.

[0045] According to the present invention, an insulating coating 45 is formed in the axial direction end of the second electrode 4 where the uncoated portion 41 of the second electrode is exposed. This coating is applied by an insulating material to a predetermined range from the boundary between the coated portion 42 of the second electrode and the uncoated portion 41 of the second electrode toward the end of the uncoated portion 41 of the second electrode.

[0046] When the insulating coating 45 covers the boundary between the coated portion 42 and the uncoated portion 41 of the second electrode, it can also cover the micro-area at the end of the coated portion 42. This further reliably reinforces the boundary between the coated portion 42 and the uncoated portion 41 of the second electrode, enabling more reliable insulation of the corresponding area.

[0047] The uncoated portion 41 of the second electrode can be bent along the centripetal direction of the electrode assembly 1. In this case, the uncoated portion 41 of the second electrode can be provided with guiding bending structures N and T to guide bending at a predetermined axial position F.

[0048] For example, the aforementioned guiding bending structures N and T can be formed by cutting the uncoated portion 41 of the second electrode along the axial direction from the front end of the uncoated portion 41 of the second electrode by an amount equivalent to the axial direction range in which the uncoated portion 41 of the second electrode needs to be bent, thereby dividing the uncoated portion 41 of the second electrode into a structure with a cut tab T.

[0049] The bending structure N and T guides the bending position F of the uncoated part 41 of the second electrode.

[0050] The insulating coating 45 can cover at least a portion of the area from the boundary between the coated portion 42 and the uncoated portion 41 of the second electrode to the bending position F.

[0051] The insulating coating 45 can extend further outward in the axial direction than the separation membrane 3. Therefore, even if the base end of the uncoated portion 41 of the second electrode is bent, the possibility of an electrical short circuit caused by the uncoated portion 41 of the second electrode and the first electrode 2 adjacent to the separation membrane 3 can be eliminated.

[0052] The aforementioned insulating coating 45 may not completely cover the aforementioned guiding bending structure 47 or the bending position, and may not cover an amount equivalent to the specified gap G. Therefore, when bending occurs at the bending position, stress is prevented from being transmitted to the insulating coating 45, thereby preventing damage to the insulating coating 45 and thus avoiding any impact on the compressive bending resistance of the insulating coating 45.

[0053] The aforementioned cut-off tab T can be bent radially at the bending position F. The aforementioned cut-off tab T can be bent in a centripetal direction. The aforementioned cut-off tab T can be bent centrifugally.

[0054] By bending the tab T as described above, the tab surface facing the axial direction can be welded to the second electrode current collector plate 6. The current collector plate 6 can be welded to the bottom 301F of the battery canister 301C or to the cover 307.

[0055] The aforementioned tab surface can be directly welded to the bottom 301F of the battery canister 301C or to the cover 307 without a current collector plate.

[0056] The uncoated portion 21 of the first electrode at the other end in the axial direction of the first electrode 2 may have a plurality of cut-off portions formed along the length direction, and the uncoated portion of the first electrode between the plurality of cut-off portions constitutes a cut-off tab.

[0057] The cut-off tab of the uncoated portion 21 of the first electrode can be bent in a centripetal or centrifugal direction and welded to the first electrode current collector 5. The first electrode current collector 5 can be welded to the electrode terminal 301R.

[0058] The electrode tabs 7 of the first electrode 2 can be soldered to the electrode terminal 301R.

[0059] Invention Effects

[0060] According to the present invention, the base end of the uncoated portion is reinforced by an insulating coating, thereby preventing the base end of the uncoated portion from being bent when the current collector is applied along the axial direction.

[0061] According to the present invention, even if the base end of the uncoated portion is bent during the process of applying pressure to the uncoated portion along the axial direction using the current collector plate, the thickness of the insulating coating is thinner than that of the electrode coated portion, and the insulating coating is separated from the separation membrane to a certain extent, so it is still possible to prevent the separation membrane from deforming.

[0062] According to the present invention, even if the base end of the uncoated portion is bent during the process of applying pressure to the uncoated portion along the axial direction using the current collector, and the bent uncoated portion comes into contact with electrodes of different polarities, the base end of the uncoated portion is coated with an insulating coating, so a short circuit will not occur.

[0063] According to the present invention, due to the insulating coating, the extension length of the separation membrane extending further outward in the axial direction from the coated portion of the second electrode can be further shortened. Therefore, the end of the separation membrane can be positioned further inward in the axial direction from the bent portion of the uncoated portion of the second electrode. This prevents the heat generated when welding the bent surface of the uncoated portion of the second electrode to the bottom or cover of the second electrode current collector or battery can from affecting the end of the separation membrane and causing deformation.

[0064] Battery cells with electrode assemblies featuring this structure offer exceptional safety. Therefore, these battery cells are ideally suited for use in electric vehicles exposed to continuous vibration or impact.

[0065] According to the present invention, the uncoated portion of the second electrode in the gel roll electrode assembly is bent radially so that adjacent uncoated portions of the second electrode overlap. Therefore, when the second electrode current collector is pressurized, the base end of the uncoated portion of the second electrode, reinforced by the insulating coating, resists bending, thereby preventing bending. Furthermore, even if the uncoated portion of the second electrode does bend, the insulating coating covers the corresponding bent portion, thus preventing a short circuit with the first electrode. This improves the safety of the cylindrical secondary battery.

[0066] The specific details for implementing the invention will be described below, along with the aforementioned effects and the specific effects of the invention. Attached Figure Description

[0067] Figure 1 A schematic diagram showing the side of an electrode assembly wound into a gel roll.

[0068] Figure 2 It shows that Figure 1 A schematic diagram showing the state in which the uncoated part of the electrode assembly is bent along the radial direction to form a flat surface.

[0069] Figure 3 It is shown as in Figure 2 The diagram shows the state of the current collector plate being welded to a flat surface and then pressurized.

[0070] Figure 4 This diagram shows the state in which the base end of the uncoated portion is bent due to pressure in the axial direction.

[0071] Figure 5 This is a diagram showing the unfolded view of the positive electrode (first electrode) used in the electrode assembly.

[0072] Figure 6 This is a diagram showing an unfolded view of an embodiment of the negative electrode (second electrode) according to the present invention for use in an electrode assembly.

[0073] Figure 7 This is a diagram viewed from the axial direction before winding, with the positive and negative electrodes and the separator layered.

[0074] Figure 8 It is a roll Figure 7 A side cross-sectional view of the electrode assembly formed by the stacked bodies.

[0075] Figure 9 It shows that Figure 8 A side cross-sectional view of the uncoated negative electrode portion extending towards the axial end of the electrode assembly, bent inward towards the radial direction.

[0076] Figure 10 and Figure 11 The diagram shows enlarged views of several embodiments of the uncoated negative electrode portion of the electrode assembly.

[0077] Figure 12 It is shown Figure 9 A side cross-sectional view of the bent, uncoated portion with a current collector welded on.

[0078] Figure 13 This is a diagram showing an unfolded view of another embodiment of the negative electrode according to the present invention.

[0079] Figure 14 It is a winding method Figure 13 A side cross-sectional view of an electrode assembly formed by a stack of negative electrodes.

[0080] Figure 15 A unfolded diagram showing another embodiment of the positive electrode.

[0081] Figure 16 It is a winding method Figure 15 A side cross-sectional view of an electrode assembly formed by a stack of positive electrodes.

[0082] Figure 17 It shows that Figure 14 or Figure 16 A perspective view of the uncoated negative electrode portion extending from the axial end of the electrode assembly, bent inward in the radial direction.

[0083] Figure 18 It is shown Figure 17 A three-dimensional view showing that the uncoated negative electrode and the uncoated positive electrode are respectively welded with current collectors.

[0084] Figure 19 It is contained inside the battery can. Figure 18A perspective view of a battery cell manufactured from the electrode assembly of the embodiment.

[0085] Figure 20 yes Figure 19 A cross-sectional view of the battery cell.

[0086] Figure 21 It is shown Figure 17 A three-dimensional diagram of the positive electrode with a current collector welded to it and no coating.

[0087] Figure 22 It is contained inside the battery can. Figure 21 A perspective view of a battery cell manufactured from the electrode assembly of the embodiment.

[0088] Figure 23 This is a side cross-sectional view of an electrode assembly with an additional electrode tab connected to the positive terminal.

[0089] Figure 24 It is containment Figure 23 A perspective view of a battery cell manufactured from the electrode assembly of the embodiment.

[0090] Figure 25 It shows the use of Figure 19 Battery packs are manufactured from battery cells.

[0091] Figure 26 It shows that it is equipped with Figure 25 Electric vehicles with battery packs.

[0092] Marker description

[0093] 1: Electrode assembly

[0094] 2: First electrode (positive electrode)

[0095] 20: First electrode foil

[0096] 21: Uncoated portion of the first electrode

[0097] 22: First electrode coating section

[0098] 23: First active substance

[0099] 3: Separation membrane

[0100] 4: Second electrode (negative electrode)

[0101] 40: Second electrode foil

[0102] 41: Uncoated portion of the second electrode

[0103] F: Bend position

[0104] G: Gap

[0105] N: Resected portion

[0106] T: Removal of the polar ear

[0107] 42: Second electrode coating section

[0108] 43: Micro-interval

[0109] 45: Insulating coating

[0110] 46: Second active substance

[0111] 5: First electrode current collector plate

[0112] 6: Second electrode current collector

[0113] 7: Electrode tabs

[0114] 300: Battery pack

[0115] 301: Battery cell

[0116] 301C: Battery Canister

[0117] 301R: Electrode terminal (rivet terminal)

[0118] 301F: Bottom

[0119] 302: Housing

[0120] 306: Gasket

[0121] 307: Cover

[0122] 308: Insulator

[0123] 309: Ministry of Fragility

[0124] B: Curled edge

[0125] C: Press-fit section

[0126] V: Vehicle

[0127] Y: Axis direction (width direction)

[0128] X: Side length direction

[0129] Z: Radial direction (normal direction) Detailed Implementation

[0130] The above-described objectives, features, and advantages will now be explained in detail with reference to the accompanying drawings, thereby enabling those skilled in the art to readily implement the technical concept of this invention. In describing this invention, detailed descriptions of well-known technologies related to this invention are omitted when they are deemed likely to obscure the spirit of the invention. Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to denote the same or similar constituent elements.

[0131] Although terms such as "first," "second," etc., are used to describe multiple constituent elements, these constituent elements are not limited to these terms. These terms are only used to distinguish one constituent element from other constituent elements, and unless otherwise specified, the first constituent element can also be the second constituent element.

[0132] Throughout the instruction manual, unless otherwise specified, each constituent element may be singular or plural.

[0133] Hereinafter, when it is described as any constituent arrangement being placed "above or below" or "on top of or below" a constituent element, in addition to any constituent element being connected to the upper or lower surface of the constituent element, it may also indicate that other constituent elements are sandwiched between the constituent element and any constituent arrangement placed above or below the constituent element.

[0134] Furthermore, when it is recorded that a certain constituent element is "connected", "combined" or "connected" with other constituent elements, multiple of the above constituent elements can be directly connected or connected. However, it should also be understood that each constituent element can be "sandwiched" with other constituent elements or that each constituent element can be "connected", "combined" or "connected" through other constituent elements.

[0135] Unless the context clearly indicates a different meaning, the singular expressions used in this specification include the plural. In this application, the terms "constituting" or "comprising" should not be construed as necessarily including all of the multiple constituent elements or steps described in the specification, but should be interpreted as excluding some of the constituent elements or steps, or further including other constituent elements or steps.

[0136] Throughout the instruction manual, when referred to as "A and / or B", it means A, B, or A and B unless otherwise specified. When referred to as "C to D", it means C and above and D and below unless otherwise specified.

[0137] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0138] In describing the embodiments, the axial direction Y refers to the direction extending from the axis of the winding center of the electrode assembly 1 constituting the gel roll, the radial direction Z refers to the direction approaching (centripetal) or away from (centrifugal) the aforementioned axis, and the periphery (circumferential) direction X refers to the direction wrapping around the aforementioned axis. The axial direction Y of this electrode assembly 1 can correspond to the width direction Y of the electrode or separation membrane constituting the laminate before winding, the periphery direction X of the electrode assembly 1 can correspond to the length direction X of the electrode or separation membrane constituting the laminate before winding, and the radial direction Z of the electrode assembly 1 can correspond to the normal direction Z of the sheet-type electrode or separation membrane constituting the laminate before winding.

[0139] The cylindrical secondary battery is manufactured by embedding an electrode assembly 1, which is wound into a gel roll inside the cylindrical battery canister.

[0140] The electrode assembly 1 housed in the cylindrical battery can is formed by sequentially stacking a sheet-like first electrode 2, a first separation membrane 3, a second electrode 4, and a second separation membrane 3 to form a laminate, and then winding it along the length X direction of the sheet. Thus, the gel-roll type electrode assembly 1 substantially has a thick-walled circular tube shape with a hollow winding shaft. That is, the length direction of the gel-roll sheet corresponds to the side direction of the cylindrical electrode assembly 1, and the width direction of the gel-roll sheet corresponds to the axial direction of the electrode assembly 1. Furthermore, the normal direction of the surface of the gel-roll sheet corresponds to the radial direction of the electrode assembly 1.

[0141] The first electrode 2 can be a positive electrode, and the second electrode 4 can be a negative electrode. The first separation membrane 3 and the second separation membrane 4 can be separation membranes of the same material, but are named first and second simply to distinguish them according to their stacking positions.

[0142] The first electrode 2 and the second electrode 4 described above have a predetermined width in the width direction Y, and can be long rectangular metal foils that extend in the length direction X. For example, the first electrode 2 can be aluminum foil, and the second electrode 4 can be copper foil.

[0143] A first active material 23 is coated on one or both surfaces of the first electrode 2 to form a first electrode coating portion 22. Similarly, a second active material 46 is coated on one or both surfaces of the second electrode 4 to form a second electrode coating portion 42. The other end in the width direction Y forms an uncoated portion 41 of the second electrode.

[0144] In one embodiment, an active material is coated on both surfaces of the first electrode 2 to form a first electrode coated portion 22. Additionally, one end in the width direction Y forms an uncoated portion 21 of the first electrode.

[0145] As a result, the first electrode uncoated portion 21 is exposed on one side of the electrode assembly 1 in the axial direction as shown in the figure, and the second electrode uncoated portion 41 is exposed on the other side of the electrode assembly 1 in the axial direction as shown in the figure.

[0146] The positive electrode active material coated on the positive electrode plate (the sheet constituting the first electrode) and the negative electrode active material coated on the negative electrode plate (the sheet constituting the second electrode) can be active materials known in the art, without any limitation.

[0147] The first electrode 2 and the second electrode 4 can be stacked with a separation membrane 3 sandwiched between them. Additionally, another separation membrane 3 can be stacked on the lower part of the second electrode 4. When stacking the first electrode 2 and the second electrode 4, they are stacked such that the first electrode coating portion 22 and the second electrode coating portion 42 are stacked on top of each other. The separation membrane 3 can be disposed between the regions of the first electrode coating portion 22 and the second electrode coating portion 42 to avoid direct contact between them.

[0148] The boundary between the uncoated portion 21 and the coated portion 22 of the first electrode is disposed further inside the separation membrane 3 in the width direction on one side, and the uncoated portion 21 of the first electrode may extend further in the width direction than the separation membrane 3. The boundary between the uncoated portion 41 and the coated portion 42 of the second electrode is disposed further inside the separation membrane 3 in the width direction on the other side, and the uncoated portion 41 of the second electrode may extend further in the width direction than the separation membrane 3.

[0149] The thickness of the first electrode 2 can be greater than the thickness of the second electrode 4. The rigidity of the material of the first electrode 2 can be greater than the rigidity of the material of the second electrode 4. The width extension length of the uncoated portion 41 of the second electrode can be longer than the width extension length of the uncoated portion 21 of the first electrode. Thus, the uncoated portion 41 of the second electrode can be made of a material with relatively weaker rigidity than the uncoated portion 21 of the first electrode, and has a longer extension length and a thinner thickness. Consequently, when the uncoated portion is pressurized in the axial direction, the uncoated portion 41 of the second electrode is more likely to buckle compared to the uncoated portion 21 of the first electrode.

[0150] The area of ​​the first electrode 2 is smaller than the area of ​​the second electrode 4. That is, the width and length of the first electrode 2 are slightly smaller than the width and length of the second electrode 4. Therefore, as... Figure 7 As shown, in the state of stacking the first electrode 2, the first separation membrane 3, the second electrode 4, and the second separation membrane 3, the second electrode 4 extends further outward in the length direction than the first electrode 2.

[0151] The width of the first electrode coating portion 22 is also smaller than the width of the second electrode coating portion 42. Therefore, in the width direction or axial direction, the second electrode coating portion 42 extends further outward than the first electrode coating portion 22. Conversely, this means that the distance by which the axial end of the first electrode 2 is recessed inward in the axial direction compared to the axial end of the separation membrane 3 is greater than the distance by which the axial end of the second electrode 4 is recessed inward in the axial direction compared to the axial end of the separation membrane 3. That is, the axial end of the first electrode 2 is more hidden inward in the separation membrane 3 than the axial end of the second electrode 4, so it is obvious that the probability of a short circuit between the first electrode 2 and the second electrode 4 occurring is higher at the axial end of the electrode assembly 1 formed by extending from the uncoated portion 21 of the first electrode.

[0152] However, it should be noted that, as mentioned above, the second electrode uncoated portion 41 is more easily bent than the first electrode uncoated portion 21. Therefore, the second electrode uncoated portion 41 is bent and thus presses against the separation membrane 3, thereby coming into contact with the other end of the first electrode 2 in the axial direction, which increases the possibility of a short circuit.

[0153] As shown in the figure, the uncoated portions 21 and 41 of the first and second electrodes, respectively, exposed on both sides of the electrode assembly 1 in the axial direction, can be folded inward in the radial direction, i.e., in the centripetal direction. The bent uncoated portions can provide a substantially flat surface facing the axial direction. The uncoated portions that are bent and flattened on both sides of the axial direction can be electrically connected by welding the first electrode current collector 5 and the second electrode current collector 6, respectively.

[0154] In this embodiment, the case where the second electrode current collector 6 is welded to the bent surface of the uncoated portion 41 of the second electrode is mainly described. During the welding process of the second electrode current collector 6 to the welding point of the uncoated portion 41 of the second electrode, the second electrode current collector 6 remains in close contact with the uncoated portion 41 of the second electrode. In this process, the second electrode current collector 6 applies pressure to the uncoated portion 41 of the second electrode in the axial direction.

[0155] At this point, in order to maintain a tight fit, considerable pressure is applied, so there is a concern that the base end of the uncoated portion 41 of the second electrode may be bent. Figure 4 As shown. Therefore, in an embodiment of the present invention, an insulating coating 45 is formed near the base end of the uncoated portion 41 of the second electrode, where there is a primary concern about bending.

[0156] The aforementioned insulating coating 45 comprises a polymer resin and may include inorganic filters such as Al2O3.

[0157] The aforementioned insulating coating 45 reinforces the rigidity near the base end of the uncoated portion 41 of the second electrode. As a result, when the uncoated portion 41 of the second electrode is subjected to axial force through the second electrode current collector 6, the bottom 301F of the battery canister 301C, or the cover 307 for welding the uncoated portion 41 of the second electrode, the base end of the uncoated portion 41 of the second electrode is not bent.

[0158] If the base end of the uncoated portion 41 of the second electrode is reinforced by the insulating coating 45, even if the base end of the uncoated portion 41 of the second electrode is bent, the uncoated portion 41 of the second electrode will not directly contact the first electrode 2, but will contact the first electrode 2 by sandwiching the insulating coating 45. Therefore, it is possible to prevent a short circuit between the first electrode 2 and the second electrode 4.

[0159] The insulating coating 45 provides bending resistance during the process of bending the uncoated portion 41 of the second electrode in the radial direction. As a result, when bending the uncoated portion 41 of the second electrode in the radial direction, the area coated with the insulating coating 45 hardly deforms, and deformation mainly occurs in the area without the insulating coating 45.

[0160] The insulating coating 45 covers a predetermined area from the boundary between the coated portion 42 and the uncoated portion 41 of the second electrode toward the end of the uncoated portion 41 of the second electrode. The insulating coating 45 starts from the inner side of the axial end of the separation membrane 3 and extends further outward in the axial direction.

[0161] The insulating coating 45 covers the micro-area 43 at the end of the second electrode coated portion 42 when covering the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41. The location where the maximum deformation occurs under bending is the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41. Since the insulating coating 45 covers the micro-area 43 at the end of the second electrode coated portion 42 at such a boundary, the bending resistance at the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41 is significantly improved.

[0162] The insulating coating 45 can be applied with a uniform thickness, or its thickness can vary along the axial direction. Figure 10 The diagram shows a structure in which the thickness of the insulating coating 45 gradually increases in the transition region (thinning region) formed at the end of the negative electrode active material. In the region covering the uncoated portion 41 of the second electrode, the thickness of the insulating coating 45 is uniform.

[0163] on the contrary, Figure 11 This shows that, apart from the area covering the uncoated portion 41 of the second electrode, the thickness of the insulating coating 45 is also uniform in the transition area.

[0164] The thickness of the insulating coating 45 can be thinner than the thickness of the negative electrode active material layer. Thus, as shown in the figure, the second electrode coating 42 is in close contact with the separation membrane 3 in the radial direction, but the insulating coating 45 is separated from the separation membrane 3 by a certain distance or, even if in contact, is not in close contact.

[0165] As a result, even if external force is applied to the uncoated portion 41 of the second electrode during the bending process and the welding process of the second electrode current collector 6 to the uncoated portion 41 of the second electrode, causing deformation of the base end of the uncoated portion 41, not only can the amount of change be suppressed, but the deformation of the base end of the uncoated portion 41 of the second electrode can also be prevented from immediately affecting the separation membrane 3. That is, the uncoated portion 41 of the second electrode has a range that allows deformation without affecting the separation membrane 3, corresponding to the amount of the gap between the insulating coating 45 and the separation membrane 3.

[0166] Furthermore, if the insulating coating 45 is separated from the separation membrane 3, it prevents the heat generated during the welding of the uncoated portion 41 of the second electrode to the second electrode current collector 6, the bottom 301F of the battery can 301C, or the cover 307 from being directly transferred to the separation membrane 3 through the insulating coating 45, thereby protecting the separation membrane 3 from the effects of welding heat. Moreover, because the insulating coating 45 can further reduce the protrusion height of the separation membrane 3 in the axial direction, it can further extend the distance from the position where welding heat is generated to the axial end of the separation membrane 3, thereby further increasing the effect of protecting the separation membrane 3 from the effects of welding heat.

[0167] The electrode assembly 1 is wound into a cylindrical shape, so the insulating coating area of ​​the uncoated portion 41 of the second electrode, which is coated with the insulating coating 45, also has a cylindrical curved surface. The cylindrical curved surface inherently possesses bending resistance due to its shape. According to the embodiment, the insulating coating area has a thicker cylindrical curved surface, so when the area located on the upper part of the cylindrical curved surface is bent radially, the insulating coating area provides higher bending resistance. This guides bending in the uncoated portion 41 of the second electrode.

[0168] At this point, the aforementioned insulating coating area provides higher bending resistance. Therefore, even if the thickness of the insulating coating 45 is thinner than the thickness of the negative electrode active material layer, causing the surface of the insulating coating 45 to separate from the separation membrane 3 in the radial direction and thus unable to obtain the support of the separation membrane 3, it can still fully exert its bending resistance.

[0169] The front end of the aforementioned insulating coating 45 is coated to maintain a small gap G with the bending position F of the uncoated portion 41 of the second electrode. This serves to guide the uncoated portion 41 of the second electrode to bend at the bending position F. Furthermore, the uncoated portion 41 of the second electrode deforms due to the small gap G between it and the insulating coating 45, thus preventing damage to the insulating coating 45 from the bending process of the uncoated portion.

[0170] like Figure 12 As shown, the uncoated portion 41 of the second electrode, which has an insulating coating 45, can be prevented from bending even when it is pressed in the axial direction by the second electrode current collector 6.

[0171] On the other hand, the uncoated portion 41 of the second electrode can be provided with guiding bending structures N and T, which guide bending at a predetermined axial position. The guiding bending structures N and T can, for example, be structures consisting of a cut-off portion N and a cut-off tab T divided by such a cut-off portion N. The cut-off portion N is formed by cutting the uncoated portion 41 from its front end along the axial direction by an amount corresponding to the axial direction range where the uncoated portion 41 needs to be bent. With these guiding bending structures N and T, the bending position F of the uncoated portion 41 can be more accurately guided to the lower end of the cut-off tab T. Of course, the same guiding bending structure can also be applied to the uncoated portion 21 of the first electrode (see reference). Figure 15 ).

[0172] Reference Figure 13 The uncoated tab T can be shaped such that its height gradually increases from the core side (left side in the figure) towards the outer periphery side (right side in the figure). As a result, the flatness of the uncoated tab T can be higher when it is laid down radially inward by the bending process of the uncoated portion 41 of the second electrode. Furthermore, by completely removing the uncoated tab on the core side, even if the uncoated tab T is bent radially inward, the phenomenon of the bent uncoated tab T obstructing the hollow portion of the electrode assembly 1 can be prevented. Moreover, if the uncoated tab T corresponding to the last winding loop on the outer periphery side is removed, the phenomenon of accidental deformation of the outermost uncoated tab T during the processing of the electrode assembly 1 can be prevented.

[0173] The insulating coating 45 can be provided in the range from the boundary between the second electrode coated portion 42 and the second electrode uncoated portion 41 to the guide bending structure N and T.

[0174] The insulating coating 45 can cover at least a portion of the aforementioned interval in the axial direction.

[0175] An example is shown in which an insulating coating 45 is applied to the base end of the uncoated portion 41 of the second electrode. However, the insulating coating 45 described above can also be applied to the uncoated portion 21 of the first electrode.

[0176] Figure 14 Showing the winding as Figure 13 The electrode assembly 1 shows a second electrode 4 with the height of the cut-off tab T gradually increasing towards the outer periphery, and a first electrode 2 with the height of the uncoated portion 21 of the first electrode being uniform.

[0177] Figure 16 Showing the winding as Figure 13 The second electrode 4, as shown, exhibits a manner in which the height of the cut-off ear T gradually increases towards the peripheral side. Figure 15 An electrode assembly is shown in which the height of the cut-off tab T gradually increases toward the outer peripheral side, representing a first electrode 2.

[0178] If the height of the uncoated portion 21 of the first electrode and / or the uncoated portion 41 of the second electrode gradually decreases towards the center, then even when they are bent in the centripetal direction, as Figure 17 As shown, the hollow portion of the core of the electrode assembly 1 can also be kept open along the axial direction. This serves as a channel through which welding fixtures, etc., can pass or as a path for injecting and impregnating electrolyte.

[0179] The first electrode current collector 5 and the second electrode current collector 6 are respectively attached and fixed to the surfaces of the multiple overlapping uncoated portions 21 of the first electrode and the multiple uncoated portions 41 of the second electrode by means of welding or other methods. Figure 18 As shown.

[0180] The aforementioned insulating coating 45 can extend further outward in the axial direction than the separation membrane 3. Therefore, even if the base end of the uncoated portion 41 of the second electrode is bent, the possibility of an electrical short circuit caused by the uncoated portion 41 of the second electrode and the first electrode 2 adjacent to the separation membrane 3 can be eliminated.

[0181] The insulating coating 45 may not completely cover the aforementioned guiding bending structure N, T, or the bending position, and may not cover the specified gap G. Therefore, when a bend occurs at the bending position, stress is prevented from being transferred to the insulating coating 45, thereby avoiding any impact on the compressive bending resistance of the insulating coating 45.

[0182] The bending resistance of the gap G region without the insulating coating 45 is weaker than that of the region with the insulating coating 45. Therefore, even if the uncoated portion 41 of the second electrode is bent by the pressure applied by the second electrode current collector 6, it can only be guided to the gap G region. The bending position is separated from the first electrode 2 by a considerable distance in the axial direction, so even if bending occurs in the gap G region, there is no possibility that a corresponding part will come into contact with the first electrode 2. In other words, the gap G region can be formed at a distance from the end opposite to the first electrode 2 in the axial direction, ensuring that even if bending occurs, there is no possibility that a corresponding part will come into contact with the first electrode 2.

[0183] The insulating coating 45 has the effect of increasing the thickness of the uncoated portion 41 of the second electrode. Therefore, in the area covered by the insulating coating 45, the resistance to bending of the uncoated portion 41 of the second electrode becomes greater.

[0184] Furthermore, even if the uncoated portion 41 of the second electrode is bent in an unexpected area of ​​the insulating coating 45, since the corresponding portion is covered by the insulating coating 45, there is no possibility of it coming into contact with the first electrode 2 and thus short-circuiting.

[0185] The aforementioned insulating coating 45 can be applied to the uncoated portion of the electrode, which is more easily bent, based on the uncoated portion area where bending is possible. Assuming that the uncoated portions including the first electrode uncoated portion 21 and the second electrode uncoated portion 41 are bent relative to a bending position F, the bending range extends from the bending position F to the boundary between the uncoated portion and the active material coated portion. This can be represented as... Figure 10 The interval from the upper part of the gap G interval to the upper part of the micro-interval 43. With the length of this interval as L, the thickness of the electrode foil as t, and the elastic modulus of the metal as E, the compressive bending load per unit length in the edge direction of the uncoated portion is inversely proportional to L2, directly proportional to the elastic modulus E, and directly proportional to the second moment of section I. The second moment of section I per unit length is directly proportional to t3. Therefore, the compressive bending resistance of the first electrode uncoated portion 21 and the second electrode uncoated portion 41 can be determined based on Et. 3 / L 2 The value is determined.

[0186] like Figure 19 as well as Figure 20 This shows that Figure 18The electrode assembly 1 can be housed inside the battery canister 301C. The battery canister 301C is connected to the second electrode current collector 6 of the electrode assembly 1, thereby forming a negative terminal. The electrode terminal 301R located at the center of one end of the battery canister 301C is connected to the first electrode current collector 5 of the electrode assembly 1, thereby forming a positive terminal. In other words, the electrode assembly 1 can be housed in the battery canister 301C to form a cylindrical battery cell 301.

[0187] Reference Figure 20 The periphery of the first electrode current collector plate 5 is welded to the uncoated portion 21 of the first electrode, and the center of the first electrode current collector plate 5 is welded to the electrode terminal 301R, so that the electrode terminal 301R can have the polarity of the first electrode. An insulator 308 is sandwiched between the first electrode current collector plate 5 and the bottom 301F of the battery canister 301C, so that the battery canister 301C is insulated from the first electrode.

[0188] The central portion of the second electrode current collector plate 6 is opened, thereby exposing the hollow portion of the core of the electrode assembly 1 in the axial direction. As shown in the attached figure, a portion of the second electrode current collector plate 6 is welded to the uncoated portion 41 of the second electrode, which is coated with an insulating coating 45, and a portion is crimped or welded to the battery canister 301C.

[0189] The open end of the battery canister 301C is clamped with a gasket 307, and the cap 307 is closed off. Figure 20 The diagram shows a cap 307 with a flexible portion 309 for ventilation and the like being crimped and fixed to a crimping portion C of a battery canister 301C, sandwiching a gasket 307. A portion of the uncoated portion 41 of the second electrode engages with the crimping portion C, thereby allowing the second electrode and the battery canister 301C to be energized.

[0190] like Figure 20 The embodiment illustrates a structure in which the second electrode current collector 6 engages with the crimping portion C. However, as long as the second electrode can be electrically connected to the battery canister 301C, for example, the second electrode current collector 6 can also be sandwiched between the rolled edge portion B and the electrode assembly 1. Furthermore, they can also be electrically connected through crimping and / or welding.

[0191] Figure 21 The diagram shows an electrode assembly 1 in which the second electrode current collector 6 is not connected to the uncoated portion 41 of the second electrode, but only the first electrode current collector 5 is connected to the uncoated portion 21 of the first electrode. According to this structure, as... Figure 22 As shown, for example, the bent portion of the uncoated portion 41 of the second electrode, which is coated with an insulating coating 45, can be directly welded to the cover 307 of the battery can 301C.

[0192] Reference Figure 22The uncoated portion 41 of the second electrode is directly welded to the cover 307. The cover 307 has the polarity of the second electrode, and the battery canister 301C can also have the polarity of the second electrode. Therefore, the cover 307 and the battery canister 301C can be fixed by welding, soldering, or other methods. A vulnerable portion 309 is provided in the center of the cover 307, thereby enabling ventilation and also serving as an injection port.

[0193] According to the embodiment, in order to weld the cover 307 to the uncoated portion 41 of the second electrode, the cover 307 is pressed against the uncoated portion 41 of the second electrode in the axial direction. At this time, the insulating coating 45 resists this pressing force with sufficient rigidity, so bending does not occur. Furthermore, due to the rigidity of the insulating coating 45, the protruding length of the separation membrane 3 in the axial direction can be reduced, thus preventing the heat generated when welding the cover 307 to the uncoated portion 41 of the second electrode from affecting the separation membrane 3.

[0194] Figure 23 and Figure 24 The diagram shows a structure in which the uncoated portion 41 of the second electrode is bent and directly connected to the bottom of the battery can 301C without the second electrode current collector 6, and the first electrode 2 is electrically connected to the electrode terminal 301R of the cover 307 via the electrode tab 7. As shown, according to this structure, the bent portion of the uncoated portion 41 of the second electrode, which is coated with an insulating coating 45, can be directly welded to the bottom 301F of the battery can 301C.

[0195] As in the embodiment, for the second electrode 4 with relatively high internal resistance, the uncoated portion 41 of the second electrode with multiple current paths significantly reduces the internal resistance. For the first electrode 2, the internal resistance is reduced by using two or more electrode tabs 7, and an open structure (vulnerable portion 309) can be applied. Although not shown in the figures, a thermal runaway prevention structure CID (Current Interrupt Device) can also be applied to the cover 307.

[0196] When the cover 307 employs this opening structure or CID structure, assembly is easy when using structures such as electrode tabs, depending on the assembly method. In this structure, as described in the above embodiment, when the first electrode 2 adopts the structure of the first electrode uncoated portion 21 and the first electrode current collector 5, they occupy a considerable volume in the axial direction, which may actually be detrimental to ensuring electrical capacitance. Therefore, in this embodiment, electrode tabs 7 are used when connecting the first electrode 2 to the electrode terminal 301R, thereby further ensuring electrical capacitance.

[0197] Furthermore, the bent uncoated portion 21 of the first electrode and the first electrode current collector 5 obstruct or hinder the internal pressure of the battery canister 301C from acting on the opening structure or CID structure, which may be detrimental to the realization of the function. Conversely, as in the embodiment, by using two or more electrode tabs 7, the internal resistance can be reduced by the required amount without affecting the opening function and the CID function.

[0198] Figure 25 A battery pack 300 is shown in which such battery cells 301 are housed in a housing 302 and connected in series and / or in parallel using busbars or the like, thereby providing appropriate voltage and current.

[0199] and Figure 26 A car V equipped with the aforementioned battery pack 300 is shown. The battery cell 301, with the insulating coating 45 of the present invention applied, can be used as a vehicle battery cell. Furthermore, the aforementioned battery cell 301 can also be applied to various other fields.

[0200] The above embodiments are merely exemplary in all respects and should be understood as non-limiting embodiments. The scope of protection of the invention will be shown by the claims, not by the detailed description above. Furthermore, it should be interpreted that all modifications and variations derived from the meaning and scope of the claims and their equivalents are included within the scope of protection of the invention.

[0201] As described above, the present invention has been illustrated with reference to the accompanying drawings. However, the present invention is not limited to the embodiments and drawings disclosed in this specification. It is obvious that those skilled in the art can obtain various modifications within the scope of the technical concept of the present invention. Moreover, even though the effects of the configuration according to the present invention are not explicitly stated in the above description of the embodiments of the present invention, it should be acknowledged that the effects that can be predicted based on the corresponding configuration are still to be recognized.

Claims

1. An electrode assembly (1), which is wound up in a state where a separation membrane (3) is stacked between a first electrode (2) and a second electrode (4), characterized in that, The surface of the first electrode (2) is provided with a first electrode coating portion (22), which is a region coated with an active material. The surface of the second electrode (4) is provided with a second electrode coating portion (42), which is a region coated with an active material. The second electrode (4) mentioned above also has: The uncoated portion (41) of the second electrode is the area on one side of the second electrode (4) in the axial direction where no active material is coated, and the axial direction is the width direction; as well as An insulating coating (45) is applied to a predetermined area from the boundary between the second electrode coated portion (42) and the second electrode uncoated portion (41) toward the end of the second electrode uncoated portion (41) by an insulating material. The boundary between the coated portion (42) and the uncoated portion (41) of the second electrode is located further inward in the axial direction than the axial end of the separation membrane (3). The insulating coating (45) extends further outward in the axial direction than the axial end of the separation membrane (3). In this case, the uncoated portion (41) of the second electrode is bent in the radial direction of the electrode assembly (1) at the bending position (F), and The aforementioned bend position (F) is positioned further outward in the axial direction compared to the end of the aforementioned separation membrane (3). The amount by which the insulating coating (45) does not cover the uncoated portion (41) of the second electrode along the axial direction from the bending position (F) is equivalent to a specified gap (G). The first electrode (2) has an uncoated portion (21) on the other side of its axial direction. This uncoated portion (21) is a region where no active material is coated. The rigidity of the uncoated portion (41) of the second electrode is lower than that of the uncoated portion (21) of the first electrode.

2. The electrode assembly according to claim 1, characterized in that, When the insulating coating (45) covers the boundary between the second electrode coated portion (42) and the second electrode uncoated portion (41), it also covers the micro-area (43) at the end of the second electrode coated portion (42).

3. The electrode assembly according to claim 1, characterized in that, The insulating coating (45) is thinner than the second electrode coating (42).

4. The electrode assembly according to claim 1, characterized in that, The insulating coating (45) covers at least a portion of the area from the boundary between the coated portion (42) and the uncoated portion (41) of the second electrode to the bending position (F) of the uncoated portion (41) of the second electrode.

5. The electrode assembly according to claim 1, characterized in that, The uncoated portion (41) of the second electrode described above has a cut-out portion (N) formed from its end toward the inner side in the axial direction. The aforementioned cut-off portions (N) are arranged in multiple separate configurations along the perimeter direction of the second electrode (4), where the perimeter direction is the length direction. The cut tab (T) is defined by the uncoated portion of the second electrode located between two adjacent cut portions (N) in the perimeter direction. The aforementioned bending position (F) is located at the base end of the aforementioned cut-off tab (T).

6. The electrode assembly according to claim 1, characterized in that, The first electrode (2) is the positive electrode and the second electrode (4) is the negative electrode.

7. The electrode assembly according to claim 1, characterized in that, The second electrode coating portion (42) is configured to have a wider width in the axial direction than the first electrode coating portion (22), thereby the two ends of the second electrode coating portion (42) in the axial direction extend further outward in the axial direction than the two ends of the first electrode coating portion (22).

8. The electrode assembly according to claim 1, characterized in that, The thickness of the second electrode (4) is thinner than that of the first electrode (2).

9. The electrode assembly according to claim 1, characterized in that, The axial length of the uncoated portion (41) of the second electrode is longer than the axial length of the uncoated portion (21) of the first electrode.

10. The electrode assembly according to claim 1, characterized in that, The aforementioned insulating coating (45) is applied to the area of ​​the uncoated portion (41) of the second electrode, which has curvature along the perimeter direction.

11. The electrode assembly according to claim 1, characterized in that, The first electrode (2) has an uncoated region where the first active material (23) is not coated, and the uncoated region is connected to two or more electrode tabs (7).

12. A battery cell, characterized in that, include: The electrode assembly (1) according to any one of claims 1 to 11 and the battery can (301C) housing the electrode assembly (1).

13. The battery cell according to claim 12, characterized in that, The uncoated portion (41) of the second electrode is welded to the second electrode current collector (6) or directly welded to the bottom (301F) or cover (307) of the battery can (301C).

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