Manufacturing method of battery assembly, battery assembly, and secondary battery including the same

Abstract

To provide a method for manufacturing a battery assembly that prevents a short separator or an end of a positive electrode from breaking in a battery assembly in which a negative electrode, a separator, and a positive electrode laminate are wound up, a battery assembly, and a secondary battery including the battery assembly.SOLUTION: A battery assembly 10 includes a negative electrode 1, a first separator 3a, a positive electrode 2, and a second separator 3b stacked and wound up, and the negative electrode includes a negative electrode active material portion 1a in which a negative electrode active material is stacked on both sides of the negative electrode current collector, and a negative electrode uncoated portion 1b in which a negative electrode active material is not stacked on the negative electrode current collector. The negative electrode uncoated portion is wound around the outermost periphery of the battery assembly and further includes a first sealing tape 4 attached to a winding end of at least one of the negative electrode, the first separator, the positive electrode, and the second separator. At least one of the first separator and the second separator and at least one of the negative electrode and the positive electrode are attached to one side of the first sealing tape.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0154714, filed with the Korean Intellectual Property Office on November 11, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a method for manufacturing a battery assembly, a battery assembly, and a secondary battery including the same. More specifically, the present invention relates to a method for manufacturing a battery assembly that prevents folding and stepping of the separator when winding a negative electrode, a separator, and a positive electrode, a battery assembly, and a secondary battery including the same. [Background technology]

[0003] Depending on the shape of the battery case, secondary batteries are classified into cylindrical batteries and prismatic batteries, in which the battery assembly (or battery subassembly) is housed in a cylindrical or prismatic metal can, and pouch-type batteries, in which the battery assembly is housed in a pouch-type case made of aluminum laminate sheet.

[0004] The battery assembly housed in the battery case is a chargeable and dischargeable power generating element consisting of a laminated structure of cathode / separator / anode, and is classified into a folding type battery assembly (jelly roll) in which a separator is interposed between a long sheet-shaped cathode and anode coated with an active material and wound up, and a stack type battery assembly in which multiple cathodes and anodes of a predetermined size are stacked in order with a separator interposed between them. Among them, the jelly roll has the advantage of being easy to manufacture and having a high energy density per weight.

[0005] In a conventional jelly roll battery assembly, when a laminated structure of a cathode / separator / anode is wound up, the separator is wound up at the outermost edge. In the conventional jelly roll battery assembly, the separator located at the outermost edge may be longer than the separators located at the cathode, anode, and between the cathode and anode. Therefore, there is a problem that the separator located at the outermost edge is bent due to the centrifugal force when winding up the separator located at the outermost edge.

[0006] Therefore, there is an emerging need for a method for manufacturing a battery assembly, a battery assembly, and a secondary battery including the same, which can fundamentally solve the above problem and alleviate the problem of short components breaking due to centrifugal force and differences in length among components included in the battery assembly when winding up a cathode / separator / anode stacked structure. Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above-mentioned problems of the conventional art, the present invention provides a method for manufacturing a battery assembly that prevents short separators or ends of the positive electrode from breaking when winding up a negative electrode, a separator, and a positive electrode stack, a battery assembly, and a secondary battery including the same. [Means for solving the problem]

[0008] One embodiment of the present invention provides a battery assembly including a negative electrode, a first separator, a positive electrode, and a second separator stacked and wound up, wherein the negative electrode included in the battery assembly includes a negative electrode active material portion in which a negative electrode active material is stacked on one surface of a negative electrode current collector, and a negative electrode uncoated portion in which a negative electrode active material is not stacked on one surface of the negative electrode current collector, and the negative electrode uncoated portion is wound up around the outermost periphery of the battery assembly.

[0009] One embodiment of the present invention provides a battery assembly further including a first sealing tape attached to a winding end of one or more of the negative electrode, the separator, and the positive electrode, wherein at least a portion of one surface of the first sealing tape is positioned to fix the winding end of one or more of the negative electrode, the separator, and the positive electrode.

[0010] One embodiment of the present invention provides a battery assembly further including a second sealing tape attached to at least one surface of the negative electrode uncoated portion, wherein at least a portion of one surface of the second sealing tape is positioned to be fixed to a winding end portion of the negative electrode uncoated portion.

[0011] Another embodiment of the present invention provides a secondary battery including the battery assembly, a can having one side open and containing the battery assembly therein, and a cap assembly coupled to an upper part of the can. Still another embodiment of the present invention provides a method for manufacturing a battery assembly, the method including supplying a negative electrode, a first separator, a positive electrode, and a second separator to a winding core in this order and winding them up, the negative electrode including a negative electrode active material portion in which a negative electrode active material is layered on one side of a negative electrode current collector, and a negative electrode uncoated portion in which a negative electrode active material is not layered on one side of the negative electrode current collector, the negative electrode uncoated portion being the outermost portion. [Effects of the Invention]

[0012] The manufacturing method of a battery assembly, the battery assembly, and the secondary battery including the same according to the embodiments of the present invention can prevent contact between the positive electrode and the negative electrode or an internal short circuit caused by folding a short end of the separator or the positive electrode when winding up the negative electrode, separator, and positive electrode laminate. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an end view showing a secondary battery including a battery assembly according to an embodiment of the present invention; [Figure 2] 1(a) is a plan view showing a battery assembly according to an embodiment of the present invention, and FIG. 1(b) is a plan view showing a battery assembly according to an embodiment of the present invention. [Figure 3] 1 is an end view showing a stack structure of a battery assembly according to one embodiment of the present invention. [Figure 4] 1 is an exploded plan view showing a state in which a battery assembly and a first sealing tape are adhered to each other according to an embodiment of the present invention. [Explanation of symbols]

[0014] 100...Secondary battery 10...Battery assembly 1...Negative electrode 1a...Negative electrode active material part 1b Negative electrode uncoated area 2...Positive electrode 2a...Cathode active material part 2b: Positive electrode uncoated area 3...Separation membrane 3a...1st separation membrane 3b...Second separation membrane 4. First sealing tape 5 Second sealing tape 20 cans 21 Beading section 22 Crimping section 30 Cap Assembly 31 Top Cap 32 Safety Vent 33 Current interruption element 40 Gasket 50 CID gasket DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below with reference to the drawings. However, the drawings are for illustrative purposes only and the scope of the present invention is not limited by the drawings.

[0016] FIG. 1 is an end view showing a secondary battery 100 including a cap assembly 30 according to one embodiment of the present invention.

[0017] A secondary battery 100 according to the present invention may include a battery assembly 10, a can 20, and a cap assembly 30 (Cap Assembly).

[0018] Fig. 2(a) is a plan view showing a battery assembly 10 according to an embodiment of the present invention, and Fig. 2(b) is a plan view showing a battery assembly 10 according to an embodiment of the present invention. Fig. 3 is an end view showing the stacked structure of the battery assembly 10 according to an embodiment of the present invention, and Fig. 4 is a separated plan view showing the battery assembly 10 according to an embodiment of the present invention and a first sealing tape 4 adhered thereto.

[0019] The battery assembly 10 is a chargeable and dischargeable power generating element having a laminated structure of a positive electrode 2 / anode 1 / separator 3, and may have a jelly roll structure in which the separator 3 is interposed between the positive electrode 2 and the cathode 1, which are long sheets coated with an active material.

[0020] More specifically, the battery assembly 10 may be wound around a core in the order of anode 1, first separator 3a, cathode 2, and second separator 3b, with anode uncoated portion 1b wound as the outermost portion. Here, anode uncoated portion 1b may refer to a region of anode current collector where anode active material is not laminated. Anode active material portion 1a may refer to a region of anode current collector where anode active material is laminated. Similarly, cathode 2 may include a cathode active material portion 2a where a cathode active material is laminated on one side of a cathode current collector, and a cathode uncoated portion 2b where a cathode active material is not laminated on one side of a cathode current collector.

[0021] In the battery assembly 10 according to the present invention, the negative electrode uncoated portion 1b is located at the outermost periphery, so that the negative electrode uncoated portion 1b can be in contact with the inside of the can 20, and therefore the negative electrode uncoated portion 1b can also serve as a negative electrode tab.

[0022] The battery assembly 10 according to the present invention may include a precursor in which the negative electrode active material portion 1a, the first separator 3a, the positive electrode 3, and the second separator 3b are wound, a negative electrode uncoated portion 1b wound around the outermost periphery of the precursor to completely enclose the precursor, and a first sealing tape 4 and a second sealing tape 5, which will be described later. In this case, the negative electrode uncoated portion 1b may be longer than the perimeter of the precursor to completely enclose the precursor. If the radius of the precursor is r, the perimeter of the precursor may be 2πr, and the length of the negative electrode uncoated portion 1b may be 2πr or more.

[0023] In one embodiment, the battery assembly 10 may include a precursor wound in the order of the negative electrode 1, first separator 3a, positive electrode 2, and second separator 3b, and the negative electrode uncoated portion 1b, which are integrated together. In this case, the negative electrode uncoated portion 1b may be in contact with the other side of the first sealing tape 4 described below. That is, the winding start portion where winding of the negative electrode uncoated portion 1b begins may be in contact with at least a portion of the other side of the first sealing tape 4, and the winding end portion where winding of the negative electrode uncoated portion 1b ends, i.e., the winding terminal portion, may be in contact with the other side of the first sealing tape 4 or the winding start portion of the negative electrode uncoated portion 1b.

[0024] In addition, according to one embodiment, the negative electrode 1 may have a negative electrode uncoated portion 1b located at one or more of a winding start portion where winding of the battery assembly 10 begins and a winding end portion where winding ends. For example, the negative electrode 1 may be arranged in the following order: negative electrode uncoated portion 1b, negative electrode active material portion 1a, and negative electrode uncoated portion 1b. Therefore, if the total length of the negative electrode current collector is l0, the length of the negative electrode active material portion 1a is l1, and the lengths of the negative electrode uncoated portions 1b located at the front and rear ends of the negative electrode 1 are l2 and l3, respectively, then l0 = l1 + l2 + l3. That is, the length of the negative electrode current collector may be longer than the length of the negative electrode active material portion 1a.

[0025] In another embodiment, the battery assembly 10 may include a precursor wound in the order of the negative electrode 1, the first separator 3a, the positive electrode 2, and the second separator 3b, and the negative electrode uncoated portion 1b, which are separate from each other.

[0026] The battery assembly 10 may further include a first sealing tape 4. The first sealing tape 4 may be attached to the winding end of the negative electrode 1, the separator 3, or the positive electrode 2. Here, the winding end may refer to the end or end surface of the wound negative electrode 1, the wound positive electrode 2, or the separator 3.

[0027] That is, at least a portion of one surface of the first sealing tape 4 can face the winding end of the negative electrode 1, the positive electrode 2, or the separator 3, and the other surface of the first sealing tape 4 can face the negative electrode plain portion 1b. In other words, at least a portion of one surface of the first sealing tape 4 can contact the winding end of the negative electrode 1, the positive electrode 2, or the separator 3.

[0028] The battery assembly 10 may include one or more first sealing tapes 4. When the battery assembly 10 includes multiple first sealing tapes 4, the first sealing tapes 4 may be positioned at a predetermined distance apart in a direction perpendicular to the direction in which the negative electrode 1, the first separator 3a, the positive electrode 2, and the second separator 3b are wound. In this specification, "one or more" may mean "including one" or "including two or more."

[0029] For example, when the battery assembly 10 includes a pair of first sealing tapes 4, each of the first sealing tapes 4 may be attached to both ends of the width direction of the negative electrode 1, positive electrode 2, or separator 3 at the winding end of the negative electrode 1, positive electrode 2, or separator 3. Here, the width direction of the negative electrode 1, positive electrode 2, or separator 3 may refer to a direction perpendicular to the winding direction of the negative electrode 1, positive electrode 2, or separator 3.

[0030] The first sealing tape 4 fixes the winding end of the wound negative electrode 1, positive electrode 2, or separator 3, and prevents the negative electrode 1, positive electrode 2, or separator 3 from being folded due to centrifugal force applied to the precursor by additional winding of the negative electrode uncoated portion 1b, thereby preventing contact between the negative electrode 1 and the positive electrode 2 and causing a short circuit inside the battery assembly 10.

[0031] The size of the first sealing tape 4 is not limited as long as it can secure the winding end of the negative electrode 1, the positive electrode 2, or the separator 3. For example, the first sealing tape 4 may have a major axis length L of 5 mm to 50 mm, a minor axis length W of 0.1 mm to 30 mm, and a thickness of 0.1 μm to 80 μm; preferably, the first sealing tape 4 may have a major axis length L of 10 mm to 30 mm, a minor axis length W of 1 mm to 15 mm, and a thickness of 1 μm to 50 μm.

[0032] In this specification, the length of the major axis of each component refers to the length in the direction in which the battery assembly 10, the first sealing tape 4, and the second sealing tape 5 are wound, and the length of the minor axis refers to the length in the direction perpendicular to the length of the major axis, i.e., the height of the battery assembly 10 or the secondary battery 100.

[0033] The battery assembly 10 may further include a second sealing tape 5. The second sealing tape 5 may be attached to at least one surface of the negative electrode uncoated portion 1b. That is, the second sealing tape 5 fixes the negative electrode uncoated portion 1b, and at least a portion of one surface of the second sealing tape 5 may contact the winding end portion of the negative electrode uncoated portion 1b.

[0034] In the battery assembly 10 of the present invention, the negative electrode uncoated portion 1b located at the outermost periphery contacts the inner surface of the can 20, so the width or length of the minor axis of the second sealing tape 5 may be shorter than the height of the battery assembly 10. There are no size restrictions on the second sealing tape 5 as long as it can secure the winding end of the negative electrode uncoated portion 1b. For example, the second sealing tape 5 may have a minor axis length W of 0.1 mm to 30 mm and a thickness of 0.1 μm to 80 μm, and preferably, the second sealing tape 5 may have a minor axis length W of 1 mm to 15 mm and a thickness of 1 μm to 50 μm.

[0035] The length L of the major axis of the second sealing tape 5 may correspond to the length of the major axis of the negative electrode uncoated portion 1b. That is, the end face of the second sealing tape 5 where winding starts may come into contact with the end face of the second sealing tape 5 where winding ends.

[0036] Alternatively, the winding start and end portions of the second sealing tape 5 may overlap. That is, a certain region of the second sealing tape 5 from the winding start end in the winding direction may overlap a certain region of the second sealing tape 5 from the winding end in the opposite winding direction. Therefore, the second sealing tape 5 may be laminated twice on the outer surface of the winding end of the negative electrode 1, the positive electrode 2, or the separator 3.

[0037] If the radius of the wound material in which the negative electrode uncoated portion 1b is wound around the outermost periphery of the precursor is R, the length around the wound material is 2πR, and therefore the length of the major axis of the second sealing tape 5, i.e., the length of the second sealing tape 5, may be the same as or longer than 2πR.

[0038] The battery assembly 10 may include one or more second sealing tapes 5. In one embodiment, when two second sealing tapes 5 are included, the two second sealing tapes 5 may be positioned at a certain distance apart. For example, the second sealing tapes 5 may be positioned at a distance along the height direction of the battery assembly 10.

[0039] In another embodiment, one second sealing tape 5 may be included, and may be located at a point between 2 / 10 and 8 / 10 in the width direction of the battery assembly 10 or the wound negative electrode uncoated portion 1b.

[0040] The first sealing tape 4 and the second sealing tape 5 may include a conductive adhesive tape. The first sealing tape 4 and the second sealing tape 5 may have an adhesive material applied to one side of a substrate, or an adhesive layer (not shown) may be laminated thereon. The first sealing tape 4 and the second sealing tape 5 may be made of a film containing one or more of polyethylene terephthalate (PET), polyphenylene sulfide, polyimide, and polypropylene. The adhesive material or adhesive layer may include an acrylic adhesive.

[0041] The secondary battery 100 according to the present invention may have a first insulating plate (not shown) and a second insulating plate (not shown) located at the top and bottom of the battery assembly 10. The first insulating plate can insulate the battery assembly 10 from the cap assembly 30, and the second insulating plate can insulate the battery assembly 10 from the bottom of the can 20.

[0042] The battery assembly 10 may further include a center pin (not shown) at the center. The center pin prevents the battery assembly 10, which is wound up in the form of a jelly roll, from unraveling and serves as a passage for gas movement inside the secondary battery 100.

[0043] The can 20 may have a columnar structure with a space formed therein. The can 20 may accommodate the battery assembly 10 including electrodes and a separator, and an electrolyte (not shown) in the space. One side of the can 20 may be open, and the other side may be sealed. Here, the terms "one side" and "other side" refer to the ends located at the top and bottom along the direction of gravity or the central axis of the can 20.

[0044] A beading portion 21 folded toward the center of the secondary battery 100 may be provided on one side of the open can 20. The can 20 may have a crimping portion 22 above the beading portion 21. That is, the crimping portion 22 may be located at the top of the can 20.

[0045] Can 20 may be constructed from a lightweight, conductive metallic material such as aluminum or an aluminum alloy.

[0046] The cap assembly 30 is coupled to the top of the can 20 and may include a top cap 31 , a safety vent 32 , and a current interrupt device 33 .

[0047] The top cap 31 may protrude from the top of the cap assembly 30 and serve as an electrode terminal for electrical connection to the outside. The top cap 31 may be coupled to the top of the can 20. That is, the top cap 31 may be coupled to the crimping portion 22 located at the top of the can 20.

[0048] The secondary battery 100 according to the present invention may include a gasket 40 between the crimping portion 22 and the top cap 31. The gasket 40 can increase the sealing force of the can 20.

[0049] The safety vent 32 may be located below the top cap 31 and may be coupled to an end of the top cap 31. The safety vent 32 may contact the end of the top cap 31 over a certain length, and the portion of the safety vent 32 excluding the contact length may be spaced a certain distance from the top cap 31. More specifically, the distance between the safety vent 32 and the top cap 31 may increase from the end that contacts the top cap 31 toward the center. Here, the end may refer to a position corresponding to the position of the crimping portion 22 or the gasket 40.

[0050] In one embodiment, the safety vent 32 may be provided with an end perpendicular to the axial direction of the can 20. In this case, the top cap 31 may be provided perpendicular to the axial direction of the can 20, just like the safety vent 32. In other words, the safety vent 32 and the top cap 31 may be positioned horizontally.

[0051] In other embodiments, the safety vent 32 may be provided with a folded end that surrounds the outer periphery of the top cap 31 .

[0052] The safety vent 32 may be provided by being bent at least one time. For example, the safety vent 32 may have two notches in a portion that does not contact the top cap 31. That is, the safety vent 32 may be bent at the notches, and the center of the safety vent 32 may be recessed to form a concave central portion (not shown). The safety vent 32 may also have a vent portion (not shown) that connects the end portion (not shown) that contacts the top cap 31 and the concave central portion.

[0053] The current interrupting element 33 may be located below the safety vent 32 and may be in at least partial contact with the safety vent 32 .

[0054] The current interrupting element 33 may include a central portion (not shown) protruding toward the safety vent 32 and a CID filter portion (not shown) located outside the central portion. Therefore, the cap assembly 30 allows the central portion of the current interrupting element 33 to come into contact with the concave central portion of the safety vent 32.

[0055] The cap assembly 30 according to the present invention may include a CID gasket 50 at the end of the CID filter portion. The CID gasket 50 can prevent the safety vent 32 from contacting the current interrupting device 33 at any portion other than the center portion.

[0056] The method may include step S10 of supplying the negative electrode, the first separator, the positive electrode, and the second separator to a winding core in this order and winding them up.

[0057] In the winding step S10, the precursor, in which the sheet-like negative electrode, the first separator, the positive electrode, and the second separator are sequentially stacked, may be wound into a jelly roll structure.

[0058] In one embodiment, the winding step S10 may include fixing the negative electrode to a winding core and rotating the winding core, supplying a first separator, supplying a positive electrode, and supplying a second separator.

[0059] In another embodiment, the winding step S10 may involve winding a precursor in which the negative electrode, the first separator, the positive electrode, and the second separator are stacked in this order around a winding core.

[0060] In another embodiment, the winding step S10 may include winding a laminate, in which the negative electrode and the first separator, the positive electrode and the second separator are stacked in this order, onto a winding core to form a jelly roll structure. That is, the winding step S10 may include fixing the negative electrode to the winding core and rotating the winding core, and, after the rotation of the negative electrode has begun, inserting the laminate so that it rotates together with the negative electrode.

[0061] In step S20 of winding the negative electrode uncoated portion to the outermost periphery, the negative electrode uncoated portion may be wound to the outermost periphery of a jelly roll structure in which the negative electrode, first separator, positive electrode, and second separator are wound in this order. The negative electrode according to the present invention may include a negative electrode active material portion in which a negative electrode active material is stacked on one surface of a negative electrode current collector, and a negative electrode uncoated portion in which no negative electrode active material is stacked. In step S20 of winding the negative electrode uncoated portion to the outermost periphery, the negative electrode uncoated portion may be located at the end where the winding of the negative electrode active material portion ends, and the negative electrode uncoated portion may be wound continuously after the negative electrode active material portion is wound, so that the negative electrode uncoated portion is wound to the outermost periphery of the battery assembly.

[0062] In one embodiment, the negative electrode included in the battery assembly may include a negative electrode active material portion and a negative electrode uncoated portion. The negative electrode may be arranged in the following order from the winding start region: negative electrode uncoated portion, negative electrode active material portion, and negative electrode uncoated portion, or the negative electrode active material portion and negative electrode uncoated portion. That is, at least the negative electrode uncoated portion may be located at the winding end of the negative electrode active material.

[0063] Therefore, in step S20 of winding the negative electrode uncoated portion to the outermost position, the negative electrode, first separator, positive electrode, and second separator are wound up, and the negative electrode uncoated portion can be wound from the winding end of the first separator, positive electrode, and second separator after the winding of the first separator, positive electrode, and second separator is completed. That is, step S10 of winding can be performed in parallel with step S20 of winding the negative electrode uncoated portion to the outermost position according to another embodiment.

[0064] In another embodiment, step S20 of winding the negative electrode uncoated portion onto the outermost layer may further wind the negative electrode uncoated portion onto a precursor that has been wound in the order of the negative electrode, first separator, positive electrode, and second separator. Thus, step S20 of winding the negative electrode uncoated portion onto the outermost layer may include adding the negative electrode uncoated portion before winding of the precursor that has been stacked in the order of the negative electrode, first separator, positive electrode, and second separator is completed.

[0065] In another embodiment, step S20 of winding the negative electrode uncoated portion to the outermost periphery may involve connecting the negative electrode uncoated portion to the negative electrode end of a precursor that is wound in the order of the negative electrode, first separator, positive electrode, and second separator, and winding the negative electrode uncoated portion to the outermost periphery of the precursor. Thus, step S20 of winding the negative electrode uncoated portion to the outermost periphery may include contacting the negative electrode uncoated portion to the winding end of the negative electrode.

[0066] The method for manufacturing a battery assembly according to the present invention may further include step S30 of attaching a first sealing tape to a winding end portion of the precursor. Step S30 of attaching the first sealing tape may include inserting the first sealing tape into the winding end portion of the precursor, in which the negative electrode, the first separator, the positive electrode, and the second separator are stacked in this order.

[0067] The method for manufacturing a battery assembly according to the present invention may further include step S40 of attaching a second sealing tape to the winding end of the negative electrode uncoated portion and winding the same. Step S40 of attaching the second sealing tape and winding the same may include inserting the second sealing tape into the winding end of the negative electrode uncoated portion.

[0068] While the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that various modifications and variations can be made thereto without departing from the spirit and scope of the invention as set forth in the following claims. Examples of embodiments of the present invention are shown as items. [Item 1] A battery assembly in which a negative electrode, a first separator, a positive electrode, and a second separator are stacked and wound, The negative electrode a negative electrode active material portion in which a negative electrode active material is laminated on one surface of a negative electrode current collector, and a negative electrode non-coating portion in which a negative electrode active material is not laminated on one surface of the negative electrode current collector, The negative electrode uncoated portion is wound around the outermost periphery of the battery assembly. [Item 2] Further comprising a first sealing tape attached to a winding end portion of one or more of the negative electrode, the first separator, the positive electrode, and the second separator; Item 2. The battery assembly according to item 1, wherein the first sealing tape is positioned so that at least a portion of one surface thereof secures the winding end of one or more of the negative electrode, the first separator, the positive electrode, and the second separator. [Item 3] further comprising a second sealing tape attached to at least one surface of the negative electrode uncoated portion, Item 2. The battery assembly according to item 1, wherein the second sealing tape is positioned so that at least a portion of one surface thereof fixes the winding end of the negative electrode uncoated portion. [Item 4] 4. The battery assembly according to item 3, wherein the second sealing tape is one or more and is positioned at a certain distance apart in a direction perpendicular to the direction in which the negative electrode uncoated portion is wound. [Item 5] 3. The battery assembly according to item 2, wherein the first sealing tape includes one or more, and is positioned at a certain distance apart in a direction perpendicular to the direction in which the negative electrode, the first separator, the positive electrode, and the second separator are wound. [Item 6] 3. The battery assembly according to item 2, wherein the first sealing tape has a major axis length of 10 mm to 30 mm. [Item 7] Item 2. The battery assembly according to item 1, wherein the negative electrode has a negative electrode uncoated portion located at least at one of a winding start portion where winding begins and a winding end portion where winding ends. [Item 8] The battery assembly according to any one of items 1 to 7; a canister having an open side and having the battery assembly placed therein; and a cap assembly that is bonded to the top of the can; A secondary battery comprising: [Item 9] The method includes supplying the negative electrode, the first separator, the positive electrode, and the second separator to a winding core in this order and winding the same, The negative electrode includes a negative electrode active material portion in which a negative electrode active material is laminated on one surface of a negative electrode current collector, and a negative electrode non-coating portion in which a negative electrode active material is not laminated on one surface of the negative electrode current collector, A method for manufacturing a battery assembly, in which the negative electrode uncoated portion is located at the outermost periphery. [Item 10] 10. The method for manufacturing a battery assembly according to item 9, further comprising the step of providing and attaching a first sealing tape to the winding end of the negative electrode, the first separator, the positive electrode, and the second separator. [Item 11] 10. The method for manufacturing a battery assembly according to item 9, further comprising the step of supplying and attaching a second sealing tape to the winding end of the negative electrode uncoated portion and winding it up.

Claims

1. A battery assembly in which a negative electrode, a first separator, a positive electrode, and a second separator are stacked and wound, The negative electrode a negative electrode active material portion in which a negative electrode active material is laminated on both sides of a negative electrode current collector, and a negative electrode non-coating portion in which a negative electrode active material is not laminated on the negative electrode current collector, The negative electrode uncoated portion is wound around the outermost periphery of the battery assembly, The battery further includes a first sealing tape attached to a winding end of at least one of the negative electrode, the first separator, the positive electrode, and the second separator, At least one of the first separator and the second separator, and at least one of the negative electrode and the positive electrode are attached to one surface of the first sealing tape.

2. a second sealing tape attached to at least one surface of the negative electrode uncoated portion; The battery assembly according to claim 1 , wherein the second sealing tape is positioned so that at least a portion of one surface thereof fixes the winding end of the negative electrode uncoated portion.

3. The battery assembly of claim 2 , wherein the second sealing tape includes two or more second sealing tapes, and the second sealing tapes are spaced apart from each other by a predetermined distance in a direction perpendicular to a direction in which the negative electrode uncoated portion is wound.

4. 2. The battery assembly of claim 1, wherein the first sealing tape includes two or more first sealing tapes, and the first sealing tapes are positioned at a predetermined distance apart in a direction perpendicular to a direction in which the negative electrode, the first separator, the positive electrode, and the second separator are wound.

5. the first sealing tape has a major axis length of 10 mm to 30 mm; The length of the major axis refers to the length in the direction in which the battery assembly and the first sealing tape are wound. The battery assembly of claim 1 .

6. The battery assembly according to claim 1 , wherein the negative electrode uncoated portion is located at at least one of a winding start portion where winding begins and a winding end portion where winding ends.

7. The battery assembly according to any one of claims 1 to 6; a can having an open side and configured to accommodate the battery assembly; and a cap assembly coupled to a top of the can; A secondary battery comprising:

8. a negative electrode including a negative electrode active material portion in which a negative electrode active material is laminated on both sides of a negative electrode current collector, and a negative electrode uncoated portion in which the negative electrode active material is not laminated on the negative electrode current collector, a first separator, a positive electrode, and a second separator are supplied to a winding core in this order and wound up; providing and attaching a first sealing tape to winding ends of the negative electrode, the first separator, the positive electrode, and the second separator; a first sealing tape having at least one of the first separator and the second separator, and at least one of the negative electrode and the positive electrode attached to one surface of the first sealing tape;

9. The method of claim 8 , further comprising the step of supplying and attaching a second sealing tape to a winding end of the negative electrode uncoated portion, and then winding the tape.

Images