Method for manufacturing a battery assembly, a battery assembly, and a secondary battery containing 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, and all of its content is incorporated herein.

[0002] The present invention relates to a method for manufacturing a battery assembly, a battery assembly, and a secondary battery including the same. Specifically, the present invention relates to a method for manufacturing a battery assembly that prevents folding and steps of a separator during winding of a negative electrode, a separator, and a positive electrode, a battery assembly, and a secondary battery including the same.

Background Art

[0003] Secondary batteries are classified into cylindrical batteries and prismatic batteries in which a battery assembly (or a battery stack) is built into a cylindrical or prismatic metal can depending on the shape of the battery case, and pouch-type batteries in which the battery assembly is built into a pouch-type case of an aluminum laminate sheet.

[0004] In addition, the battery assembly built into the battery case is a power generation element capable of charge and discharge having a laminated structure of a positive electrode / separator / negative electrode, and a folding-type battery assembly (jelly roll) wound through a separator between a long sheet-shaped positive electrode and a negative electrode coated with an active material, and a stacked-type battery assembly in which a large number of positive electrodes and negative electrodes of a predetermined size are sequentially laminated with a separator interposed therebetween. Among them, the jelly roll has the advantages of being easy to manufacture and having a high energy density per unit weight.

[0005] In a conventional jelly roll-type battery assembly, when winding a laminated structure of a positive electrode / separator / negative electrode, the outermost layer is wound with a separator. In a conventional jelly roll-type battery assembly, the length of the separator located on the outermost layer may be longer than the separators located between the positive electrode, the negative electrode, and the positive electrode and the negative electrode. Therefore, there has been a problem that the separators located between the positive electrode, the negative electrode, and the positive electrode and the negative electrode are bent due to the centrifugal force for winding the separator located on the outermost layer.

[0006] Therefore, there is a growing need for a battery assembly manufacturing method, a battery assembly, and a secondary battery containing them that can fundamentally solve this problem and improve the issue of shorter components breaking due to centrifugal force and differences in the lengths of the components included in the battery assembly when winding up the stacked structure of positive electrode / separator / negative electrode. [Overview of the project] [Problems that the invention aims to solve]

[0007] Focusing on the problems of the conventional technology described above, the present invention aims to provide a method for manufacturing a battery assembly, a battery assembly, and a secondary battery containing the same, which prevents the ends of short separator membranes or positive electrodes from breaking when winding up the negative electrode, separator membrane, and positive electrode stack. [Means for solving the problem]

[0008] One embodiment of the present invention provides a battery assembly in which a negative electrode, a first separator membrane, a positive electrode, and a second separator membrane are laminated and wound together, wherein the negative electrode included in the battery assembly includes a negative electrode active material portion in which a negative electrode active material is laminated on one surface of the negative electrode current collector and a negative electrode blank portion in which the negative electrode active material is not laminated on one surface of the negative electrode current collector, and the negative electrode blank portion is wound around the outermost edge of the battery assembly.

[0009] One embodiment of the present invention further includes a first sealing tape attached to one or more winding ends of the negative electrode, the separator membrane, and the positive electrode, providing a battery assembly in which at least a portion of one side of the first sealing tape is positioned to secure one or more winding ends of the negative electrode, the separator membrane, and the positive electrode.

[0010] One embodiment of the present invention further includes a second sealing tape affixed to at least one surface of the negative electrode blank portion, wherein the second sealing tape is positioned such that at least a portion of one surface is fixed to the winding end of the negative electrode blank portion.

[0011] Another embodiment of the present invention provides a secondary battery comprising the battery assembly; a can having one side open and in which the battery assembly is placed; and a cap assembly coupled to the top of the can. Yet another embodiment of the present invention provides a method for manufacturing a battery assembly comprising the steps of supplying and winding a negative electrode, a first separator membrane, a positive electrode, and a second separator membrane in that order onto a winding core, wherein the negative electrode comprises a negative electrode active material portion having a negative electrode active material laminated on one surface of a negative electrode current collector, and a negative electrode plain portion having no negative electrode active material laminated on one surface of the negative electrode current collector, with the negative electrode plain portion located on the outermost edge. [Effects of the Invention]

[0012] A method for manufacturing a battery assembly according to an embodiment of the present invention, a battery assembly, and a secondary battery containing the same can prevent the positive and negative electrodes from coming into contact or an internal short circuit from occurring when the short ends of the separator membrane or positive electrode are folded during winding of the negative electrode, separator membrane, and positive electrode stack. [Brief explanation of the drawing]

[0013] [Figure 1] This is an end view showing a secondary battery including a battery assembly according to one embodiment of the present invention. [Figure 2] (a) is a plan view showing a battery assembly according to one embodiment of the present invention, and (b) is a plan view showing a battery assembly according to one embodiment of the present invention. [Figure 3] This is an end view showing the stacked structure of a battery assembly according to one embodiment of the present invention. [Figure 4] This is a separated plan view showing a state in which a battery assembly and a first sealing tape are bonded together according to one 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 blank area 2 ··· Positive electrode 2a ··· Positive electrode active material part 2b ··· Positive electrode non-patterned part 3 ··· Separator 3a ··· First separator 3b ··· Second separator 4 ··· First sealing tape 5 ··· Second sealing tape 20 ··· Can 21 ··· Beading part 22 ··· Crimping part 30 ··· Cap assembly 31 ··· Top cap 32 ··· Safety vent 33 ··· Current interruption element 40 ··· Gasket 50 ··· CID gasket

Best Mode for Carrying Out the Invention

[0015] Hereinafter, the present invention will be described in detail 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 an embodiment of the present invention.

[0017] The 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 laminated structure of the battery assembly 10 according to an embodiment of the present invention, and FIG. 4 is a separated plan view showing the state where the battery assembly 10 and the first sealing tape 4 are adhered according to an embodiment of the present invention.

[0019] The battery assembly 10 is a chargeable and dischargeable power generation element consisting of a stacked structure of a positive electrode 2 / separating membrane 3 / negative electrode 1, and may include a jelly roll type structure in which a long sheet-like positive electrode 2 coated with an active material is wound between the negative electrode 1 with a separating membrane 3 in between.

[0020] More specifically, the battery assembly 10 is wound from the core in the order of negative electrode 1, first separator 3a, positive electrode 2, and second separator 3b, with the outermost outer layer being the negative electrode blank portion 1b. Here, the negative electrode blank portion 1b can mean an area on one surface of the negative electrode current collector where the negative electrode active material is not laminated. The negative electrode active material portion 1a can mean an area on one surface of the negative electrode current collector where the negative electrode active material is laminated. Similarly, the positive electrode 2 may include a positive electrode active material portion 2a on one surface of the positive electrode current collector where the positive electrode active material is laminated, and a positive electrode blank portion 2b on one surface of the positive electrode current collector where the positive electrode active material is not laminated.

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

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

[0023] In one embodiment, the battery assembly 10 may integrally include a precursor wound in the order of negative electrode 1, first separator membrane 3a, positive electrode 2, and second separator membrane 3b, and a blank negative electrode portion 1b. In this case, the blank negative electrode portion 1b can come into contact with the other side of the first sealing tape 4, which will be described later. That is, the winding start portion where the winding of the blank negative electrode portion 1b begins can come into contact with at least a part of the other side of the first sealing tape 4, and the winding end portion where the winding of the blank negative electrode portion 1b ends, i.e., the winding end portion, can come into contact with the other side of the first sealing tape 4 or the winding start portion of the blank negative electrode portion 1b.

[0024] Furthermore, in one embodiment, the negative electrode 1 may have a negative electrode blank portion 1b located at one or more of the winding start portion where winding of the battery assembly 10 begins and the winding end portion where winding ends. For example, the negative electrode 1 may be arranged in the order of negative electrode blank portion 1b, negative electrode active material portion 1a, and negative electrode blank 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 blank portions 1b located at the front and rear ends of the negative electrode 1 are l2 and l3, respectively, then l0 = l1 + l2 + l3. In other words, the length of the negative electrode current collector can be made longer than the length of the negative electrode active material portion 1a.

[0025] In another embodiment, the battery assembly 10 may contain a precursor wound in the order of negative electrode 1, first separator membrane 3a, positive electrode 2, and second separator membrane 3b, and a blank negative electrode portion 1b, which are separated.

[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 membrane 3, or the positive electrode 2. Here, the winding end can mean the end or end face of the wound-up negative electrode 1, positive electrode 2, or separator membrane 3.

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

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

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

[0030] The first sealing tape 4 secures the end of the wound-up negative electrode 1, positive electrode 2, or separator membrane 3, and prevents the negative electrode 1, positive electrode 2, or separator membrane 3 from bending due to the centrifugal force applied to the precursor by the additional winding of the plain negative electrode portion 1b, thereby preventing the negative electrode 1 and positive electrode 2 from coming into contact and preventing a short circuit from occurring inside the battery assembly 10.

[0031] The size of the first sealing tape 4 is not limited as long as it can fix the negative electrode 1, positive electrode 2, or the winding end of the separation membrane 3. For example, the first sealing tape 4 may have a long axis length L of 5 mm to 50 mm, a short 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 long axis length L of 10 mm to 30 mm, a short 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 means 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 may mean 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 can be attached to at least one surface of the negative electrode blank portion 1b. That is, the second sealing tape 5 secures the negative electrode blank portion 1b, and at least a portion of one surface of the second sealing tape 5 can come into contact with the winding end of the negative electrode blank portion 1b.

[0034] In the battery assembly 10 of the present invention, the width or length of the short axis of the second sealing tape 5 can be made shorter than the height of the battery assembly 10, because the plain negative electrode portion 1b located on the outermost casing is in contact with the inner surface of the can 20. The size of the second sealing tape 5 is not limited as long as the winding end of the plain negative electrode portion 1b can be fixed, but for example, the second sealing tape 5 may have a short axis length W of 0.1 mm to 30 mm and a thickness of 0.1 μm to 80 μm, preferably, the second sealing tape 5 may have a short axis length W of 1 mm to 15 mm and a thickness of 1 μm to 50 μm.

[0035] The length L of the long axis of the second sealing tape 5 can correspond to the length of the long axis of the negative electrode blank portion 1b. That is, the end face of the second sealing tape 5 where winding begins and the end face of the second sealing tape 5 in the region where winding ends can be in contact.

[0036] Alternatively, the second sealing tape 5 may have an overlap between the beginning and end of winding. That is, a certain region of the second sealing tape 5 from the winding start end in the winding direction may overlap with a certain region from the winding end in the reverse direction of winding. Therefore, the second sealing tape 5 can be laminated twice on the outer surface of the winding end of the negative electrode 1, positive electrode 2, or separation membrane 3.

[0037] If R is the radius of the winding in which the negative electrode plain section 1b is wound around the outermost edge of the precursor, then the length around the winding is 2πR. 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 second sealing tape 5 may consist of one or more pieces. In one embodiment, if there are two second sealing tapes 5, 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 intervals along the height direction of the battery assembly 10.

[0039] In other embodiments, the second sealing tape 5 may consist of only one tape and may be positioned at a point between 2 / 10 and 8 / 10 of the width of the battery assembly 10 or the wound negative electrode blank portion 1b.

[0040] The first sealing tape 4 and the second sealing tape 5 may include conductive adhesive tape. The first sealing tape 4 and the second sealing tape 5 may have an adhesive substance applied to one surface of the substrate, or an adhesive layer (not shown) may be laminated on them. 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 substance 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, respectively. 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] Furthermore, the battery assembly 10 may include a center pin (not shown) in the center. The center pin prevents the battery assembly 10, which is wound in the form of a jelly roll, from unraveling and can serve as a passage for the movement of gas inside the secondary battery 100.

[0043] The can 20 may be provided as a columnar structure with an internal space. The can 20 can house a battery assembly 10 including electrodes and a separation membrane, and an electrolyte (not shown) in its internal space. One side of the can 20 may have an open structure, and the other side may have a sealed structure. Here, one side and the other side of the can 20 refer to the ends located at the top and bottom, respectively, 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. Furthermore, a crimping portion 22 may be provided above the beading portion 21 of the can 20. That is, the crimping portion 22 can be located at the uppermost side of the can 20.

[0045] Can 20 may be made of a lightweight conductive metal material such as aluminum or an aluminum alloy.

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

[0047] The top cap 31 can act as an electrode terminal, protruding from the top of the cap assembly 30 and electrically connecting 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 a 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 is located on the underside of the top cap 31 and can be coupled to the end of the top cap 31. The safety vent 32 may be in contact with the end of the top cap 31 for a certain length, while the portion excluding the contact length may be positioned at a certain distance from the top cap 31. More specifically, the distance from the top cap 31 can increase as the safety vent 32 moves from the end in contact with the top cap 31 towards the center. Here, the end can mean a position corresponding to the position of the crimping portion 22 or the gasket 40.

[0050] In one embodiment, the end of the safety vent 32 may be provided perpendicular to the axial direction of the can 20. In this case, the top cap 31 may also be provided perpendicular to the axial direction of the can 20, similar to the safety vent 32. That is, the safety vent 32 and the top cap 31 may be positioned horizontally.

[0051] In another embodiment, the safety vent 32 may be provided such that its ends are bent to surround the outer circumferential surface of the top cap 31.

[0052] The safety vent 32 may be provided by being bent at least once. For example, the safety vent 32 may have two notches in the portion that does not come into contact with the top cap 31. That is, the safety vent 32 may be bent by the notches, and the center of the safety vent 32 may be recessed to form a curved central portion (not shown). The safety vent 32 may then have an end portion (not shown) that comes into contact with the top cap 31 and a vent portion (not shown) that connects the curved central portion.

[0053] The current interruption element 33 is located below the safety vent 32 and may be in contact with the safety vent 32, at least partially.

[0054] The current interruption element 33 may include a central portion (not shown) protruding in the direction of the safety vent 32 and a CID filter portion (not shown) located outside the central portion. Therefore, the cap assembly 30 allows the current interruption element 33 to be in contact with the central portion of the safety vent 32's concave central portion.

[0055] The cap assembly 30 according to the present invention may be provided with a CID gasket 50 at the end of the CID filter portion. The CID gasket 50 can prevent the safety vent 32 from making contact with the current interruption element 33 at any point other than the central portion.

[0056] The process may include step S10, in which the negative electrode, the first separation membrane, the positive electrode, and the second separation membrane are supplied to the winding core in that order and wound up.

[0057] In the winding step S10, the precursor, which consists of a sheet-like negative electrode, a first separation membrane, a positive electrode, and a second separation membrane stacked in sequence, can be wound into a jelly roll-like structure.

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

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

[0060] In another embodiment, the winding step S10 may involve winding the laminate, which is stacked in the order of the negative electrode and the first separation membrane, the positive electrode and the second separation membrane, onto a winding core to form a jelly roll-type structure. That is, the winding step S10 may include the step of fixing the negative electrode to the winding core and rotating the winding core, and the step of introducing the laminate so that it rotates together with the negative electrode after the rotation of the negative electrode has started.

[0061] Step S20, in which the plain negative electrode portion is wound onto the outermost casing, allows the plain negative electrode portion to be wound onto the outermost casing of a jelly roll-type structure wound in the order of negative electrode, first separator membrane, positive electrode, and second separator membrane. The negative electrode according to the present invention may include a negative electrode active material portion in which negative electrode active material is laminated on one surface of the negative electrode current collector, and a plain negative electrode portion in which the negative electrode active material is not laminated. In step S20, in which the plain negative electrode portion is wound onto the outermost casing, the plain negative electrode portion may be located at the end where the winding of the negative electrode active material portion ends, and after the negative electrode active material portion is wound, the plain negative electrode portion may be wound continuously, so that the plain negative electrode portion is wound onto the outermost casing 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 blank portion. The negative electrode may be positioned in the order of negative electrode blank portion, negative electrode active material portion and negative electrode blank portion from the winding start region, or in the order of negative electrode active material portion and negative electrode blank portion. That is, at least the negative electrode blank portion can be located at the winding end of the negative electrode active material.

[0063] Therefore, in step S20, in which the plain negative electrode portion is wound to the outermost layer, the negative electrode, first separator membrane, positive electrode, and second separator membrane are wound up, and after the winding of the first separator membrane, positive electrode, and second separator membrane is complete, the plain negative electrode portion can be wound up from the winding ends of the first separator membrane, positive electrode, and second separator membrane. In other words, the winding step S10 may be performed in parallel with step S20 in which the plain negative electrode portion is wound to the outermost layer according to other embodiments.

[0064] In other embodiments, step S20, in which the plain negative electrode portion is wound onto the outermost layer, may also involve further winding of the plain negative electrode portion onto a precursor that has been wound in the order of negative electrode, first separation membrane, positive electrode, and second separation membrane. Therefore, step S20, in which the plain negative electrode portion is wound onto the outermost layer, may include a step of introducing the plain negative electrode portion before the winding of the precursor, which has been stacked in the order of negative electrode, first separation membrane, positive electrode, and second separation membrane, is completed.

[0065] In another embodiment, step S20, in which the negative electrode plain portion is wound onto the outermost casing, may involve connecting the negative electrode plain portion to the negative electrode end of the precursor, which is wound in the order of negative electrode, first separator membrane, positive electrode, and second separator membrane, and winding the negative electrode plain portion onto the outermost casing of the precursor. Therefore, step S20, in which the negative electrode plain portion is wound onto the outermost casing, may include a step of bringing the negative electrode plain portion into contact with the negative electrode winding end.

[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 the end of the winding of the precursor. Step S30 of attaching the first sealing tape may include the step of putting the first sealing tape onto the end of the winding of the precursor, which is stacked in the order of negative electrode, first separator membrane, positive electrode, and second separator membrane.

[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 plain negative electrode portion and winding it up. Step S40 of attaching the second sealing tape and winding it up may include step of inserting the second sealing tape into the winding end of the plain negative electrode portion.

[0068] While preferred embodiments of the present invention have been described above with reference to those skilled in the art, it will be understood that various modifications and changes to the present invention are possible 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 membrane, a positive electrode, and a second separator membrane are laminated and wound together, The negative electrode is The negative electrode current collector includes a negative electrode active material portion in which negative electrode active material is laminated on one surface, and a negative electrode plain portion in which negative electrode active material is not laminated on one surface of the negative electrode current collector. The plain negative electrode section is wound around the outermost casing of the battery assembly. [Item 2] The present invention further includes a first sealing tape attached to one or more of the negative electrode, first separation membrane, positive electrode, and second separation membrane at the end of the winding, The battery assembly according to item 1, wherein at least a portion of one side of the first sealing tape is positioned to secure one or more winding ends of the negative electrode, the first separator, the positive electrode, and the second separator. [Item 3] The device further includes a second sealing tape that is attached to at least one surface of the plain portion of the negative electrode, The battery assembly as described in item 1, wherein the second sealing tape is positioned so that at least a portion of one side secures the winding end of the plain negative electrode portion. [Item 4] The second sealing tape is a battery assembly as described in item 3, which includes one or more tapes positioned at a certain distance apart in the direction perpendicular to the direction in which the negative terminal plain portion is wound. [Item 5] The battery assembly described in item 2 includes one or more first sealing tapes, which are positioned at a certain distance apart from the negative electrode, first separator, positive electrode, and second separator in the direction in which they are wound. [Item 6] The first sealing tape is the battery assembly described in item 2, with a long axis length of 10mm to 30mm. [Item 7] The battery assembly according to item 1, wherein the negative electrode has a blank negative electrode portion located at at least one of the winding start portion where winding begins and the winding end portion where winding ends. [Item 8] A battery assembly as described in any one of items 1 through 7; A can with one side open and in which a battery assembly is placed; and A cap assembly that attaches to the top of the can; Rechargeable batteries, including those mentioned above. [Item 9] The process includes the step of supplying the negative electrode, the first separation membrane, the positive electrode, and the second separation membrane to the core in that order and winding them up. The negative electrode includes a negative electrode active material portion in which negative electrode active material is laminated on one surface of the negative electrode current collector, and a negative electrode plain portion in which 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 blank area is located on the outermost casing. [Item 10] A method for manufacturing a battery assembly according to item 9, further comprising the step of supplying and applying a first sealing tape to the winding ends of the negative electrode, the first separator membrane, the positive electrode, and the second separator membrane. [Item 11] A method for manufacturing a battery assembly according to item 9, further comprising the step of supplying and applying a second sealing tape to the winding end of the plain negative electrode portion and winding it up.

Claims

1. A battery assembly in which a negative electrode, a first separator membrane, a positive electrode, and a second separator membrane are laminated and wound together, The aforementioned negative electrode is The negative electrode current collector includes a negative electrode active material portion in which negative electrode active material is laminated on both sides, and a negative electrode plain portion in which negative electrode active material is not laminated on the negative electrode current collector. The plain negative electrode portion is wound around the outermost casing of the battery assembly, The first sealing tape is further attached to one or more of the negative electrode, the first separation membrane, the positive electrode, and the second separation membrane at the end of the winding, A battery assembly characterized in that at least one of the first and second separator membranes and at least one of the negative electrode and the positive electrode are attached to one side of the first sealing tape.

2. The present invention further includes a second sealing tape that is attached to at least one surface of the plain negative electrode portion, The battery assembly according to claim 1, wherein at least a portion of one side of the second sealing tape is positioned to secure the winding end of the plain negative electrode portion.

3. The battery assembly according to claim 2, wherein the second sealing tape comprises two or more tapes, and is positioned at a certain distance apart in the direction perpendicular to the direction in which the plain negative electrode portion is wound.

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

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

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

7. A battery assembly according to any one of claims 1 to 6; A can with one side open and in which the battery assembly is placed; and A cap assembly that is attached to the top of the can; Rechargeable batteries, including those mentioned above.

8. A negative electrode comprising a negative electrode active material portion in which negative electrode active material is laminated on both sides of the negative electrode current collector, and a negative electrode plain portion in which the negative electrode current collector does not have the negative electrode active material laminated, a first separator membrane, a positive electrode, and a second separator membrane are supplied to the core in that order and wound up, and The step includes supplying and applying a first sealing tape to the winding end portions of the negative electrode, the first separation membrane, the positive electrode, and the second separation membrane. A method for manufacturing a battery assembly, characterized in that at least one of the first and second separation membranes and at least one of the negative electrode and the positive electrode are attached to one surface of the first sealing tape.

9. The method for manufacturing a battery assembly according to claim 8, further comprising the step of supplying and attaching a second sealing tape to the winding end of the plain negative electrode portion and winding it up.

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