Electrode assembly and method for manufacturing the electrode assembly

Abstract

An electrode assembly according to one embodiment of the present invention is an electrode assembly in which electrode units and assembly positive electrodes are sequentially stacked, and the electrode units include a negative electrode folded in a direction such that first surfaces face each other; a unit positive electrode positioned between the folded first surfaces; and a first separator positioned between the first surfaces and the unit positive electrode, wherein the first surfaces enclose the upper and lower surfaces of the unit positive electrode and one side surface of the unit positive electrode, and both ends of the first surfaces extend along the upper and lower surfaces of the unit positive electrode.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0051864 filed April 20, 2023 and Korean Patent Application No. 10-2024-0052125 filed April 18, 2024, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to an electrode assembly and a method for manufacturing an electrode assembly, and more particularly to an electrode assembly and a method for manufacturing an electrode assembly with improved manufacturing stability and productivity. [Background technology]

[0003] With technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting attention as an energy source for not only mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] These secondary batteries are classified into cylindrical and prismatic batteries, in which an electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries, in which an electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet, depending on the shape of the battery case. The electrode assembly housed in the battery case is a chargeable and dischargeable power-generating element that includes a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes. These batteries are classified into a jelly-roll type, in which a long sheet-type positive electrode and a negative electrode coated with an active material are wound up with a separator interposed between them; a stack type, in which multiple positive electrodes and negative electrodes are stacked sequentially with a separator interposed between them; and a zigzag type, in which a negative electrode is wrapped in a separator and then folded in a zigzag pattern with the positive electrodes cross-stacked on both sides of the separator.

[0005] 1 and 2 are cross-sectional views of a conventional electrode assembly.

[0006] 1, the stacked electrode assembly 10 has a structure in which a negative electrode 11 having a negative electrode active material layer 11a disposed on the upper and lower surfaces of a negative electrode current collector 11b, a positive electrode 15 having a positive electrode active material layer 15b disposed on the upper and lower surfaces of a positive electrode current collector 15a, and a separator interposed between the negative electrode 11 and the positive electrode 15. In particular, because the sides of the stacked electrode assembly 10 are exposed to the outside, each component may be easily damaged by external impact, which may reduce stability due to the risk of a short circuit.

[0007] 2, the zigzag electrode assembly 20 has a structure in which a negative electrode 21 is wrapped in separators 29a and 29b, and then positive electrodes 25 are cross-laminated on both sides of the separators 29a and 29b, and the negative electrode 21 is folded in a zigzag pattern. Here, the negative electrode 21 includes a negative electrode active material layer 21a, a negative electrode current collector (not shown), and a negative electrode tab 21b, and the positive electrode 25 includes a positive electrode active material layer 25a, a negative electrode current collector (not shown), and a positive electrode tab 25b. Here, the negative electrode current collector (not shown) is located inside the negative electrode active material layer 21a, and the negative electrode tab 21b extending from the negative electrode current collector (not shown) extends outside the negative electrode 21. The same can be said for the positive electrode 25.

[0008] However, in the case of a zigzag-type electrode assembly 20, since one negative electrode 21 has a structure in which it is folded in a zigzag shape, it is difficult to disassemble and reassemble the electrode assembly 20 in the event of a manufacturing defect. That is, the negative electrode 21 cannot be reused, which results in a problem of reduced productivity.

[0009] Furthermore, in the case of the zigzag electrode assembly 20, since the negative electrode 21 has a relatively long length, it may not be easy to fold it at regular intervals when folding it in a zigzag pattern. In particular, during the manufacture of the zigzag electrode assembly 20, there is a possibility that the folded structure of the negative electrode 21 may not be manufactured consistently due to an error in the position where the positive electrode 25 is stacked on the negative electrode 21. Furthermore, if an abnormality occurs during the manufacturing process of the zigzag electrode assembly 20, the entire manufacturing process must be interrupted, resulting in a problem of reduced productivity.

[0010] 1 and 2, a jelly-roll type electrode assembly, which is similar to the zigzag type electrode assembly 20 in that it is wound with a separator interposed between a long sheet-type positive electrode and a negative electrode coated with an active material, may not be easily wound at regular intervals, and if an abnormality occurs during the manufacturing process, the entire manufacturing process must be interrupted, resulting in reduced productivity. In particular, in the case of a jelly-roll type electrode assembly, the thickness of the active material layer may vary depending on the top and bottom positions to facilitate winding, resulting in problems such as reduced battery capacity.

[0011] Therefore, it is necessary to develop an electrode assembly having a structure that is different from conventional electrode assemblies and that has improved manufacturing stability and productivity. Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide an electrode assembly and a method for manufacturing the electrode assembly, which have improved manufacturing stability and productivity.

[0013] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Means for solving the problem]

[0014] An electrode assembly according to one embodiment of the present invention is an electrode assembly in which electrode units and assembly positive electrodes are sequentially stacked, and the electrode units include a negative electrode folded in a direction such that first surfaces face each other; a unit positive electrode positioned between the folded first surfaces; and a first separator positioned between the first surfaces and the unit positive electrode, wherein the first surfaces enclose the upper and lower surfaces of the unit positive electrode and one side surface of the unit positive electrode, and both ends of the first surfaces extend along the upper and lower surfaces of the unit positive electrode.

[0015] The first separator may be attached to the first surface, and both ends of the first separator may extend to both ends of the first surface.

[0016] Both ends of the first separation membrane may extend across the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, and the both ends of the first separation membrane may be joined to each other on the other side surface of the unit positive electrode.

[0017] Both ends of the negative electrode may extend across the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, and the both ends of the negative electrode may be joined to each other at the other side surface of the unit positive electrode.

[0018] The first separator may be attached to the upper and lower surfaces of the unit positive electrode and to both side surfaces of the unit positive electrode.

[0019] The first separator may be attached to upper and lower surfaces of the unit positive electrode and one side surface of the unit positive electrode, and both ends of the first separator may extend along the upper and lower surfaces of the unit positive electrode, respectively.

[0020] Both ends of the first separation membrane may extend across the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, and the both ends of the first separation membrane may be joined to each other on the other side surface of the unit positive electrode.

[0021] The assembly positive electrode may be located on a second surface opposite the first surface, and may further include a second separator located between the assembly positive electrode and the second surface and attached to the second surface, and both ends of the second separator may extend to both ends of the second surface.

[0022] Both ends of the second separator may extend over side surfaces of both ends of the negative electrode to side surfaces of the unit positive electrode, and both ends of the second separator may be joined to each other on the other side surface of the unit positive electrode.

[0023] Both ends of the negative electrode may extend across the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, and the both ends of the negative electrode may be joined to each other at the other side surface of the unit positive electrode.

[0024] The positive electrode assembly may further include an external separator located on a second surface opposite the first surface, between the positive electrode assembly and the second surface, and attached to at least a portion of the surface of the positive electrode assembly.

[0025] The external separator may include a first external separator attached to an upper surface of the positive electrode assembly and a second external separator attached to a lower surface of the positive electrode assembly.

[0026] The external separator may be attached to the top and bottom surfaces of the positive electrode assembly and to both sides of the positive electrode assembly.

[0027] The external separator may be attached to upper and lower surfaces of the assembly positive electrode and one side of the assembly positive electrode, and both ends of the external separator may extend along the upper and lower surfaces of the assembly positive electrode, respectively.

[0028] Both ends of the external separator may extend across the upper and lower surfaces of the assembly positive electrode to the other side of the assembly positive electrode, and the both ends of the external separator may be joined to each other at the other side of the assembly positive electrode.

[0029] At least one negative electrode tab included in the negative electrode and a unit positive electrode tab included in the unit positive electrode may extend in the same direction, and the at least one negative electrode tab may be positioned on the same vertical line, and the at least one negative electrode tab and the unit positive electrode tab may be positioned on different vertical lines.

[0030] At least one negative electrode tab included in the negative electrode and a unit positive electrode tab included in the unit positive electrode may extend in different directions.

[0031] The at least one negative electrode tab may be one negative electrode tab extending along one side of the negative electrode.

[0032] A manufacturing method of an electrode assembly according to another embodiment of the present invention is a manufacturing method of an electrode assembly for manufacturing the above-mentioned electrode assembly, and includes the steps of: marking a folding line at the center of a first surface of the negative electrode; folding the first surface of the negative electrode based on the folding line; positioning the unit positive electrode on a portion of the folded first surface; and folding the remaining portion of the first surface toward an upper surface of the unit positive electrode based on the folding line, and the first separator may be attached to the first surface or to at least a portion of an outer surface of the unit positive electrode.

[0033] The method may further include a step of positioning an assembly positive electrode on a second surface, which is the surface opposite to the first surface, positioned on the upper surface of the unit positive electrode, and may include a second separator or an external separator positioned between the second surface and the assembly positive electrode, wherein the second separator is attached to the second surface, and the external separator is attached to at least a portion of the outer surface of the assembly positive electrode. [Effects of the Invention]

[0034] According to the embodiments, the present invention provides an electrode assembly in which an electrode unit and an assembly positive electrode are sequentially stacked, and a manufacturing method thereof. The negative electrode included in the electrode unit has a folded structure that encloses the top, bottom, and one side of the positive electrode, thereby improving manufacturing stability and productivity.

[0035] The effects of the present invention are not limited to those described above, and effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a cross-sectional view of a conventional electrode assembly. [Figure 2] 1 is a cross-sectional view of a conventional electrode assembly. [Figure 3] 1 is a perspective view of an electrode assembly according to one embodiment of the present invention. [Figure 4] 4 is a cross-sectional view of the electrode assembly of FIG. 3. [Figure 5] FIG. 10 is a perspective view of an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 6] FIG. 10 is a perspective view of an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 7] FIG. 10 is a perspective view of an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view of an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 9] FIG. 10 is a perspective view of an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view of an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 11] FIG. 10 is a perspective view of an assembly positive electrode included in an electrode assembly according to another embodiment of the present invention. [Figure 12] 1 is a diagram illustrating a method for manufacturing an electrode unit included in an electrode assembly according to an embodiment of the present invention. [Figure 13] 1 is a diagram illustrating a method for manufacturing an electrode unit included in an electrode assembly according to an embodiment of the present invention. [Figure 14] 10A to 10C are perspective views showing various arrangements of positive and negative electrode tabs in an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 15] 10A to 10C are perspective views showing various arrangements of positive and negative electrode tabs in an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 16] 10A to 10C are perspective views showing various arrangements of positive and negative electrode tabs in an electrode unit included in an electrode assembly according to another embodiment of the present invention. [Figure 17] 1 is a diagram illustrating a storage state of an electrode unit and an assembly positive electrode included in an electrode assembly according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention will now be described in detail with reference to the accompanying drawings, in which various embodiments of the present invention can be easily implemented by those skilled in the art. The present invention can be implemented in several different forms and is not limited to the examples described herein.

[0038] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0039] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0040] Also, throughout the specification, when a part is said to "comprise" a certain element, this means that it can further include other elements, rather than excluding other elements, unless otherwise specified.

[0041] Also, throughout the specification, "on a plane" means when the target part is viewed from above, and "on a cross section" means when the target part is cut vertically and viewed from the side.

[0042] An electrode assembly according to an embodiment of the present invention will now be described in detail.

[0043] 3 is a perspective view of an electrode assembly according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view of the electrode assembly of FIG.

[0044] 3 and 4, an electrode assembly 100 according to an embodiment of the present invention may be an electrode assembly in which an electrode unit 200 and a positive electrode assembly 300 are sequentially stacked. More specifically, the electrode assembly 100 may have the positive electrode assembly 300 stacked on the electrode unit 200 with the electrode unit 200 located at the bottom, and such a structure may be repeated multiple times.

[0045] Here, the positive electrode assembly 300 is a component separate from the electrode unit 200, and the positive electrode assembly 300 is sequentially stacked with the electrode unit 200 to form the electrode assembly 100, and the positive electrode assembly 300 may be located outside the electrode unit 200. That is, the positive electrode assembly 300 may refer to a positive electrode located on the upper and / or lower surface of the electrode unit 200.

[0046] 3 and 4, an electrode assembly 100 according to an embodiment of the present invention includes electrode units 200 and assembly positive electrodes 300 stacked in sequence, and the negative electrodes 210 included in one electrode unit 200 may be separated from the negative electrodes 210 included in another electrode unit 200, and one assembly positive electrode 300 may also be separated from another assembly positive electrode 300. That is, the assembly positive electrode 300 may be disposed between adjacent electrode units 200, and the negative electrodes 210 included in the adjacent electrode units 200 may be spaced apart. Also, the electrode unit 200 may be disposed between adjacent assembly positive electrodes 300, and the adjacent assembly positive electrodes 300 may be spaced apart.

[0047] As a result, the electrode assembly 100 according to this embodiment can be manufactured by sequentially stacking the electrode units 200 and the assembly positive electrodes 300 that have been manufactured and / or stored in advance as semi-finished products, thereby simplifying the manufacturing process of the electrode assembly 100 and increasing the production speed. Furthermore, the electrode assembly 100 according to this embodiment allows the electrode units 200 and the assembly positive electrodes 300 to be manufactured and / or stored separately, thereby separating the manufacturing and storage processes of the electrode units 200 and the assembly positive electrodes 300, thereby improving the productivity and manufacturing stability of the electrode assembly 100. Referring to FIGS. 3 and 4 , the electrode unit 200 includes a negative electrode 210 folded in a direction such that first surfaces face each other; unit positive electrodes 250 positioned between the folded first surfaces; and a first separator 410 positioned between the first surfaces and the unit positive electrodes 250.

[0048] Here, the unit positive electrode 250 is a component included in the electrode unit 200, and the unit positive electrode 250 constitutes the electrode unit 200 by being positioned between the first surfaces of the folded negative electrodes 210, and the unit positive electrode 250 may be positioned inside the electrode unit 200. In other words, the unit positive electrode 250 may refer to a positive electrode positioned between the first surfaces of the folded negative electrodes 210 of the electrode unit 200.

[0049] More specifically, the anode 210 may include an anode active material layer 211 and an anode tab 215. Although not shown in FIGS. 3 and 4, the anode active material layer 211 may be located on at least one of the upper and lower surfaces of an anode current collector (not shown). For example, as shown in FIGS. 3 and 4, the anode 210 may have the anode active material layers 211 formed on upper and lower portions with the anode current collector (not shown) interposed therebetween. Here, since the anode current collector (not shown) is located inside the anode active material layer 211, the anode current collector (not shown) is omitted from the drawings for ease of explanation. The anode tab 215 may be a portion extending from the anode current collector (not shown) and may be a portion of the anode current collector (not shown) on which the anode active material layer 211 is not located. For example, the negative electrode tab 215 may protrude outward from one side of a negative electrode current collector (not shown) located inside the negative electrode active material layer 211 .

[0050] The negative electrode current collector (not shown) is not particularly limited as long as it does not induce chemical changes in the battery and has high conductivity. For example, copper, stainless steel, aluminum, nickel, titanium, baked carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like, aluminum-cadmium alloy, etc. can be used.

[0051] The negative electrode active material layer 211 may be manufactured by attaching or coating a negative electrode slurry containing a negative electrode active material onto the negative electrode current collector (not shown). The negative electrode slurry may further include a conductive material and a polymer material in addition to the negative electrode active material.

[0052] More preferably, the negative electrode active material may be lithium metal. That is, in this case, the negative electrode active material layer 211 may refer to a lithium metal layer. In particular, lithium metal is softer than graphite used in conventional negative electrodes and is foldable. In addition, lithium metal has the advantage of being easily bonded to other components with only relatively weak compression compared to materials used in conventional negative electrodes.

[0053] As a result, in the electrode assembly 100 according to this embodiment, the negative electrode active material layer 211 included in the negative electrode 210 includes lithium metal, and the negative electrode 210 may have a folded structure with the unit positive electrode 250 interposed therebetween, as shown in Figures 3 and 4. In addition, as will be described later, since the negative electrode 210 included in the electrode unit 200 has relatively high bonding strength, there is an advantage that the electrode unit 200 and the positive electrode 300 can be assembled in a pick and place (P&P) manner during the manufacture of the electrode assembly 100.

[0054] The unit cathode 250 may include a unit cathode active material layer 251, a unit cathode current collector (not shown), and a unit cathode tab 255. Although not shown in FIGS. 3 and 4, the unit cathode active material layer 251 may be located on at least one of the upper and lower surfaces of the unit cathode current collector (not shown). For example, as shown in FIGS. 3 and 4, the unit cathode 250 may have the unit cathode active material layers 251 formed on the upper and lower surfaces, with the unit cathode current collector (not shown) interposed therebetween. Here, since the unit cathode current collector (not shown) is located inside the unit cathode active material layer 251, the unit cathode current collector (not shown) is omitted from the drawings for ease of explanation. The unit cathode tab 255 may be located on the upper and lower surfaces of the unit cathode current collector (not shown), where the unit cathode active material layer 251 is not located. For example, the unit positive electrode tab 255 may protrude outward from one side surface of the unit positive electrode current collector (not shown) located inside the unit positive electrode active material layer 251 .

[0055] The unit positive electrode current collector (not shown) is not particularly limited as long as it does not induce chemical changes in the battery and has high conductivity. For example, stainless steel, aluminum, nickel, titanium, baked carbon, or aluminum or stainless steel surface treated with carbon, nickel, titanium, silver, etc. may be used.

[0056] The unit positive electrode active material layer 251 may be fabricated by depositing or coating a positive electrode slurry containing a positive electrode active material on the unit positive electrode current collector (not shown). The positive electrode slurry may further include a conductive material and a polymer material in addition to the positive electrode active material. Examples of the positive electrode active material include lithium cobalt oxide (LiCoO), lithium nickel oxide (LiNiO), lithium manganese oxide, lithium copper oxide (LiCuO), vanadium oxide, Ni-site lithium nickel oxide, lithium manganese composite oxide, spinel-structured lithium manganese composite oxide, LiMnO in which a portion of the Li in the chemical formula is replaced with an alkaline earth metal ion, disulfide compounds, Fe(MoO), and the like. However, the positive electrode active material is not limited thereto, and materials commonly used in lithium secondary batteries may be used.

[0057] More specifically, based on the state before the negative electrode 210 is folded as shown in FIGS. 3 and 4, the first surface may be one of the upper surface and the lower surface of the negative electrode 210. For example, when the first surface is the upper surface of the negative electrode 210, the negative electrode 210 may be folded in a direction in which the upper surfaces of the negative electrodes 210 face each other. Conversely, when the first surface is the lower surface of the negative electrode 210, the negative electrode 210 may be folded in a direction in which the lower surfaces of the negative electrodes 210 face each other. In addition, the unit positive electrodes 250 may be located between the folded first surfaces. More specifically, the distance between the folded first surfaces of the negative electrode 210 may be equal to or greater than the thickness of the unit positive electrodes 250.

[0058] In addition, in the electrode unit 200, the first surface of the negative electrode 210 covers the top and bottom surfaces and one side surface of the unit positive electrode 250, and both ends of the first surface extend along the top and bottom surfaces of the unit positive electrode 250. As one example, the negative electrode 210 may have a structure that is folded once, and cover the top and bottom surfaces and one side surface of the unit positive electrode 250. As another example, the negative electrode 210 may be curved like the letter C, and cover the top and bottom surfaces and one side surface of the unit positive electrode 250. In other words, the other side surface of the unit positive electrode 250 may not be covered by the negative electrode 210.

[0059] In addition, in the electrode unit 200, the first separator 410 may be located between the first surface of the negative electrode 210 and the unit positive electrode 250. As will be described later, the first separator 410 may be attached to the first surface of the negative electrode 210 or the unit positive electrode 250.

[0060] Here, the first separator 410 separates the negative electrode 210 and the unit positive electrode 250 from each other and provides a path for lithium ions to move. Any separator that is generally used as a separator in a lithium secondary battery can be used without any particular limitation. In particular, a separator that has low resistance to the movement of electrolyte ions and excellent electrolyte solution impregnation ability is preferred.

[0061] As a result, in the electrode assembly 100 according to this embodiment, the negative electrode 210 included in the electrode unit 200 has a structure in which it is folded while wrapping the unit positive electrode 250, preventing the unit positive electrode 250 from being exposed to the outside and making it less susceptible to damage due to external impact, thereby improving stability against the risk of short circuit. Additionally, the electrode unit 200 can be stored in a semi-finished state having the above-described structure, and can be stored separately even if an abnormality occurs during the manufacturing process, which has the advantage of improving productivity and manufacturing stability.

[0062] 5 to 10 are perspective views of an electrode unit included in an electrode assembly according to another embodiment of the present invention.

[0063] 4 to 7, in the electrode units 200, 200a, and 200b included in the electrode assembly 100 according to an embodiment of the present invention, the first separator 410, 410a, and 410b may be attached to the first surface of the negative electrode 210, 210a, and 210b. More specifically, in the electrode units 200, 200a, and 200b, both ends of the first separator 410 may extend to both ends of the first surface of the negative electrode 210, 210a, and 210b.

[0064] 8 to 10, in the electrode units 200c, 200d, and 200e included in the electrode assembly 100 according to this embodiment, the first separators 410c, 410d, and 410e are attached to the first surfaces of the negative electrodes 210c, 210d, and 210e, and both ends of the first separators 410c, 410d, and 410e may extend across the top and bottom surfaces of the unit positive electrodes 250c, 250d, and 250e to the other sides of the unit positive electrodes 250c, 250d, and 250e. In particular, both ends of the first separators 410c, 410d, and 410e may be joined to each other on the other sides of the unit positive electrodes 250c, 250d, and 250e.

[0065] For example, both ends of the first separators 410c, 410d, and 410e may be bonded to each other using ultrasonic or heat sealing. For another example, both ends of the first separators 410c, 410d, and 410e may be bonded to each other using an adhesive or pressure-sensitive adhesive. However, the present invention is not limited to this, and any method capable of bonding both ends of the first separators 410c, 410d, and 410e may be applied to this embodiment.

[0066] 8 to 10, in the electrode units 200c, 200d, and 200e, both ends of the negative electrodes 210c, 210d, and 210e may extend across the top and bottom surfaces of the unit positive electrodes 250c, 250d, and 250e to the other side surfaces of the unit positive electrodes 250c, 250d, and 250e. More specifically, the negative electrodes 210c, 210d, and 210e may extend outward from the other side surfaces of the unit positive electrodes 250c, 250d, and 250e, and both ends of the negative electrodes 210c, 210d, and 210e may be folded along the other side surfaces of the unit positive electrodes 250c, 250d, and 250e.

[0067] In particular, both ends of the negative electrodes 210c, 210d, and 210e may be joined to each other on the other side of the unit positive electrodes 250c, 250d, and 250e. That is, as shown in Figures 8 to 10, in the electrode units 200c, 200d, and 200e, negative electrode joints 219c, 219d, and 219e may be formed in which both ends of the negative electrodes 210c, 210d, and 210e are joined to each other.

[0068] For example, both ends of the negative electrodes 210c, 210d, and 210e may be bonded to each other using ultrasonic or heat sealing. For another example, both ends of the negative electrodes 210c, 210d, and 210e may be bonded to each other using an adhesive or pressure-sensitive adhesive. However, this is not a limitation, and any method capable of bonding both ends of the negative electrodes 210c, 210d, and 210e may be applied to this embodiment.

[0069] Accordingly, in the electrode assembly 100 according to this embodiment, as shown in FIGS. 5 to 10, the electrode units 200, 200a, 200b, 200c, 200d, and 200e may have first separators 410, 410a, 410b, 410c, 410d, and 410e attached in various forms to the first surfaces of the negative electrodes 210, 210a, 210b, 210c, 210d, and 210e.

[0070] In this case, the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e may be inserted between the folded first surfaces of the negative electrodes 210, 210a, 210b, 210c, 210d, and 210e without a separate separator attached thereto. In addition, since the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e do not have a separate separator attached thereto, they may be used in the assembly positive electrode 300 or in other manufacturing processes.

[0071] In particular, in the process of folding the negative electrodes 210, 210a, 210b, 210c, 210d, and 210e in the electrode units 200, 200a, 200b, 200c, 200d, and 200e shown in FIGS. 5 to 10, the first surfaces of the negative electrodes can be protected by the first separators 410, 410a, 410b, 410c, 410d, and 410e, thereby preventing the negative electrodes 210, 210a, 210b, 210c, 210d, and 210e from being damaged during the manufacturing process.

[0072] In addition, in the electrode assembly 100 according to this embodiment, as shown in Figures 8 to 10, the upper, lower and both side surfaces of the unit positive electrodes 250c, 250d and 250e of the electrode units 200c, 200d and 200e may be covered with first separators 410c, 410d and 410e, which has the advantage of improving stability against the risk of short circuits.

[0073] In addition, as shown in Figures 9 and 10, the electrode units 200d, 200e have both ends of the negative electrodes 210d, 210e joined to each other, so that even if the electrode units 200d, 200e are lifted upward, the shape of the electrode units 200d, 200e is maintained, which has the advantage that the electrode units 200d, 200e can be assembled using a P&P (Pick and Place) method when manufacturing the electrode assembly 100.

[0074] 4 to 7, unlike the above, in the electrode units 200, 200a, 200b included in the electrode assembly 100 according to another embodiment of the present invention, the first separators 410, 410a, 410b may be attached to the upper and lower surfaces of the unit positive electrodes 250, 250a, 250b and one side of the unit positive electrodes 250, 250a, 250b. More specifically, in the electrode units 200, 200a, 200b, both ends of the first separator 410 may extend along the upper and lower surfaces of the unit positive electrodes 250, 250a, 250b, respectively. For example, as shown in FIGS. 4 to 7, in the electrode units 200, 200a, 200b, one side of the unit positive electrodes 250, 250a, 250b may not be covered by the first separators 410, 410a, 410b.

[0075] 8 to 10, in the electrode units 200c, 200d, and 200e included in the electrode assembly 100 according to this embodiment, the first separators 410c, 410d, and 410e may be attached to the top and bottom surfaces of the unit positive electrodes 250c, 250d, and 250e and to both sides of the unit positive electrodes 250, 250a, and 250b. More specifically, both ends of the first separators 410c, 410d, and 410e may extend from the top and bottom surfaces of the unit positive electrodes 250c, 250d, and 250e to the other sides of the unit positive electrodes 250c, 250d, and 250e, respectively. In particular, on the other side of the unit positive electrodes 250c, 250d, 250e, both ends of the first separators 410c, 410d, 410e may be joined to each other, or both ends of the first separators 410c, 410d, 410e may be integrated with each other.

[0076] For example, the first separators 410, 410a, 410b, 410c, 410d, and 410e may be bonded to at least one surface of the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e by ultrasonic or heat sealing. As another example, the first separators 410, 410a, 410b, 410c, 410d, and 410e may be bonded to at least one surface of the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e by adhesive or pressure-sensitive adhesive. As another example, the first separators 410, 410a, 410b, 410c, 410d, and 410e may be bonded to at least one surface of the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e by a lamination method, but are not limited thereto, and any method that can bond the first separators 410, 410a, 410b, 410c, 410d, and 410e to the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e may be applied to this embodiment.

[0077] 5 to 10, in the electrode assembly 100 according to this embodiment, the electrode units 200, 200a, 200b, 200c, 200d, and 200e may have first separators 410, 410a, 410b, 410c, 410d, and 410e attached to the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e in various forms. In this case, the unit positive electrodes 250, 250a, 250b, 250c, 250d, and 250e may be inserted between the folded first surfaces of the negative electrodes 210, 210a, 210b, 210c, 210d, and 210e, without a separate separator attached to the first surfaces of the negative electrodes 210, 210a, 210b, 210c, 210d, and 210e.

[0078] In addition, as described above, in the electrode assembly 100 according to this embodiment, as shown in Figures 8 to 10, the electrode units 200c, 200d, and 200e have first separators 410c, 410d, and 410e attached to the upper, lower, and both side surfaces of the unit positive electrodes 250c, 250d, and 250e, which has the advantage of improving stability against the risk of short circuits.

[0079] 3 and 4, in the electrode unit 200 included in the electrode assembly 100 according to another embodiment of the present invention, the assembly positive electrode 300 may be located on a second surface, which is the surface opposite to the first surface, of the negative electrode 210. The electrode unit 200 may further include a second separator 450 located between the second surface of the negative electrode 210 and the assembly positive electrode 300. More specifically, at least a portion of the second separator 450 may be located between the second surface of the negative electrode 210 and the assembly positive electrode 300.

[0080] Here, the second separator 450 separates the negative electrode 210 and the assembly positive electrode 300 from each other and provides a path for lithium ions to move. Any separator typically used as a separator in a lithium secondary battery may be used without any particular limitation. In particular, a separator that has low resistance to the movement of electrolyte ions and excellent electrolyte solution impregnation ability is preferred.

[0081] 3 to 6, 8, and 9, in the electrode units 200, 200a, 200c, and 200d included in the electrode assembly 100 according to another embodiment of the present invention, the second separators 450, 450a, 450c, and 450d may be attached to the second surfaces of the negative electrodes 210, 210a, 210c, and 210d.

[0082] As shown in FIGS. 3 and 4, in the electrode unit 200 according to one embodiment of the present invention, the second separator 450 extends along the second surface of the negative electrode 210, and both ends of the second separator 450 may extend to both ends of the second surface of the negative electrode 210, respectively.

[0083] 5 and 6, in an electrode unit 200a according to another embodiment of the present invention, both ends 451a and 455a of a second separator 450a may extend over the side surfaces of both ends of the negative electrode 210a to the side surfaces of the unit positive electrode 250a. More specifically, both ends 451a and 455a of the second separator 450a may extend outward from both ends of the second surface of the negative electrode 210a, and both ends 451a and 455a of the second separator 450a may be folded along the side surfaces of both ends of the negative electrode 210a and the side surfaces of the unit positive electrode 250a. In particular, both ends 451a and 455a of the second separator 450a may be joined to each other on the other side of the unit positive electrode 250a. That is, as shown in FIG. 5, in the electrode unit 200a, a second separation membrane joint 459a may be formed in which both ends 451a, 455a of a second separation membrane 450a are joined to each other.

[0084] For example, both ends 451a and 455a of second separation membrane 450a may be bonded to each other using ultrasonic or heat sealing. As another example, both ends 451a and 455a of second separation membrane 450a may be bonded to each other using an adhesive or pressure-sensitive adhesive. However, this is not a limitation, and any method capable of bonding both ends 451a and 455a of second separation membrane 450a may be applied to this embodiment.

[0085] 8 and 9, in the electrode units 200c and 200d, both ends of the negative electrodes 210c and 210d may extend across the top and bottom surfaces of the unit positive electrodes 250c and 250d to the other side surfaces of the unit positive electrodes 250c and 250d. In particular, both ends of the negative electrodes 210c and 210d may be joined to each other on the other side surfaces of the unit positive electrodes 250c and 250d. That is, as shown in FIGS. 8 and 9, in the electrode units 200c and 200d, negative electrode joints 219c and 219d may be formed where both ends of the negative electrodes 210c and 210d are joined to each other.

[0086] Here, as shown in FIG. 8, the second separator 450c is attached to the second surface of the negative electrode 210c, but the second separator 450c may not be attached to the side of the negative electrode 210c on which the negative electrode joint portion 219c is formed.

[0087] Alternatively, as shown in Fig. 9, the second separator 450d may be attached to the second surface of the anode 210d, but the second separator 450d may extend to the side of the anode 210d where the anode joint 219d is formed. In this case, both ends of the second separator 450d may be joined in the same manner as described above, and the second separator joint 459d may be formed on one surface of the anode 210d. For example, both ends of the second separator 450d may be formed on the side of the anode 210d where the anode joints 219c and 219d are formed.

[0088] As a result, in the electrode assembly 100 according to this embodiment, as shown in Figures 3 to 6, 8, and 9, the electrode units 200, 200a, 200c, and 200d may have second separators 450, 450a, 450c, and 450d attached in various shapes to the second surfaces of the negative electrodes 210, 210a, 210c, and 210d.

[0089] In this case, the cathode assembly 300 may be laminated on the second surface of the anode 210 without a separate separator attached thereto. In addition, since the cathode assembly 300 does not have a separate separator attached thereto, it may also be used as the unit cathodes 250, 250a, 250b, 250c, 250d, and 250e or in other manufacturing processes.

[0090] In particular, in the process of stacking the electrode units 200, 200a, 200c, and 200d and the positive electrode assembly 300 as shown in FIGS. 3 to 6, 8, and 9, the second surfaces of the negative electrodes 210, 210a, 210c, and 210d included in the electrode units 200, 200a, 200c, and 200d may be protected by the second separators 450, 450a, 450c, and 450d, thereby preventing the negative electrodes 210, 210a, 210c, and 210d from being damaged during the manufacturing process.

[0091] 5 and 6, the electrode unit 200a of the electrode assembly 100 according to this embodiment may have the other side of the unit positive electrode 250a covered with a second separator 450a, which is advantageous in terms of improving stability against the risk of short circuiting. Also, as shown in FIG. 9, the electrode unit 200d of the electrode assembly 100 according to this embodiment may have the other side of the unit positive electrode 250d covered with both ends of the negative electrode 210d and a second separator 450d, which is advantageous in terms of improving stability against the risk of short circuiting.

[0092] 5, 6, and 9, the electrode units 200a, 200d have the other sides of the unit positive electrodes 250a, 250d covered with second separators 450a, 450d and both ends of the negative electrode 210d joined together, so that the shape of the electrode units 200a, 200d can be maintained even when the electrode units 200a, 200d are lifted upward. That is, there is an advantage that the electrode units 200a, 200d can be assembled using a pick and place (P&P) method when manufacturing the electrode assembly 100.

[0093] FIG. 11 is a perspective view of an assembly positive electrode included in an electrode assembly according to another embodiment of the present invention.

[0094] 4 and 11, a positive electrode assembly 300 may be positioned on the second surface of a negative electrode 210 included in an electrode unit 200. Unlike in FIG. 4, the second separator 450 of the electrode unit 200 may be omitted, and external separators 390a, 390b, 390c, and 390d may be attached to at least some surfaces of the positive electrodes 300a, 300b, 300c, and 300d. More specifically, at least some of the external separators 390a, 390b, 390c, and 390d may be positioned between the positive electrode assembly 300a and the second surface of the negative electrode 210.

[0095] Similar to the unit positive electrode 250, the assembly positive electrodes 300, 300a, 300b, 300c, and 300d can include assembly positive electrode active material layers 310, 310a, 310b, 310c, and 310d and assembly positive electrode tabs 350, 350a, 350b, 350c, and 350d, and other aspects can be described in the same manner as for the unit positive electrode 250 described above.

[0096] The outer separator 390 separates the anode 210 and the cathode assembly 300 from each other and provides a path for lithium ions to move. Any material commonly used as a separator in lithium secondary batteries can be used without any particular restrictions. In particular, a material that has low resistance to the movement of electrolyte ions and excellent electrolyte solution impregnation ability is preferred.

[0097] 11(a), the external separators 390a, 390b, 390c, and 390d may include a first external separator 391a attached to the upper surface of the assembly positive electrode 300a and a second external separator 395a attached to the lower surface of the assembly positive electrode 300a. For example, the first external separator 391a and the second external separator 395a may be larger than or the same size as the upper and lower surfaces of the assembly positive electrode 300a, and the first external separator 391a and the second external separator 395a may be the same size as each other.

[0098] Referring to Figures 11(b) and (c), external separators 390b and 390c are attached to the upper and lower surfaces of the assembly positive electrodes 300b and 300c and one side of the assembly positive electrodes 300b and 300c, and both ends of the external separators 390b and 390c may extend along the upper and lower surfaces of the assembly positive electrodes 300b and 300c, respectively.

[0099] 11(b), both ends of the external separator 390b may extend from the top and bottom surfaces of the assembly positive electrode 300b to the other side of the assembly positive electrode 300b. In particular, both ends of the external separator 390b may be joined to each other on the other side of the assembly positive electrode 300b. That is, as shown in FIG. 11(b), an external separator joining portion 399b may be formed where both ends of the external separator 390b are joined to each other. For example, both ends of the external separator 390b may be joined to each other using an ultrasonic or heat sealing method. As another example, both ends of the external separator 390b may be joined to each other using an adhesive or a pressure-sensitive adhesive. However, the present invention is not limited thereto, and any method capable of joining both ends of the external separator 390b may be applied to this embodiment.

[0100] 11(d), external separators 390d may be attached to the top and bottom surfaces of assembly positive electrode 300d and to both side surfaces of assembly positive electrode 300d. As one example, external separators 390d may be attached to the top and bottom surfaces of assembly positive electrode 300d and to both side surfaces of assembly positive electrode 300d in a mutually integrated form. As another example, external separators 390d may be attached to the top and bottom surfaces of assembly positive electrode 300d and to both side surfaces of assembly positive electrode 300d in a mutually separated form for each side of assembly positive electrode 300d.

[0101] As a result, in the electrode assembly 100 according to this embodiment, external separators 390a, 390b, 390c, and 390d may be attached in various forms to at least one surface of each of the positive electrode assemblies 300a, 300b, 300c, and 300d, as shown in Fig. 11. In this case, as shown in Figs. 7 and 10, the positive electrode assemblies 300a, 300b, 300c, and 300d, each having the external separator 390a, 390b, 390c, and 390d attached thereto, may be stacked on the electrode units 200b and 200e, each of which does not have a second separator 450 attached to the second surface of the negative electrode 210b and 210e.

[0102] 12 and 13 are views showing a method of manufacturing an electrode unit included in an electrode assembly according to an embodiment of the present invention.

[0103] 12 and 13, a method for manufacturing an electrode assembly according to another embodiment of the present invention may be a method for manufacturing the electrode assembly 100 described above.

[0104] 3, 12(a), and 13(a), the method for manufacturing an electrode assembly according to this embodiment may include a step of displaying a folding line at the center of the first surface of the negative electrode 210. Here, the folding line display portion 1000 may be located on the same vertical line as the position corresponding to the center of the first surface of the negative electrode 210.

[0105] 3, 12(b), and 13(b), the method for manufacturing an electrode assembly according to this embodiment may include folding a first surface of the negative electrode 210 based on the folding line and positioning a unit positive electrode 250 on a portion of the folded first surface. Here, the first surface of the negative electrode 210 may be folded primarily at a predetermined angle. For example, the first surface of the negative electrode 210 may be folded at an angle greater than 90 degrees.

[0106] As described above, for example, as shown in Fig. 12, the first separator 410 may be attached to the first surface of the anode 210, and in this case, a separate separator may not be attached to the outer surface of the unit cathode 250. As another example, as shown in Fig. 13, the first separator 410 may be attached to at least a portion of the outer surface of the unit cathode 250, and in this case, a separate separator may not be attached to the first surface of the anode 210.

[0107] Also, referring to Figures 3, 12(c) and 13(c), the manufacturing method of the electrode assembly according to this embodiment may include a step of folding the remaining surface of the first surface of the negative electrode 210 toward the upper surface of the unit positive electrode 250 based on the folding line.

[0108] Although not shown in FIGS. 12 and 13, referring to FIG. 3, the method further includes a step of placing an assembly positive electrode 300 on a second surface, which is the opposite surface to the first surface located on the upper surface of the unit positive electrode 250.

[0109] As described above, for example, as shown in Fig. 3, the battery may include a second separator 450 positioned between the second surface of the negative electrode 210 and the assembly positive electrode 300, and the second separator 450 may be attached to the second surface of the negative electrode 210. In this case, a separate separator may not be attached to the outer surface of the assembly positive electrode 300. As another example, as shown in Fig. 11, the battery may include an external separator 390 positioned between the second surface of the negative electrode 210 and the assembly positive electrode 300, and the external separator 390 may be attached to at least a portion of the outer surface of the assembly positive electrode 300. In this case, a separate separator may not be attached to the second surface of the negative electrode 210.

[0110] As a result, the manufacturing method of the electrode assembly according to this embodiment can easily manufacture the electrode unit 200 and the positive electrode assembly 300 by repeating the above-described steps, and can also easily manufacture the electrode assembly 100 in which the electrode unit 200 and the positive electrode assembly 300 are stacked. In addition, the electrode unit 200 and the positive electrode assembly 300 manufactured through the above-described manufacturing method can be stored in a semi-finished state, and can be stored separately even if an abnormality occurs during the manufacturing process, which is advantageous in that productivity and manufacturing stability are improved.

[0111] 14 to 16 are perspective views showing various arrangements of positive and negative electrode tabs in an electrode unit included in an electrode assembly according to another embodiment of the present invention.

[0112] 14 to 16, the arrangement of the electrode tabs included in the electrode unit 200 will be described in detail. However, for convenience of explanation, as shown in Figs. 14 to 16, the description will be based on a structure in which a first surface of the negative electrode 210 is folded at a predetermined angle and a unit positive electrode 250 is arranged on the first surface, and the first separator 410 located between the negative electrode 210 and the unit positive electrode 250 is omitted.

[0113] 14, in the electrode unit 200 according to this embodiment, when the first surface of the negative electrode 210 is fully folded toward the unit positive electrode 250 with the first surface of the negative electrode 210 folded at a predetermined angle, at least one negative electrode tab 215 included in the negative electrode 210 and one unit positive electrode tab 255 included in the unit positive electrode 250 may extend in the same direction. More specifically, when the first surface of the negative electrode 210 is fully folded toward the unit positive electrode 250 with the first surface of the negative electrode 210 folded at a predetermined angle, the at least one negative electrode tab 215 may be positioned on the same vertical line, and the at least one negative electrode tab 215 and the unit positive electrode tab 255 may be positioned on different vertical lines.

[0114] As a result, as shown in FIG. 14 , when the first surface of the negative electrode 210 is completely folded toward the unit positive electrode 250 with the first surface of the negative electrode 210 folded at a predetermined angle, the electrode unit 200 has the negative electrode tab 215 and the unit positive electrode tab 255 positioned in one direction, thereby minimizing the space that must be secured for arranging the electrical connection structures of the negative electrode tab 215 and the unit positive electrode tab 255 between other electrode units 200.

[0115] 15 and 16, in the electrode unit 200 according to this embodiment, when the first surface of the negative electrode 210 is completely folded toward the unit positive electrode 250 with the first surface of the negative electrode 210 folded at a predetermined angle, at least one negative electrode tab 215 included in the negative electrode 210 and one unit positive electrode tab 255 included in the unit positive electrode 250 may extend in different directions.

[0116] As an example, referring to Figures 15(b), 16(b), and 16(c), in the electrode unit 200 according to this embodiment, at least one negative electrode tab 215 may be one negative electrode tab 215 extending along one side of the negative electrode 210.

[0117] 15 and 16 , when the first surface of the negative electrode 210 is folded at a predetermined angle and then completely folded toward the unit positive electrode 250, the electrode unit 200 has the negative electrode tab 215 and the unit positive electrode tab 255 positioned on both sides, preventing interference between the negative electrode tab 215 and the unit positive electrode tab 255. That is, this embodiment has the advantage of being able to omit the notching process for the negative electrode tab 215 and the unit positive electrode tab 255. More specifically, this can shorten the manufacturing time required for the notching process for the negative electrode tab 215 and the unit positive electrode tab 255 and minimize defects that may occur during the notching process.

[0118] FIG. 17 is a view showing a storage form of an electrode unit and an assembly positive electrode included in an electrode assembly according to an embodiment of the present invention.

[0119] 17, in the electrode assembly 100 according to this embodiment, the electrode units 200 may be stored in a stacked state in an electrode unit tray 2000, and the assembly positive electrode 300 may be stored in a stacked state in an assembly positive electrode tray 3000. Although not shown in FIG. 17, the electrode unit 200 may be replaced with the electrode units 200a, 200b, 200c, 200d, and 200e shown in FIGS. 5 to 10, and the assembly positive electrode 300 may be replaced with the assembly positive electrode 300a, 300b, 300c, and 300d shown in FIG. 11.

[0120] Therefore, unlike the conventional stacked electrode assembly 10 and zigzag electrode assembly 20, in the electrode assembly 100 according to this embodiment, the electrode unit 200 and the assembly positive electrode 300 can be manufactured separately and then stored in a semi-finished state in the electrode unit tray 2000 or the positive electrode tray 3000, respectively. That is, in the case of the electrode assembly 100 according to this embodiment, even if an abnormality occurs in one of the manufacturing processes, the electrode unit 200 and the assembly positive electrode 300 can be manufactured and stored separately, which is advantageous in that productivity and manufacturing stability are improved.

[0121] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0122] 100 Electrode Assembly 200 electrode units 210 negative electrode 211 Negative electrode active material layer 215 Negative electrode tab 250 units positive pole 251 unit positive electrode active material layer 255 unit positive tab 300 Assembly Positive Electrode 310 Assembly positive electrode active material layer 350 Assembly Positive Tab 390a, 390b, 390c, 390d external separation membrane 410 1st separation membrane 450 Second separation membrane 2000 electrode unit tray 3000 Assembly Positive Tray

Claims

1. An electrode assembly in which an electrode unit and an assembly positive electrode are sequentially stacked, The electrode unit comprises: a negative electrode folded in a direction such that the first surfaces face each other; a unit positive electrode positioned between the folded first surfaces; and a first separator located between the first surface and the unit positive electrode; an electrode assembly in which the first surface covers the upper and lower surfaces of the unit positive electrode and one side surface of the unit positive electrode, and both ends of the first surface extend along the upper and lower surfaces of the unit positive electrode;

2. the first separation membrane is attached to the first surface; The electrode assembly according to claim 1 , wherein both ends of the first separator extend to both ends of the first surface.

3. both ends of the first separation membrane extend across the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, The electrode assembly according to claim 2 , wherein both ends of the first separator are joined together on the other side of the unit positive electrode.

4. both ends of the negative electrode extend over the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, The electrode assembly according to claim 2 , wherein both ends of the negative electrode are joined together on the other side of the unit positive electrode.

5. The electrode assembly according to claim 1 , wherein the first separator is attached to the upper and lower surfaces of the unit positive electrode and to both side surfaces of the unit positive electrode.

6. the first separator is attached to upper and lower surfaces of the unit positive electrode and one side surface of the unit positive electrode; The electrode assembly according to claim 1 , wherein both ends of the first separator extend along the upper and lower surfaces of the unit positive electrode, respectively.

7. both ends of the first separation membrane extend across the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, The electrode assembly according to claim 6 , wherein both ends of the first separator are joined together on the other side of the unit positive electrode.

8. the assembly positive electrode is located on a second surface opposite the first surface, a second separator located between the assembly positive electrode and the second surface and attached to the second surface; The electrode assembly according to claim 1 , wherein both ends of the second separator extend to both ends of the second surface.

9. both ends of the second separator extend over the side surfaces of both ends of the negative electrode to the side surfaces of the unit positive electrode, The electrode assembly according to claim 8 , wherein both ends of the second separator are joined together on the other side of the unit positive electrode.

10. both ends of the negative electrode extend over the upper and lower surfaces of the unit positive electrode to the other side surface of the unit positive electrode, The electrode assembly according to claim 9 , wherein both ends of the negative electrode are joined together on the other side of the unit positive electrode.

11. the assembly positive electrode is located on a second surface opposite the first surface, The electrode assembly according to claim 1 , further comprising an external separator located between the assembly positive electrode and the second surface and attached to at least a portion of the surface of the assembly positive electrode.

12. The electrode assembly according to claim 11 , wherein the external separator comprises a first external separator attached to an upper surface of the assembly positive electrode and a second external separator attached to a lower surface of the assembly positive electrode.

13. The electrode assembly according to claim 11 , wherein the external separator is attached to the top and bottom surfaces of the positive electrode assembly and to both sides of the positive electrode assembly.

14. the external separator is attached to the upper and lower surfaces of the positive electrode assembly and one side surface of the positive electrode assembly; The electrode assembly according to claim 11 , wherein both ends of the external separator extend along the upper and lower surfaces of the assembly positive electrode, respectively.

15. both ends of the external separator extend from the upper and lower surfaces of the assembly positive electrode to the other side of the assembly positive electrode; The electrode assembly according to claim 14 , wherein both ends of the external separator are joined together on the other side of the assembly positive electrode.

16. At least one negative electrode tab included in the negative electrode and one unit positive electrode tab included in the unit positive electrode extend in the same direction, The at least one negative electrode tab is positioned on the same vertical line as another negative electrode tab, The electrode assembly according to claim 1 , wherein the at least one negative electrode tab and the unit positive electrode tab are positioned on different vertical lines.

17. The electrode assembly according to claim 1 , wherein at least one negative electrode tab included in the negative electrode and one unit positive electrode tab included in the unit positive electrode extend in different directions.

18. 18. The electrode assembly according to claim 17, wherein the at least one negative electrode tab is one negative electrode tab extending along one side of the negative electrode.

19. A method for manufacturing the electrode assembly according to claim 1, comprising the steps of: a step of displaying a folding line at the center of the first surface of the negative electrode; folding the first surface of the negative electrode along the folding line; positioning the unit positive electrodes on a part of the folded first surface; a step of folding the remaining surface of the first surface toward the upper surface of the unit positive electrode with respect to the folding line; The method for manufacturing an electrode assembly, wherein the first separator is attached to the first surface or to at least a portion of an outer surface of the unit positive electrode.

20. The method further includes a step of placing an assembly positive electrode on a second surface opposite to the first surface located on the upper surface of the unit positive electrode, a second or external separator located between the second surface and the assembly positive electrode; 20. The method of claim 19, wherein the second separator is attached to the second surface, and the outer separator is attached to at least a portion of the outer surface of the assembly positive electrode.

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