Electrode for lithium secondary battery with adhesive coating and method for manufacturing the same

Abstract

The present invention relates to an electrode for a lithium secondary battery, in which an electrode mixture layer is formed on at least one of a first surface and a second surface of an electrode current collector, the electrode current collector including an electrode tab that is an uncoated portion extending from the outer periphery of the electrode mixture layer in a portion other than the portion where the electrode mixture layer is formed, and an adhesive coating portion is attached to at least a portion of an upper surface of the electrode tab and an upper surface of the electrode mixture layer, and the adhesive coating portion can bond the electrode and a separator.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2021-0136064 filed on October 13, 2021, and all the contents disclosed in the document of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an electrode for a lithium secondary battery to which an adhesive coating part is added and a method for manufacturing the same. Specifically, the present invention relates to an electrode for a lithium secondary battery to which an adhesive coating part is added so that the electrode and the separator are integrated to prevent the separator from being bent, and a method for manufacturing the same.

Background Art

[0003] A lithium secondary battery that can be repeatedly charged and discharged and has a high energy density not only significantly reduces the use of fossil fuels but also does not generate by-products due to energy use, and thus is attracting attention as a new energy source having environmentally friendly characteristics.

[0004] The lithium secondary battery is manufactured by accommodating an electrode assembly including a positive electrode, a negative electrode, and a separator together with an electrolyte in a battery case and sealing the battery case.

[0005] The electrodes including the positive electrode and the negative electrode are manufactured by applying an electrode binder layer to a portion of the electrode current collector excluding the electrode tab, and after disposing a separator on the outer surface of the electrodes, the electrode assembly can be manufactured by laminating.

[0006] When the adhesive force between the laminated electrode and the separator is weak, the separator may be separated from the electrode and bent or folded during the transfer process, lamination process, and assembly process of the electrode assembly.

[0007] Thus, if the separator is bent or the like, the positive electrode and the negative electrode may come into contact with each other, causing problems such as an internal short circuit.

[0008] On the other hand, when a lithium secondary battery is exposed to high temperatures, or when it malfunctions due to internal or external short circuits, overcharging, or over-discharging, the heat generated causes the separator membrane to contract, increasing the likelihood that the positive and negative electrodes will come into direct contact with each other and a short circuit will occur.

[0009] Therefore, various studies are being conducted to prevent internal short circuits and ensure the safety of battery cells.

[0010] In Patent Document 1, in a jelly roll type electrode assembly, the outermost periphery of the positive electrode has a plain area on the outer surface of the electrode foil where the positive electrode mixture layer is not formed, and an adhesive tape is attached to a part of the plain area, and the adhesive tape is also attached to a separation membrane that protrudes above and below the positive electrode.

[0011] In other words, in Patent Document 1, the position of the separation membrane is fixed by attaching an adhesive tape so as to connect a part of the electrode foil and a part of the separation membrane. Since a part of the peripheral portion of the separation membrane is fixed to the positive electrode in such an electrode assembly, it is possible to prevent internal short circuits caused by the shrinkage of the separation membrane during heating.

[0012] However, Patent Document 1 utilizes a structure in which a plain area is formed on the outermost or innermost part of a jelly roll-type electrode assembly, making it difficult to apply to stack-type electrode assemblies. Furthermore, since the separation membrane cannot be fixed above the melting point of the adhesive tape, the positive and negative electrodes may come into contact, potentially causing an internal short circuit.

[0013] Therefore, there is a need for a method that can prevent bending of the separation membrane that may occur in stacked electrode assemblies, and that can prevent short circuits even if shrinkage of the separation membrane occurs. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] Patent No. 3932096 [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] The present invention aims to solve the aforementioned problems and provides an electrode for a lithium secondary battery in which an adhesive coating portion is added so as to maintain a stable adhesion between the electrode and the separation film during the electrode manufacturing process, thereby ensuring insulation between the positive electrode and the negative electrode.

[0016] Furthermore, the present invention aims to provide a method for manufacturing electrodes for lithium secondary batteries. [Means for solving the problem]

[0017] To achieve this objective, the electrode for a lithium secondary battery according to the present invention has an electrode mixture layer formed on at least one of the first and second surfaces of the electrode current collector, and the electrode current collector includes an electrode tab which is an uncoated portion extending from the outer periphery of the electrode mixture layer, other than the portion on which the electrode mixture layer is formed, and an adhesive coating portion is added to at least a part of the upper surface of the electrode tab and the upper surface of the electrode mixture layer.

[0018] The adhesive coating portion can be applied to at least a portion of the upper surface of the electrode tab.

[0019] The adhesive coating portion can be applied to the upper surface of the electrode mixture layer, specifically to the outer peripheral surface adjacent to the electrode tab.

[0020] The adhesive coating portion can be applied to the upper surface of the electrode mixture layer, specifically to the outer surface opposite to the outer surface on the side where the electrode tab is formed.

[0021] The adhesive coating portion can be applied to the upper surface of the electrode tab and to the upper surface of the electrode mixture layer, specifically to the outer peripheral side adjacent to the electrode tab.

[0022] The adhesive coating portion can be applied to the upper surface of the electrode tab, the upper surface of the outer peripheral side adjacent to the electrode tab among the upper surfaces of the electrode mixture layer, and the upper surface of the outer peripheral side opposite to the one outer peripheral side among the upper surfaces of the electrode mixture layer.

[0023] The adhesive coating portion can contain a non-conductive adhesive.

[0024] The non-conductive adhesive can be made of a polymer material having a glass transition temperature (Tg) of 100 °C or lower.

[0025] The adhesive coating portion is added to at least one of the first surface and the second surface, and at least one of the first surface and the second surface to which the adhesive coating portion is added can include a separator adhered to the adhesive coating portion.

[0026] The present invention provides a method for manufacturing the electrode for a lithium secondary battery. Specifically, it can include (a) a step of forming an electrode mixture layer on at least one surface of an electrode current collector, (b) a step of adding an adhesive coating portion to at least a part of the upper surface of the electrode tab extending from the outer peripheral side of the electrode mixture layer and the upper surface of the electrode mixture layer, (c) a step of disposing a separator on the electrode mixture layer and the adhesive coating portion in the step (b), and (d) a step of pressing the separator.

[0027] The step (d) can include a process of heating.

[0028] The adhesive coating portion can be formed on at least one of the positive electrode and the negative electrode.

[0029] The present invention is an electrode assembly including the electrode for a lithium secondary battery, which can include a stacked electrode assembly, a stacked folding electrode assembly, a laminated stacked electrode assembly, or a jelly roll type electrode assembly.

[0030] Furthermore, the present invention can also be provided in forms that combine various means for solving the aforementioned problems. [Effects of the Invention]

[0031] As explained above, the lithium secondary battery electrode according to the present invention can ensure adhesion between the electrode and the separator membrane by adding an adhesive coating, thereby preventing bending of the separator membrane. Therefore, insulation between the positive electrode and the negative electrode can be ensured, improving the safety of the lithium secondary battery.

[0032] Furthermore, the adhesive strength can be adjusted by controlling the glass transition temperature of the adhesive constituting the adhesive coating, the coating area, and the temperature and / or time of the heating process.

[0033] Furthermore, since the shrinkage of the separation membrane can be suppressed even at high temperatures, it is possible to prevent the formation of a contact area between the positive and negative electrodes when the battery cell is exposed to high temperatures.

[0034] On the other hand, when the adhesive coating is applied across the electrode mixture layer and the electrode tab, it is possible to prevent the formation of lithium deposits even if the outer peripheral end of the negative electrode is formed to be shorter than the outer peripheral end of the positive electrode. [Brief explanation of the drawing]

[0035] [Figure 1] These are a plan view and a partially enlarged cross-sectional view of the electrode according to the first embodiment. [Figure 2] These are a plan view and a partially enlarged cross-sectional view of the electrode according to the second embodiment. [Figure 3] These are a plan view and a partially enlarged cross-sectional view of the electrode according to the third embodiment. [Figure 4] These are a plan view and a partially enlarged cross-sectional view of the electrode according to the fourth embodiment. [Figure 5] These are a plan view and a partially enlarged cross-sectional view of the electrode according to the fifth embodiment. [Figure 6] These are a plan view and a partially enlarged cross-sectional view of the electrode according to the sixth embodiment. [Figure 7] This is a partial perspective view of the electrode according to the seventh and eighth embodiments. [Figure 8] This diagram shows the manufacturing process for electrodes used in lithium-ion batteries. [Modes for carrying out the invention]

[0036] Hereinafter, embodiments that allow a person with ordinary skill in the art to easily implement the present invention will be described in detail with reference to the attached drawings. However, in describing the operating principles of preferred embodiments of the present invention in detail, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0037] Furthermore, the same reference numerals shall be used throughout the drawings for parts that have similar functions and operations. Throughout the specification, when it is said that one part is connected to another part, this includes not only direct connections but also indirect connections through other elements in between. Also, when it is said that a component is included, unless otherwise stated, it does not mean that other components are excluded, but rather that other components may be included.

[0038] Furthermore, any description that limits or adds to the constituent elements is applicable to all inventions and is not limited to a specific invention, unless otherwise specified.

[0039] Furthermore, unless otherwise specified, the singular form used throughout the description of this invention and the claims also includes the plural form.

[0040] Furthermore, throughout the description and claims of this invention, "or" includes "and" unless otherwise specified. Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0041] The present invention will be described in detail with reference to the drawings.

[0042] The electrode according to the present invention may have a configuration in which, in a plan view, an electrode tab protrudes from the outer periphery of one side of a rectangular electrode current collector, and an electrode mixture layer is formed on the electrode current collector. Alternatively, the electrode according to the present invention may have a configuration in which an electrode tab is attached to a long sheet-like electrode current collector, and an electrode mixture layer is formed on the electrode current collector.

[0043] The electrode current collector has an electrode mixture layer formed on at least one of its upper surface (first surface) and lower surface (second surface).

[0044] The electrode current collector includes an electrode tab, which is an uncoated portion extending from the outer periphery of the electrode mixture layer, excluding the portion where the electrode mixture layer is formed. An adhesive coating is applied to at least a portion of the upper surface of the electrode tab and the upper surface of the electrode mixture layer. The uncoated portion refers to the portion where the electrode mixture layer is not formed.

[0045] The adhesive coating portion not only provides the function of adhering the separation film, but is also made of an insulating material. Therefore, even if the adhesive coating portion reaches a temperature at which it loses its adhesive function and the separation film shrinks, the adhesive coating portion remains attached, thus preventing contact between different electrodes.

[0046] Figure 1 is a plan view and a partially enlarged cross-sectional view of the electrode according to the first embodiment.

[0047] Referring to Figure 1, the electrode current collector 110 includes an electrode body 101 on which an electrode mixture layer 120 is formed, and an electrode tab 130 which is an uncoated portion extending from the outer periphery of the electrode mixture layer 120.

[0048] An adhesive coating portion 140 is added to a part of the upper surface of the electrode tab 130, adjacent to the electrode mixture layer 120.

[0049] Since the adhesive coating portion 140 can improve the adhesion between the separation membrane and the electrode, the bonding force between the electrode and the separation membrane can be increased, and the electrode and the separation membrane can be integrally bonded.

[0050] Internal short circuits between the positive and negative electrodes can occur in the following cases: contact between the positive electrode mixture layer and the negative electrode mixture layer, contact between the positive electrode mixture layer and the negative electrode current collector, contact between the positive electrode current collector and the negative electrode mixture layer, and contact between the positive electrode current collector and the negative electrode current collector. In this case, the greatest amount of heat is generated when the positive electrode current collector (positive electrode tab) and the negative electrode mixture layer are in contact.

[0051] As shown in Figure 1, when the adhesive coating portion 140 is applied to the upper surface of the electrode tab, adhesive strength between the electrode tab and the separation film can be ensured. Furthermore, even if the temperature rises to a level where the adhesive coating portion 140 loses its adhesive function, since the adhesive coating portion 140 is applied to the outer surface of the electrode tab, contact between the positive electrode tab and the negative electrode mixture layer can be prevented.

[0052] The electrode tab 130 can be connected to the electrode lead and then extend to the outside of the battery case to be used as an electrode terminal.

[0053] Therefore, an adhesive coating portion 140 is added to the portion of the electrode tab 130 adjacent to the electrode mixture layer 120, but the end of the electrode tab 130 opposite to the electrode mixture layer 120 has an uncoated portion exposed in order to connect with the electrode lead.

[0054] To ensure that the adhesive coating portion and the separation film adhere easily to each other, the thickness H2 of the adhesive coating portion 140 can be the same as or greater than the thickness H1 of the electrode mixture layer 120.

[0055] Alternatively, by changing the shape of the lamination press roll or adjusting the pressing method, lamination may be possible even when the thickness H2 of the adhesive coating portion is thinner than the thickness H1 of the electrode mixture layer.

[0056] Figure 2 is a plan view and a partially enlarged cross-sectional view of the electrode according to the second embodiment.

[0057] Referring to Figure 2, the electrode current collector 210 includes an electrode body 201 on which an electrode mixture layer 220 is formed, and an electrode tab 230 which is an uncoated portion extending from the outer periphery of the electrode mixture layer 220.

[0058] The electrode tab 230 has a form in which a portion of one side of the outer periphery of the electrode body 201 extends further outward and connects to the electrode lead.

[0059] The adhesive coating portion 240 is applied to the upper surface of the electrode tab 230 and to the upper surface of the electrode mixture layer 220, specifically the outer periphery on one side adjacent to the electrode tab 230. When the adhesive coating portion is applied along the outer periphery on one side of the electrode mixture layer in this manner, an even wider adhesive surface can be secured between the separation film and the adhesive coating portion.

[0060] The adhesive coating portion 240 is applied only to the remaining portion of the electrode tab, excluding the outer end. The portion of the electrode tab 230 that functions as an electrode tab is not coated with the adhesive coating portion 240, forming a welded portion for joining with the electrode lead.

[0061] On the other hand, generally, when manufacturing electrode assemblies, the area of ​​the negative electrode is manufactured to be larger than the area of ​​the positive electrode. However, due to misalignment of the positive and negative electrodes during the lamination process, lamination may occur with the negative electrode missing from the opposite side of the positive electrode.

[0062] In such cases, the terminal region of the negative electrode may become overcharged, causing deposits to form and grow as lithium dendrites. These can grow towards the positive electrode through the release film, potentially causing an internal short circuit. Therefore, as shown in Figure 2 of the present invention, if an adhesive coating is formed on the positive electrode so as to extend further from the outer periphery of the positive electrode mixture layer toward the positive electrode tab, it is possible to prevent lithium dendrites that have grown toward the positive electrode from coming into contact with the positive electrode tab and causing a short circuit.

[0063] Figure 3 is a plan view and a partially enlarged cross-sectional view of the electrode according to the third embodiment.

[0064] Referring to Figure 3, the structure of the electrode mixture layer 320 and electrode tab 330 formed on the electrode current collector 310 in electrode 300 is the same as that of the electrodes shown in Figures 1 and 2.

[0065] The adhesive coating portion 340 is formed only on the upper surface of the electrode mixture layer 320, specifically, only on the upper surface of the outer periphery of the electrode tab 330 adjacent to the electrode tab 330.

[0066] Therefore, in the outer peripheral area of ​​the electrode mixture layer adjacent to the electrode tab, the separation film and the electrode can be stably bonded via the adhesive coating portion.

[0067] Figure 4 is a plan view and a partially enlarged cross-sectional view of the electrode according to the fourth embodiment.

[0068] Referring to Figure 4, the structure of the electrode mixture layer 420 and the electrode tab 430 formed on the electrode current collector 410 in electrode 400 is the same as that of the electrodes shown in Figures 1 to 3.

[0069] The adhesive coating portion 440 is formed on the upper surface of the electrode mixture layer 420, on the opposite outer surface from the outer surface on the side where the electrode tab 430 is formed.

[0070] Figure 5 is a plan view and a partially enlarged cross-sectional view of the electrode according to the fifth embodiment.

[0071] Referring to Figure 5, the structure of the electrode mixture layer 520 and electrode tab 530 formed on the electrode current collector 510 in electrode 500 is the same as that of the electrodes shown in Figures 1 to 4.

[0072] The adhesive coating portion 540 is formed on the upper surface of the electrode tab 530, on the upper surface of the electrode mixture layer 520, specifically on the outer peripheral surface on one side adjacent to the electrode tab 530, and on the upper surface of the electrode mixture layer 520, specifically on the outer peripheral surface on the opposite side of the aforementioned outer peripheral surface.

[0073] Figure 5 discloses an electrode 500 in which the adhesive coating portion 540 is formed on the outer periphery of both sides in the overall width direction W of the electrode mixture layer. However, the present invention can also have a configuration in which the adhesive coating portion is formed on the outer periphery of both sides in the overall length direction L of the electrode mixture layer. Furthermore, the present invention includes a configuration in which the adhesive coating portion is formed on the outer periphery of both sides in the overall length direction L of the electrode mixture layer and on the upper surface of the electrode tab.

[0074] Figure 6 is a plan view and a partially enlarged cross-sectional view of the electrode according to the sixth embodiment.

[0075] Referring to Figure 6, the structure of the electrode mixture layer 620 and electrode tab 630 formed on the electrode current collector in electrode 600 is the same as that of the electrodes shown in Figures 1 to 5.

[0076] The adhesive coating portion 640 is formed over the entire outer periphery of the upper surface of the rectangular electrode mixture layer 620 in a plan view. Alternatively, it can be formed over the entire outer periphery of the upper surface of the electrode mixture layer and on the upper surface of the electrode tab 630.

[0077] In an electrode 600 to which such an adhesive coating portion is attached, a wide adhesive surface is formed between the adhesive coating portion 640 and the separation membrane, allowing the separation membrane and the electrode to be stably bonded.

[0078] Figure 7 is a partial perspective view of the electrodes according to the seventh and eighth embodiments.

[0079] Referring to Figure 7, electrode 700 is an electrode according to the seventh embodiment, and electrode 800 is an electrode according to the eighth embodiment.

[0080] The electrode shown in Figure 7 includes inclined portions 722, 822 on the outer periphery of the electrode mixture layers 720, 820 that meet the electrode tabs 730, 830, where the outer surface in the thickness direction is inclined. The adhesive coating portion 740 is shown as being applied only to the portion of the upper surface of the inclined portion 722 of the electrode mixture layer 720 adjacent to the electrode tab 730, but alternatively, the adhesive coating portion can be added in a form that extends to the top of the electrode tab 730.

[0081] Therefore, the adhesive strength between the separation film and the electrode can be ensured via the adhesive coating portion at the portion adjacent to the electrode tab where the most heat is generated.

[0082] In Figure 7, the adhesive coating portion 840 is shown as being applied along the outer periphery adjacent to the electrode tab 830 on the upper surface of the inclined portion 822 of the electrode mixture layer 820. However, in contrast, the adhesive coating portion 840 can be added in a form that extends up to the top of the electrode tab 830.

[0083] Therefore, the adhesive strength between the separation film and the electrode can be ensured via the adhesive coating portion in the outer periphery of the electrode mixture layer 820 adjacent to the electrode tab 830.

[0084] The adhesive coating portions 740, 840 added to the inclined portions 722, 822 are added in a manner that increases in thickness towards the outer periphery of the electrode mixture layers 720, 820. Therefore, the maximum thickness of the adhesive coating portions 740, 840 is formed to be the same as or greater than the thickness of the electrode mixture layers 720, 820. Consequently, the separation membrane and the adhesive coating portions can adhere closely together during the process of pressing and attaching the electrodes and the separation membrane.

[0085] Alternatively, the maximum thickness of the adhesive coating portions 740 and 840 can be formed to be smaller than the thickness of the electrode mixture layers 720 and 820. In such cases as well, a configuration in which the adhesive coating portion and the separation film are attached by lamination can be realized.

[0086] In the present invention, the electrodes according to the first to eighth embodiments include an adhesive coating portion attached to at least one of the first and second surfaces of the electrode current collector, and at least one of the first and second surfaces of the electrode current collector to which the adhesive coating portion is attached may include a separation film to which the adhesive coating portion is attached.

[0087] The electrodes may be a positive electrode and / or a negative electrode. A separation film can be attached to the outer surface of the positive electrode to which an adhesive coating is applied, a separation film can be attached to the outer surface of the negative electrode to which an adhesive coating is applied, and a separation film can be attached to the outer surfaces of both the positive and negative electrodes to which an adhesive coating is applied.

[0088] In this way, the adhesive coating portion forms an integrated structure in which the electrode and the separation membrane are bonded together, so that the separation membrane can be separated from the electrode and it is possible to prevent the separation membrane from being folded or bent.

[0089] The aforementioned adhesive coating portion includes an adhesive.

[0090] The adhesive may include polymer materials having a glass transition temperature (Tg) of 100°C or less. For example, the adhesive may be polyacrylate, polyacrylic acid, polymethacrylate, polymethyl methacrylate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene, polypropylene, polybutadiene, polyisoprene, styrene-butadiene rubber, polyvinyl acetate, polyester, polysiloxane, polydimethylsiloxane, polyethylene terephthalate, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polyvinyl acetal, polyvinyl propionate, ethylcellulose, carboxymethylcellulose, polyperfluoropropylene, natural rubber, or derivatives or copolymers thereof.

[0091] The adhesive coating portion is the part that adheres to the separation film, and in order to ensure insulation between different electrodes, the adhesive contained in the adhesive coating portion may be a non-conductive adhesive.

[0092] The present invention allows for the adjustment of the glass transition temperature of the adhesive by adjusting the type of adhesive contained in the adhesive coating and the composition ratio of the adhesive. Furthermore, the area of ​​the adhesive coating or the time and temperature of pressing to adhere the separation film can be adjusted. In this way, the adhesive strength of the adhesive coating can be adjusted by adjusting the composition and area of ​​the adhesive coating, as well as the pressing time and temperature.

[0093] Figure 8 shows the manufacturing process for electrodes used in lithium secondary batteries.

[0094] An electrode mixture layer 220 is formed on at least one surface of the electrode current collector 210. However, unlike the one shown in Figure 8, it is also possible to form the electrode mixture layer 220 on both sides of the electrode current collector 210. Furthermore, the electrode mixture layer 220 can be formed to have a uniform thickness overall, or it can include inclined portions where the outer surface in the thickness direction is inclined around the outer periphery adjacent to the electrode tab 230, as shown in the electrode mixture layers 720 and 820 in Figure 7.

[0095] The adhesive coating portion 240 is applied to a part of the upper surface of the electrode tab 230 and to the upper surface of the electrode mixture layer 220, specifically the outer peripheral portion of the electrode mixture layer 220 adjacent to the electrode tab 230.

[0096] The adhesive coating portion 240 is applied only to the remaining portion of the electrode tab, excluding the outer end, and the outer end of the electrode tab, which does not have the adhesive coating portion applied, can be coupled to the electrode lead to form an electrical connection.

[0097] A separation membrane 910 is positioned above the electrode mixture layer 220 and the adhesive coating portion 240. The left end of the separation membrane 910 extends beyond the electrode mixture layer 220. The right end of the separation membrane 910 is sized to extend to the outer end of the adhesive coating portion 240, or beyond the outer end of the adhesive coating portion 240.

[0098] In this manner, with the electrodes and the separation membrane arranged to overlap, the electrodes and the separation membrane are pressed together and attached by a pair of press rolls 900 positioned above and below them, respectively.

[0099] Since the adhesive coating portion contains a non-conductive adhesive made of a polymer material with a glass transition temperature (Tg) of 100°C or lower, the bonding strength between the adhesive coating portion 240 and the separation film 910 can be ensured by heating the press roll 900 to a temperature higher than the glass transition temperature of the non-conductive adhesive and applying pressure.

[0100] Since electrodes manufactured in this manner have an integrated structure with the separator membrane, it is possible to prevent the separator membrane from separating from the electrode and being folded or bent, thereby ensuring insulation between the positive and negative electrodes.

[0101] The electrodes manufactured as described above can be used as electrodes for lithium secondary batteries and can form stacked electrode assemblies, stacked-folding electrode assemblies, laminated-stacked electrode assemblies, or jelly roll type electrode assemblies.

[0102] Furthermore, by housing the electrode assembly described above in a battery case, a unit battery can be constructed, and a battery module and battery pack including the unit battery can be provided.

[0103] A person with ordinary skill in the field to which this invention belongs will be able to make various applications and modifications within the scope of this invention based on the above content. [Explanation of Symbols]

[0104] 101, 201 Electrode body 110, 210, 310, 410, 510 electrode current collectors 120, 220, 320, 420, 520, 620, 720, 820 Electrode combination layer 130, 230, 330, 430, 530, 630, 730, 830 electrode tabs 140, 240, 340, 440, 540, 640, 740, 840 Adhesive coating section 722, 822 Slope 300, 400, 500, 600, 700, 800 electrodes 900 press roll 910 Separation membrane H1 Thickness of the electrode mixture layer H2 thickness of the adhesive coating area L Full length direction W Full width direction

Claims

1. An electrode mixture layer is formed on at least one of the first and second surfaces of the electrode current collector. The electrode current collector includes an electrode tab, which is a portion other than the portion on which the electrode mixture layer is formed, and which protrudes from one outer periphery of a rectangle in a plan view. The adhesive coating is applied to at least a portion of the upper surface of the electrode mixture layer, but not to the upper surface of the electrode tab, and not along the outer periphery of the rectangle of the electrode current collector. Furthermore, the adhesive coating portion is applied to at least a portion of the upper surface of the electrode mixture layer, specifically the outer peripheral area on one side adjacent to the electrode tab and the outer peripheral area on the opposite side of that side. A separation film is attached to the adhesive coating portion and the electrode mixture layer to which the adhesive coating portion is attached. An electrode for a lithium secondary battery, wherein the electrode mixture layer and the separation membrane are integrated into a single structure by the adhesive coating portion.

2. The electrode for a lithium secondary battery according to claim 1, wherein the adhesive coating portion is added to the upper surface of the electrode mixture layer, specifically to the upper surface of the outer periphery opposite to the outer periphery on the side where the electrode tab is formed.

3. The electrode for a lithium secondary battery according to claim 1, wherein the adhesive coating portion is applied to the upper surface of the electrode tab and to the upper surface of the electrode mixture layer, specifically to the outer peripheral surface on one side adjacent to the electrode tab.

4. The electrode for a lithium secondary battery according to claim 1, wherein the adhesive coating portion is applied to the upper surface of the electrode tab, the upper surface of the electrode mixture layer adjacent to the electrode tab on one outer peripheral side, and the upper surface of the electrode mixture layer opposite to the one outer peripheral side.

5. The electrode for a lithium secondary battery according to claim 1, wherein the adhesive coating portion includes a non-conductive adhesive.

6. The electrode for a lithium secondary battery according to claim 5, wherein the non-conductive adhesive is made of a polymer material having a glass transition temperature (Tg) of 100°C or less.

7. A method for manufacturing an electrode for a lithium secondary battery according to any one of claims 1 to 6, (a) The step of forming an electrode mixture layer on at least one surface of the electrode current collector, (b) The step of adding the adhesive coating portion to at least a portion of the upper surface of the electrode tab extending from the outer periphery of the electrode mixture layer and the upper surface of the electrode mixture layer, such that the height of the adhesive coating portion from the upper surface of the electrode tab is greater than the height of the electrode mixture layer from the upper surface of the electrode tab, (c) The step of placing a separation film on the electrode mixture layer and the adhesive coating portion, (d) The step of pressing the separation membrane, A method for manufacturing electrodes for lithium secondary batteries, including the method described above.

8. The method for manufacturing an electrode for a lithium secondary battery according to claim 7, wherein step (d) includes a heating step.

9. The method for manufacturing an electrode for a lithium secondary battery according to claim 7, wherein the adhesive coating portion is formed on at least one of the positive electrode and the negative electrode.

10. An electrode assembly comprising an electrode for a lithium secondary battery according to any one of claims 1 to 6, An electrode assembly including a stacked electrode assembly, a stacked folding electrode assembly, a lamination stacked electrode assembly, or a jelly roll type electrode assembly.

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