Positive electrode for secondary battery and secondary battery comprising same

Abstract

The present invention relates to a positive electrode for a lithium secondary battery and a lithium secondary battery comprising the same, and more particularly, to a positive electrode for a lithium secondary battery in which a positive electrode composite layer is configured so as to have a smaller area than a positive electrode current collector, and a lithium secondary battery comprising the same.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority of Korean Patent Application No. 10 - 2023 - 0146522, filed on October 30, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical field

[0003] The present invention relates to a positive electrode for a lithium secondary battery and a lithium secondary battery including the same, and more particularly to a positive electrode for a lithium secondary battery, in which a positive electrode composite layer is configured to have an area smaller than that of a positive electrode current collector, and a lithium secondary battery including the same. Background art

[0004] With the development of technology and the increasing demand for mobile devices, rechargeable secondary batteries are widely used as an energy source for various mobile devices. Secondary batteries are also attracting attention as an energy source for electric vehicles and hybrid vehicles, which are proposed as a way to solve air pollution from conventional gasoline and diesel vehicles.

[0005] Secondary batteries are classified into coin - type batteries, cylindrical batteries, prismatic batteries, and pouch - type batteries according to the shape of the battery case. Among them, pouch - type batteries have received a great deal of attention because they use a pouch exterior material composed of a multi - layer film of a metal layer (foil) and synthetic resins coated on the upper and lower surfaces of the metal layer to form the exterior, which can significantly reduce the weight of the battery compared to cylindrical or prismatic batteries using a metal can, making it possible to reduce the weight of the battery, and they have the advantage of being able to be changed into various shapes.

[0006] Pouch - type batteries are generally manufactured through a process of activating a unit cell after the battery assembly process. The activation process generally involves pressing the unit cell with a jig and applying a current to the unit cell to charge and discharge it to a predetermined voltage.

[0007] When manufacturing a pouch - type battery, the cell assembly process may include applying high pressure to the unit cell under high - temperature conditions. In particular, the manufacturing process of an all - solid - state cell may include a hot isostatic pressing (HIP) process, in which a positive electrode and a positive electrode current collector are assembled. In the isostatic pressing process, the positive electrode composite layer is stretched in the area direction, and the area of the positive electrode composite layer is larger than the area of the positive electrode current collector. The enlarged area of the positive electrode composite layer protrudes beyond the edge of the positive electrode current collector and bends along the surface of the positive electrode current collector, thereby causing cracking. The problem with the above - mentioned cracking is that when the cell is assembled with a negative electrode, a short - circuit occurs, which deteriorates the battery performance.

[0008] Therefore, in order to achieve good performance of an all - solid - state battery, it is necessary to develop a positive electrode that prevents electrode cracking even after the isostatic pressing process.

[0009] [Prior Art Documents]

[0010] (Patent Document 1) Korean Patent Publication No. 10-2023-0084872 (June 13, 2023) Summary of the Invention

[0011] Technical Problem

[0012] One object of the present invention is to provide a positive electrode for a lithium secondary battery that prevents cracking of the electrode during the application of high temperature and high pressure in the manufacture of the lithium secondary battery.

[0013] Another object of the present invention is to provide a positive electrode for a lithium secondary battery that can prevent deterioration of the performance and lifespan of a unit cell.

[0014] Technical Solution

[0015] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, comprising: a positive electrode current collector and a positive electrode composite layer laminated on the positive electrode current collector, wherein the positive electrode composite layer is configured to have an area smaller than that of the positive electrode current collector.

[0016] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, wherein the area of the positive electrode composite layer is smaller than the area of the positive electrode current collector by more than 0% and less than 30%.

[0017] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, wherein the positive electrode composite layer is disposed at an inward interval from at least one edge of the positive electrode current collector.

[0018] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, wherein the positive electrode current collector includes a laminated region on which the positive electrode composite layer is laminated and a remaining region on which the positive electrode composite layer is not laminated.

[0019] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, wherein the remaining region is disposed along at least a part of the edge of the laminated region.

[0020] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, wherein the positive electrode current collector includes a first side provided with a positive electrode terminal portion, a second side formed on the other side of the first side, a third side and a fourth side connecting the first side and the second side, and a remaining region formed to include at least one of the first side to the fourth side.

[0021] In one embodiment of the present invention, there is provided a positive electrode for a lithium secondary battery, wherein the center point of the positive electrode current collector is aligned with the center point of the positive electrode composite layer.

[0022] In one embodiment of the present invention, a positive electrode for a lithium secondary battery is provided, wherein the positive electrode composite layer includes a positive electrode active material, a conductive material, and a binder.

[0023] In one embodiment of the present invention, a positive electrode for a lithium secondary battery is provided, wherein the positive electrode current collector is at least one metal selected from the group consisting of copper, aluminum, stainless steel, titanium, silver, palladium, nickel, their alloys, and combinations thereof.

[0024] In one embodiment of the present invention, a lithium secondary battery is provided, which includes a positive electrode, a negative electrode, and a solid electrolyte.

[0025] Advantageous Effects

[0026] The present invention can provide a positive electrode for a lithium secondary battery that prevents the electrode from cracking during the application of high temperature and high pressure in the manufacture of a lithium secondary battery.

[0027] Another object of the present invention is to provide a positive electrode for a lithium secondary battery that can prevent deterioration of the performance and lifespan of a unit cell. Description of the Drawings

[0028] Figure 1 and Figure 2 is a diagram showing a positive electrode assembly of a positive electrode for a lithium secondary battery according to an embodiment of the present invention.

[0029] Figure 3 is a diagram showing a positive electrode for a lithium secondary battery according to an embodiment of the present invention.

[0030] Figures 4 to 7 is a diagram showing the arrangement of a positive electrode composite layer in a positive electrode for a lithium secondary battery according to an embodiment of the present invention. Detailed Description of the Embodiments

[0031] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The drawings may exaggerate all or part of the configurations for illustrative purposes only.

[0032] It will be obvious to those skilled in the art that the present invention is not limited to what is shown in the drawings or described herein, and the present invention can be implemented in various forms without departing from the technical concept of the present invention.

[0033] The manufacturing process of a lithium secondary battery, particularly that of a all-solid-state battery, may include a hot isostatic pressing (HIP) process. In the conventional process of a positive electrode, when the positive electrode composite layer and the positive electrode current collector have the same area and the above-mentioned hot isostatic pressing process is performed on the positive electrode composite layer and the positive electrode current collector, the positive electrode composite layer is stretched in the area direction, and the area of the positive electrode composite layer becomes larger than that of the positive electrode current collector. The enlarged area of the positive electrode composite layer protrudes beyond the edge of the positive electrode current collector and bends along the surface of the positive electrode current collector, thereby causing cracking. These cracks can cause a short circuit when assembled with the negative electrode to manufacture an electrode assembly, which may lead to poor battery performance and lifespan.

[0034] To solve this problem, the inventors of the present invention have developed a positive electrode for a lithium secondary battery that can prevent cracking of the positive electrode even after high-temperature and high-pressure processing.

[0035] Referring to the following drawings, before specifically describing the structure of the positive electrode for a lithium secondary battery according to an embodiment of the present invention, the positive electrode assembly of the positive electrode for a lithium secondary battery will be briefly described first.

[0036] Figure 1 and Figure 2 are diagrams showing the positive electrode assembly of the positive electrode for a lithium secondary battery according to an embodiment of the present invention.

[0037] The positive electrode for a lithium secondary battery may include a positive electrode current collector (100) and a positive electrode composite layer (200) laminated to the positive electrode current collector.

[0038] The positive electrode current collector may further include a positive electrode terminal portion (110) on one side. Although Figure 1 the positive electrode terminal portion (110) is depicted as being connected to the end portion on one side of the positive electrode current collector, the position of the positive electrode terminal portion may be connected to any position on one side of the positive electrode current collector without limitation.

[0039] The positive electrode composite layer (200) may be laminated to one surface of the positive electrode current collector (100).

[0040] Figure 3 is a diagram showing the positive electrode for a lithium secondary battery according to an embodiment of the present invention.

[0041] In an embodiment of the present invention, the positive electrode for a lithium secondary battery includes a positive electrode current collector and a positive electrode composite layer laminated to the positive electrode current collector, wherein the area of the positive electrode composite layer may be smaller than that of the positive electrode current collector.

[0042] The area of the positive electrode composite layer is smaller than the area of the positive electrode current collector by more than 0% and less than 30%. More specifically, the area of the positive electrode composite layer is smaller than the area of the positive electrode current collector by 0.1% to less than 30%, 0.5% to less than 30%, 1.0% to less than 30%, 1.5% to less than 30%, 2.0% to less than 30%, 2.5% to less than 30%, 3.0% to less than 30%, 3.5% to less than 30%, 4.0% to less than 30%, 4.5% to less than 30%, 5.0% to less than 30%.

[0043] 0.1% to 29.0% or less, 0.5% to 29.0% or less, 1.0% to 29.0% or less, 1.5% to 29.0% or less, 2.0% to 29.0% or less, 2.5% to 29.0% or less, 3.0% to 29.0% or less, 3.5% to 29.0% or less, 4.0% to 29.0% or less, 4.5% to 29.0% or less, 5.0% to 29.0% or less.

[0044] 0.1% to 28.0% or less, 0.5% to 28.0% or less, 1.0% to 28.0% or less, 1.5% to 28.0% or less, 2.0% to 28.0% or less, 2.5% to 28.0% or less, 3.0% to 28.0% or less, 3.5% to 28.0% or less, 4.0% to 28.0% or less, 4.5% to 28.0% or less, 5.0% to 28.0% or less.

[0045] 0.1% to 27.0% or less, 0.5% to 27.0% or less, 1.0% to 27.0% or less, 1.5% to 27.0% or less, 2.0% to 27.0% or less, 2.5% to 27.0% or less, 3.0% to 27.0% or less, 3.5% to 27.0% or less, 4.0% to 27.0% or less, 4.5% to 27.0% or less, 5.0% to 27.0% or less.

[0046] 0.1% to 26.0% or less, 0.5% to 26.0% or less, 1.0% to 26.0% or less, 1.5% to 26.0% or less, 2.0% to 26.0% or less, 2.5% to 26.0% or less, 3.0% to 26.0% or less, 3.5% to 26.0% or less, 4.0% to 26.0% or less, 4.5% to 26.0% or less, 5.0% to 26.0% or less.

[0047] from 0.1% to less than 25.0%, from 0.5% to less than 25.0%, from 1.0% to less than 25.0%, from 1.5% to less than 25.0%, from 2.0% to less than 25.0%, from 2.5% to less than 25.0%, from 3.0% to less than 25.0%, from 3.5% to less than 25.0%, from 4.0% to less than 25.0%, from 4.5% to less than 25.0%, from 5.0% to less than 25.0%,

[0048] from 0.1% to less than 24.0%, from 0.5% to less than 24.0%, from 1.0% to less than 24.0%, from 1.5% to less than 24.0%, from 2.0% to less than 24.0%, from 2.5% to less than 24.0%, from 3.0% to less than 24.0%, from 3.5% to less than 24.0%, from 4.0% to less than 24.0%, from 4.5% to less than 24.0%, from 5.0% to less than 24.0%,

[0049] from 0.1% to less than 23.0%, from 0.5% to less than 23.0%, from 1.0% to less than 23.0%, from 1.5% to less than 23.0%, from 2.0% to less than 23.0%, from 2.5% to less than 23.0%, from 3.0% to less than 23.0%, from 3.5% to less than 23.0%, from 4.0% to less than 23.0%, from 4.5% to less than 23.0%, from 5.0% to less than 23.0%,

[0050] from 0.1% to less than 22.0%, from 0.5% to less than 22.0%, from 1.0% to less than 22.0%, from 1.5% to less than 22.0%, from 2.0% to less than 22.0%, from 2.5% to less than 22.0%, from 3.0% to less than 22.0%, from 3.5% to less than 22.0%, from 4.0% to less than 22.0%, from 4.5% to less than 22.0%, from 5.0% to less than 22.0%, but not limited thereto.

[0051] In one example of the present invention, in the positive electrode for a lithium secondary battery, the positive electrode composite layer is disposed at an inward interval from at least one edge of the positive electrode current collector.

[0052] In one example of the present invention, the positive electrode current collector includes a stacked region (300) where the positive electrode composite layer is stacked and a remaining region (400) where the positive electrode composite layer is not stacked.

[0053] The remaining region (400) may be disposed along at least a part of the edge of the stacked region (300).

[0054] The positive electrode current collector includes: a first side provided with a positive electrode terminal portion, a second side formed on the other side of the first side, third and fourth sides connecting the first side and the second side, and a remaining region formed to include at least one of the first side to the fourth side.

[0055] Figures 4 to 7 It is a diagram showing the arrangement of the positive electrode composite layer in the positive electrode for a lithium secondary battery according to an embodiment of the present invention.

[0056] The positive electrode current collector may include a first remaining region (410) formed to include a first side where the positive electrode terminal portion (110) is provided.

[0057] The positive electrode current collector may include a second remaining region (420) formed to include a second side formed on the other side of the first side.

[0058] The positive electrode current collector may include a third remaining region (430) formed to include a third side connecting the first side and the second side.

[0059] The positive electrode current collector may include a fourth remaining region (440) formed to connect the first side and the second side and include a fourth side formed on the other side of the third side.

[0060] The remaining region (400) may include any one of the first remaining region (410), the second remaining region (420), the third remaining region (430), and the fourth remaining region (440).

[0061] In an example of the present invention, the remaining region (400) may include any one of the first remaining region (410), the second remaining region (420), the third remaining region (430), and the fourth remaining region (440).

[0062] Although not shown, in an embodiment of the present invention, the remaining region (400) may include two remaining regions. For example, the remaining region (400) may include the first remaining region (410) and the second remaining region (420); the first remaining region (410) and the third remaining region (430); the first remaining region (410) and the fourth remaining region (440); the second remaining region (420) and the third remaining region (430); the second remaining region (420) and the fourth remaining region (440); or the third remaining region (430) and the fourth remaining region (440).

[0063] Although not shown, in an embodiment of the present invention, the remaining region (400) may include three remaining regions. For example, the remaining region (400) may include the first remaining region (410), the second remaining region (420), and the third remaining region (430); the first remaining region (410), the second remaining region (420), and the fourth remaining region (440); the first remaining region (410), the third remaining region (430), and the fourth remaining region (440); or the second remaining region (420), the third remaining region (430), and the fourth remaining region (440).

[0064] Although not shown, in one embodiment of the present invention, the remaining region (400) may include four remaining regions. That is, the remaining region (400) may include all of a first remaining region (410), a second remaining region (420), a third remaining region (430), and a fourth remaining region (440).

[0065] In one embodiment of the present invention, the center point of the positive electrode current collector is aligned with the center point of the positive electrode composite layer.

[0066] In one embodiment of the present invention, the positive electrode composite layer may include a positive electrode current collector and a positive electrode active material applied to one or both sides of the positive electrode current collector.

[0067] The positive electrode current collector is intended to support the positive electrode active material and is not particularly limited as long as it has good electrical conductivity and is electrochemically stable within the voltage range of the lithium secondary battery. For example, the positive electrode current collector may be any metal selected from the group consisting of copper, aluminum, stainless steel, titanium, silver, palladium, nickel, their alloys, and combinations thereof, wherein the stainless steel may be surface-treated with carbon, nickel, titanium, or silver, and the alloy may preferably be an aluminum-cadmium alloy, but may also be a non-conductive polymer or a conductive polymer whose surface is treated with calcined carbon or a conductive material.

[0068] The positive electrode current collector may form fine irregularities on its surface to enhance the bonding force with the positive electrode active material and may be used in various forms, such as a film, sheet, foil, grid, net, porous body, foam, non-woven body, etc.

[0069] The positive electrode composite layer may include a positive electrode active material and optionally a conductive material and a binder.

[0070] The positive electrode active material may vary depending on the type of all-solid-state battery. For example, the positive electrode active material may include, but is not limited to, layered compounds such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or compounds substituted with one or more transition metals; lithium manganese oxides such as Li 1+x Mn 2-x O4 (where 0 ≤ x ≤ 0.3), LiMnO3, LiMn2O3, or LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, or Cu2V2O7; LiNi 1-x M x O2 (where M is Co, Mn, Al, Cu, Fe, Mg, B, or Ga; and 0.01 ≤ x ≤ 0.3) represents a Ni-site type lithium nickel compound; LiMn 2-x M xLithium manganese composite oxides represented by O2 (where M is Co, Ni, Fe, Cr, Zn or Ta; and 0.01 ≤ x ≤ 0.1) or Li2Mn3MO8 (where M is Fe, Co, Ni, Cu or Zn); LiNi x Mn 2-x Lithium manganese composite oxides with a spinel structure represented by O4; LiCoPO4; LiFePO4; elemental sulfur (S8); sulfur compounds, such as Li2S n (where n is 1), organic sulfur compounds or carbon-sulfur polymers ((C2S x ) n , where x is from 2.5 to 50 and n is 2).

[0071] The conductive material is a material that electrically connects the electrolyte and the positive electrode active material and serves as a path for electrons to migrate from the current collector to the positive electrode active material. The conductive material can be used without limitation as long as it does not cause chemical changes in the lithium secondary battery and has porosity and conductivity.

[0072] For example, porous carbon materials can be used as conductive materials, where the carbon materials include carbon black, graphite, graphene, activated carbon and carbon fiber; and metal fibers, such as metal mesh; metal powders, such as copper, silver, nickel or aluminum; or organic conductive materials, such as polyphenylene derivatives. The conductive materials can be used alone or in combination.

[0073] Commercially available products currently used as conductive materials include acetylene black (from Chevron Chemical Company or Gulf Oil Company), Ketjen Black EC (from Armak Company), Vulcan XC-72 (from Cabot Company) and Super P (from MMM). Examples can include acetylene black, carbon black and graphite.

[0074] In addition, the positive electrode composite layer can further contain a binder, where the binder further increases the adhesion between the components constituting the positive electrode composite layer or the adhesion between the components and the current collector, and any binder known in the art can be used.

[0075] For example, the binder may be one or a mixture or copolymer of two or more selected from the group consisting of: fluoroplastic binders, including polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); rubbery binders, including styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber, or styrene-isoprene rubber; cellulose binders, including carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, and regenerated cellulose; polyol binders; polyolefin binders, including polyethylene or polypropylene; polyimide binders; polyester binders; and silane binders.

[0076] In one embodiment of the present invention, the lithium secondary battery may include a positive electrode, a negative electrode, and a solid electrolyte disposed between the positive electrode and the negative electrode, wherein the positive electrode may be the positive electrode for the lithium secondary battery of the present invention described above.

[0077] The negative electrode may include a negative electrode current collector and a negative electrode active material located on the negative electrode current collector. In addition, similar to the positive electrode, the negative electrode may optionally include a conductive material and a binder. The negative electrode current collector, conductive material, and binder are as described above.

[0078] The negative electrode active material may be any material capable of reversibly intercalating or deintercalating lithium ions (Li + ) and any material capable of reacting with lithium ions to reversibly form a lithium-containing compound.

[0079] The solid electrolyte may include at least one selected from the group consisting of: sulfide solid electrolytes, polymer solid electrolytes, and oxide solid electrolytes, preferably sulfide solid electrolytes. The solid electrolyte may be in particulate form.

[0080] The sulfide solid electrolyte contains sulfur (S) and has an ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and it may include Li-P-S glasses or Li-P-S glass ceramics.

[0081] The polymer solid electrolyte is a composite of a lithium salt and a polymer resin, i.e., a polymer electrolyte material in a form formed by adding a polymer resin to a solvated lithium salt, and may have an ionic conductivity of about 1×10 -7 S / cm or more, preferably about 1×10 -5 S / cm or more.

[0082] The oxide solid electrolyte may contain oxygen (O) and has an ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table.

[0083] Examples

[0084] In the following, preferred embodiments are described for the purpose of clarifying the present invention. However, it is obvious to those skilled in the art that various changes and modifications can be made within the scope and technical concept of the present invention, and these changes and modifications fall within the scope of the appended claims.

[0085] Example 1

[0086] The positive electrode is manufactured by using an aluminum electrode as the positive electrode current collector, laminating a 142-μm-thick positive electrode composite layer on the positive electrode current collector, and subjecting the laminate to hot isostatic pressing (HIP) at 5000 bar and 80 °C. The area of the positive electrode current collector is 400 mm 2 , and the area of the positive electrode composite layer is 360 mm 2 .

[0087] Example 2

[0088] The positive electrode is prepared in the same manner as in Example 1, except that the area of the positive electrode composite layer is 320 mm 2 .

[0089] Comparative Example 1

[0090] The positive electrode is prepared in the same manner as in Example 1, except that the area of the positive electrode current collector is 400 mm 2 , and the area of the positive electrode composite layer is 400 mm 2 .

[0091] Comparative Example 2

[0092] The positive electrode is prepared in the same manner as in Example 1, except that the area of the positive electrode composite layer is 280 mm 2 .

[0093] Experimental Example 1: Comparison of the length and area of the positive electrode composite layer before and after isostatic pressing

[0094] In the positive electrodes of Example 1 and Comparative Example 1, the change in the length or width of the positive electrode composite layer before and after isostatic pressing was measured. The results are shown in Table 1 below.

[0095] [Table 1]

[0096]

[0097] As shown in Table 1, the positive electrodes prepared in Example 1 and Comparative Example 1 both showed an increase in the positive electrode composite layer after the isostatic pressing process. After isostatic pressing, the positive electrode composite layer increased by 0.1 to 2.0% of the length before isostatic pressing and increased by 1.0 to 4.0% of the area before isostatic pressing.

[0098] Experimental Example 2: Cell Performance Data According to Area Ratio

[0099] In the positive electrodes of Example 1, Example 2, Comparative Example 1, and Comparative Example 2, the area and capacity retention rate of the positive electrode composite layer after isostatic pressing of the positive electrode composite layer were measured. The results are shown in Table 2 below.

[0100] [Table 2]

[0101] <![CDATA[Positive composite layer area after isostatic pressing (mm 2 )]]> Capacity retention rate (%) Example 1 364.0 150 Example 2 323.8 150 Comparative Example 1 412.0 100 Comparative Example 2 283.1 50

[0102] As shown in Table 2 above, for Examples 1 and 2 where the area of the positive electrode composite layer is more than 0% to less than 30% smaller than the area of the positive electrode current collector, good capacity retention rates were observed. On the other hand, in the cases of Comparative Examples 1 and 2 where the area of the positive electrode composite layer is the same as or 30% smaller than the area of the positive electrode current collector, it was found that the capacity retention rate was significantly worse compared to Examples 1 and 2.

[0103] Although embodiments of the present invention have been described above, it is not intended to limit the present invention to the above embodiments. Those skilled in the art will be able to implement embodiments of the present invention with appropriate modifications including omissions, changes, substitutions, or additions of other configurations of all or part of the components of the present invention by referring to this specification and the drawings without departing from the technical concept of the present invention.

[0104] The terms and expressions used herein should be interpreted broadly and should not be interpreted in a restrictive sense. In this specification, the expression "comprising" does not exclude the presence or addition of one or more other components other than the recited configuration.

[0105] In this specification, singular expressions include the plural unless the context clearly excludes them.

[0106] The various exemplary embodiments described herein can be combined with each other, and the content described in a particular instance can equally apply to other embodiments unless there is a contradiction, even if it is not described in other embodiments.

[0107] [Reference Signs]

[0108] 100: Positive electrode current collector

[0109] 110: Positive electrode terminal portion

[0110] 200: Positive electrode composite layer

[0111] 300: Laminated region

[0112] 400: Remaining region

[0113] 410: First remaining region

[0114] 420: Second remaining region

[0115] 430: Third remaining area

[0116] 440: Fourth remaining area

Claims

1. A positive electrode for a lithium secondary battery, comprising: a positive electrode current collector; and a positive electrode composite layer laminated on the positive electrode current collector, in, The positive electrode composite layer is configured to have an area smaller than that of the positive electrode current collector.

2. The lithium secondary battery positive electrode according to claim 1, in, The area of ​​the positive electrode composite layer is smaller than the area of ​​the positive electrode current collector by more than 0% to less than 30%.

3. The lithium secondary battery positive electrode according to claim 1, in, The positive electrode composite layer is disposed to be spaced inwardly from at least one edge of the positive electrode collector.

4. The lithium secondary battery positive electrode according to claim 1, in, The positive electrode current collector includes a stacking region where the positive electrode composite layers are stacked; and The remaining region of the positive electrode composite layer is not laminated.

5. The positive electrode for a lithium secondary battery according to claim 4, wherein in, The remaining region is disposed along at least a portion of an edge of the stacked region.

6. The positive electrode for a lithium secondary battery according to claim 4, wherein in, The positive electrode current collector includes a first side provided with a positive terminal portion, a second side formed on the other side of the first side, and a third side and a fourth side connecting the first side and the second side. The remaining area is formed to include at least one side from the first side to the fourth side.

7. The lithium secondary battery positive electrode according to claim 1, in, The center point of the positive electrode current collector is aligned with the center point of the positive electrode composite layer.

8. The lithium secondary battery positive electrode according to claim 1, in, The positive electrode composite layer comprises a positive electrode active material, a conductive material and a binder.

9. The lithium secondary battery positive electrode according to claim 1, The positive electrode current collector is at least one metal selected from the group consisting of copper, aluminum, stainless steel, titanium, silver, palladium, nickel, alloys thereof, and combinations thereof. 10 . A lithium secondary battery comprising: a positive electrode for a lithium secondary battery according to claim 1 ; a negative electrode; and a solid electrolyte disposed therebetween.

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