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KR-20260065281-A - Method of producing cathode and lithium secondary battery

KR20260065281AKR 20260065281 AKR20260065281 AKR 20260065281AKR-20260065281-A

Abstract

A method for manufacturing an anode is provided, comprising the steps of: forming a lithium supplement layer comprising a first anode active material and a lithium supplement on an anode current collector; and forming an active material layer comprising a second anode active material on the lithium supplement layer, wherein the step of forming the lithium supplement layer comprises spraying the lithium supplement slurry directly onto the anode current collector.

Inventors

  • 김주희
  • 김도연
  • 안세영
  • 최명훈
  • 구대근
  • 김연경
  • 유지혁
  • 김도형
  • 김상우
  • 김믿음

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260508
Application Date
20241101

Claims (14)

  1. A step of forming a lithium supplement layer comprising a first positive active material and a lithium supplement on a positive current collector; and A step of forming an active material layer containing a second positive active material on the lithium supplement layer; Includes, A method for manufacturing an anode, comprising the step of forming the lithium supplement layer by spraying the lithium supplement slurry directly onto the anode current collector.
  2. In Article 1, A method for manufacturing an anode, characterized in that, in the spraying step, the lithium replenishment slurry has a viscosity of about 5,000 cPa to about 10,000 cPa at 25°C.
  3. In Article 1, A method for manufacturing an anode characterized in that the first anode active material and the second anode active material comprise the same type of active material.
  4. In Article 1, A method for manufacturing an anode characterized in that the lithium supplementary layer further comprises a binder and a conductive material.
  5. In Article 4, A method for manufacturing an anode characterized by the above lithium replenishment slurry containing about 1.5 weight% to about 4.5 weight% of a lithium replenishing agent among the solids.
  6. In Article 1, A method for manufacturing an anode characterized in that the thickness of the lithium supplement layer is about 0.05 to about 0.4 times the thickness of the active material layer.
  7. In Article 1, A method for manufacturing an anode characterized by comprising the above lithium supplement Li₂O , Li₂O₂ , LiF , Li₂S , Li₃N , Li₅FeO₄ , Li₆CoO₄ , Li₂NiO₂ , Li₂MnO₃ , Li₂MoO₃ , Li₂DHBN (3,4-dihydroxybenzonitrile dilithium salt ) , Li₂C₂O₄ , or a mixture thereof.
  8. In Article 7, A method for manufacturing an anode characterized in that the above lithium supplement is Li 5 FeO 4 .
  9. In Article 1, A method for manufacturing an anode characterized by the step of forming the active material layer comprising the step of forming a first active material layer on the lithium supplement layer and the step of forming a second active material layer on the first active material layer.
  10. In Article 1, A method for manufacturing an anode, characterized in that the above-mentioned spraying step is performed by uniformly spraying the lithium supplement slurry onto the anode current collector.
  11. In Article 1, A method for manufacturing an anode, characterized in that the above-mentioned spraying step is performed by spraying the lithium supplement slurry onto the anode current collector in the form of a localized pattern.
  12. An anode manufactured by an anode manufacturing method according to any one of claims 1 to 11; A cathode comprising a cathode active material on a cathode current collector; A separator provided between the anode and the cathode; and Electrolytes; Includes, A lithium secondary battery in which the positive electrode comprises a lithium supplementary layer containing the first positive electrode active material between the positive electrode current collector and the active material layer, and the lithium supplementary layer comprises LiFeO2 .
  13. In Article 12, A lithium secondary battery characterized in that the lithium supplementary layer further comprises a compound of the following chemical formula 1. <Chemical Formula 1> Li a Fe 1-x M x O y (Here, 1<a≤5, 0≤x≤0.35, 2<y≤4, M is Ga, Zr, Ti, Mg, Ca, Ba, Sc, Mn, Zn, Cu, V, Cr, Sr, In, Al, or a combination thereof)
  14. In Article 12, A lithium secondary battery characterized in that the lithium supplementary layer further comprises Li 5 FeO 4 .

Description

Method of producing cathode and lithium secondary battery The present invention relates to a method for manufacturing a positive electrode and a lithium secondary battery, and more specifically, to a method for manufacturing a positive electrode and a lithium secondary battery capable of securing strong adhesion between a positive electrode current collector and an active material layer and increasing charge/discharge capacity. Rechargeable batteries are a representative example of electrochemical devices that utilize electrochemical energy, and their application areas are increasingly expanding. Recently, with the technological development and growing demand for portable devices such as portable computers, mobile phones, and cameras, the demand for rechargeable batteries as an energy source has been rapidly increasing. Among these rechargeable batteries, much research has been conducted on lithium-ion batteries, which have high energy density—that is, high capacity—and have been commercialized and are widely used. Various studies are underway to improve the charge/discharge characteristics and durability of secondary batteries, and there is still room for improvement. FIG. 1 is a schematic diagram showing an anode manufacturing apparatus according to one embodiment of the present invention. FIG. 2 is a flowchart illustrating a method for manufacturing an anode according to one embodiment of the present invention. FIG. 3 is a schematic diagram showing a cross-section of an anode manufactured according to one embodiment of the present invention. FIG. 4 is a schematic diagram showing a cross-section of an anode according to another embodiment of the present invention. FIG. 5 is a front view showing a lithium secondary battery according to one embodiment of the present invention. FIG. 6 is a cross-sectional view showing an electrode assembly according to one embodiment of the present invention. FIG. 7 is a cross-sectional view showing a cathode according to one embodiment of the present invention. Hereinafter, preferred embodiments of the concept of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the concept of the present invention may be modified in various different forms, and the scope of the concept of the present invention should not be interpreted as being limited by the embodiments described below. It is preferable to interpret the embodiments of the concept of the present invention as being provided to more completely explain the concept of the present invention to those with average knowledge in the art. Identical reference numerals denote identical elements throughout. Furthermore, various elements and areas in the drawings are depicted schematically. Accordingly, the concept of the present invention is not limited by the relative sizes or spacing depicted in the accompanying drawings. Terms such as first, second, etc. may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the concept of the present invention, the first component may be named the second component, and conversely, the second component may be named the first component. The terms used in this application are used merely to describe specific embodiments and are not intended to limit the concept of the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, expressions such as "comprising" or "having" are intended to indicate the existence of the features, number, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, actions, components, parts, or combinations thereof. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art to which the concept of the present invention pertains. Furthermore, it will be understood that commonly used terms, such as those defined in advance, should be interpreted as having meanings consistent with their intent in the context of the relevant technology, and should not be interpreted in an overly formal sense unless explicitly defined herein. Where an embodiment can be implemented differently, a specific process sequence may be performed differently from the order described. For example, two processes described in succession may be performed substantially simultaneously or in the reverse order of the description. In the accompanying drawings, variations of the depicted shapes may be anticipated, for example, depending on manufacturing techniques and/or tolerances. Accordingly, embodiments of the present invention should not be interprete