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KR-102964601-B1 - POSITIVE ACTIVE MATERIAL, PREPARATION METHOD THEREOF, POSITIVE ELECTRODE, AND RECHARGEABLE LITHIUM BATTERIES

KR102964601B1KR 102964601 B1KR102964601 B1KR 102964601B1KR-102964601-B1

Abstract

The present invention relates to a positive electrode active material comprising a core particle containing a layered lithium nickel-manganese-based composite oxide, a first coating layer located on the surface of the core particle and containing Al, and a second coating layer located on the first coating layer and containing Ni, a method for manufacturing the same, and a positive electrode and a lithium secondary battery comprising the same.

Inventors

  • 강병욱
  • 윤재상
  • 두성욱
  • 김영기
  • 추성호
  • 전도욱
  • 강귀운
  • 정재용
  • 공영선
  • 강석문

Assignees

  • 삼성에스디아이 주식회사

Dates

Publication Date
20260512
Application Date
20230824

Claims (20)

  1. Core particles containing layered lithium nickel-manganese-based composite oxide, A first coating layer containing Al located on the surface of the core particle, and It includes a second coating layer located on a first coating layer and containing Ni, and A positive electrode active material having a layered lithium nickel-manganese-based composite oxide of the above-mentioned core particles, wherein the content of cobalt relative to 100 mol% of the total metal excluding lithium is 0 mol% to 0.01 mol%.
  2. In paragraph 1, A positive electrode active material in a layered lithium nickel-manganese composite oxide of the above-mentioned core particles, wherein the nickel content is 60 mol% to 80 mol% and the manganese content is 15 mol% or more relative to 100 mol% of the total metal excluding lithium.
  3. In paragraph 1, A positive electrode active material wherein the layered lithium nickel-manganese composite oxide of the core particles further comprises aluminum, and the content of aluminum in the core particles is 1 mol% to 3 mol% relative to 100 mol% of the total metal excluding lithium.
  4. delete
  5. In paragraph 1, A positive active material in which the layered lithium nickel-manganese-based composite oxide of the above core particles is represented by Chemical Formula 1: [Chemical Formula 1] Li a1 Ni x1 Mn y1 Al z1 M 1 w1 O 2- b1 In Chemical Formula 1, 0.9≤a1≤1.8, 0.6≤x1≤0.8, 0.1≤y1≤0.4, 0≤z1≤0.03, 0≤w1≤0.3, 0.9≤x1+y1+z1+w1≤1.1, and 0≤b1≤0.1, M1 is one or more elements selected from B, Ba, Ca, Ce, Cr, Fe, Mg, Mo, Nb, Si, Sn, Sr, Ti, V, W, Y, and Zr, and X is one or more elements selected from F, P, and S.
  6. In Paragraph 1, The first coating layer and the second coating layer are positive active materials in the form of continuous films.
  7. In paragraph 1, The thickness of the first coating layer is 5 nm to 40 nm, and A positive active material having a second coating layer thickness of 10 nm or less.
  8. In paragraph 1, A positive active material in which the ratio of the thickness of the second coating layer to the thickness of the first coating layer is less than 0.5.
  9. In paragraph 1, The Al content of the first coating layer is 0.1 mol% to 2 mol% with respect to 100 mol% of the total metal excluding lithium in the positive electrode active material, and A positive electrode active material in which the Ni content of the second coating layer is 0.01 mol% to 1 mol% with respect to 100 mol% of the total metal excluding lithium in the positive electrode active material.
  10. In paragraph 1, The Al content of the first coating layer is 0.5 mol% to 1.5 mol% with respect to 100 mol% of the total metal excluding lithium in the positive electrode active material, and A positive electrode active material in which the Ni content of the second coating layer is 0.05 mol% to 0.5 mol% with respect to 100 mol% of the total metal excluding lithium in the positive electrode active material.
  11. In Paragraph 1, A positive electrode active material in which the ratio of the Ni content of the second coating layer to the Al content of the first coating layer is less than 0.5.
  12. In paragraph 1, The first coating layer comprises aluminum oxide, lithium-aluminum oxide, or a combination thereof, and The second coating layer is an anode active material comprising nickel oxide, lithium-nickel oxide, aluminum-nickel oxide, lithium-aluminum-nickel oxide, or a combination thereof.
  13. In Paragraph 1, The first coating layer and the second coating layer are a positive active material having a layered structure.
  14. In paragraph 1, The above-mentioned core particle is in the form of a secondary particle formed by the aggregation of a plurality of primary particles, and A positive electrode active material further comprising a grain boundary coating portion containing Al located on the surface of primary particles inside the secondary particles.
  15. In Paragraph 14, A positive active material in which the Al content in the grain boundary coating portion is less than the Al content in the first coating layer.
  16. In paragraph 1, The above positive active material has an average particle size (D 50 ) of 10 μm to 20 μm.
  17. A layered nickel-manganese-based composite hydroxide and a lithium raw material are mixed and subjected to a first heat treatment to obtain a layered lithium nickel-manganese-based composite oxide, and Al raw material is added to an aqueous solvent and the above lithium nickel-manganese-based composite oxide is added and mixed, then Ni raw material is added and mixed, and It includes drying and performing a second heat treatment, A method for manufacturing an anode active material in which, in the above-mentioned layered nickel-manganese-based composite hydroxide, the cobalt content is 0 mol% to 0.01 mol% with respect to 100 mol% of the total metal.
  18. In Paragraph 17, A method for manufacturing an anode active material in the above-mentioned layered nickel-manganese composite hydroxide, wherein the nickel content is 60 mol% to 80 mol%, the manganese content is 15 mol% or more, and the aluminum content is 0 mol% to 3 mol% with respect to 100 mol% of the total metal.
  19. In Paragraph 17, The Al content in the above Al raw material is 0.1 mol% to 2 mol% with respect to 100 mol% of the total metal excluding lithium in the above cathode active material, and A method for manufacturing a positive electrode active material in which the Ni content in the above Ni raw material is 0.01 mol% to 1 mol% with respect to 100 mol% of the total metal excluding lithium in the above positive electrode active material.
  20. In Paragraph 17, The above Al raw material includes aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum hydroxide, or a combination thereof, and A method for manufacturing a positive electrode active material comprising the above Ni raw material, nickel nitrate, nickel sulfate, nickel carbonate, nickel hydroxide, or a combination thereof.

Description

Positive active material, method of preparing the same, positive electrode including the same, and rechargeable lithium batteries The invention relates to a positive electrode active material, a method for manufacturing the same, a positive electrode containing the same, and a lithium secondary battery. Lithium-ion batteries, which offer high energy density and portability, are primarily used as the power source for mobile information terminals such as mobile phones, laptops, and smartphones. Recently, active research is being conducted to utilize high-energy-density lithium-ion batteries as power sources for driving or energy storage in hybrid and electric vehicles. Various cathode active materials are being considered to realize lithium secondary batteries suitable for these applications. Among them, lithium nickel-based oxides, lithium nickel manganese cobalt composite oxides, lithium nickel cobalt aluminum composite oxides, and lithium cobalt oxides are primarily used as cathode active materials. However, while the demand for large-capacity or high-energy-density lithium secondary batteries has recently surged, the supply of cathode active materials containing the rare metal cobalt is expected to be woefully insufficient. In other words, because cobalt is expensive and its remaining reserves are limited, there is a need to develop cathode active materials that exclude cobalt or reduce its content. FIGS. 1 to 4 are cross-sectional views schematically illustrating a lithium secondary battery according to one embodiment. Figure 5 is an HR-STEM image of the cross-section of the positive active material of Example 1. Figure 6 is an EDS (Energy Dispersive X-ray Spectrometry) analysis image highlighting Ni in the cross-section of the positive electrode active material of Example 1. Figure 7 is an EDS analysis image highlighting Al in the cross-section of the positive electrode active material of Example 1. Specific embodiments are described below in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. The terms used herein are for describing exemplary embodiments only and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. Here, "combinations of these" refers to mixtures of components, laminates, composites, copolymers, alloys, blends, reaction products, etc. The terms "include," "equip," or "have" used herein are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. In the drawings, thicknesses have been enlarged to clearly represent various layers and regions, and the same reference numerals have been used for similar parts throughout the specification. When a part such as a layer, film, region, or plate is described as being "on" or "on" another part, this includes not only cases where it is "immediately on" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately on" another part, it means that there is no other part in between. In addition, the term “layer” here includes not only shapes formed on the entire surface when viewed in a plan view, but also shapes formed on some surfaces. The average particle size can be measured by methods widely known to those skilled in the art, for example, by measuring with a particle size analyzer, or by using transmission electron microscope images or scanning electron microscope images. Alternatively, the average particle size value can be obtained by measuring using dynamic light scattering and performing data analysis to count the number of particles for each particle size range, and then calculating from this. Unless otherwise defined, the average particle size may refer to the diameter (D 50 ) of a particle whose cumulative volume is 50% of the particle size distribution. Additionally, unless otherwise defined, the average particle size may be obtained by randomly measuring the size (diameter or length of the major axis) of about 20 particles from a scanning electron microscope image to obtain a particle size distribution, and taking the diameter (D 50 ) of the particle whose cumulative volume is 50% of the particle size distribution as the average particle size. Here, “or” is not interpreted in an exclusive sense; for example, “A or B” is interpreted to include A, B, A+B, etc. The term “metal” is interpreted as a concept that includes ordinary metals, transition metals, and metalloids (semimetals). positive electrode active material In one embodiment, a positive electrode active material is provided comprising a core particle containing a layered