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KR-20260064007-A - Negative Electrode Active Material for Li Secondary Battery and the Negative Electrode Including the Same

KR20260064007AKR 20260064007 AKR20260064007 AKR 20260064007AKR-20260064007-A

Abstract

The present invention relates to a negative electrode material for a lithium secondary battery, and more specifically, the negative electrode material comprises spherical natural graphite and a surface layer containing carbon located on the surface of said spherical natural graphite, wherein the reinforcing orientation index defined by Formula 1 is 4.6 or higher: (Equation 1) In Equation 1, A(110), A(102), A(103) and A(002) are the area intensities of the (110) diffraction peak, (102) diffraction peak, (103) diffraction peak, and (002) diffraction peak in the X-ray diffraction pattern of the cathode material.

Inventors

  • 고승현
  • 김원기
  • 이원규

Assignees

  • (주)포스코퓨처엠

Dates

Publication Date
20260507
Application Date
20241031

Claims (9)

  1. It comprises spherical natural graphite and a surface layer located on the surface of said spherical natural graphite and containing carbon, A negative electrode material for a lithium secondary battery having a reinforcement orientation index of 4.6 or higher as defined by Formula 1 below. (Equation 1) (In Equation 1, A(110), A(102), A(103) and A(002) are the area intensities of the (110) diffraction peak, (102) diffraction peak, (103) diffraction peak, and (002) diffraction peak in the X-ray diffraction pattern of the cathode material.)
  2. In Article 1, A negative electrode material for a lithium secondary battery having the above-mentioned reinforcement orientation index of 5.0 or higher.
  3. In Article 1, A negative electrode material for a lithium secondary battery, wherein the full width at half maximum of the (002) diffraction peak in the above X-ray diffraction pattern is 0.20 to 0.40°.
  4. In any one of paragraphs 1 to 3, A negative electrode material for a lithium secondary battery having the above-mentioned reinforcement orientation index of 6.5 or higher.
  5. In any one of paragraphs 1 to 3, A negative electrode material for a lithium secondary battery having a sphericity of 0.86 or higher.
  6. In any one of paragraphs 1 to 3, A negative electrode material for a lithium secondary battery having a tap density of 0.85 g/cm³ or higher .
  7. In any one of paragraphs 1 to 3, A negative electrode material for a lithium secondary battery, wherein the cumulative volume-based median diameter (D 50 ) is 10 to 25 μm.
  8. In any one of paragraphs 1 to 3, The above surface layer comprises a carbon layer, a negative electrode material for a lithium secondary battery.
  9. A negative electrode for a lithium secondary battery containing a negative electrode material according to any one of claims 1 to 3.

Description

Negative Electrode Active Material for Lithium Secondary Battery and the Negative Electrode Including the Same The present invention relates to a negative electrode material for a lithium secondary battery and a negative electrode including the same, and more specifically, to a natural graphite-based negative electrode material for a lithium secondary battery. As the market for electronic devices such as mobile phones, laptops, and PCs grows, the market for lithium-ion batteries, their power source, is also expanding rapidly. Furthermore, as interest in environmental issues grows and the demand for eco-friendly vehicles like electric cars increases, there is a growing trend of research into lithium-ion batteries capable of meeting various applications. Among the components of a lithium secondary battery, the negative electrode active material stores lithium ions during charging and plays an important role in improving charging speed and determining battery capacity. Natural graphite, a representative cathode active material, has high cost competitiveness and a higher capacity than artificial graphite, but it has problems such as large irreversible reactions due to exposed edge surfaces, reduced output characteristics due to the limited lithium ion diffusion path caused by the uniaxial orientation of the graphite layer plane (graphene layer), and low electrode density and reduced high-rate characteristics because it is easy to orient in a plane on the current collector. To address these issues, technology is being developed to process natural graphite into a spherical shape through mechanical processing and to form a carbon coating layer on the surface of the spherical natural graphite. Technological development regarding the spherical processing of natural graphite is continuously progressing in the direction of improving the degree of sphericity, crystallographic isotropy, and density of the natural graphite. However, as the application fields for secondary batteries requiring superior high-rate characteristics—such as electric vehicles—increase, there is a demand for natural graphite with enhanced crystallographic isotropy. Preferred embodiments of the present invention are described below. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field. In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described. Unless otherwise specifically defined in the specification of the present invention, % units mean weight %. Additionally, throughout the specification, when it is said that one part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between. The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention. The inventors have conducted a long-term, in-depth study on natural graphite spheroidization technology, which mechanically spheroidizes natural graphite. As a result, it was discovered that when natural g