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KR-20260067802-A - CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

KR20260067802AKR 20260067802 AKR20260067802 AKR 20260067802AKR-20260067802-A

Abstract

A positive electrode active material for a lithium secondary battery according to the embodiments of the present disclosure comprises active material particles including lithium-transition metal oxide particles having a single particle form. In the volume-weighted particle size distribution of the active material particles, the particle size (D50) at 50% of the volume fraction when accumulated starting from the smallest particle size is 2 μm to 5 μm. When the D50 of the active material particles is denoted as a, the volume fraction of the active material particles having a particle size of 2 a μm or more is 4% to 15%.

Inventors

  • 유영빈
  • 김종화
  • 공녕주
  • 박성순
  • 윤정배

Assignees

  • 에스케이온 주식회사

Dates

Publication Date
20260513
Application Date
20241106

Claims (13)

  1. It comprises active material particles including lithium-transition metal oxide particles having a single particle form, and In the volume-weighted particle size distribution of the above active material particles, when accumulated starting from the smallest particle size, the particle size (D50) at a volume fraction of 50% is 2㎛ to 10㎛, and A positive electrode active material for a lithium secondary battery, wherein, when the D50 of the active material particles is denoted as a, the volume fraction of the active material particles having a particle size of 2a㎛ or more is 4% to 15%.
  2. A positive electrode active material for a lithium secondary battery according to claim 1, wherein the D50 of the active material particles is 2.5 μm to 5 μm.
  3. A positive electrode active material for a lithium secondary battery according to claim 1, wherein the volume fraction of particles having a particle size of 2a㎛ or more among the active material particles is 5% to 10%.
  4. A positive electrode active material for a lithium secondary battery according to claim 1, wherein the volume fraction of particles having a particle size of 1 μm or less among the active material particles is 5% or less.
  5. A positive electrode active material for a lithium secondary battery according to claim 1, wherein the volume fraction of particles having a particle size of 1 μm or less among the active material particles is 0.1% to 4.5%.
  6. A positive electrode active material for a lithium secondary battery according to claim 1, wherein the span of the active material particles defined by the following formula 1 is 1.0 to 1.5: [Equation 1] Span = (D90-D10)/D50 (In Equation 1, D50 is the particle size at the 50% volume fraction when accumulating from the smallest particle size in the volume-weighted particle size distribution of the active material particles, D90 is the particle size at the 90% volume fraction when accumulating from the smallest particle size in the volume-weighted particle size distribution of the active material particles, and D10 is the particle size at the 10% volume fraction when accumulating from the smallest particle size in the volume-weighted particle size distribution of the active material particles).
  7. A positive electrode active material for a lithium secondary battery according to claim 6, wherein the span of the active material particles is 1.1 to 1.4.
  8. A positive electrode active material for a lithium secondary battery according to claim 6, wherein the D10 of the active material particles is 1.3 μm to 4 μm.
  9. A positive electrode active material for a lithium secondary battery according to claim 6, wherein the D90 of the active material particles is 4㎛ to 15㎛.
  10. A positive electrode active material for a lithium secondary battery according to claim 1, wherein the lithium-transition metal oxide particles comprise nickel, and the mole fraction of nickel among the elements excluding lithium and oxygen among the lithium-transition metal oxide particles is 0.6 or more.
  11. A positive electrode active material for a lithium secondary battery according to claim 10, wherein the lithium-transition metal oxide particles further comprise at least one element selected from the group consisting of Na, Mg, Ca, Sr, Ba, La, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Fe, Cu, Ag, Zn, B, Al, Ga, C, Si, Sn and Zr.
  12. A positive electrode active material for a lithium secondary battery according to claim 11, wherein the content of lanthanum relative to the total weight of the lithium-transition metal oxide particles is 500 ppm to 4000 ppm.
  13. A positive electrode comprising the positive electrode active material for a lithium secondary battery according to claim 1; and A lithium secondary battery comprising a negative electrode facing the above positive electrode.

Description

Cathode active material for lithium secondary battery and lithium secondary battery including the same The present disclosure relates to a positive electrode active material for a lithium secondary battery and a lithium secondary battery comprising the same. More specifically, it relates to a positive electrode active material for a lithium secondary battery comprising a lithium-transition metal oxide and a lithium secondary battery comprising the same. Rechargeable batteries are batteries capable of repeated charging and discharging, and with the advancement of the information and communication and display industries, they are widely applied as power sources for portable electronic communication devices such as camcorders, mobile phones, and laptop PCs. Furthermore, recently, battery packs containing rechargeable batteries are being developed and applied as power sources for eco-friendly vehicles, such as hybrid cars. Examples of secondary batteries include lithium-ion batteries, nickel-cadmium batteries, and nickel-hydrogen batteries; among these, lithium-ion batteries are being actively developed and applied due to their high operating voltage and energy density per unit weight, as well as advantages in charging speed and weight reduction. For example, a lithium secondary battery may include an electrode assembly comprising a positive electrode, a negative electrode, and a separator, and an electrolyte impregnating the electrode assembly. The lithium secondary battery may further include an outer casing, for example, in the form of a pouch, that accommodates the electrode assembly and the electrolyte. A lithium metal oxide is used as the positive electrode active material of the above-mentioned lithium secondary battery, and it is desirable that it possesses high capacity, high power output, and long lifespan characteristics. However, if the above-mentioned lithium metal oxide is designed with a high-power composition, thermal and mechanical stability may be reduced, which may lead to a decrease in the lifespan characteristics and operational stability of the lithium secondary battery. FIGS. 1 and FIGS. 2 are SEM images of a positive electrode active material for a lithium secondary battery according to exemplary embodiments. FIGS. 3 and FIGS. 4 are a schematic plan view and a cross-sectional view, respectively, showing a lithium secondary battery according to exemplary embodiments. FIGS. 5 to 7 are SEM images of positive electrode active materials for lithium secondary batteries according to Example 1, Example 4, and Comparative Example 1, respectively. Embodiments of the present disclosure provide a positive electrode active material for a lithium secondary battery comprising lithium-transition metal oxide particles (hereinafter may be abbreviated as positive electrode active material) and a lithium secondary battery comprising the same. Hereinafter, embodiments of the present disclosure will be described in detail. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively. The positive electrode active material according to exemplary embodiments comprises active material particles including lithium-transition metal oxide particles having a single particle form. The term “single particle form” as used in this disclosure may be used to mean excluding secondary particles formed by the aggregation of a plurality of primary particles, for example. For example, the lithium-transition metal oxide particles are substantially composed of particles in a single particle form, and secondary particle structures formed by the assembly or aggregation of primary particles may be excluded. The term “single particle form” as used in this disclosure does not exclude, for example, a range of 2 to 10 single particles being attached or closely bonded to each other to form a single body form. In some embodiments, the lithium-transition metal oxide particles may include a structure in which a plurality of primary particles are merged together as a single unit and converted into a substantially single particle form. For example, the lithium-transition metal oxide particles may have a granular or spherical single-particle form. For example, the lithium-transition metal oxide particles may include nickel (Ni) and may further include at least one of cobalt (Co) or manganese (Mn). For example, the lithium-transition metal oxide particles can be represented by the following chemical formula 1. [Chemical Formula 1] Li x Ni y M z O 2+w In the above chemical formula 1, 0.9≤x≤1.5, 0.6≤y≤0.99, 0.01≤z≤0.4, and -0.1≤w≤0.1 may be present. M may be one or more elements selected from Na, Mg, Ca, Sr, Ba, La, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Fe, Cu, Ag, Zn, B, Al, Ga, C, Si, Sn, or Zr. The chemical structure represented by Chemical Formula 1 represents the bonding relationships contained within the layered or crystal structure of the positive electrode activ