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CN-122000346-A - Positive electrode active material for lithium secondary battery and lithium secondary battery comprising same

CN122000346ACN 122000346 ACN122000346 ACN 122000346ACN-122000346-A

Abstract

The positive electrode active material for a lithium secondary battery according to an embodiment of the present invention contains active material particles containing lithium-transition metal oxide particles having a single particle form. In the volume weighted particle size distribution of the active material particles, the particle diameter (D50) at which the volume fraction is 50% when particles having the smallest particle diameter are accumulated is 2 μm to 5 μm. When D50 of the active material particles is represented as a, the volume fraction of particles having a particle diameter of 2a μm or more in the active material particles is 4% to 15%.

Inventors

  • YU YONGBIN
  • JIN ZHONGHE
  • Kong Ningzhu
  • PU CHENGCHUN
  • Yin Zhenpei

Assignees

  • SK新能源株式会社

Dates

Publication Date
20260508
Application Date
20251105
Priority Date
20241106

Claims (13)

  1. 1. A positive electrode active material for a lithium secondary battery, comprising active material particles comprising lithium-transition metal oxide particles having a single particle form, In the volume weighted particle size distribution of the active material particles, the particle diameter D50 at which the volume fraction is 50% from the particle having the smallest particle diameter is 2 μm to 10 μm, When D50 of the active material particles is represented as a, the volume fraction of particles having a particle diameter of 2a μm or more in the active material particles is 4% to 15%.
  2. 2. The 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. 3. The positive electrode active material for a lithium secondary battery according to claim 1, wherein a volume fraction of particles having a particle diameter of 2a μm or more in the active material particles is 5% to 10%.
  4. 4. The positive electrode active material for a lithium secondary battery according to claim 1, wherein a volume fraction of particles having a particle diameter of 1 μm or less in the active material particles is 5% or less.
  5. 5. The positive electrode active material for a lithium secondary battery according to claim 1, wherein a volume fraction of particles having a particle diameter of 1 μm or less in the active material particles is 0.1% to 4.5%.
  6. 6. The 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: [ 1] Span = (D90-D10)/D50 In formula 1, D50 is the particle diameter at which the volume fraction is 50% from the particle having the smallest particle diameter in the volume-weighted particle size distribution of the active material particles, D90 is the particle diameter at which the volume fraction is 90% from the particle having the smallest particle diameter in the volume-weighted particle size distribution of the active material particles, and D10 is the particle diameter at which the volume fraction is 10% from the particle having the smallest particle diameter in the volume-weighted particle size distribution of the active material particles.
  7. 7. The 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. 8. The positive electrode active material for a lithium secondary battery according to claim 6, wherein D10 of the active material particles is 1.3 μm to 4 μm.
  9. 9. The positive electrode active material for a lithium secondary battery according to claim 6, wherein the D90 of the active material particles is 4 μm to 15 μm.
  10. 10. The positive electrode active material for a lithium secondary battery according to claim 1, wherein the lithium-transition metal oxide particles contain nickel, and in the lithium-transition metal oxide particles, the mole fraction of nickel among elements other than lithium and oxygen is 0.6 or more.
  11. 11. The positive electrode active material for a lithium secondary battery according to claim 10, wherein the lithium-transition metal oxide particles further contain at least one element 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 and Sn.
  12. 12. The positive electrode active material for a lithium secondary battery according to claim 11, wherein the lithium-transition metal oxide particles contain lanthanum in a content of 500ppm to 4000ppm with respect to the total weight of the lithium-transition metal oxide particles.
  13. 13. A lithium secondary battery comprising a positive electrode comprising the positive electrode active material for a lithium secondary battery according to claim 1, and a negative electrode provided opposite to the positive electrode.

Description

Positive electrode active material for lithium secondary battery and lithium secondary battery comprising same Technical Field The present invention relates to a positive electrode active material for a lithium secondary battery and a lithium secondary battery including the same. More particularly, the present invention relates to a positive electrode active material for a lithium secondary battery including a lithium-transition metal oxide, and a lithium secondary battery including the same. Background Secondary batteries are rechargeable and dischargeable batteries, and with the development of information communication and display industries, secondary batteries are widely used as power sources for portable electronic communication devices such as camcorders, cellular phones, notebook computers, and the like. In addition, in recent years, a battery pack including a secondary battery is being developed and used as a power source for an environment-friendly vehicle such as a hybrid vehicle. The secondary battery includes, for example, a lithium secondary battery having a high operating voltage and an energy density per unit weight, which is advantageous in terms of charging speed and weight reduction, a nickel-cadmium battery, a nickel-hydrogen battery, and the like, and thus is being actively developed and applied. For example, a lithium secondary battery may include an electrode assembly including a positive electrode, a negative electrode, and a separator, and an electrolyte impregnating the electrode assembly. The lithium secondary battery may further include an exterior material, such as a soft pack type exterior material, accommodating the electrode assembly and the electrolyte. A lithium metal oxide is used as the positive electrode active material of the lithium secondary battery, and preferably has high capacity, high power, and long life characteristics. However, when the lithium metal oxide is designed to have a high power composition, thermal stability and mechanical stability may be reduced, and thus life characteristics and operation stability of the lithium secondary battery may be reduced. Disclosure of Invention First, the technical problem to be solved An object of the present invention is to provide a positive electrode active material for a lithium secondary battery having improved operation stability and life characteristics. An object of the present invention is to provide a lithium secondary battery including a positive electrode active material having improved operational stability and life characteristics. (II) technical scheme The positive electrode active material for a lithium secondary battery according to an embodiment of the present invention contains active material particles containing lithium-transition metal oxide particles having a single particle form (SINGLE PARTICLE). In the volume weighted particle size distribution of the active material particles, the particle diameter (D50) at which the volume fraction is 50% when particles having the smallest particle diameter are accumulated is 2 μm to 10 μm. When D50 of the active material particles is expressed as a, the volume fraction of particles having a particle diameter of 2a μm or more in the active material particles is 4% to 15%. In some embodiments, the D50 of the active particles may be 2.5 μm to 5 μm. In some embodiments, the volume fraction of particles having a particle size of 2a μm or more in the active material particles may be 5% to 10%. In some embodiments, the volume fraction of particles having a particle size of 1 μm or less in the active material particles may be 5% or less. In some embodiments, the volume fraction of particles having a particle size of 1 μm or less in the active material particles may be 0.1% to 4.5%. In some embodiments, the active particles may have a span (span) defined by formula 1 below of 1.0 to 1.5. [ 1] Span = (D90-D10)/D50 In the formula 1, D50 is the particle diameter at which the volume fraction is 50% when particles having the smallest particle diameter are accumulated from the volume weighted particle size distribution of the active material particles. D90 is the particle diameter at which the volume fraction is 90% from the particle whose particle diameter is smallest when the particles are accumulated in the volume-weighted particle size distribution of the active material particles. D10 is the particle diameter at which the volume fraction is 10% when particles having the smallest particle diameter are accumulated from the volume weighted particle size distribution of the active material particles. In some embodiments, the span of the active material particles may be 1.1 to 1.4. In some embodiments, the D10 of the active particles may be 1.3 μm to 4 μm. In some embodiments, the D90 of the active particles may be 4 μm to 15 μm. In some embodiments, the lithium-transition metal oxide particles may include nickel, and in the lithium-transition metal oxide particles, a mole f