US-20260128300-A1 - CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

US20260128300A1US 20260128300 A1US20260128300 A1US 20260128300A1US-20260128300-A1

Abstract

A cathode active material for a lithium secondary battery includes active material particles that include lithium-transition metal oxide particles having a single particle shape. A particle diameter (D50) of the active material particles at a volume fraction of 50% in a volume-weighted particle size distribution accumulated from particles having the smallest particle diameter is in a range from 2 μm to 10 μm. A volume fraction of particles having a particle diameter of 2a μm or greater among the active material particles is in a range from 4% to 15%, and a represents the D50 of the active material particles.

Inventors

Yeong Bin YOO
Jong Hwa Kim
Nyung Joo Kong
Sung Soon Park
Jeong Bae YOON

Assignees

SK ON CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251105
Priority Date: 20241106

Claims (13)

1 . A cathode active material for a lithium secondary battery comprising active material particles that comprise lithium-transition metal oxide particles having a single particle shape, wherein, a particle diameter (D50) of the active material particles at a volume fraction of 50% in a volume-weighted particle size distribution accumulated from particles having the smallest particle diameter is in a range from 2 μm to 10 μm, wherein a volume fraction of particles having a particle diameter of 2a μm or greater among the active material particles is in a range from 4% to 15%, and a represents the D50 of the active material particles.
2 . A cathode active material for a lithium secondary battery of claim 1 , wherein the D50 of the active material particles is in a range from 2.5 μm to 5 μm.
3 . The cathode active material for a lithium secondary battery of claim 1 , wherein the volume fraction of particles having the particle diameter of 2a μm or greater among the active material particles is in a range from 5% to 10%.
4 . The cathode active material for a lithium secondary battery of claim 1 , wherein a volume fraction of particles having a particle diameter of 1 μm or less among the active material particles is 5% or less.
5 . The cathode active material for a lithium secondary battery of claim 1 , wherein the volume fraction of particles having the particle diameter of 1 μm or less among the active material particles is in a range from 0.1% to 4.5%.
6 . The cathode active material for a lithium secondary battery of claim 1 , wherein a span of the active material particles defined by Formula 1 is in a range from 1.0 to 1.5: Span = ( D ⁢ 90 - D ⁢ 10 ) / D ⁢ 50 [ Formula ⁢ 1 ] wherein, in Equation 1, D50 is a particle diameter of the active material particles at the volume fraction of 50% in the volume-weighted particle size distribution accumulated from particles having the smallest particle diameter, D90 is a particle diameter of the active material particles at a volume fraction of 90% in the volume-weighted particle size distribution accumulated from particles having the smallest particle diameter, and D10 is a particle diameter of the active material particles at a volume fraction of 10% in the volume-weighted particle size distribution accumulated from particles having the smallest particle diameter.
7 . The cathode active material for a lithium secondary battery of claim 6 , wherein the span of the active material particles is in a range from 1.1 to 1.4.
8 . The cathode active material for a lithium secondary battery of claim 6 , wherein the D10 of the active material particles is in a range from 1.3 μm to 4 μm.
9 . The cathode active material for a lithium secondary battery of claim 6 , wherein the D90 of the active material particles is in a range from 4 μm to 15 μm.
10 . The cathode active material for a lithium secondary battery of claim 1 , wherein the lithium-transition metal oxide particles comprise nickel, and a mole fraction of nickel among elements excluding lithium and oxygen in the lithium-transition metal oxide particles is 0.6 or greater.
11 . The cathode active material for a lithium secondary battery of 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 and Sn.
12 . The cathode active material for a lithium secondary battery of claim 11 , wherein the lithium-transition metal oxide particles comprise lanthanum in a content from 500 ppm to 4,000 ppm based on a total weight of the lithium-transition metal oxide particles.
13 . A lithium secondary battery, comprising: a cathode comprising the cathode active material for a lithium secondary battery of claim 1 ; and an anode facing the cathode.

Description

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY This application claims priority to Korean Patent Application No. 10-2024-0156373 filed on Nov. 6, 2024 in the Korean Intellectual Property Office (KIPO), the entire disclosure of which is incorporated by reference herein. TECHNICAL FIELD The present disclosure relates to a cathode active material for a lithium secondary battery and a lithium secondary battery including the same. More particularly, the present disclosure relates to a cathode active material for a lithium secondary battery including a lithium-transition metal oxide and a lithium secondary battery including the same. BACKGROUND A secondary battery which can be charged and discharged repeatedly has been widely employed as a power source of a mobile electronic device such as a camcorder, a mobile phone, a laptop computer, etc., according to developments of information and display technologies. Recently, a battery pack including the secondary battery is being developed and applied as a power source of eco-friendly vehicle such as an electric vehicle, an hybrid vehicle, etc. Examples of the secondary battery include a lithium secondary battery, a sodium secondary battery, a potassium secondary battery, a nickel-cadmium battery, a nickel-hydrogen battery, etc. The lithium secondary battery among the secondary batteries is being actively developed due to high operational voltage and energy density per unit weight, a high charging rate, a compact dimension, etc. For example, the lithium secondary battery may include an electrode assembly including a cathode, an anode, and a separation layer (separator), and an electrolyte impregnating the electrode assembly. The lithium secondary battery may further include an outer packaging material, e.g., a pouch-shaped packaging material, that accommodates the electrode assembly and the electrolyte. A lithium metal oxide may be used as a cathode active material of the lithium secondary battery to preferably provide high capacity, high power and enhanced life-span properties. However, when the lithium metal oxide is designed to have high power properties, thermal and mechanical stability may be deteriorated, thereby degrading the life-span properties and operational stability of the lithium secondary battery. SUMMARY According to an aspect of the present disclosure, there is provided a cathode active material for a lithium secondary battery having improved operational stability and life-span properties. According to an aspect of the present disclosure, there is provided a lithium secondary battery including a cathode active material for a lithium secondary battery with improved operational stability and life-span properties. A cathode active material for a lithium secondary battery includes active material particles that include lithium-transition metal oxide particles having a single particle shape. A particle diameter (D50) of the active material particles at a volume fraction of 50% in a volume-weighted particle size distribution accumulated from particles having the smallest particle diameter is in a range from 2 μm to 10 μm. A volume fraction of particles having a particle diameter of 2a μm or greater among the active material particles is in a range from 4% to 15%, and a represents the D50 of the active material particles. In some embodiments, the D50 of the active material particles may be in a range from 2.5 μm to 5 μm. In some embodiments, the volume fraction of particles having the particle diameter of 2a μm or greater among the active material particles may be in a range from 5% to 10%. In some embodiments, a volume fraction of particles having a particle diameter of 1 m or less among the active material particles may be 5% or less. In some embodiments, the volume fraction of particles having the particle diameter of 1 m or less among the active material particles may be in a range from 0.1% to 4.5%. In some embodiments, a span of the active material particles defined by Formula 1 may be in a range from 1.0 to 1.5. Span=(D⁢90-D⁢10)/D⁢50[Formula⁢ 1] In Equation 1, D50 is a particle diameter of the active material particles at the volume fraction of 50% in the volume-weighted particle size distribution accumulated from particles having the smallest particle diameter, D90 is a particle diameter of the active material particles at a volume fraction of 90% in the volume-weighted particle size distribution accumulated from particles having the smallest particle diameter, and D10 is a particle diameter of the active material particles at a volume fraction of 10% in the volume-weighted particle size distribution accumulated from particles having the smallest particle diameter, In some embodiments, the span of the active material particles may be in a range from 1.1 to 1.4. In some embodiments, the D10 of the active material particles may be in a range from 1.3 μm to 4 μm. In some embodiments, the D90 of the active material particles may be in a ran