KR-20260062404-A - POSITIVE ELECTRODE ACTIVE MATERIAL AND MANUFACTURING METHOD OF THE SAME

Abstract

A positive electrode active material according to one embodiment of the present invention is a cobalt-free positive electrode active material having a single particle form, comprising a lithium transition metal composite oxide; and a coating portion surrounding the lithium transition metal composite oxide, wherein the coating portion may comprise a Li-Al-O composite.

Inventors

• 이준원
• 예성지
• 임채진
• 정병훈
• 김선우
• 김성욱
• 함미림

Assignees

• 주식회사 엘지화학

Dates

Publication Date

20260507

Application Date

20241029

Claims (14)

1. As a cobalt-free positive electrode active material having a single-particle form, Lithium transition metal complex oxide; and It includes a coating portion surrounding the above lithium transition metal composite oxide, and The above coating portion is a positive active material comprising a Li-Al-O complex.
2. In paragraph 1, The above lithium transition metal composite oxide is a positive electrode active material having a Co content of 0.04 mol% or less among the total transition metals.
3. In paragraph 1, The above lithium transition metal composite oxide is a positive active material that does not contain Co.
4. In paragraph 1, The above lithium transition metal composite oxide is a positive active material represented by the following chemical formula 1. [Chemical Formula 1] Li a1 Ni b1 Mn c1 M1 d1 O 2 In the above chemical formula 1, M1 is Cr, Mg, Zr, Nb, Hf, Ta, La, Sr, Ba, Zn, F, P, S, Y, W, Mo, B or a combination thereof, and 0.8≤a1≤1.2, 0.5≤b1<1.0, 0.2≤c1≤0.5, 0≤d1≤0.01, b1+c1+d1 = 1.
5. In paragraph 1, The above Li-Al-O composite is a positive active material that is Li₂AlO₃ .
6. In paragraph 1, It further includes an island pattern portion disposed on the surface of the above lithium transition metal composite oxide, and The above-mentioned island pattern portion is a positive active material comprising a Li-Zr-O complex.
7. In paragraph 6, The above Li-Zr-O composite is a positive active material that is Li₂ZrO₃ .
8. In paragraph 1, The above lithium transition metal composite oxide is a positive active material represented by the following chemical formula 2. [Chemical Formula 2] Li a2 Ni b2 Mn c2 M2 d2 M3 e2 O 2 In the above chemical formula 2, M2 is Mg, Zr, or a combination thereof, and M3 is Cr, Nb, Hf, Ta, La, Sr, Ba, Zn, F, P, S, Y, W, Mo, B or a combination thereof, and 0.8≤a2≤1.2, 0.5≤b2<1.0, 0.2≤c2≤0.5, 0<d2≤0.009, 0≤e2≤0.01, b2+c2+d2+e2 = 1.
9. In paragraph 8, M2 of the above chemical formula 2 is a positive active material incorporated into the crystal lattice structure of the above lithium transition metal composite oxide.
10. A positive electrode comprising a positive electrode active material according to any one of claims 1 to 9.
11. A lithium secondary battery comprising a positive electrode according to claim 10.
12. A step (S1) of preparing a positive electrode active material precursor containing nickel and manganese by mixing a nickel raw material and a manganese raw material; A step (S2) of mixing a first lithium raw material with the above positive active material precursor and calcining it to obtain a first calcined product; and A method for manufacturing a positive electrode active material comprising the step (S3) of mixing a second lithium raw material and an aluminum raw material with the first calcined product and calcining the mixture.
13. In Paragraph 12, The above step (S3) involves mixing the second lithium raw material, the aluminum raw material, and the additive element raw material into the above first calcined product and calcining it, and The above additive element raw material is one or more raw materials among Mg and Zr, and A method for manufacturing a positive electrode active material in which the content of the above-mentioned additive element raw material is 0.9 mol% or less relative to the total transition metal content of the positive electrode active material to be manufactured.
14. In Paragraph 12, The firing of the above (S2) step is performed in the range of 900℃ to 1000℃, and A method for manufacturing an anode active material in which the calcination of the above (S3) step is performed in the range of 750℃ to 850℃.

Description

Positive ELECTRODE ACTIVE MATERIAL AND MANUFACTURING METHOD OF THE SAME The present invention relates to a positive electrode active material and a method for manufacturing the same. Lithium secondary batteries capable of repeated charging and discharging are gaining attention as an alternative to fossil energy. Lithium secondary batteries have primarily been used in traditional handheld devices such as mobile phones, video cameras, and power tools. However, recently, their application fields are gradually increasing to include electric vehicles (EVs, HEVs, PHEVs), large-capacity energy storage systems (ESS), and uninterruptible power supply systems (UPS). A lithium secondary battery comprises an electrode assembly comprising unit cells having a structure in which a positive electrode plate coated with an active material on a current collector and a negative electrode plate are arranged with a separator in between, and an outer casing, namely a battery case, that seals and houses this electrode assembly together with an electrolyte. Lithium composite transition metal oxides are used as cathode active materials for lithium secondary batteries, and among these, lithium cobalt oxide of LiCoO2 , lithium manganese oxide ( LiMnO2 or LiMn2O4 , etc. ), lithium iron phosphate compound ( LiFePO4 ), or LiNiO2 are mainly used. In addition, as a method to improve the low thermal stability while maintaining the excellent reversible capacity of LiNiO2 , nickel-manganese-based lithium composite metal oxides in which some of the nickel is substituted with manganese, which has excellent thermal stability, and NCMs substituted with manganese and cobalt are used. However, due to the high cost of cobalt and environmental issues in the raw material supply process, research is currently underway on methods to manufacture cobalt-free cathode active materials containing no or extremely small amounts of cobalt. However, in the case of cobalt-free cathode active materials, the lack of cobalt leads to a relative increase in Li + /Ni2 + cation mixing, resulting in inferior capacity and initial resistance performance. Furthermore, there was a problem in that driving at a relatively high voltage (4.4V or higher) was essential to overcome the insufficient energy density and capacity performance compared to cathode materials with high cobalt content. Accordingly, cobalt-free cathode active materials are manufactured in the form of single particles to prevent cracks caused by greater shrinkage and expansion of lattice parameters during the charge-discharge process when operating at high voltage. However, when single particles are operated at high voltage, degradation occurs, such as the occurrence of irreversible phase transitions due to cation mixing of Li + /Ni2 +, which further exacerbates the inferiority in capacity, lifespan characteristics, and initial resistance performance. Therefore, to prevent this, there is a need for doping technology that can lower resistance while maintaining structural stability. Figure 1 is an EPMA measurement image of an electrode containing the positive active material prepared in Example 2. Figure 2 is an EPMA measurement image of an electrode containing the positive active material prepared in Example 3. Figure 3 is an EPMA measurement image of an electrode containing a positive electrode active material prepared in Comparative Example 3. Figure 4 is an EPMA measurement image of an electrode containing a positive electrode active material prepared in Comparative Example 4. Hereinafter, the present invention will be described in more detail to aid in understanding the invention. In this case, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. In the present invention, the term 'primary particle' refers to a minimum particle unit that is distinguished as a single mass when the cross-section of the positive active material is observed through a scanning electron microscope (SEM), and may consist of multiple crystal grains. In the present invention, the term 'secondary particle' refers to a secondary structure formed by the aggregation of a plurality of primary particles. The average particle size of the secondary particles can be measured using a particle size analyzer. In the present invention, the term 'single particle form' may be used as a substitute for the term 'single particle type,' and refers to a form contrasted with a secondary particle form formed by the aggregation of hundreds of primary particles manufactured by conventional methods. Furthermore, 'single particle type cathode active material' or 'single particle type lithium transition metal oxide' refers to a cathode active materia