CN-121990621-A - Positive electrode active material precursor for lithium secondary battery, method for producing same, positive electrode active material for lithium secondary battery, and lithium secondary battery

CN121990621ACN 121990621 ACN121990621 ACN 121990621ACN-121990621-A

Abstract

The positive electrode active material precursor for a lithium secondary battery according to an embodiment of the present invention may include first positive electrode active material precursor particles including a core portion and a shell portion including a transition metal containing nickel, and second positive electrode active material precursor particles including a transition metal containing nickel. The mole fraction of nickel in the transition metal of the second positive electrode active material precursor particles may remain constant throughout the second positive electrode active material precursor particles. The average particle diameter (D 50 ) of the core portion of the first positive electrode active material precursor particle may be larger than the average particle diameter (D 50 ) of the second positive electrode active material precursor particle.

Inventors

Sun Bingji
Li Xiaen
CUI ZAIHAO
CUI ZHIXUN

Assignees

SK新能源株式会社

Dates

Publication Date: 20260508
Application Date: 20251107
Priority Date: 20241108

Claims (15)

1. A positive electrode active material precursor for a lithium secondary battery, comprising: A first positive electrode active material precursor particle comprising a core portion and a shell portion, the core portion and the shell portion comprising a transition metal comprising nickel, and A second positive electrode active material precursor particle comprising a transition metal comprising nickel, Wherein the mole fraction of nickel in the transition metal of the second positive electrode active material precursor particles is kept constant throughout the second positive electrode active material precursor particles, The average particle diameter D 50 of the core portion of the first positive electrode active material precursor particle is larger than the average particle diameter D 50 of the second positive electrode active material precursor particle.
2. The positive electrode active material precursor for a lithium secondary battery according to claim 1, wherein the average particle diameter D 50 of the core portion is 8 μm to 13 μm.
3. The positive electrode active material precursor for a lithium secondary battery according to claim 1, wherein the average particle diameter D 50 of the second positive electrode active material precursor particles is 3 μm to 6 μm.
4. The positive electrode active material precursor for a lithium secondary battery according to claim 1, wherein an average molar fraction of the nickel in the transition metal of the first positive electrode active material precursor particle is larger than an average molar fraction of the nickel in the transition metal of the second positive electrode active material precursor particle.
5. The positive electrode active material precursor for a lithium secondary battery according to claim 1, wherein the transition metal further comprises cobalt and manganese.
6. A positive electrode active material for a lithium secondary battery comprising lithium transition metal oxide particles formed from the positive electrode active material precursor for a lithium secondary battery according to claim 1.
7. A lithium secondary battery, comprising: A positive electrode comprising the positive electrode active material for a lithium secondary battery according to claim 6; Negative electrode, and And a separator disposed between the positive electrode and the negative electrode.
8. A method for preparing a positive electrode active material precursor for a lithium secondary battery, comprising the steps of: adding a first transition metal source comprising nickel to a first reactor to produce a primary precursor; Adding the primary precursor and a nickel-containing second transition metal source to a second reactor to prepare a first positive electrode active material precursor having a core-shell structure, and Preparing a second positive electrode active material precursor having a uniform nickel content throughout particles in one or more reactors of the first reactor and the second reactor, Wherein the first reactor and the second reactor are Continuous Stirred Tank Reactors (CSTRs) or batch reactors, respectively, and the first reactor and the second reactor are different from each other.
9. The method for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 8, wherein the first reactor is the batch reactor, the second reactor is the Continuous Stirred Tank Reactor (CSTR), and the step of preparing the second positive electrode active material precursor and the step of preparing the first positive electrode active material precursor in the second reactor are performed simultaneously.
10. The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 9, wherein the step of producing the second positive electrode active material precursor and the formation of the shell portion of the first positive electrode active material precursor are performed simultaneously.
11. The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 8, wherein the first reactor is the Continuous Stirred Tank Reactor (CSTR), the second reactor is the batch reactor, The step of preparing the primary precursor includes preparing a first primary precursor and a second primary precursor having different average particle diameters D 50 from each other in the first reactor, The step of preparing the second positive electrode active material precursor includes adding the second primary precursor and the second transition metal source to the second reactor to prepare the second positive electrode active material precursor.
12. The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 11, wherein the first primary precursor and the second primary precursor produced in the first reactor are fed together into the second reactor, The step of preparing the first positive electrode active material precursor includes forming a shell portion only on the first primary precursor charged into the second reactor.
13. The method for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 8, wherein the first reactor is a Continuous Stirred Tank Reactor (CSTR), and the content of nickel in the total weight of the first transition metal source is greater than the content of nickel in the total weight of the second transition metal source.
14. The method for producing a positive electrode active material precursor for a lithium secondary battery according to claim 8, wherein the first reactor is a batch reactor, and the content of nickel in the total weight of the first transition metal source is smaller than the content of nickel in the total weight of the second transition metal source.
15. The method for preparing a positive electrode active material precursor for a lithium secondary battery according to claim 8, wherein the method for preparing further comprises the step of adding the primary precursor to an intermediate reactor before adding the primary precursor to the second reactor.

Description

Positive electrode active material precursor for lithium secondary battery, method for producing same, positive electrode active material for lithium secondary battery, and lithium secondary battery Technical Field The present invention relates to a positive electrode active material precursor for a lithium secondary battery, a positive electrode active material for a lithium secondary battery, and a lithium secondary battery including the positive electrode active material. More specifically, the present invention relates to a positive electrode active material precursor for a nickel-containing lithium secondary battery, a positive electrode active material for a lithium secondary battery, and a lithium secondary battery containing the positive electrode active material. 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 (PCs), and the like. In addition, in recent years, a battery pack including a secondary battery is being developed and used as a power source of an environment-friendly automobile such as an electric automobile. 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, development is actively underway. In order to improve the capacity characteristics of the lithium secondary battery, a High nickel (High-Ni) -based lithium oxide having an increased nickel content may be used as the positive electrode active material included in the lithium secondary battery. The positive electrode active material may be prepared by reacting a precursor containing a transition metal with a lithium source. However, the high nickel-based lithium oxide may be structurally unstable. Therefore, it is required to develop a transition metal-containing precursor that can improve the structural stability while improving the capacity characteristics of the secondary battery. Disclosure of Invention First, the technical problem to be solved An object of the present invention is to provide a positive electrode active material precursor for a lithium secondary battery, which can improve the life characteristics and initial efficiency of the lithium secondary battery. The technical problem of the invention is to provide a preparation method of the positive electrode active material precursor for the lithium secondary battery. An object of the present invention is to provide a positive electrode active material for a lithium secondary battery, which is formed from the positive electrode active material precursor. An object of the present invention is to provide a lithium secondary battery comprising the positive electrode active material for a lithium secondary battery. (II) technical scheme The positive electrode active material precursor for a lithium secondary battery according to an exemplary embodiment of the present invention includes first positive electrode active material precursor particles including a core portion and a shell portion including a transition metal containing nickel, and second positive electrode active material precursor particles including a transition metal containing nickel. The mole fraction of nickel in the transition metal of the second positive electrode active material precursor particles remains constant throughout the second positive electrode active material precursor particles. The average particle diameter (D 50) of the core portion of the first positive electrode active material precursor particle is larger than the average particle diameter (D 50) of the second positive electrode active material precursor particle. In some embodiments, the core may have an average particle size (D 50) of 8 μm to 13 μm. In some embodiments, the second positive electrode active material precursor particles may have an average particle diameter (D 50) of 3 μm to 6 μm. In some embodiments, the average mole fraction of the nickel in the transition metal of the first positive electrode active material precursor particles may be greater than the average mole fraction of the nickel in the transition metal of the second positive electrode active material precursor particles. In some embodiments, the transition metal may further comprise cobalt and manganese. The positive electrode active material for a lithium secondary battery according to an exemplary embodiment contains lithium transition metal oxide particles formed from the positive electrode active material precursor for a lithium secondary battery described above. The lithium secondary battery according to an exemplary embodiment includes a positive electrode includin