Search

KR-20260064443-A - Positive electrode active material for lithium secondary battery, positive electrode including the positive electrode active material, and lithium secondary battery including the same

KR20260064443AKR 20260064443 AKR20260064443 AKR 20260064443AKR-20260064443-A

Abstract

The present invention relates to a positive electrode active material for a lithium secondary battery, a positive electrode comprising the positive electrode active material, and a lithium secondary battery comprising the same. More specifically, the invention provides a positive electrode with improved electrochemical performance through particle size control of the positive electrode active material and a lithium secondary battery comprising the same.

Inventors

  • 명민훈

Assignees

  • (주)포스코퓨처엠

Dates

Publication Date
20260507
Application Date
20250318
Priority Date
20241030

Claims (17)

  1. A lithium transition metal oxide containing particles with a single-crystal structure, The above lithium transition metal oxide is a high-concentration nickel (High-Ni) NCM system in which nickel (Ni) is 80 mol% or more among the metals excluding lithium, and The D5 of the above single crystal grain is 1.76㎛ to 2.34㎛, and The D10 of the above single crystal grain is 2.00㎛ to 2.65㎛, and A positive electrode active material for a lithium secondary battery having a particle uniformity index (I p ) expressed by the following formula (1) of 0.150 to 0.200. Equation (1): I p = ((D10-D5)/D5)×SPAN (Here, D5 is the average diameter of particles corresponding to a cumulative volume of 5 volume% in the particle size distribution, D10 is the average diameter of particles corresponding to a cumulative volume of 10 volume% in the particle size distribution, and SPAN is the particle size distribution index of the single crystal particle, expressed as (D90-D10)/D50.)
  2. In claim 1, D5 of the above single crystal particle is, A positive electrode active material for a lithium secondary battery having a thickness of 1.76㎛ to 1.99㎛.
  3. In claim 1, D10 of the above single crystal particle is, A positive electrode active material for a lithium secondary battery, having a diameter of 2.00㎛ to 2.30㎛.
  4. In claim 1, The SPAN of the above single crystal particle is, 0.95 ~ 1.15 phosphorus, positive electrode active material for lithium secondary batteries.
  5. In claim 1, Dmin, the minimum diameter of the above single-crystal grain, is, A positive electrode active material for a lithium secondary battery having a thickness of 1.00㎛ or more.
  6. In claim 1, Dmax, the maximum diameter of the above single-crystal grain, is, A positive electrode active material for a lithium secondary battery having a thickness of 15.60㎛ or less.
  7. In claim 1, The D50 of the above single crystal particle is, A positive electrode active material for a lithium secondary battery having a thickness of 3.45㎛ to 3.90㎛.
  8. In claim 1, The D90 of the above single crystal particle is, A positive electrode active material for a lithium secondary battery having a thickness of 5.70㎛ to 6.60㎛.
  9. In claim 1, The specific surface area of the above single-crystal particle is, A positive electrode active material for a lithium secondary battery having a g/g of 0.45 m²/g to 0.80 m²/g.
  10. In claim 1, The above lithium transition metal oxide is, A positive electrode active material for a lithium secondary battery comprising a compound represented by the following chemical formula 1. [Chemical Formula 1] Li a [Ni x Co y Mn z M1 w1 M2 w2 ]O 2 (In the above Chemical Formula 1, M1 comprises one or more of Al, Y, or Zr, and M2 comprises one or more of B, Al, Mg, Ti, Nb, W, Sc, Si, V, Fe, Y, Mo, Ce, Hf, Ta, La, or Sr, and a, x, y, z, w1, w2 satisfy 0.8≤a≤1.2, 0.80≤x≤0.99, 0<y≤0.06, 0<z≤0.15, 0<w1≤0.1, 0≤w2≤0.1, and x+y+z+w1+w2=1)
  11. In claim 1, The above positive active material is, A positive electrode active material for a lithium secondary battery, wherein a coating layer is disposed on the surface of a lithium transition metal oxide.
  12. In claim 11, The above coating layer is, A positive electrode active material for a lithium secondary battery comprising one or more of lithium cobalt oxide ( LiCoO2 ) or lithium aluminum oxide ( LiAlO2 ).
  13. In claim 11, The thickness of the above coating layer is, A positive electrode active material for a lithium secondary battery, having a diameter of 0.30 nm to 100.00 nm.
  14. A positive electrode comprising a positive electrode active material according to any one of claims 1 to 13.
  15. A positive electrode comprising a positive electrode active material according to any one of claims 1 to 13, cathode, A separator interposed between the anode and the cathode, and electrolytes, A lithium secondary battery including
  16. In claim 15, The above lithium secondary battery is, A lithium secondary battery with a discharge capacity of 205 mAh/g or more.
  17. In claim 15, The above lithium secondary battery is, A lithium secondary battery with a charge/discharge efficiency of 88% or higher.

Description

Positive electrode active material for lithium secondary battery, positive electrode including the positive electrode active material, and lithium secondary battery including the same The present disclosure relates to a positive electrode active material for a lithium secondary battery, a positive electrode comprising the positive electrode active material, and a lithium secondary battery comprising the same. A lithium secondary battery generally consists of a positive electrode, a negative electrode, a separator, and an electrolyte, and the positive and negative electrodes include an active material capable of lithium ion intercalation and deintercalation. At this time, since the characteristics of the cathode active material of a lithium secondary battery significantly affect the overall electrochemical performance of the lithium secondary battery, the composition, crystal structure, particle size distribution, and specific surface area of such cathode active material are evaluated as major factors, and excellent battery performance can be achieved only when each factor is controlled within an appropriate range. Conventionally, polycrystalline lithium transition metal oxides have been used as cathode active materials. However, these polycrystalline materials have low energy density and lifespan, making them difficult to apply to devices requiring high-performance batteries, such as smartphones and electric vehicles. Consequently, research on single-crystal lithium transition metal oxides is currently underway to improve battery performance. Preferred embodiments of the present invention are described below. However, embodiments of the present invention may be modified in various other forms, and the technical concept of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more completely explain the present invention to those with average knowledge in the relevant technical field. The terms used in this application are used merely to describe specific examples. For this reason, singular expressions include plural expressions unless the context clearly requires them to be singular. Additionally, it should be noted that terms such as “comprising” or “comprising” used in this application are used to clearly indicate the presence of features, steps, functions, components, or combinations thereof described in the specification, and are not used to preliminarily exclude the existence of other features, steps, functions, components, or combinations thereof. Meanwhile, unless otherwise defined, all terms used in this specification shall be understood to have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Accordingly, unless explicitly defined in this specification, specific terms should not be interpreted in an overly ideal or formal sense. Additionally, terms such as "about," "substantially," etc., in this specification are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the said sense, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content in which precise or absolute values are mentioned to aid in understanding the invention. The present invention will be described in more detail below through examples. These examples are intended solely to explain the invention more specifically, and it will be obvious to those skilled in the art that the scope of the invention is not limited by these examples according to the gist of the invention. Unless otherwise specifically stated in this specification, the % indicating the content of each element is based on weight. Cathode active material for lithium secondary batteries First, a positive electrode active material for a lithium secondary battery according to the present invention will be described. A positive electrode active material for a lithium secondary battery according to one embodiment of the present invention comprises a lithium transition metal oxide. The above lithium transition metal oxide comprises primary particles with a single-crystal structure and is a high-concentration nickel (High-Ni) NCM system containing nickel (Ni), cobalt (Co), and manganese (Mn), wherein the nickel (Ni) content among the metals excluding lithium is 80 mol% or more. Preferably, the nickel (Ni) content among the metals excluding lithium may be 85 mol% or more, and more preferably, 88 mol% or more. By satisfying the nickel (Ni) content among the metals excluding lithium of the above lithium composite transition metal oxide at 80 mol% or more, it is possible to secure a high capacity. More specifically, the lithium transition metal oxide can be represented by the following chemical formula 1. [Chemical Formula 1] Li a [Ni x Co y Mn z M1 w1 M2 w2 ]O 2 (Here, 0.8≤a≤1.2, 0.80≤x≤0.99, 0<y≤0.06, 0<z≤0.15, 0<w1≤0.1, 0≤w2≤0.1, and x+y+z+w1