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KR-20260063871-A - METHOD FOR PREPARING POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY COMPRISING THE POSITIVE ELECTRODE ACTIVE MATERIAL PREPARED BY USING THE SAME

KR20260063871AKR 20260063871 AKR20260063871 AKR 20260063871AKR-20260063871-A

Abstract

A method for manufacturing a positive electrode active material for a lithium secondary battery according to the present invention comprises: a mixing step of mixing a transition metal precursor and a lithium raw material to prepare a mixture; a heating step of heating the mixture to a calcination temperature; a calcination step of calcining the mixture to obtain a positive electrode active material; and a cooling step of cooling the calcined positive electrode active material, wherein in the calcination step, bottom air supply may be performed at an average flow rate of 15.0 to 75.0 m³ /hr.

Inventors

  • 이의태
  • 최창민
  • 김정민
  • 이학봉

Assignees

  • (주)포스코퓨처엠

Dates

Publication Date
20260507
Application Date
20241031

Claims (14)

  1. A mixing step for preparing a mixture by mixing a transition metal precursor and a lithium raw material; A heating step of heating the above mixture to the calcination temperature; A calcination step of calcining the above mixture to obtain an anode active material; and It includes a cooling step for cooling the above-mentioned calcined positive active material, and In the above calcination step, bottom air supply is performed at an average flow rate of 15.0 to 75.0 m³ /hr, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  2. In paragraph 1, Bottom air supply is performed at an average flow rate of 15.0 to 90.0 m³ /hr during the 50 to 100% interval of the total time of the above calcination step, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  3. In paragraph 1, In the above calcination step, lateral air supply is performed at an average flow rate of 60.0 to 300.0 m³ /hr, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  4. In paragraph 1, The above firing step includes first firing and second firing, and The above first calcination step is performed in an oxygen ( O2 ) atmosphere at a temperature of 800 to 1000°C for 2 to 8 hours, and The above second calcination step is performed at a temperature of 800 to 1000°C for 2 to 8 hours in a carbon dioxide-free atmosphere ( CO2 free air, CFA). Method for manufacturing a positive electrode active material for a lithium secondary battery.
  5. In paragraph 4, The product of the average bottom air supply flow rate in the 25–65% interval of the total time of the first firing and the average bottom air supply flow rate of the second firing satisfies the range of 400 to 7000 ( m³ /hr). Method for manufacturing a positive electrode active material for a lithium secondary battery.
  6. In paragraph 4, In the above secondary firing, lateral air supply is performed at an average flow rate of 60.0 to 300.0 m³ /hr, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  7. In paragraph 1, The above heating step is performed for 1 to 4 hours in an oxygen ( O2 ) atmosphere, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  8. In paragraph 1, In the above cooling stage, bottom supply is performed at an average flow rate of 15.0 to 500.0 m³ /hr, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  9. In paragraph 1, The above cooling step involves cooling the calcined anode active material to a temperature of 10 to 100°C for 2 to 5.5 hours in a CO2 - free air (CFA) atmosphere. Method for manufacturing a positive electrode active material for a lithium secondary battery.
  10. In paragraph 1, In the above firing step, exhaust is performed to discharge gas from the internal space of the kiln to the outside of the kiln. Method for manufacturing a positive electrode active material for a lithium secondary battery.
  11. In paragraph 1, The above positive active material comprises a lithium metal oxide in the form of a single particle, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  12. In paragraph 1, The above lithium raw material is lithium carbonate, Method for manufacturing a positive electrode active material for a lithium secondary battery.
  13. In paragraph 1, The above positive active material is represented by the following chemical formula 1, Method for manufacturing a positive electrode active material for a lithium secondary battery: [Chemical Formula 1] Li a Ni x Co y Mn z M1 k O 2 In the above chemical formula 1, 0.9 ≤ a ≤ 1.1, 0.3 ≤ x ≤ 0.73, 0.01 ≤ y ≤ 0.3, 0.01 ≤ z ≤ 0.4, 0 ≤ k ≤ 0.2, x + y + z + k = 1, M1 is one or more elements selected from the group consisting of Al, Mg, Zr, Sn, Ca, Ge, Ti, Cr, Fe, Zn, Y, Ba, La, Ce, Sm, Gd, Yb, Sr, Cu, and Ga.
  14. Anode comprising a positive active material manufactured according to claim 1; cathode; and A lithium secondary battery containing a non-aqueous electrolyte.

Description

Method for preparing a positive electric active material for a lithium secondary battery and a lithium secondary battery comprising the positive electric active material prepared using the same The present embodiments relate to a method for manufacturing a positive electrode active material for a lithium secondary battery and a lithium secondary battery comprising a positive electrode active material manufactured using the same. Driven by the recent explosive demand for electric vehicles and the need for increased driving range, the development of high-capacity, high-energy-density secondary batteries to meet these demands is actively underway worldwide. In particular, to satisfy these requirements, manufacturing methods for cathode active materials are being developed that enable uniform particle growth and the stable formation of the structure. However, if the actual temperature inside the kiln is higher than the set temperature, it may be difficult to grow the positive electrode active material uniformly or form a stable structure. In addition, temperature sensor malfunction may occur, and under-calcination may occur due to the increase in calcination temperature above the set value. Lithium secondary batteries containing under-calcined positive electrode active material may experience degradation in electrochemical properties, such as reduced charge/discharge capacity. Therefore, there is a need to develop a manufacturing method that enables the calcination of cathode active materials in a state where the calcination temperature set in the calcination furnace matches the actual calcination temperature or differs only slightly. FIG. 1 is a schematic diagram of a calcination apparatus used in a method for manufacturing a positive electrode active material according to one embodiment of the present invention, viewed from the side. Figure 2 is a schematic diagram of one cell of the firing apparatus of Figure 1 viewed from the front. Figure 3 is an SEM image of the cathode active material prepared in Comparative Example 4, magnified 10,000 times. Figure 4 is an SEM image of the cathode active material prepared in Example 4, magnified 10,000 times. Terms such as first, second, and third are used to describe various parts, components, regions, layers, and/or sections, but are not limited thereto. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, the first part, component, region, layer, or section described below may be referred to as the second part, component, region, layer, or section without departing from the scope of the present invention. The technical terms used herein are for the reference of specific embodiments only and are not intended to limit the invention. The singular forms used herein include plural forms unless phrases clearly indicate otherwise. As used in the specification, the meaning of "comprising" specifies certain characteristics, areas, integers, steps, actions, elements, and/or components, and does not exclude the presence or addition of other characteristics, areas, integers, steps, actions, elements, and/or components. When it is stated that one part is "above" or "on" another part, it may be directly above or on the other part, or other parts may be involved in between. In contrast, when it is stated that one part is "directly above" another part, no other parts are interposed in between. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined. Also, unless otherwise specified, % means weight %, and 1 ppm is 0.0001 weight %. In this specification, the term “combination(s) of these” described in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including any one or more selected from the group consisting of said components. Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Method for manufacturing a positive electrode active material for a lithium secondary battery A method for manufacturing a positive electrode active material for a lithium secondary battery according to one embodiment comprises: a mixing step of mixing a transition metal precursor and a lithium raw material to prepare a mixture; a heating step of heating the mixture to a calcination t