KR-20260063870-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

KR20260063870AKR 20260063870 AKR20260063870 AKR 20260063870AKR-20260063870-A

Abstract

A method for manufacturing a positive electrode active material for a lithium secondary battery according to the present invention comprises: a step of preparing a transition metal precursor including nickel, cobalt, and manganese; a mixing step of mixing the transition metal precursor and a lithium raw material to prepare a mixture; and a calcination step of calcining the mixture to obtain a positive electrode active material, wherein the calcination step comprises a heating step of heating the mixture to a calcination temperature; and a holding step of calcining the mixture by maintaining the calcination temperature, wherein side air supply may be performed at an average flow rate of 30 to 330 m³ /hr during the heating step to the holding step.

Inventors

이의태
최창민
김정민
이학봉

Assignees

(주)포스코퓨처엠

Dates

Publication Date: 20260507
Application Date: 20241031

Claims (14)

A step of preparing a transition metal precursor containing nickel, cobalt, and manganese; A mixing step of preparing a mixture by mixing the above-mentioned transition metal precursor and lithium raw material; and A calcination step for obtaining an anode active material by calcining the above mixture; comprising The above calcination step includes a heating step for heating the mixture to the calcination temperature; and A holding step of maintaining the above-mentioned calcination temperature to calcine the mixture; is included, In the above heating step to maintenance step, lateral air supply is performed at an average flow rate of 30 to 330 m³ /hr, Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, Exhaust is performed to discharge gas from the internal space of the kiln to the outside of the kiln during a stage that is 0 to 50% of the total time of the heating step, the holding step, or a combination thereof. Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above calcination step is performed in a carbon dioxide-free atmosphere ( CO2 free air, CFA). Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above heating step is performed for 1 to 4 hours, Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above maintenance step is performed at a temperature of 800 to 1000℃ for 5 to 10 hours, Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above firing step is performed at a temperature where the upper temperature is 10 to 40°C higher than the lower temperature, Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, After the above maintenance step The method further includes a cooling step of cooling the above-mentioned calcined positive active material to a temperature of 10 to 100°C, and The above cooling step is performed for 2 to 5.5 hours, Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above mixture is filled into a refractory box at a loading weight in the range of 500.0 to 750.0 kg/m³ per internal volume of the refractory box, and a heating step is performed. Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above lithium raw material is lithium carbonate, Method for manufacturing a positive electrode active material for a lithium secondary battery.
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.
In paragraph 1, The residual lithium content of the above-mentioned positive electrode active material is 0.25 wt% or less, Method for manufacturing a positive electrode active material for a lithium secondary battery.
In paragraph 1, The above positive active material has an average grain size of 225 to 400 nm, Method for manufacturing a positive electrode active material for a lithium secondary battery.
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.
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, high-nickel NCM cathode materials with high nickel content are being used to satisfy these requirements. However, while capacity characteristics improve as nickel content increases, microcracks may occur during charging and discharging due to reduced particle strength. Consequently, the specific surface area of the cathode material increases, leading to increased reaction with the electrolyte and potentially increased gas generation. Additionally, due to structural instability, the phenomenon of cation mixing—where unstable Ni³⁺ is reduced to stable Ni²⁺ and converted into stable NiO—increases, which may degrade the battery's lifespan characteristics. To solve the above problem, a method is proposed to increase the calcination temperature and perform calcination for a long time during the manufacture of lithium nickel metal oxide to form single particles or similar single particles with the size of the primary particles maximized. However, this method requires firing at a relatively high temperature for a long time compared to conventional processes, which can lead to oxygen vacancy. As a result, crystal defects in the layered structure of the final cathode active material may occur, which can degrade electrochemical properties such as capacity and output. Therefore, there is a need to develop a manufacturing method capable of calcining the cathode active material within a short period of time. 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. 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 lith