KR-20260064113-A - CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, MANUFACTURING METHOD OF THE SAME AND LITHIUM SECONDARY BATTERY COMPRISING THE SAME

KR20260064113AKR 20260064113 AKR20260064113 AKR 20260064113AKR-20260064113-A

Abstract

The present invention relates to a method for manufacturing a positive electrode active material for a lithium secondary battery, comprising the steps of: preparing a single-particle nickel (Ni)-containing layered lithium metal oxide; and mixing the lithium metal oxide and a tungsten (W) raw material, followed by a coating heat treatment to produce a positive electrode active material having a coating layer formed thereon, wherein the tungsten raw material has a BET specific surface area of 13 m² /g or more.

Inventors

서성화
김성인
박혜정
이수진
박정현
신동기

Assignees

(주)포스코퓨처엠

Dates

Publication Date: 20260507
Application Date: 20241031

Claims (12)

A step of preparing a nickel (Ni)-containing layered lithium metal oxide in a single-particle form; and The method includes the step of manufacturing an anode active material having a coating layer formed by mixing the lithium metal oxide and tungsten (W) raw materials and then performing a coating heat treatment. The above tungsten raw material is a method for manufacturing a positive electrode active material for a lithium secondary battery having a BET specific surface area of 13 m² /g or more.
In paragraph 1, The above tungsten raw material is a method for manufacturing a positive electrode active material for a lithium secondary battery having a BET specific surface area of 13 to 20 m² /g.
In paragraph 1, The above tungsten raw material is a method for manufacturing a positive electrode active material for a lithium secondary battery having a maximum particle size (Dmax) of 0.6 to 1.3 μm.
In paragraph 1, The above tungsten raw material is a method for manufacturing a positive electrode active material for a lithium secondary battery having an average particle size (D50) of 0.2 μm or less.
In paragraph 1, A method for manufacturing a positive electrode active material for a lithium secondary battery, wherein the cation mixing ratio of the manufactured positive electrode active material is controlled by controlling the BET specific surface area of the above-mentioned tungsten raw material.
In paragraph 1, A method for manufacturing a positive electrode active material for a lithium secondary battery in which the c-axis lattice constant of the manufactured positive electrode active material is controlled by controlling the BET specific surface area of the above-mentioned tungsten raw material.
In paragraph 1, A method for manufacturing a positive electrode active material for a lithium secondary battery in which the average crystallite size of the manufactured positive electrode active material is controlled by controlling the BET specific surface area of the above-mentioned tungsten raw material.
In paragraph 1, The above-described cathode active material is a method for manufacturing a cathode active material for a lithium secondary battery having an average crystallite size of 274.5 nm or more.
In paragraph 1, The prepared lithium metal oxide above is a method for manufacturing a positive electrode active material for a lithium secondary battery having an average particle size (D50) of 2 to 6 μm.
A single-particle nickel (Ni)-containing layered lithium metal oxide; and a coating layer containing tungsten (W) located on the surface of the lithium metal oxide, comprising Active material for lithium secondary batteries having an average crystallite size of 274.5 nm or more.
A positive electrode for a lithium secondary battery comprising the positive electrode active material of claim 10.
A lithium secondary battery comprising a positive electrode for a lithium secondary battery according to claim 11.

Description

Cathode active material for lithium secondary battery, manufacturing method of the same, and lithium secondary battery comprising the same The present invention relates to a positive electrode active material for a lithium secondary battery, a method for manufacturing the same, and a lithium secondary battery including the same. In a lithium secondary battery, electrical energy is produced by oxidation and reduction reactions when lithium ions are inserted/extracted from the positive and negative electrodes while an organic or polymer electrolyte is charged between the positive and negative electrodes, which are composed of active materials capable of lithium ion intercalation and deintercalation. Lithium cobalt oxide ( LiCoO2 ), lithium nickel oxide ( LiNiO2 ), lithium manganese oxide ( LiMnO2 or LiMn2O4 , etc. ), and lithium iron phosphate compounds ( LiFePO4 ) have been used as cathode active materials for lithium secondary batteries. Among these, lithium cobalt oxide ( LiCoO2 ) is widely used and applied as a cathode active material for high voltage applications due to its advantages of high operating voltage and excellent capacity characteristics. However, due to the rising price and supply instability of cobalt (Co), there are limitations to its mass use as a power source in fields such as electric vehicles, leading to the need for the development of cathode active materials that can replace it. Accordingly, a nickel-cobalt-manganese-based lithium composite transition metal oxide (hereinafter simply referred to as 'NCM-based lithium composite transition metal oxide') was developed in which a portion of the cobalt (Co) was substituted with nickel (Ni) and manganese (Mn). Meanwhile, while the development of so-called high-nickel (High-Ni) cathode active materials containing a high nickel content was pursued to achieve high capacity, high-nickel cathode active materials have serious safety issues, leading to a resurgence of interest in cathode active materials with a so-called mid-nickel (Mid-Ni) composition that have reduced nickel content. However, cathode active materials with a mid-nickel composition had a problem where capacity characteristics were excessively degraded due to the low nickel content, and to compensate for this, they are generally being developed in the form of single particles capable of realizing high energy density. These single-particle cathode active materials have a small specific surface area and high particle strength, which results in low gas generation during cell operation and offers the advantages of improved lifespan and safety. However, since single-particle cathode active materials are manufactured at relatively higher calcination temperatures compared to secondary-particle cathode active materials, a rock salt phase is formed on the particle surface, resulting in high surface resistance. This causes an imbalance in lithium mobility, leading to deformation of the crystal structure of the active material and consequently a problem of some degradation in lifespan characteristics. Furthermore, this degradation in lifespan characteristics is exacerbated during high-temperature operation. Figure 1 is an SEM image of the positive electrode active material prepared according to Example 1. 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 un