KR-20260063500-A - Positive electrode active material for secondary battery

KR20260063500AKR 20260063500 AKR20260063500 AKR 20260063500AKR-20260063500-A

Abstract

A positive electrode active material particle according to one embodiment of the present invention comprises a bulk material and a first coating material, wherein the first coating material comprises zirconium (Zr), and in a scanning electron microscope (SEM) image of one surface of the positive electrode active material particle, the first coating material may have a dot shape.

Inventors

이동근
이슬기
오성호
신세희
권오현

Assignees

주식회사 에코프로비엠

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (11)

Comprising a bulk material; and a first coating material; and The first coating material above comprises zirconium (Zr), and In a scanning electron microscope (SEM) image of one surface of a positive electrode active material particle, the first coating material is in the shape of a dot, Cathode active material particles.
In Article 1, The first coating material comprises one or more selected from ZrO2 and lithium zirconium oxide, Cathode active material particles.
In Article 1, The molar percentage of zirconium (Zr) contained in the cathode active material particles relative to the cathode active material particles is 0.01 mol% to 1.0 mol%, Cathode active material particles.
In Article 1, The above positive active material particles comprise 2 to 20 of the above first coating materials, Cathode active material particles.
In Article 1, The average particle size (D50) of the first coating material included in the above positive electrode active material particles is 50 nm to 150 nm, Cathode active material particles.
In Article 1, The above-mentioned positive electrode active material particles further comprise a second coating material, and The second coating material above comprises cobalt (Co), Cathode active material particles.
In Article 6, The second coating material above coats a portion of the surface of the bulk material, Cathode active material particles.
In Article 6, In a scanning electron microscope (SEM) image of one surface of the above-mentioned positive electrode active material particle, the ratio of the coating area of the second coating material to the total area of the one surface is 30% to 98%, Cathode active material particles.
In Article 1, The average particle size (D50) of the above positive active material particles is 1.0 μm to 6.0 μm, Cathode active material particles.
In Article 1, The above bulk material consists of a single particle, or 2 to 8 single particles contained in contact, Cathode active material particles.
Comprising positive electrode active material particles according to claim 1, Cathode active material.

Description

Positive electrode active material for secondary battery The present invention relates to positive electrode active material particles and a positive electrode active material for a secondary battery containing the same, and more specifically, to a positive electrode active material that significantly improves the stability, charge/discharge capacity, and efficiency characteristics of a secondary battery when applied by controlling the composition, coating method, and coating form of a coating material containing zirconium (Zr) in a lithium composite oxide. With the advancement of portable mobile electronic devices such as smartphones, MP3 players, and tablet PCs, the demand for rechargeable batteries capable of storing electrical energy is increasing explosively. In particular, the demand for lithium-ion batteries is rising due to the emergence of electric vehicles, medium-to-large energy storage systems, and portable devices requiring high energy density. As a lithium composite oxide included in the cathode active material, the material that has recently been receiving the most attention is lithium nickel (manganese/aluminum) cobalt oxide Li(Ni x Co y( Mn/Al) z )O 2 (where x, y, and z are the atomic fractions of independent oxide composition elements, 0<x≤1, 0<y≤1, 0<z≤1, and 0<x+y+z≤1). This cathode active material has the advantage of producing a high capacity because it is used at high voltage compared to LiCoO 2 , which has been actively researched and used as a cathode active material, and has the advantage of a low cost because the Co content is relatively low. However, these lithium composite oxides undergo volume changes due to the intercalation and deintercalation of lithium ions during charging and discharging. There are problems such as the primary particles of the lithium composite oxide rapidly changing in volume during charging and discharging, cracks occurring in the secondary particles due to repeated charging and discharging, or the collapse of the crystal structure or phase transition of the crystal structure. To compensate for these drawbacks, the demand for high-nickel cathode active materials for secondary batteries, which have a high nickel (Ni) content relative to the total metal content excluding lithium (Li), has begun to increase. However, high-nickel cathode active materials have the disadvantage of reduced lifespan due to poor stability caused by the high Ni content. In addition, due to the high Li/M ratio during manufacturing, the residual lithium content after calcination is high, making cell manufacturing difficult due to gelation during the preparation of the electrode slurry. Accordingly, a washing process is introduced to remove residual lithium, but there is a problem in that the cathode surface is damaged during the washing process, resulting in reduced battery performance. In addition, due to the high Ni content, the structure becomes unstable, and increased reactions with the electrolyte at the particle surface and interface lead to the release of large amounts of gas during repeated charge-discharge processes, resulting in a problem of reduced lifespan characteristics. Figure 1 is an SEM image of the surface of a positive electrode active material particle according to one embodiment of the present invention. Figure 2 is an SEM image of the surface of a positive electrode active material particle according to one embodiment of the present invention. Figure 3 is an SEM image of the surface of a positive electrode active material particle according to one embodiment of the present invention. Expressions such as "comprising" as used in this specification should be understood as open-ended terms implying the possibility of including other configurations. As used herein, "preferably" and "preferably" refer to embodiments of the invention that can provide certain advantages under certain conditions. However, it is not intended to exclude other embodiments from the scope of the invention. Furthermore, the singular form used in the specification and appended claims may be intended to include the plural form unless specifically indicated otherwise in the context. That is, a technical feature of a single particle may mean a technical feature of multiple particles, or may be intended to mean an average technical feature of multiple particles. The numerical ranges used in this specification include lower and upper limits and all values within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of numerical ranges limited in different forms. Unless otherwise specifically defined in this specification, values outside the numerical range that may occur due to experimental error or rounding are also included in the defined numerical range. The meanings of '≤', 'greater than or equal to', or 'less than or equal to' as described in this specification may be replac