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KR-20260063796-A - ANODE ACTIVE MATERIL FOR LITHIUM SECONDARY BATTERY, MANUFACTURING METHOD OF THE SAME AND LITHIUM SECONDARY BATTERY COMPRISING THE SAME

KR20260063796AKR 20260063796 AKR20260063796 AKR 20260063796AKR-20260063796-A

Abstract

The present embodiments relate to a negative electrode active material for a lithium secondary battery, a method for manufacturing the same, and a lithium secondary battery including the same. A negative electrode active material for a lithium secondary battery according to one embodiment comprises: a first negative electrode active material having a tap density of 0.80 g/cc or less; and a second negative electrode active material having a tap density of 0.81 g/cc or more; wherein the first negative electrode active material may have an orientation peak intensity ratio (I110/I004) of 75 or more when analyzing an XRD pattern.

Inventors

  • 권해준
  • 이경묵

Assignees

  • (주)포스코퓨처엠

Dates

Publication Date
20260507
Application Date
20241031

Claims (20)

  1. A first negative active material having a tap density of 0.80 g/cc or less; and A second negative active material having a tap density of 0.81 g/cc or higher; Includes, The first negative electrode active material is a negative electrode active material for a lithium secondary battery having an orientation peak intensity ratio (I110/I004) of 75 or higher when analyzing an XRD pattern.
  2. In paragraph 1, The above-mentioned first negative electrode active material is, Natural graphite particles in the form of secondary particles including primary particles having an average particle size (D50) of 3 to 5 μm, and a first coating layer located on the surface of said natural graphite particles, A negative electrode active material for a lithium secondary battery, wherein the interior of the natural graphite particles in the form of secondary particles and the first coating layer comprise first amorphous carbon.
  3. In paragraph 2, A negative electrode active material for a lithium secondary battery, wherein the content of the first amorphous carbon is in the range of 1% to 30% by weight based on the total weight of the first negative electrode active material.
  4. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the BET (Brunauer-Emmett-Teller) specific surface area of the first negative electrode active material is 3 m² /g or more.
  5. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the tap density of the first negative electrode active material is 1.0 g/cc or less.
  6. In paragraph 1, The above-mentioned first negative electrode active material is a negative electrode active material for a lithium secondary battery that satisfies the following formula 1. [Equation 1] 2.5 ≤ [D90]/[D10] ≤ 6.5 (In Equation 1 above, [D10] and [D90] represent particle sizes corresponding to 10% and 90% of the cumulative volume of the first cathode active material measured using the Laser Diffraction Method.)
  7. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the average particle size (D50) of the first negative electrode active material is 10 to 13 μm.
  8. In paragraph 1, The second cathode active material comprises natural graphite and a second coating layer located on the surface of the natural graphite, and The above second coating layer comprises a second amorphous carbon, a negative electrode active material for a lithium secondary battery.
  9. In paragraph 8, A negative electrode active material for a lithium secondary battery, wherein the content of the second amorphous carbon is in the range of 1 to 20 weight percent based on the total weight of the second negative electrode active material.
  10. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the BET (Brunauer-Emmett-Teller) specific surface area of the second negative electrode active material is 3 m² /g or less.
  11. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the tap density of the second negative electrode active material is 1.0 g/cc or higher.
  12. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the weight ratio of the first negative electrode active material and the second negative electrode active material is in the range of 1:9 to 5:5.
  13. In paragraph 1, A negative electrode active material for a lithium secondary battery, wherein the BET (Brunauer-Emmett-Teller) specific surface area of the above negative electrode active material is in the range of 3.5 to 4.5 m² /g.
  14. In paragraph 1, The above negative electrode active material is a negative electrode active material for a lithium secondary battery having an orientation peak intensity ratio (I110/I004) in the range of 70 to 85 when analyzed by XRD pattern.
  15. A negative electrode active material is prepared by mixing a first negative electrode active material and a second negative electrode active material, wherein The above-mentioned first negative electrode active material is, A step of preparing primary particles having an average particle size (D50) of 3 to 5 μm; A step of preparing a mixture by mixing the above primary particles and the first amorphous carbon; A step of manufacturing a molded body by pressurizing the above mixture at a temperature of 50°C or higher; A step of crushing the above-mentioned molded body; and It is manufactured by a method including the step of heat-treating the above-mentioned crushed molded body, and The above second negative active material is, A step of sphericalizing natural graphite powder to a high density; and A method manufactured by including the step of coating the above-mentioned high-density spherical natural graphite powder with a second amorphous carbon. Method for manufacturing a negative electrode active material for a lithium secondary battery.
  16. In paragraph 15, A method for manufacturing a negative electrode active material for a lithium secondary battery, wherein the mixing weight ratio of the first negative electrode active material and the second negative electrode active material is in the range of 1:9 to 5:5.
  17. In paragraph 15, A method for manufacturing a negative electrode active material for a lithium secondary battery, wherein the BET (Brunauer-Emmett-Teller) specific surface area of the primary particles is 15 m² /g or more.
  18. In paragraph 15, A method for manufacturing a negative electrode active material for a lithium secondary battery, wherein the tap density of the primary particles is in the range of 0.05 to 0.5 g/cc.
  19. In paragraph 15, A method for manufacturing a negative electrode active material for a lithium secondary battery, wherein the above primary particles satisfy the following formula 2. [Equation 2] 2.5 ≤ [D90]/[D10] ≤ 6.5 (In Equation 2 above, [D10] and [D90] represent the particle diameters corresponding to 10% and 90% of the cumulative volume of primary particles measured using the Laser Diffraction Method.)
  20. In paragraph 15, A method for manufacturing a negative electrode active material for a lithium secondary battery, wherein the above-mentioned pressurization is performed in a temperature range of 200℃ to 700℃.

Description

Anode active material for lithium secondary battery, manufacturing method of the same, and lithium secondary battery comprising the same The present embodiments relate to a negative electrode active material for a lithium secondary battery, a method for manufacturing the same, and a lithium secondary battery including the same. Due to technological development and increasing demand for mobile devices, as well as the rapid rise of electric vehicles (EVs), the demand for lithium-ion batteries as an energy source for these devices is increasing rapidly. As the negative electrode active material for such lithium-ion secondary batteries, graphite-based materials such as synthetic graphite and natural graphite are generally used. These materials reversibly accept or supply lithium ions while maintaining structural and electrical properties, and possess chemical potential characteristics nearly similar to metallic lithium during lithium ion insertion and extraction. Artificial graphite has a higher charge-to-discharge efficiency than natural graphite and exhibits excellent lifespan characteristics due to less swelling during charging and discharging. However, it has a lower reversible capacity compared to natural graphite, and its hard grains make rolling difficult during electrode manufacturing. Additionally, it has the problem of poor orientation due to minimal shape change. In particular, it has the disadvantage of high manufacturing costs as it requires graphitization heat treatment at around 3,000°C. In contrast, natural graphite is widely used as a negative electrode active material because it is cheaper than synthetic graphite, has a high reversible capacity, and exhibits similar electrochemical properties. However, since natural graphite generally has a plate-like shape, it has a large surface area and exposed edges. Consequently, the penetration or decomposition of electrolytes causes the edges to peel off or break, leading to significant irreversible reactions and an increased expansion rate, which degrades long-term lifespan characteristics. To address this, a method using spherical natural graphite has been proposed; however, in this case, the increase in internal pores leads to longer lithium diffusion distances and larger particle sizes, resulting in a problem of reduced output characteristics when applied to batteries. Therefore, there is an urgent need to develop technology capable of realizing lithium secondary batteries with excellent long-term lifespan and output characteristics while using natural graphite. 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. Negati