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KR-20260062977-A - SECONDARY BATTERY AND FABRICATION METHOD THEREFOR, AND APPARATUS CONTAINING SECONDARY BATTERY

KR20260062977AKR 20260062977 AKR20260062977 AKR 20260062977AKR-20260062977-A

Abstract

The present invention discloses a secondary battery, a method for manufacturing the same, and an apparatus including the secondary battery, wherein the secondary battery comprises a negative electrode sheet, the negative electrode sheet comprises a negative electrode current collector and a negative electrode film; the negative electrode film comprises a first negative electrode film layer and a second negative electrode film layer; the first negative electrode film layer is disposed on at least one surface of the negative electrode current collector and comprises a first negative electrode active material, wherein the first negative electrode active material comprises graphite, and furthermore, the first negative electrode active material may or may not comprise a silicon-based material; the second negative electrode film layer is disposed on the surface of the first negative electrode film layer and comprises a second negative electrode active material, wherein the second negative electrode active material comprises artificial graphite and a silicon-based material; the mass share of the silicon-based material among the first negative electrode active material is recorded as W1, the mass share of the silicon-based material among the second negative electrode active material is recorded as W2, and the negative electrode sheet satisfies W2 ≥ W1.

Inventors

  • 왕 유웬
  • 유 바오젠
  • 예 용후앙

Assignees

  • 컨템포러리 엠퍼렉스 테크놀로지 (홍콩) 리미티드

Dates

Publication Date
20260507
Application Date
20200430

Claims (13)

  1. In secondary batteries, The above secondary battery includes a negative electrode sheet, and the negative electrode sheet includes a negative electrode current collector and a negative electrode film; The above negative electrode film comprises a first negative electrode film layer and a second negative electrode film layer; The first negative electrode film layer is disposed on at least one surface of the negative electrode current collector and includes a first negative electrode active material, wherein the first negative electrode active material includes graphite, and furthermore, the first negative electrode active material may or may not include a silicon-based material; The second negative electrode film layer is disposed on the surface of the first negative electrode film layer and includes a second negative electrode active material, wherein the second negative electrode active material includes artificial graphite and silicon-based materials; The mass share of the silicon-based material among the first negative electrode active material is recorded as W1, and the mass share of the silicon-based material among the second negative electrode active material is recorded as W2, and the negative electrode sheet satisfies W2≥W1, 0%≤W1≤5.0%, 0.5%≤W2≤6.0%, and 0.5%≤W1+W2≤10.0%; A secondary battery characterized in that the volume average particle size D v 50 of the first negative electrode active material is larger than the volume average particle size D v 50 of the second negative electrode active material.
  2. In paragraph 1, A secondary battery characterized by 0.5% ≤ W1 + W2 ≤ 6%.
  3. In paragraph 1, A secondary battery characterized in that the silicon-based material comprises a first silicon-based material and a second silicon-based material, and the particle size of the first silicon-based material is smaller than the particle size of the second silicon-based material.
  4. In paragraph 3, The above secondary battery is, (1) The particle size of the first silicon-based material is 0.05㎛ to 7㎛; (2) The particle size of the second silicon-based material is 7㎛ to 15㎛. A secondary battery characterized by satisfying at least one of the following.
  5. In paragraph 1, A secondary battery characterized in that the first negative electrode active material comprises one or more types of artificial graphite and natural graphite.
  6. In paragraph 5, A secondary battery characterized by having a mass share of the artificial graphite in the first negative electrode active material of ≥50%.
  7. In paragraph 1, The above secondary battery is, (1) The first negative electrode active material comprises primary particles, and the quantity share of the primary particles in the first negative electrode active material is ≥60%; (2) The second negative electrode active material comprises secondary particles, wherein the quantity share of the secondary particles in the second negative electrode active material is ≥50%. A secondary battery characterized by satisfying at least one of the following.
  8. In paragraph 1, The above secondary battery is, (1) The volume average particle size D v 50 of the first negative electrode active material is 12㎛ to 18㎛; (2) The volume average particle size D v 50 of the second negative electrode active material is 9㎛ to 15㎛. A secondary battery characterized by satisfying at least one of the following.
  9. In paragraph 1, A secondary battery characterized by the above silicon-based material comprising one or more types of silicon element, silicon-oxygen compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy.
  10. In paragraph 1, The above negative electrode film is, (1) The area density of the above negative electrode film is 8 mg/ cm² to 13 mg/ cm² ; (2) The degree of consolidation of the above negative electrode film is 1.4 mg/ cm³ to 1.7 mg/ cm³ ; (3) The porosity of the second negative electrode film layer is greater than the porosity of the first negative electrode film layer; (4) The ratio of the surface density of the first negative electrode film layer and the second negative electrode film layer is 2:3 to 3:2; (5) The thickness ratio of the first negative electrode film layer and the second negative electrode film layer is 4:6 to 7:3. A secondary battery characterized by satisfying one or more of the following.
  11. In paragraph 1, The secondary battery comprises a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector and a positive electrode film disposed on at least one surface of the positive electrode current collector and comprising a positive electrode active material, wherein the positive electrode active material comprises one or more types of lithium transition metal oxides, lithium-containing phosphates having an olivine structure, and modified compounds thereof; The above positive electrode active material comprises one or more types of lithium transition metal oxides represented by Formula 1 and modified compounds thereof, and Li a Ni b Co c M d O e A f Equation 1, A secondary battery characterized in that, in the above Equation 1, 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M is one or more types selected from Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, and B, and A is one or more types selected from N, F, S, and Cl.
  12. In a method for manufacturing a secondary battery, The negative electrode sheet of a secondary battery is manufactured through the following steps, and A step of forming a first negative electrode film layer comprising a first negative electrode active material on at least one surface of a negative electrode current collector—the first negative electrode active material comprises graphite, and the first negative electrode active material may or may not comprise a silicon-based material—; A step of forming a second negative electrode film layer comprising a second negative electrode active material on the surface of the first negative electrode film layer—the second negative electrode active material comprises artificial graphite and silicon-based materials—; Here, the mass share of the silicon-based material among the first negative electrode active material is recorded as W1, and the mass share of the silicon-based material among the second negative electrode active material is recorded as W2, and the negative electrode sheet satisfies W2≥W1, 0%≤W1≤5.0%, 0.5%≤W2≤6.0%, and 0.5%≤W1+W2≤10.0%; A method for manufacturing a secondary battery characterized in that the volume average particle size D v 50 of the first negative electrode active material is larger than the volume average particle size D v 50 of the second negative electrode active material.
  13. In the device, An apparatus characterized by including a secondary battery according to claim 1 or a secondary battery manufactured by the method for manufacturing a secondary battery according to claim 12.

Description

Secondary battery, method of manufacturing therefrom, and apparatus containing secondary battery The present invention belongs to the technical field of secondary batteries, and specifically relates to a secondary battery, a method for manufacturing the same, and an apparatus including a secondary battery. Rechargeable batteries, including lithium-ion batteries, are widely utilized in the new energy industry due to their advantages such as high specific energy, long lifespan, and low cost. For example, as environmental and energy issues become increasingly serious, there is an urgent demand for the development of new energy electric vehicles; this not only provides opportunities for the rechargeable battery industry but also sets higher standards for these batteries. Ensuring that secondary batteries possess excellent electrochemical and safety performance while maintaining high energy density is becoming a key challenge in the field of secondary batteries. In order to more clearly explain the technical solution of the embodiments of the present invention, the attached drawings necessary for the embodiments of the present invention are briefly introduced below. The attached drawings described below are merely some embodiments of the present invention, and it is obvious to those skilled in the art that other drawings can be obtained based on these drawings without any creative effort. FIG. 1 is a schematic diagram of one embodiment of a secondary battery of the present invention. FIG. 2 is a schematic diagram of one embodiment of a negative electrode sheet among the secondary batteries of the present invention. FIG. 3 is a schematic diagram of another embodiment of a negative electrode sheet among the secondary batteries of the present invention. FIG. 4 is an exploded schematic diagram of one embodiment of the secondary battery of the present invention. FIG. 5 is a schematic diagram of one embodiment of the battery module of the present invention. FIG. 6 is a schematic diagram of one embodiment of the battery pack of the present invention. Figure 7 is an exploded view of Figure 6. FIG. 8 is a schematic diagram of one embodiment of a device in which a secondary battery of the present invention is used as a power source. To clarify the inventive purpose, technical solution, and beneficial technical effects of the present invention, the present invention is described in more detail below in combination with examples. It should be understood that the examples described herein are merely for interpreting the present invention and are not intended to limit the present invention. For the sake of brevity, this specification explicitly discloses only some numerical ranges. However, any lower limit may be combined with any upper limit to form a range not explicitly described, any lower limit may be combined with another lower limit to form a range not explicitly described, and likewise any upper limit may be combined with another upper limit to form a range not explicitly described. Furthermore, although not explicitly described, every point or single number between the endpoints of a range is included within that range. Thus, each point or single number, as its own lower or upper limit, may be combined with any other point or single number, or combined with other lower or upper limits, to form a range not explicitly described. In the description of this specification, unless otherwise noted, “more than” and “less than” include the subject number, and the meaning of “more than” in “one type or more types” means two types or more than two types. The above description of the invention is not intended to explain each disclosed embodiment or various implementation method within this application. The following description illustrates exemplary embodiments in more detail. Throughout this application, guidance is provided through a series of embodiments, which may be used in various combinations. In each example, the enumeration is merely a representative group and should not be interpreted as all enumerations. secondary battery A first embodiment of the present invention provides a secondary battery. The secondary battery comprises a positive electrode sheet, a negative electrode sheet, and an electrolyte. During the charging and discharging process of the battery, active ions are inserted and removed in a reciprocal manner between the positive electrode sheet and the negative electrode sheet. The electrolyte serves to conduct ions between the positive electrode sheet and the negative electrode sheet. [Polar Sheet] A negative electrode sheet comprises a negative electrode current collector and a negative electrode film, wherein the negative electrode film comprises a first negative electrode film layer and a second negative electrode film layer, wherein the first negative electrode film layer is disposed on at least one surface of the negative electrode current collector and comprises a first negative electrode active mater