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KR-102964290-B1 - Electrodes, lithium batteries, and motor vehicles

KR102964290B1KR 102964290 B1KR102964290 B1KR 102964290B1KR-102964290-B1

Abstract

An electrode, a lithium battery, and a motor vehicle are provided. The electrode comprises a current collector and an electrode active material layer disposed on at least one side of the current collector. The electrode active material layer comprises at least two electrode active material sublayers. The electrode active material sublayers satisfy n × δ i ≤ 10000, n ≥ 2, and δ i ≤ 5000, and satisfy H i⁻¹ < H i . The first electrode active material sublayer is in contact with the current collector.

Inventors

  • 게, 리핑
  • 하오, 롱
  • 좡, 밍하오
  • 티안, 예청
  • 수, 비즈허

Assignees

  • 비와이디 컴퍼니 리미티드

Dates

Publication Date
20260513
Application Date
20230324
Priority Date
20220324

Claims (20)

  1. As an electrode (100), it comprises a current collector (11) and an electrode active material layer (10) disposed on at least one side surface of the current collector (11), wherein the electrode active material layer (10) comprises at least two electrode active material sublayers, and the electrode active material sublayers are formed by the following relationship n×δ i ≤10000, n≥2 and δ i ≤5000; and H i-1 <H i , - In the above formula, n is the total amount of the electrode active material sublayer, i is any integer value between 2 and n, H i represents the hardness of the i-th electrode active material sublayer, H 1 represents the hardness of the first electrode active material sublayer (101) in MPa units, the first electrode active material sublayer (101) is in contact with the current collector (11), and δ i represents the absolute value of the hardness difference between the i-th electrode active material sublayer and the (i-1)-th electrode active material sublayer in MPa units - satisfying, When n, δ i , and maximum compressive density α of the electrode (100) satisfy the quantitative relationship n ≥ 2 and δ i ≤ 1000, when 1.4 g/ cm³ ≤ α < 1.7 g/ cm³ , Electrode (100).
  2. As an electrode (100), it comprises a current collector (11) and an electrode active material layer (10) disposed on at least one side surface of the current collector (11), wherein the electrode active material layer (10) comprises at least two electrode active material sublayers, and the electrode active material sublayers are formed by the following relationship n×δ i ≤10000, n≥2 and δ i ≤5000; and H i-1 <H i , - In the above formula, n is the total amount of the electrode active material sublayer, i is any integer value between 2 and n, H i represents the hardness of the i-th electrode active material sublayer, H 1 represents the hardness of the first electrode active material sublayer (101) in MPa units, the first electrode active material sublayer (101) is in contact with the current collector (11), and δ i represents the absolute value of the hardness difference between the i-th electrode active material sublayer and the (i-1)-th electrode active material sublayer in MPa units - satisfying, When n, δ i , and maximum compressive density α of the electrode (100) satisfy the quantitative relationship n ≥ 2 and δ i ≤ 700, when 2.5 g/ cm³ ≤ α < 2.75 g/ cm³ , Electrode (100)
  3. As an electrode (100), it comprises a current collector (11) and an electrode active material layer (10) disposed on at least one side surface of the current collector (11), wherein the electrode active material layer (10) comprises at least two electrode active material sublayers, and the electrode active material sublayers are formed by the following relationship n×δ i ≤10000, n≥2 and δ i ≤5000; and H i-1 <H i , - In the above formula, n is the total amount of the electrode active material sublayer, i is any integer value between 2 and n, H i represents the hardness of the i-th electrode active material sublayer, H 1 represents the hardness of the first electrode active material sublayer (101) in MPa units, the first electrode active material sublayer (101) is in contact with the current collector (11), and δ i represents the absolute value of the hardness difference between the i-th electrode active material sublayer and the (i-1)-th electrode active material sublayer in MPa units - satisfying, When n, δ i , and maximum compressive density α of the electrode (100) satisfy the quantitative relationship n ≥ 2 and δ i ≤ 600, when 3.3 g/ cm³ ≤ α < 3.75 g/ cm³ , Electrode (100).
  4. As an electrode (100), it comprises a current collector (11) and an electrode active material layer (10) disposed on at least one side surface of the current collector (11), wherein the electrode active material layer (10) comprises at least two electrode active material sublayers, and the electrode active material sublayers are formed by the following relationship n×δ i ≤10000, n≥2 and δ i ≤5000; and H i-1 <H i , - In the above formula, n is the total amount of the electrode active material sublayer, i is any integer value between 2 and n, H i represents the hardness of the i-th electrode active material sublayer, H 1 represents the hardness of the first electrode active material sublayer (101) in MPa units, the first electrode active material sublayer (101) is in contact with the current collector (11), and δ i represents the absolute value of the hardness difference between the i-th electrode active material sublayer and the (i-1)-th electrode active material sublayer in MPa units - satisfying, When n, δ i , and maximum compressive density α of the electrode (100) satisfy the quantitative relationship n≥10 and δ i ≤5, where 1.3 g/cm³ ≤ α<1.8 g/ cm³ , or 2.6 g/cm³ ≤ α<2.8 g/ cm³ , or 3.65 g/ cm³ ≤ α <5 g/ cm³ , Electrode (100).
  5. In any one of paragraphs 1 through 3, Electrode (100) in which δ i ≤ 100.
  6. In paragraph 5, Electrode (100) in which δ i ≤ 50.
  7. As an electrode (100), it comprises a current collector (11) and an electrode active material layer (10) disposed on at least one side surface of the current collector (11), wherein the electrode active material layer (10) comprises at least two electrode active material sublayers, and the electrode active material sublayers are formed by the following relationship n×δ i ≤10000, n≥2 and δ i ≤5000; and H i-1 <H i , - In the above formula, n is the total amount of the electrode active material sublayer, i is any integer value between 2 and n, H i represents the hardness of the i-th electrode active material sublayer, H 1 represents the hardness of the first electrode active material sublayer (101) in MPa units, the first electrode active material sublayer (101) is in contact with the current collector (11), and δ i represents the absolute value of the hardness difference between the i-th electrode active material sublayer and the (i-1)-th electrode active material sublayer in MPa units - satisfying, The value of the maximum compression density α of the electrode (100) satisfies 0 g/ cm³ < α < 10 g/ cm³ .
  8. In Paragraph 7, The value of the maximum compression density α of the electrode (100) satisfies 0 g/ cm³ < α < 5 g/ cm³ .
  9. In any one of paragraphs 1 through 4 and 7, The above electrode (100) is an electrode (100) in which the absolute value of the difference in hardness between any two adjacent electrode active material sublayers is the same.
  10. In any one of paragraphs 1 through 4 and 7, The electrode (100) is a positive electrode, and a positive electrode active material is loaded onto the positive electrode, wherein the positive electrode active material comprises at least one of lithium iron phosphate, lithium manganese phosphate, lithium iron manganese phosphate, lithium vanadium phosphate, lithium cobalt phosphate, lithium cobaltate, lithium manganate, lithium nickel manganate, lithium nickel cobalt manganese oxygen ternary material, lithium nickel cobalt aluminum oxygen ternary material, or lithium nickel manganese cobalt aluminum oxygen quaternary material.
  11. In any one of paragraphs 1 through 4 and 7, The electrode (100) is a cathode, and a cathode active material is loaded onto the cathode, and the cathode active material comprises at least one of graphite, natural graphite, mesocarbon micro beads, or silicon-carbon cathode material.
  12. In any one of paragraphs 1 through 4 and 7, The electrode (100) is a positive electrode, and a positive electrode active material is loaded onto the positive electrode, and the positive electrode active material comprises a magnesium-doped multi-element nickel-containing active material, and the multi-element nickel-containing active material comprises at least one of a lithium nickel cobalt manganese oxygen ternary material, a lithium nickel cobalt aluminum oxygen ternary material, or a lithium nickel manganese cobalt aluminum oxygen quaternary material.
  13. In Paragraph 12, The electrode (100), wherein the mass content of the magnesium element in the magnesium-doped multi-element nickel-containing active material is greater than 0 and less than 4000 ppm.
  14. In Paragraph 12, The general structural formula of the above lithium nickel cobalt manganese oxygen ternary material is Li 1+m Ni x Co y Mn 1-xy O 2 , and the electrode (100) has x≥0.33, 0≤y≤0.4, and 0≤m≤0.1.
  15. In Paragraph 12, The general structural formula of the above lithium nickel cobalt aluminum oxygen ternary material is Li 1+m Ni x Co y Al 1- x - yO 2 , and the electrode (100) has x≥0.33, 0≤y≤0.4, and 0≤m≤0.1.
  16. In Paragraph 12, The general structural formula of the above lithium nickel manganese cobalt aluminum oxygen quaternary material is Li 1+m Ni x Co y Mn z Al 1-xy- zO 2 , and the electrode (100) has x≥0.33, 0≤y≤0.4, 0≤z≤0.4, and 0≤m≤0.1.
  17. In Paragraph 14, The electrode (100) has a range of x values of 0.70 ≤ x ≤ 0.98.
  18. In paragraph 15, The electrode (100) has a range of x values of 0.70 ≤ x ≤ 0.98.
  19. In Paragraph 16, The electrode (100) has a range of x values of 0.70 ≤ x ≤ 0.98.
  20. A lithium battery (200) comprising an electrode (100) according to any one of claims 1 to 4 and 7.

Description

Electrodes, lithium batteries, and motor vehicles This application claims the priority and benefit of Chinese Patent Application No. 202210296429.4, filed on March 24, 2022, with the title of the invention "ELECTRODE, LITHIUM BATTERY, AND MOTOR VEHICLE". The entire contents of said application are incorporated by reference into this specification. The present disclosure relates to the field of lithium battery technology, and in particular to electrodes, lithium batteries, and motor vehicles. With the development of new energy industries, market demand for the energy density of lithium batteries is increasing. Increasing the compaction density of electrodes is one of the key methods to enhance the energy density of lithium batteries. However, when electrodes are rolled during manufacturing, the force exerted by the electrode active material on the current collector in the thickness direction is uneven. This tends to induce cracking of the electrode active material particles in the surface layer, thereby affecting the stability of the electrode active material. Furthermore, cracked electrode active material can consume more electrolyte, affect electrode porosity, increase the battery's internal resistance, hinder capacity utilization, and shorten battery life. FIG. 1 is a schematic diagram showing the cross-sectional structure of an electrode according to one embodiment of the present disclosure. FIG. 2 is a schematic diagram of a lithium battery according to one embodiment of the present disclosure. FIG. 3 is a schematic diagram of a motor vehicle according to one embodiment of the present disclosure. Reference numerals are described as 100-electrode; 10-electrode active material layer; 11-current collector; 101-first electrode active material sublayer; 102-second electrode active material sublayer; 10n-n-second active material sublayer; 200-lithium battery; and 300-motor vehicle. Hereinafter, the technical concept of the present disclosure will be explained in detail with reference to specific embodiments. Generally, the consolidation density achievable by each electrode active material is within a specific range. A single electrode active material cannot achieve the maximum consolidation density of the electrode while ensuring the grain integrity of the electrode active material. Manufacturing an electrode with gradient hardness can effectively solve the aforementioned problem. One embodiment of the present disclosure provides an electrode. The electrode comprises a current collector and an electrode active material layer disposed on at least one side of the current collector. The electrode active material layer comprises at least two electrode active material sublayers. The electrode active material sublayers satisfy the following relationship: n×δ i ≤10000, n≥2 and δ i ≤5000; and H i-1 < H i (Relation 1) n represents the total amount of the electrode active material sublayer, and i is any integer value between 2 and n. H i represents the hardness of the i-th electrode active material sublayer, and H 1 represents the hardness of the first electrode active material sublayer. The first electrode active material sublayer is in contact with the current collector. δ i represents the absolute value of the hardness difference between the i-th electrode active material sublayer and the i-1-th electrode active material sublayer in MPa units. The electrode comprises a plurality of electrode active material sublayers. The electrode active material sublayer in contact with the current collector is defined as the first electrode active material sublayer. In the thickness direction of the electrode, the sublayers extending from the current collector side to the surface of the electrode are each the second electrode active material sublayer, the third electrode active material sublayer, the fourth electrode active material sublayer, the fifth electrode active material sublayer, ..., the nth electrode active material sublayer. The hardness from the first electrode active material sublayer to the nth electrode active material sublayer gradually increases (as shown in FIG. 1, the electrode (100) includes a current collector (11) and an electrode active material layer (10) disposed on the current collector (11). The electrode active material layer (10) is formed by a first electrode active material sublayer (101), a second electrode active material sublayer (102), ..., and an nth electrode active material sublayer (10n). When the above relationship 1 is satisfied, it can be ensured that the difference in hardness between two adjacent electrode active material sublayers falls within an allowable range. During the process of rolling the electrode, the pressure received by the electrode active material sublayer of the surface layer becomes maximum. When pressure is applied to the current collector side, the pressure received by the electrode active material sublayer decreases layer by layer. Since the pressure received by each