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EP-4738444-A1 - METHOD FOR MANUFACTURING ELECTRODE FOR LITHIUM SECONDARY BATTERY, ELECTRODE, LITHIUM SECONDARY BATTERY INCLUDING THE SAME

EP4738444A1EP 4738444 A1EP4738444 A1EP 4738444A1EP-4738444-A1

Abstract

Methods for manufacturing an electrode for a lithium secondary battery, electrodes for a lithium secondary battery, and lithium secondary batteries including the electrodes are disclosed. In one embodiment, the method for manufacturing an electrode for a lithium secondary batteries may include: forming an electrode active material layer on at least one side of the electrode current collector, forming a plurality of grooves in the electrode active material layer, and rolling the electrode active material layer that includes the plurality of grooves.

Inventors

  • YU, Gyeong Hwa
  • KANG, BYUNG CHAN
  • YIM, HYUNG JOO
  • JIN, BO GYEONG
  • HEO, KYUN

Assignees

  • SK On Co., Ltd.

Dates

Publication Date
20260506
Application Date
20251028

Claims (14)

  1. A method for manufacturing an electrode for a lithium secondary battery, comprising: forming an electrode active material layer on at least one surface of an electrode current collector; forming a plurality of grooves in the electrode active material layer; and rolling the electrode active material layer that includes the plurality of grooves.
  2. The method according to claim 1, wherein the electrode is a negative electrode.
  3. The method according to claims 1 or 2, wherein (a) the plurality of grooves is arranged such that each pitch between two adjacent grooves of the plurality of grooves is in a range of 50 µm to 200 µm, and/or (b) the plurality of grooves has a depth of 10 µm to 250 µm, and/or (c) the plurality of grooves has a width of 10 µm to 200 µm.
  4. The method according to any one of claims 1 to 3, wherein the plurality of grooves is formed such that, in a cross-section view taken in a thickness direction of the electrode active material layer, each groove includes a shape that includes at least a part of a circle, at least a part of a square, at least a part of a triangle, or at least part of a trapezoid.
  5. The method according to claim 4, wherein the plurality of grooves has a common shape.
  6. The method according to any one of claims 1 to 5, wherein the electrode active material layer is processed by rolling to have a first thickness deviation of 4.5% or less, as defined by Equation 1: First thickness deviation % = T h − T a T a × 100 wherein T h is a maximum thickness of the electrode after the rolling is performed, and T a is an average thickness of the electrode before the forming of the plurality of grooves.
  7. An electrode for a lithium secondary battery comprising: an electrode current collector and an electrode active material layer formed on at least one surface of the electrode current collector, wherein the electrode active material layer includes a plurality of grooves and corresponding closed portions adjacent to each of the plurality of grooves.
  8. The electrode for a lithium secondary battery according to claim 7, wherein the electrode is a negative electrode.
  9. The electrode for a lithium secondary battery according to claims 7 or 8, wherein (a) the plurality of grooves is arranged such that each pitch between two adjacent grooves of the plurality of grooves is in a range of 50 µm to 200 µm, and/or (b) each of the plurality of grooves has a depth of 10 µm to 250 µm, and/or (c) each of the plurality of grooves has a width of 10 µm to 200 µm.
  10. The electrode for a lithium secondary battery according to any one of claims 7 to 9, wherein the plurality of grooves is formed such that, in a cross-section view taken in a thickness direction of the electrode active material layer, each groove includes a shape which includes at least a part of a circle, at least a part of a square, at least a part of a triangle, or at least part of a trapezoid.
  11. The electrode for a lithium secondary battery according to claim 10, wherein the plurality of grooves have a common shape.
  12. The electrode for a lithium secondary battery according to any one of claims 7 to 11, wherein the electrode has a second thickness deviation of 4.5% or less, as defined by Equation 2: Second thickness deviation % = L 5 − L 4 L 4 × 100 wherein L4 is an average thickness of the electrode and L5 is a maximum thickness of the electrode.
  13. The electrode for a lithium secondary battery according to any one of claims 7 to 12, wherein the closed portion seals a corresponding groove.
  14. A lithium secondary battery comprising the electrode manufactured by the method according to any one of claims 1 to 6, or the electrode according to any one of claims 7 to 13.

Description

TECHNICAL FIELD The technology and implementations disclosed in this patent document generally relate to electrodes for a lithium secondary battery and lithium secondary batteries including the electrodes. BACKGROUND As the charging speed of lithium secondary batteries increases, the time required to prepare them for use after discharge can be shortened. Therefore, research on lithium secondary batteries capable of rapid charging has recently attracted significant attention. SUMMARY In an aspect of the disclosed technology, an electrode for a lithium secondary battery and a method for manufacturing the same are desired to minimize electrode resistance without reducing electrode density. In another aspect of the disclosed technology, a lithium secondary battery is designed to maintain its lifespan characteristics even during rapid charging. In addition, some embodiments of the disclosed technology can be widely applied to electric vehicles, battery charging stations, energy storage systems (ESS), and other green technology fields such as photovoltaics and wind power using batteries. The disclosed technology may also be used in eco-friendly mobility solutions, including electric vehicles and hybrid vehicles, to help mitigate climate change by suppressing air pollution and greenhouse gas emissions. The disclosed technology can be implemented in some embodiments to address the issued discussed above by providing a method of manufacturing an electrode for a lithium secondary battery, including: forming an electrode active material layer on at least one surface of an electrode current collector; forming a plurality of grooves in the electrode active material layer; and rolling the electrode active material layers that include the plurality of grooves. In some implementations, the electrode may be a negative electrode. In some implementations, the plurality of grooves may be arranged such that each pitch between two adjacent grooves of the plurality of grooves is in a range of 50 µm to 200 µm. In some implementations, the term "pitch" can be used to indicate the center-to-center distance between two adjacent grooves. In some implementations, each of the plurality of grooves has a depth of 10 µm to 250 µm. In some implementations, each of the plurality of grooves has a width of 10 µm to 200 µm. In some implementations, the plurality of grooves is formed such that, in the cross-section view taken in a thickness direction of the electrode active material layer, each groove includes a shape that includes at least a part of a circle, at least a part of a square, at least a part of a triangle, or at least part of a trapezoid. In some implementations, the plurality of grooves has a common shape. In some implementations, the electrode active material layer may be processed by rolling to have a first thickness deviation of 4.5% or less, as defined by the following equation 1.Firstthicknessdeviation%=Th−TaTa×100 wherein Th is a maximum thickness of the electrode after the rolling is performed, and Ta is an average thickness of the electrode before the forming of the plurality of grooves. In some implementations, an electrode for a lithium secondary battery based on the disclosed technology may include: an electrode current collector, and an electrode active material layer formed on at least one surface of the electrode current collector, wherein the electrode active material layer may include a plurality of grooves and corresponding closed portions adjacent to each of the plurality of grooves. In some implementations, the electrode may be a negative electrode for lithium secondary batteries. In some implementations, the plurality of grooves may be arranged such that each pitch between two adjacent grooves of the plurality of grooves is in a range of 50 µm to 200 µm. In some implementations, each of the plurality of grooves may have a depth of 10 µm to 250 µm. In some implementations, each of the plurality of grooves may have a width of 10 µm to 200 µm. In some implementations, each of the plurality of grooves may include a shape that includes at least a part of a circle, at least a part of a square, at least a part of a triangle, or at least a part of a trapezoid, when observed in a cross section in a thickness direction of the electrode active material layer. In some implementations, the plurality of grooves in the electrode may have a common shape. In some implementations, the electrode may have a second thickness deviation of 4.5% or less, as defined by the following equation 2.Secondthicknessdeviation%=L5−L4L4×100 wherein L4 is an average thickness of the electrode and L5 is a maximum thickness of the electrode. In some implementations, each of the closed portions in the electrode may seal a corresponding groove. The disclosed technology can also be implemented in some embodiments to provide an electrode manufactured by the method discussed above such as an electrode for a lithium secondary battery. BRIEF DESCRIPTION OF