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EP-4738474-A1 - ELECTRODE FOR SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY INCLUDING THE SAME

EP4738474A1EP 4738474 A1EP4738474 A1EP 4738474A1EP-4738474-A1

Abstract

The present disclosure provides an electrode for a secondary battery and a lithium secondary battery including the same. The electrode for a secondary battery according to the present disclosure includes an electrode current collector, and an electrode active material layer disposed on one surface of the electrode current collector, and including an electrode active material and a graphene conductive material. The number of layers of the graphene conductive material, as defined by Equation 1, is 2 to 15. Number of layers = Lc / D + 1 (in Equation 1, Lc represents a grain size (Å) and D represents a d-spacing (Å), calculated from X-ray diffraction (XRD) analysis results of the graphene conductive material)

Inventors

  • KO, BYOUNG HO

Assignees

  • SK On Co., Ltd.

Dates

Publication Date
20260506
Application Date
20251029

Claims (12)

  1. An electrode for a secondary battery comprising: an electrode current collector; and an electrode active material layer disposed on one surface of the electrode current collector and comprising an electrode active material and a graphene conductive material, wherein the number of layers of the graphene conductive material, as defined by Equation 1 below, is 2 to 15: Number of layers = Lc / D + 1 (in Equation 1, Lc represents a grain size (Å) and D represents a d-spacing (Å), calculated from X-ray diffraction (XRD) analysis results of the graphene conductive material).
  2. The electrode for a secondary battery according to claim 1, wherein the number of layers is 3 to 12.
  3. The electrode for a secondary battery according to claim 1 or claim 2, wherein in Equation 1, D is 2.5 Å to 3.5 Å.
  4. The electrode for a secondary battery according to any one of claims 1 to 3, wherein in Equation 1, Lc is 7.5 Å to 50 Å.
  5. The electrode for a secondary battery according to any one of claims 1 to 4, wherein the ratio (I D /I G ) of the maximum peak intensity of the D band to the maximum peak intensity of the G band, calculated from the Raman spectroscopy results of the graphene conductive material, is greater than 0 and less than or equal to 1.
  6. The electrode for a secondary battery according to any one of claims 1 to 5, wherein the graphene conductive material has a 1 g/cm 3 powder resistivity of 0.005 Ω·cm or less.
  7. The electrode for a secondary battery according to any one of claims 1 to 6, wherein the graphene conductive material has a BET specific surface area of 100 m 2 /g to 1000 m 2 /g.
  8. The electrode for a secondary battery according to any one of claims 1 to 7, wherein the content of the graphene conductive material is 0.01% by weight to 1% by weight based on the total weight of the electrode active material layer.
  9. The electrode for a secondary battery according to any one of claims 1 to 8, wherein the content of the graphene conductive material is 0.1% by weight to 0.5% by weight based on the total weight of the electrode active material layer.
  10. The electrode for a secondary battery according to any one of claims 1 to 9, wherein the electrode active material comprises a lithium metal oxide.
  11. The electrode for a secondary battery according to any one of claims 1 to 10, wherein the electrode active material comprises a graphite-based active material or a silicon-based active material.
  12. A lithium secondary battery comprising a cathode and an anode disposed opposite to the cathode, wherein the cathode or the anode is the electrode for a secondary battery according to any one of claims 1 to 11.

Description

BACKGROUND 1. Field of the Invention The present disclosure relates to an electrode for a secondary battery and a lithium secondary battery including the same. 2. Description of the Related Art Secondary batteries are batteries that can be repeatedly charged and discharged. With the development of information and communication and display industries, they have been widely applied as power sources for portable electronic communication devices, such as camcorders, mobile phones, and laptop PCs. In addition, battery packs including secondary batteries have recently been developed and applied as power sources for eco-friendly vehicles, such as hybrid vehicles. Examples of secondary batteries may include a lithium secondary battery, a nickel-cadmium battery, and a nickel-hydrogen battery. Among these, lithium secondary batteries are actively developed and applied due to their high operating voltage, high energy density per unit weight, and advantages in charging speed and weight reduction. For example, the lithium secondary battery may include: an electrode assembly including a cathode, an anode, and a separation membrane (separator); and an electrolyte in which the electrode assembly is impregnated. The lithium secondary battery may further include, for example, a pouch-type outer case in which the electrode assembly and the electrolyte are accommodated. It is preferable for lithium secondary batteries to have low internal resistance and high rate characteristics, thereby exhibiting improved fast charge and discharge characteristics. Therefore, the development of electrodes capable of achieving lithium secondary batteries with low resistance and high rate characteristics is required. SUMMARY An object of the present disclosure is to provide an electrode for a secondary battery having improved electrochemical properties. Another object of the present disclosure is to provide a lithium secondary battery including the electrode for a secondary battery. An electrode for a secondary battery according to exemplary embodiments of the present disclosure includes: an electrode current collector; and an electrode active material layer disposed on one surface of the electrode current collector and including an electrode active material and a graphene conductive material. The number of layers of the graphene conductive material, as defined by Equation 1 below, is 2 to 15. Numberoflayers=Lc/D+1 In Equation 1, Lc represents a grain size (Å) and D represents a d-spacing (Å), calculated from X-ray diffraction (XRD) analysis results of the graphene conductive material. According to exemplary embodiments, the number of layers may be 3 to 12. According to exemplary embodiments, in Equation 1, D may be 2.5 Å to 3.5 Å. According to exemplary embodiments, in Equation 1, Lc may be 7.5 Å to 50 Å. According to exemplary embodiments, the ratio (ID/IG) of the maximum peak intensity of the D band to the maximum peak intensity of the G band, calculated from the Raman spectroscopy results of the graphene conductive material, may be greater than 0 and less than or equal to 1. According to exemplary embodiments, the graphene conductive material may have a 1 g/cm3 powder resistivity of 0.005 Ω·cm or less. According to exemplary embodiments, the graphene conductive material may have a BET specific surface area of 100 m2/g to 1000 m2/g. According to exemplary embodiments, the content of the graphene conductive material may be 0.01% by weight to 1% by weight based on the total weight of the electrode active material layer. According to exemplary embodiments, the content of the graphene conductive material may be 0.1% by weight to 0.5% by weight based on the total weight of the electrode active material layer. According to exemplary embodiments, the electrode active material may include a lithium metal oxide. According to exemplary embodiments, the electrode active material may include a graphite-based active material or a silicon-based active material. A lithium secondary battery according to exemplary embodiments of the present disclosure includes a cathode and an anode disposed opposite to the cathode. The cathode or the anode is the electrode for a secondary battery. The electrode for a secondary battery according to exemplary embodiments of the present disclosure may have improved electrode internal resistance. Accordingly, the fast charge and discharge performance of a battery including the electrode may be improved. The electrode for a secondary battery according to exemplary embodiments of the present disclosure may have improved rate characteristics. Accordingly, a battery with improved cycle life characteristics may be achieved. The electrode for a secondary battery according to the present disclosure and the lithium secondary battery including the same may be widely applied in green technology fields, such as electric vehicles, battery charging stations, as well as solar power generation, wind power generation, and the like, which use