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US-20260128272-A1 - METHOD FOR MANUFACTURING DRY ELECTRODE FILM, DRY ELECTRODE FILM, AND DRY ELECTRODE INCLUDING SAME

US20260128272A1US 20260128272 A1US20260128272 A1US 20260128272A1US-20260128272-A1

Abstract

The present disclosure includes a method for manufacturing a dry electrode film, a dry electrode film, and a dry electrode including the dry electrode film. The method for manufacturing a dry electrode film includes preparing a dry mixture by dry mixing an active material, a conductive material, and a binder, manufacturing a mixture lump by kneading the dry mixture, obtaining an electrode powder by crushing the mixture lump, manufacturing a specimen using the electrode powder through a mold, testing a yield strength of the specimen, and manufacturing, when a test result of the yield strength satisfies a desired criterion, a sheet type dry electrode film having a given thickness by calendaring the electrode powder.

Inventors

  • Sangpil Kim
  • Kangmin Kim
  • Gaeon LEE
  • Jinhyon Lee
  • Dong Hee YEON

Assignees

  • SAMSUNG SDI CO., LTD.

Dates

Publication Date
20260507
Application Date
20250923
Priority Date
20241107

Claims (20)

  1. 1 . A method for manufacturing a dry electrode film, the method comprising: preparing a dry mixture by dry mixing an active material, a conductive material, and a binder; manufacturing a mixture lump by kneading the dry mixture; obtaining an electrode powder by crushing the mixture lump; manufacturing a specimen using the electrode powder through a mold; testing a yield strength of the specimen; and manufacturing, when a test result of the yield strength satisfies a desired criterion, a sheet type dry electrode film having a given thickness by calendaring the electrode powder.
  2. 2 . The method as claimed in claim 1 , wherein the manufacturing the specimen using the electrode powder through the mold comprises: filling the electrode powder in the mold; and pressurizing the electrode powder filled in the mold.
  3. 3 . The method as claimed in claim 2 , wherein the filling of the electrode powder in the mold comprises filling the electrode powder in the mold so that a weight of the electrode powder filled in the mold is in a range of about 1 g to about 5 g.
  4. 4 . The method as claimed in claim 2 , wherein the pressurizing of the electrode powder filled in the mold comprises pressurizing the electrode powder at a pressure in a range of about 10 MPa to about 100 MPa using a pressurizing member.
  5. 5 . The method as claimed in claim 1 , wherein the testing of the yield strength of the specimen comprises: pressurizing the specimen to be destroyed using a jig; measuring a load applied to the specimen when the specimen is destroyed; and calculating the yield strength of the specimen based on the measured load.
  6. 6 . The method as claimed in claim 5 , wherein the calculating of the yield strength of the specimen comprises calculating the yield strength of the specimen based on Equation 1; Yield ⁢ strength ⁢ ( kPa ) = 0 . 0 ⁢ 0 ⁢ 1 × { measured ⁢ load ⁢ ( kg ) × acceleration ⁢ of ⁢ gravity ⁢ ( m s 2 ) cross - sectional ⁢ area ⁢ of ⁢ specimen ⁢ ( m 2 ) } . Equation ⁢ 1
  7. 7 . The method as claimed in claim 6 , further comprising, after the calculating of the yield strength of the specimen: crushing the electrode powder when the yield strength calculated by Equation 1 is less than a given value.
  8. 8 . The method as claimed in claim 7 , wherein the given value is equal to about 2.3 MPa.
  9. 9 . The method as claimed in claim 6 , further comprising, after the calculating of the yield strength of the specimen: measuring an angle of internal friction of the electrode powder; and calculating a tensile strength of the specimen.
  10. 10 . The method as claimed in claim 9 , wherein the measuring of the angle of internal friction of the electrode powder comprises measuring the angle of internal friction of the electrode powder using a powder fluidity evaluation method.
  11. 11 . The method as claimed in claim 9 , wherein the calculating of the tensile strength of the specimen comprises calculating the tensile strength of the specimen based on Equation 2; Tensile ⁢ strength ⁢ ( kPa ) = { 1 - sin ⁡ ( angle ⁢ of ⁢ internal ⁢ friction ( ∘ ) ) 1 + sin ⁡ ( angle ⁢ of ⁢ internal ⁢ friction ( ∘ ) ) } × yield ⁢ strength ⁢ ( kPa ) . Equation ⁢ 2
  12. 12 . The method as claimed in claim 11 , further comprising, after the calculating of the tensile strength of the specimen, crushing the electrode powder when the tensile strength calculated by Equation 2 is less than a given value.
  13. 13 . The method as claimed in claim 12 , wherein the given value is equal to about 0.5 MPa.
  14. 14 . A dry electrode film comprising: an electrode powder comprising an active material, a conductive material, and a binder, wherein the electrode powder has a sheet shape manufactured through calendaring and has a given thickness, and a yield strength of the electrode powder is in a range of about 2.3 MPa or more in a sheet shape state.
  15. 15 . The dry electrode film as claimed in claim 14 , wherein an angle of internal friction of the electrode powder is in a range of about 30° to about 50°.
  16. 16 . The dry electrode film as claimed in claim 14 , wherein a tensile strength of the dry electrode film is in a range of about 0.5 MPa or more.
  17. 17 . The dry electrode film as claimed in claim 14 , wherein a porosity of the dry electrode film is in a range of about 50% to about 70%.
  18. 18 . The dry electrode film as claimed in claim 14 , wherein the active material comprises at least one of nickel cobalt aluminum (NCA), lithium ferrophosphate (LFP), and graphite.
  19. 19 . The dry electrode film as claimed in claim 14 , wherein the binder comprises at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN).
  20. 20 . A dry electrode comprising: a substrate; and a dry electrode film on at least one surface of the substrate, wherein the dry electrode film comprises an electrode powder comprising an active material, a conductive material, and a binder, and wherein the electrode powder has a sheet shape manufactured through calendaring and having a given thickness, and a yield strength of the electrode powder is in a range of about 2.3 MPa or more in a sheet shape state.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority under 35 U.S.C § 119 to Korean Patent Application No. 10-2024-0157039, filed in the Korean Intellectual Property Office on Nov. 7, 2024, the entire contents of which are hereby incorporated by reference. BACKGROUND Field Aspects of embodiments of the present disclosure relate to a method for manufacturing a dry electrode film, a dry electrode film, and a dry electrode including the dry electrode film. Description of the Related Art Unlike primary batteries that are not designed to be (re)charged, secondary (or rechargeable) batteries are typically designed to be discharged and recharged. Low-capacity secondary batteries are typically used in portable, small electronic devices, such as smart phones, feature phones, notebook computers, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for driving motors in hybrid vehicles and electric vehicles and for storing power (e.g., home and/or utility scale power storage). A secondary battery generally includes an electrode assembly including a positive electrode and a negative electrode, a case accommodating the same, and electrode terminals connected to the electrode assembly. A dry electrode may include an electrode substrate, an active material, a binder, and a conductive material. A film type dry electrode film may be formed by pressurizing the active material, the binder, and the conductive material. The dry electrode may be manufactured by joining the electrode substrate and the dry electrode film through a lamination process. The mechanical stability of the dry electrode film may be an advantageous factor, and thus various efforts may be made to predict a mechanical property in advance. The above information disclosed in this Background section is for enhancement of understanding of the background of the present disclosure, and therefore, it may contain information that does not constitute related (or prior) art. SUMMARY The present disclosure addresses at least the above technical problems, and aspects of example embodiments of the present disclosure include a method for manufacturing a dry electrode film, a dry electrode film, and a dry electrode including same. These and other aspects and features of the present disclosure are described in, or are apparent from, the following description of example embodiments of the present disclosure. In order to realize the objective, according to example embodiments of the present disclosure, a method for manufacturing a dry electrode film includes preparing a dry mixture by dry mixing an active material, a conductive material, and a binder, manufacturing a mixture lump by kneading the dry mixture, obtaining an electrode powder by crushing the mixture lump, manufacturing a specimen using the electrode powder through a mold, testing a yield strength of the specimen, and manufacturing, when a test result of the yield strength satisfies a predetermined or desired criterion, a sheet type dry electrode film having a given thickness by calendaring the electrode powder. According to example embodiments, the manufacturing of the specimen using the electrode powder through the mold may include filling the electrode powder in the mold, and pressurizing the electrode powder filled in the mold. According to example embodiments, the filling of the electrode powder in the mold may include filling the electrode powder in the mold so that a weight of the electrode powder filled in the mold is in a range of about 1 g to about 5 g. According to example embodiments, the pressurizing of the electrode powder filled in the mold may include pressurizing the electrode powder at a pressure of in a range of about 10 MPa to about 100 MPa using a pressurizing member. According to example embodiments, the testing of the yield strength of the specimen may include pressurizing the specimen to be destroyed using a jig, measuring a load applied to the specimen at a moment when the specimen is destroyed, and calculating the yield strength of the specimen based on the measured load. According to example embodiments, the calculating of the yield strength of the specimen may include calculating the yield strength of the specimen based on Equation 1 below. Yield⁢ strength⁢ (kPa)=0.0⁢0⁢1×{measured⁢ load⁢ (kg)×acceleration⁢ of⁢ gravity⁢ (ms2)cross-sectional⁢ area⁢ of⁢ specimen⁢ (m2)}.Equation⁢ 1 According to example embodiments, the testing of the yield strength of the specimen may further include, after the calculating of the yield strength of the specimen, crushing the electrode powder when the yield strength calculated by Equation 1 is less than a given value. According to example embodiments, the given value may be about 2.3 MPa. According to example embodiments, the testing of the yield strength of the specimen may further include, after the calculating of the yield strength of the specimen, measuring an