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EP-4742310-A1 - METHOD FOR MANUFACTURING DRY ELECTRODE FILM, DRY ELECTRODE FILM, AND DRY ELECTRODE INCLUDING SAME

EP4742310A1EP 4742310 A1EP4742310 A1EP 4742310A1EP-4742310-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

  • KIM, Sangpil
  • KIM, Kangmin
  • Lee, Gaeon
  • LEE, JINHYON
  • YEON, DONG HEE

Assignees

  • SAMSUNG SDI CO., LTD.

Dates

Publication Date
20260513
Application Date
20251105

Claims (15)

  1. A method (S300) for manufacturing a dry electrode film, the method comprising: preparing (S310) a dry mixture by dry mixing an active material, a conductive material, and a binder; manufacturing (S320) a mixture lump by kneading the prepared dry mixture; obtaining (S330) an electrode powder (520) by crushing the manufactured mixture lump; manufacturing (S340) a specimen (800) using the obtained electrode powder (520) through a mold (510); testing (S350) a yield strength of the manufactured specimen (800); and manufacturing (S360), 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 obtained electrode powder (520).
  2. The method (S300) as claimed in claim 1, wherein the step of manufacturing the specimen (800) using the obtained electrode powder through the mold (510) comprises: filling the electrode powder (520) in the mold (510); and pressurizing the electrode powder (520) filled in the mold (510).
  3. The method (S300) as claimed in claim 2, wherein the step of filling the electrode powder (520) in the mold (510) comprises filling the electrode powder (520) in the mold (510) so that a weight of the electrode powder (520) filled in the mold (510) is in a range of 1 g to 5 g.
  4. The method (S300) as claimed in claim 2 or 3, wherein the step of pressurizing the electrode powder (520) filled in the mold (510) comprises pressurizing the electrode powder (520) at a pressure in a range of 10 MPa to 100 MPa using a pressurizing member (530).
  5. The method (S300) as claimed in any of the previous claims, wherein the step of testing the yield strength of the manufactured specimen (800) comprises: pressurizing the manufactured specimen (800) to be destroyed using a jig (900); measuring a load applied to the specimen (800) when the specimen is destroyed; and calculating the yield strength of the specimen (800) based on the measured load.
  6. The method (S300) as claimed in claim 5, wherein the step of calculating the yield strength of the specimen (800) comprises calculating the yield strength of the specimen (800) based on Equation 1; Yield strenght kPa = 0.001 × measured load kg × acceleration of gravity m s 2 cross - sectional area of specimen m 2 .
  7. The method (S300) as claimed in claim 5 or 6, further comprising, after the step of calculating the yield strength of the specimen (800): crushing the electrode powder (520) when the yield strength is less than a given value, and preferably less than 2.3 MPa.
  8. The method (S300) as claimed in any of claims 5 to 7, further comprising, after the step of calculating of the yield strength of the specimen (800): measuring an angle of internal friction of the electrode powder (520), preferably by using a powder fluidity evaluation method; and calculating a tensile strength of the specimen (800).
  9. The method (S300) as claimed in claim 8, wherein the step of calculating the tensile strength of the specimen (800) comprises calculating the tensile strength of the specimen (800) based on Equation 2; Tensile strength kPa = 1 − sin angle of internal friction ° 1 + sin angle of internal friction ° × yield strength kPa .
  10. The method (S300) as claimed in claim 8 or 9, further comprising, after the step of calculating the tensile strength of the specimen (800), crushing the electrode powder (520) when the tensile strength calculated by Equation 2 is less than a given value, and preferably less than 0.5 MPa.
  11. A dry electrode film (110), preferably manufactured by a method according to any of claims 1 to 10, the dry electrode film (110) comprising: an electrode powder (520) comprising an active material, a conductive material, and a binder, wherein the electrode powder (520) has a sheet shape manufactured through calendaring and has a given thickness, and a yield strength of the electrode powder (520) is in a range of 2.3 MPa or more in a sheet shape state.
  12. The dry electrode film (110) as claimed in claim 11, wherein an angle of internal friction of the electrode powder (520) is in a range of 30° to 50°.
  13. The dry electrode film (110) as claimed in claims 11 or 12, wherein a tensile strength of the dry electrode film (110) is in a range of 0.5 MPa or more; and/or wherein a porosity of the dry electrode film (110) is in a range of 50 % to 70 %.
  14. The dry electrode film (110) as claimed in any of claims 11 to 13, wherein the active material comprises at least one of nickel cobalt aluminum (NCA), lithium ferrophosphate (LFP), and graphite; and/or wherein the binder comprises at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and polyacrylonitrile (PAN).
  15. A dry electrode comprising: a substrate (120); and a dry electrode film (110) on at least one surface of the substrate (120), and wherein the dry electrode film (110) is configured according to any of claims 11 to 14.

Description

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. YieldstrengthkPa=0.001×measuredloadkg×accelerationofgravityms2cross-sectionalareaofspecimenm2. 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 angle of internal friction of the electrode powder, and calculating a tensile strength of the specimen. According to example embodiments, the measuring of the angle of internal friction of the electrode powder may include measuring the angle of internal friction of the electrode powder using a powder fluidity evaluation method. According to ex