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KR-20260066554-A - MANUFACTURING METHOD OF SEPERATOR FOR SECONDARY BATTERY

KR20260066554AKR 20260066554 AKR20260066554 AKR 20260066554AKR-20260066554-A

Abstract

The present invention relates to a method for manufacturing a separator for a secondary battery, comprising the steps of: mixing a polymer resin, a paraffinic wax, and a ceramic material to form a mixed raw material; and melting and cooling the mixed raw material to form a separator. According to the present invention, a separator is formed by forming a mixed raw material together with a polymer resin and a paraffinic wax without coating the ceramic material. By manufacturing, ceramic material can be uniformly distributed on the surface and inside.

Inventors

  • 오지민
  • 허다연
  • 박다솔

Assignees

  • 경북대학교 산학협력단

Dates

Publication Date
20260512
Application Date
20241104

Claims (10)

  1. A step of forming a mixed raw material by mixing a polymer resin, a paraffinic wax, and a ceramic material; and A step comprising melting and cooling the above mixed raw materials to form a separation membrane; Method for manufacturing a separator for a secondary battery.
  2. In paragraph 1, A method for manufacturing a separator for a secondary battery, wherein the above polymer resin comprises a polyolefin-based resin.
  3. In paragraph 1, A method for manufacturing a separator for a secondary battery, wherein each of the above polymer resin, the above paraffinic wax, and the above ceramic material is in the form of a powder or slurry.
  4. In paragraph 1, A method for manufacturing a separator for a secondary battery, wherein the polymer resin is included in an amount of 30 to 70 parts by weight per 100 parts by weight of the above mixed raw materials.
  5. In paragraph 1, The ceramic material is silicon dioxide ( SiO₂ ), aluminum oxide ( Al₂O₃ ), titanium dioxide ( TiO₂ ) , tin oxide ( SnO₂ ), cerium dioxide ( CeO₂ ), zirconium dioxide ( ZrO₂ ), and barium titaniumate ( BaTiO₃ ). A method for manufacturing a separator for a secondary battery, comprising one or more selected from the group consisting of and yttrium oxide ( Y₂O₃ ).
  6. In paragraph 1, A method for manufacturing a separator for a secondary battery, wherein the ceramic material is included in an amount of 5 to 40 parts by weight per 100 parts by weight of the above mixed raw material.
  7. A separator for a secondary battery manufactured according to the manufacturing method of any one of claims 1 to 6.
  8. In Paragraph 7, The above ceramic material is a separator for a secondary battery distributed on the surface and inside of the separator.
  9. In Paragraph 7, A separator for a secondary battery, wherein the thickness of the separator is 7 to 25 μm.
  10. A secondary battery comprising a separator for a secondary battery manufactured according to any one of the manufacturing methods of paragraphs 1 to 6.

Description

Manufacturing Method of Seperator for Secondary Battery The present invention relates to a method for manufacturing a separator for a secondary battery, and more specifically, to a method for manufacturing a separator for a secondary battery in which a ceramic material is uniformly formed on the surface and inside by forming a mixed raw material together with a polymer resin and a paraffin-based wax without coating the ceramic material. This result is the research result of the Phase 3 Leading University Industry-Academic Cooperation Project (LINC 3.0), conducted in 2024 with funding from the Ministry of Education and support from the National Research Foundation of Korea (202408612000). The application of rechargeable batteries, such as lithium-ion batteries, is continuously expanding in high-capacity, high-output fields like power tools and electric vehicles. Consequently, the importance of battery safety—including risks of explosion and ignition—and energy density is becoming increasingly significant. Considering that battery safety issues ultimately arise from internal short circuits caused by the anode and cathode coming into contact, the separator, which physically isolates the two electrodes, can be considered one of the most critical materials for battery safety. Furthermore, the separator acts as a pathway for ion transport, influencing ion mobility and, ultimately, the electrochemical performance of the rechargeable battery. Furthermore, as the demand for secondary batteries increases in various fields recently, there is a continuously growing need for batteries that operate stably over diverse temperature ranges and are capable of rapid charging, and active research is being conducted to overcome the stability and performance limitations of existing polyolefin-based separators. Furthermore, since lithium metal electrodes suffer damage to the separator due to dendrite growth at charge densities of 2 C or higher, and problems such as dendrite growth and reduced available lithium due to lithium plating occur at -20 ℃ or lower, research is being conducted to apply ceramic materials with excellent thermal properties to improve the problem of battery performance degradation caused by dendrite growth. Meanwhile, in the case of conventional methods for manufacturing ceramic-coated separators, a ceramic coating layer is provided on the surface of the separator by coating a ceramic material exhibiting thermal stability on one or both sides of a polyolefin-based separator to improve the thermal stability of the separator. However, this process has limitations in that the ceramic is not uniformly distributed on the separator, and the thermal runaway caused by internal short circuits is accelerated due to the shrinkage of the separator caused by external impact or thermal runaway after manufacturing, thereby degrading the stability and electrochemical performance of the secondary battery. Accordingly, there is a need for research and development on a manufacturing method for secondary battery separators that allows ceramic materials to be uniformly distributed on the separator. FIG. 1 is a flowchart illustrating a method for manufacturing a separator for a secondary battery according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a manufacturing process of a separator for a secondary battery according to one embodiment of the present invention. FIG. 3 is a schematic diagram illustrating the material composition and material distribution of a separator for a secondary battery according to one embodiment of the present invention. The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals are used for similar components when describing each drawing. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. The term "and/or" includes a combination of a plurality of related described items or any of a plurality of related described items. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted