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JP-7856789-B2 - Electrode protective layer of carboxylated microporous polymer substrate and method for manufacturing the same

JP7856789B2JP 7856789 B2JP7856789 B2JP 7856789B2JP-7856789-B2

Inventors

  • ビョン・ガク・キム
  • ジュン・ウ・ジョン

Assignees

  • コリア リサーチ インスティテュート オブ ケミカル テクノロジー

Dates

Publication Date
20260511
Application Date
20230427
Priority Date
20220429

Claims (13)

  1. Chemical formula 1 below: An electrode protective layer formed by crosslinking a homopolymer or copolymer containing repeating units represented by, or a mixture containing one or more thereof, by reaction with a crosslinking agent, In chemical formula 1, X is one of the following selected from the group consisting of X1 to X17. An electrode protective layer in which the number of repeating units is in the range of 10 to 500 .
  2. The aforementioned crosslinking agent has the following chemical formula 2: It has the following chemical structure: The electrode protective layer according to claim 1, wherein in chemical formula 2, R is one of a linear or branched alkylene group, a linear or branched alkylene group containing an oxygen atom, or an arylene group.
  3. In chemical formula 2, R is represented by the following chemical formula: -(CH 2 ) m -, -(CH 2 ) m -O-(CH 2 ) l -, -(CH 2 ) m -O-(CH 2 ) l -, -CH 2 -O-(CH 2 ) 4 -O-CH 2 -, It is one of the following: The electrode protective layer according to claim 2, wherein m and l are identical or distinct integers from 1 to 6, and n is an integer from 1 to 10000.
  4. A-scatter, An electrode comprising an electrode protective layer according to any one of claims 1 to 3 , coated on the anode.
  5. The electrode according to claim 4 , wherein the anode is capable of storing and releasing lithium ions.
  6. The electrode according to claim 4 , wherein the anode is one or more selected from the group including Li, Na, K, Mg, Ca, Zn, Al, Si, Ge, Sn, or alloys thereof.
  7. The electrode according to claim 4 as an anode, Electrolytes, An electrochemical cell, including a cathode.
  8. The electrochemical cell according to claim 7 , further comprising a separation membrane between the anode and the cathode.
  9. The stage of preparing the anode, Chemical formula 1 below: A polymer providing step of providing a homopolymer or copolymer containing repeating units represented by, or a mixture containing one or more thereof, A film-forming composition manufacturing step involves mixing the polymer, crosslinking agent, and solvent, A film formation step in which a film is formed on the anode using the film-forming composition, A step of manufacturing a crosslinked polymerized film that crosslinks the aforementioned film, Includes, In chemical formula 1, X is one of the following selected from the group consisting of X1 to X17. A method for forming an electrode protective layer , wherein the number of repeating units is in the range of 10 to 500 : .
  10. The aforementioned crosslinking agent has the following chemical formula 2: It has the following chemical structure: The method for forming an electrode protective layer according to claim 9 , wherein in chemical formula 2, R is one of a linear or branched alkylene group, a linear or branched alkylene group containing an oxygen atom, or an arylene group.
  11. In chemical formula 2, R is represented by the following chemical formula: -(CH 2 ) m -, -(CH 2 ) m -O-(CH 2 ) l -, -(CH 2 ) m -O-(CH 2 ) l -, -CH 2 -O-(CH 2 ) 4 -O-CH 2 -, It is one of the following: The method for forming an electrode protective layer according to claim 10 , wherein m and l are each the same or different integers from 1 to 6, and n is an integer from 1 to 10000.
  12. The method for forming an electrode protective layer according to claim 9 , wherein the solvent is one or more selected from the group consisting of tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and dimethylacetamide (DMAc).
  13. The crosslinked polymer film manufacturing step for crosslinking the aforementioned film is performed using the following reaction formula 1: This is done through the reaction of The method for forming an electrode protective layer according to claim 9, wherein in the reaction formula 1, n is a repeating unit and is an integer from 10 to 500, and R is one of a linear or branched alkylene group, a linear or branched alkylene group containing an oxygen atom, or an arylene group.

Description

This invention relates to an electrode protective layer based on carboxylated intrinsic microporosity polymers, and to a method for producing the same. More specifically, this invention relates to a crosslinked polymerized electrode protective layer made from a microporous polymer substrate, prepared by mixing a carboxylated microporous polymer with a crosslinking agent and a solvent; coated onto the surface of an electrode with the film-forming composition; dried at room temperature to remove the solvent; and finally subjected to a crosslinking reaction. It also relates to a method for producing the same. This application claims priority under Korean Patent Application No. 10-2022-0053793 filed on April 29, 2022, and Korean Patent Application No. 10-2023-0054353 filed on April 25, 2023, and all content disclosed in the specifications and drawings of said applications is incorporated herein. As demand for high-capacity energy storage devices usable in electric vehicles, smart electronics, and drones increases, technologies using lithium metal (Li) as an anode material are being actively developed. This is because lithium metal, when used as an anode, exhibits a higher theoretical capacity of 3860 mAh g⁻¹ compared to currently commercially available carbon-based anodes (372 mAh g⁻¹ ), has a lower standard reduction potential (-3.04 V vs. standard hydrogen electrode (SHE)), and has a lower density of 0.534 g cm⁻³ . Due to these advantages, batteries using lithium metal as an anode were commercialized in the 1980s. However, due to the instability of lithium metal anodes during battery use, accidents occurred where batteries exploded, and measures were taken to recall all batteries. Therefore, in order to commercialize secondary batteries that take advantage of the benefits of lithium metal anodes, ensuring the stability of the lithium metal anode is of paramount importance. The instability of lithium metal anodes is caused by the formation of lithium dendrites, which are sharp, resinous structures generated during charging and discharging. Specifically, the non-uniformity of the solid electrolyte interface (SEI) layer—a passive film naturally formed on the surface of the lithium metal anode through reaction with the electrolyte during charging and discharging—leads to localized differences in current density. This variation in current distribution causes the lithium metal to grow into sharp, resinous structures during charging. These grown resinous lithium structures become "dead lithium," which not only reduces the battery's Coulombic efficiency but, in the worst-case scenario, can cause explosions due to internal short circuits. Therefore, this is a problem that must be solved to ensure the long-term lifespan and stability of batteries. To ensure the stability and long lifespan of the lithium resin described above, research is actively being conducted on the introduction of artificial anode protective layers (Artificial SEI), the introduction of new electrolytes and additives, the structural design of metal current collectors, and the regulation of crystal nucleation growth. Among these, the introduction of artificial anode protective layers involves introducing an SEI layer, a passive film favorable for lithium migration and interfacial properties, onto the surface of the lithium metal, primarily utilizing polymers advantageous for lithium ion conduction and interfacial properties. Such anode protective layers mainly contain various ion-conducting polymers, such as poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), which are typical lithium-ion conductive polymers. Poly(ethylene oxide) (PEO) polymers are polymers containing ether groups that can interact with lithium ions and have a structure in which crystalline and amorphous regions coexist at room temperature. Above the glass transition temperature, the flexibility of the amorphous region facilitates the dissolution of lithium salts and the movement of lithium ions, while the movement of lithium ions is restricted in the crystalline phase. As a result, PEO exhibits a low lithium-ion conductivity of 10⁻⁸ to 10⁻⁹ S/cm at room temperature, making it difficult to apply PEO polymers to commercial batteries. Therefore, in order to develop PEO-based materials that exhibit high ionic conductivity, research is actively being conducted to reduce the degree of crystallinity through approaches such as the introduction of organic and inorganic particles and plasticizers, increasing the lithium salt content, and manufacturing copolymers. However, such efforts to reduce crystallinity can sometimes lead to a decrease in mechanical properties, so for the practical application of PEO-based materials for batteries, it is necessary to satisfy both ionic conductivity and mechanical properties simultaneously. In addition, materials such as covalent organic frameworks (COFs) and polymers of intrinsic microporosity (PIMs), which utilize micropores favorable for lithium