Search

CN-121975467-A - Glue solution, preparation method and application thereof, sulfide electrolyte membrane and preparation method thereof

CN121975467ACN 121975467 ACN121975467 ACN 121975467ACN-121975467-A

Abstract

The invention relates to the technical field of batteries, in particular to a glue solution, a preparation method and application thereof, a sulfide electrolyte membrane and a preparation method thereof. The glue solution comprises a binder, a nonpolar solvent and a weak polar solvent, wherein the binder comprises a first polymer and a second polymer, the first polymer has nonpolar property, and a molecular chain of the second polymer has a polar structure. The sulfide electrolyte membrane prepared by the glue solution has excellent electrochemical performance and high air stability.

Inventors

  • YAO YUAN
  • ZHANG JINGJING
  • LI WANLONG
  • LI YUNMING

Assignees

  • 蜂巢能源科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260407

Claims (10)

  1. 1. The glue solution is characterized by comprising a binder, a nonpolar solvent and a weak polar solvent; wherein the binder comprises a first polymer and a second polymer, the first polymer having a nonpolar nature, and the molecular chain of the second polymer having a polar structure.
  2. 2. The glue of claim 1, wherein the glue meets at least one of the following conditions: (1) The first polymer comprises a styrenic block copolymer and/or a polyolefin; (2) The second polymer has a property of weak polarity; (3) The polar structure in the second polymer is located in the main chain of the second polymer and/or in the side chains of the second polymer; (4) The average molecular weight of the first polymer is greater than 200000g/mol; (5) The average molecular weight of the second polymer is 200000g/mol-1000000g/mol.
  3. 3. The glue of claim 2, wherein the glue meets at least one of the following conditions: (1) The side chains of the second polymer contain the polar structure including a polar structure provided by at least one monomer of chloromethyl, polyphenylene ether, dibutyl maleate, diethyl maleate, maleic anhydride, glycidyl methacrylate, acrylic acid, p-chloromethylstyrene, bis-trimethylsilylated vinyl phosphate, Z-hydroxyethyl methacrylate phosphate, ethylenediamine tetraacetic dianhydride, N-substituted maleimide, oleic acid, methacrylic acid, acrylamide, vinylsilane, and caprolactam; (2) The side chain of the second polymer contains the polar structure, and the mass grafting rate of the polar structure in the second polymer is 0.1% -3%; (3) The side chains of the second polymer contain the polar structure, and the second polymer comprises a first polymer grafted with the polar structure; (4) The backbone of the second polymer comprising the polar structure, the second polymer comprising hydrogenated nitrile rubber and/or acrylate rubber; (5) The styrenic block copolymer comprises at least one of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, polystyrene-b-poly [ ethylene- (ethylene-propylene) ] -b-polystyrene, and styrene-ethylene-propylene-styrene; (6) The polyolefin includes at least one of polyethylene, polypropylene, polyisobutylene, and amorphous polyalphaolefin.
  4. 4. The glue of claim 1, wherein the glue meets at least one of the following conditions: (1) The dielectric constant of the nonpolar solvent is less than or equal to 2.5; (2) The dielectric constant of the weak polar solvent is 2-5; (3) The flash point of the nonpolar solvent is more than or equal to 45 ℃; (4) The flash point of the weak polar solvent is more than or equal to 45 ℃; (5) The nonpolar solvent does not react with the sulfide electrolyte; (6) The nonpolar solvent includes at least one of a heavy aromatic hydrocarbon solvent, an alkane solvent, and a mono-olefin solvent; (7) The weak polar solvent comprises an ester solvent and/or an ether solvent; (8) The mass ratio of the first polymer to the second polymer is (0.25-4) 1; (9) The mass ratio of the nonpolar solvent to the first polymer is (12.5-50): 1; (10) The mass ratio of the weakly polar solvent to the second polymer is (12.5-50): 1.
  5. 5. The glue of claim 4, wherein the glue meets at least one of the following conditions: (1) The heavy aromatic hydrocarbon solvent comprises trimethylbenzene and/or tetramethylbenzene; (2) The alkane solvent comprises a C10-C15 alkane solvent; (3) The monoethylenically unsaturated hydrocarbon solvent includes a C10-C15 monoethylenically unsaturated hydrocarbon solvent; (4) The ester solvent comprises a C1-C6 fatty alcohol ester of a C4-C10 fatty acid; (5) The ether solvent comprises C5-C8 aliphatic ether and/or aromatic ether.
  6. 6. A method for preparing a dope according to any one of claims 1 to 5, wherein the method comprises: s1, dissolving a first polymer in a nonpolar solvent to obtain a first glue solution; s2, dissolving a second polymer in a weak polar solvent to obtain a second glue solution; s3, mixing the first glue solution and the second glue solution to obtain the glue solution.
  7. 7. Use of the dope of any one of claims 1 to 5 for producing a sulfide electrolyte membrane.
  8. 8. A method for producing a sulfide electrolyte membrane sheet, characterized by comprising: (1) Homogenizing the glue solution and sulfide electrolyte powder to obtain slurry; (2) Coating the slurry on the surface of a substrate, and then drying to obtain a sulfide electrolyte membrane; wherein the glue solution comprises the glue solution according to any one of claims 1-5.
  9. 9. The method of preparation of claim 8, wherein the method of preparation meets at least one of the following conditions: (1) The solid content of the slurry is 40-70 wt%; (2) The sulfide electrolyte powder includes at least one of Li 6 PS 5 Cl、Li 10 GeP 2 S 12 、Li 10 SnP 2 S 12 、Li 2 S-P 2 S 5 、Li 2 S-SiS 2 and Li 2 S-B 2 S 3 ; (3) The substrate comprises at least one of aluminum foil, PET film, PP film and non-woven fabric.
  10. 10. A sulfide electrolyte membrane, characterized in that the sulfide electrolyte membrane is produced by the production method of the sulfide electrolyte membrane according to claim 8 or 9.

Description

Glue solution, preparation method and application thereof, sulfide electrolyte membrane and preparation method thereof Technical Field The invention relates to the technical field of batteries, in particular to a glue solution, a preparation method and application thereof, a sulfide electrolyte membrane and a preparation method thereof. Background Sulfide electrolyte powder easily reacts with moisture and oxygen in the air, resulting in a change in crystal structure and a decrease in ion conductivity. Researchers found that sulfide electrolyte membrane sheets prepared by wet coating process show inferior air stability compared to sulfide electrolyte powder due to the fact that they are directly mixed with solvent and binder to make slurry. The electrolyte membrane is characterized in that the sulfide electrolyte membrane is more prone to side reactions with water and oxygen, so that the electrochemical performance of the electrolyte membrane is remarkably reduced. Disclosure of Invention The invention aims to solve the problems that the sulfide electrolyte membrane in the prior art is poor in air stability, is more easy to react with moisture and oxygen, and causes crystal structure change and ion conductivity to be obviously reduced. Provided are a glue solution, a preparation method and application thereof, a sulfide electrolyte membrane and a preparation method thereof. The glue solution can effectively reduce the probability of the reaction of sulfide electrolyte with moisture and oxygen in the air in the preparation process of the sulfide electrolyte membrane, and simultaneously can ensure that the prepared sulfide electrolyte membrane has high air stability. In order to solve the technical problems, the invention is realized as follows: according to a first aspect of the invention, the invention provides a glue solution, which comprises a binder, a nonpolar solvent and a weak polar solvent, wherein the binder comprises a first polymer and a second polymer, the first polymer has nonpolar property, and a molecular chain of the second polymer has a polar structure. In some embodiments thereof, the first polymer comprises a styrenic block copolymer and/or a polyolefin. In some of these embodiments, the second polymer has a weak polar nature. In some embodiments, the polar structure in the second polymer is located in the backbone of the second polymer and/or in the side chains of the second polymer. In some of these embodiments, the first polymer has an average molecular weight greater than 200000g/mol. In some of these embodiments, the second polymer has an average molecular weight of 200000g/mol to 1000000g/mol. In some embodiments, the side chains of the second polymer contain the polar structure including a polar structure provided by at least one monomer of chloromethyl, polyphenylene ether, dibutyl maleate, diethyl maleate, maleic anhydride, glycidyl methacrylate, acrylic acid, p-chloromethylstyrene, bis-trimethylsilylated vinyl phosphate, Z-hydroxyethyl methacrylate phosphate, ethylenediamine tetraacetic dianhydride, N-substituted maleimide, oleic acid, methacrylic acid, acrylamide, vinyl silane, and caprolactam. In some of these embodiments, the side chains of the second polymer contain the polar structure, and the mass grafting ratio of the polar structure in the second polymer is 0.1% to 3%. In some of these embodiments, the side chains of the second polymer contain the polar structure, and the second polymer comprises a first polymer grafted with the polar structure. In some of these embodiments, the backbone of the second polymer comprises the polar structure, and the second polymer comprises hydrogenated nitrile rubber and/or acrylate rubber. In some embodiments thereof, the styrenic block copolymer comprises at least one of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, polystyrene-b-poly [ ethylene- (ethylene-propylene) ] -b-polystyrene, and styrene-ethylene-propylene-styrene. In some embodiments thereof, the polyolefin comprises at least one of polyethylene, polypropylene, polyisobutylene, and amorphous polyalphaolefin. In some embodiments, the nonpolar solvent has a dielectric constant of 2.5 or less. In some embodiments, the weak polar solvent has a dielectric constant of 2 to 5. In some embodiments, the non-polar solvent has a flash point of 45 ℃ or greater. In some of these embodiments, the weak polar solvent has a flash point of 45 ℃ or greater. In some embodiments, the non-polar solvent does not react with the sulfide electrolyte. In some embodiments thereof, the nonpolar solvent includes at least one of a heavy aromatic hydrocarbon solvent, an alkane solvent, and a mono-olefin solvent. In some embodiments thereof, the less polar solvent comprises an ester solvent and/or an ether solvent. In some of these embodiments, the mass ratio of the first polymer to the second polymer is (0.25-4): 1. In some embodiments, the mass ratio of the non-polar