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CN-122025533-A - Positive electrolyte membrane slurry, positive electrolyte membrane, preparation method of positive electrolyte membrane and sulfide all-solid-state battery

CN122025533ACN 122025533 ACN122025533 ACN 122025533ACN-122025533-A

Abstract

The invention provides positive electrolyte membrane slurry, a positive electrolyte membrane, a preparation method of the positive electrolyte membrane and a sulfide all-solid-state battery, and relates to the technical field of sulfide all-solid-state batteries. The positive electrode film slurry comprises a slurry I, a slurry II and an emulsifying agent, wherein the slurry I contains a binder, a conductive agent and a polar organic solvent, the slurry II contains an electrolyte, an active substance and a nonpolar organic solvent, the electrolyte is sulfide electrolyte, the active substance is at least one selected from iFePO 4 、LiCoO 2 、NCM、NCA、LiMn 2 O 4 , and the emulsifying agent is one or more selected from sorbitol esters, fatty acid esters, polyoxyethylene ethers, block copolymer emulsifying agents and anionic emulsifying agents. The invention reduces the reactivity of the positive electrode film and improves the cohesiveness by improving the preparation method of the positive electrode film.

Inventors

  • YU TINGTING
  • LIU LIWEN
  • WANG CHENG
  • LIU JINYUN
  • ZHU LINGYUN
  • ZHENG SIYAN
  • HU MINGTAO
  • HUANG XIUYING

Assignees

  • 广州融捷能源科技有限公司

Dates

Publication Date
20260512
Application Date
20260206

Claims (10)

  1. 1. The positive electrolyte membrane slurry is characterized by comprising slurry I, slurry II and an emulsifier; the slurry I contains a binder, a conductive agent and a polar organic solvent; The slurry II contains electrolyte, active substances and nonpolar organic solvent, wherein the electrolyte is sulfide electrolyte, and the active substances are at least one selected from LiFePO 4 、LiCoO 2 、NCM、NCA、LiMn 2 O 4 ; The emulsifier is one or more selected from sorbitol ester glyceride, fatty acid ester, polyoxyethylene ether, block copolymer emulsifier and anionic emulsifier.
  2. 2. The positive electrode electrolyte slurry according to claim 1, wherein, The mass ratio of the binder to the conductive agent to the polar organic solvent is 1 (0.1-0.5) (8-20); And/or the mass ratio of the electrolyte, the active substance and the nonpolar organic solvent is 1 (1-4): 1-8 And/or the mass ratio of the emulsifier to the slurry I to the slurry II is 1 (50-150) (20-80).
  3. 3. The positive electrolyte membrane slurry according to claim 1, wherein, The sulfide electrolyte is selected from at least one of LGPS, LPSC, LPSI. And/or the binder is selected from at least one of PVDF, PTFE, SBR, CMC, PAA, PVA.
  4. 4. The positive electrolyte membrane slurry according to claim 1, wherein, The conductive agent is at least one selected from Super P, acetylene black, carbon nanotubes, graphene and carbon fibers.
  5. 5. The positive electrolyte membrane slurry according to claim 1, wherein, The polar organic solvent is at least one selected from NMP, DMF, DMSO, acetone, THF, ethyl acetate, dichloromethane and isopropanol; and/or the nonpolar organic solvent is selected from one or more of toluene, xylene, cyclohexane and n-hexane.
  6. 6. The preparation method of the positive electrolyte membrane is characterized by comprising the following steps: S1, mixing a binder, a conductive agent and a polar organic solvent to obtain slurry I; s2, mixing electrolyte, active substances and nonpolar organic solvent II to obtain slurry II; S3, mixing the mixed slurry II, the emulsifying agent and the slurry I with III to obtain positive electrode film slurry; And S4, carrying out blade coating or spraying on the anode film slurry on an aluminum foil by a tape casting method, and drying and hot-pressing to obtain the anode electrolyte film.
  7. 7. The method for producing a positive electrode electrolyte membrane according to claim 6, wherein, The conditions of the mixture I, the mixture II and the mixture III are respectively and independently selected from one or more of ball milling, stirring, acoustic resonance and vibration, and the mixing time is 0.5-3 h; the drying conditions comprise that the drying mode is preferably baking, the drying temperature is 30-60 ℃, and the drying time is 20-80 h; The hot pressing conditions comprise a flat plate hot pressing mode, the hot pressing pressure is 0.1-5 mpa, the hot pressing temperature is 150-200 ℃, and the hot pressing time is 2-10 min.
  8. 8. A positive electrode electrolyte membrane prepared from the positive electrode electrolyte membrane slurry according to any one of claims 1 to 5 or prepared by the method according to claim 6 or 7.
  9. 9. The positive electrolyte membrane according to claim 8, wherein, The elastic modulus of the positive electrolyte membrane is 0.1 Gpa-1 Gpa; The tensile strength of the positive electrolyte membrane is 1 mpa-35 mpa.
  10. 10. A sulfide all-solid battery comprising the positive electrode electrolyte membrane according to claim 8 or 9.

Description

Positive electrolyte membrane slurry, positive electrolyte membrane, preparation method of positive electrolyte membrane and sulfide all-solid-state battery Technical Field The invention relates to the technical field of sulfide all-solid-state batteries, in particular to positive electrolyte membrane slurry, a positive electrolyte membrane, a preparation method of the positive electrolyte membrane and a sulfide all-solid-state battery. Background Sulfide all-solid-state batteries (ASSB) are favored in the field of energy storage for their excellent safety and high energy density. In solution processing, a suitable solvent in combination with a binder has a significant impact on battery performance. The ideal solvent can be well compatible with sulfide Solid Electrolyte (SE), avoid degradation, ensure the inherent performance of the electrolyte, and the adaptive binder can enhance the stability of the electrode structure, ensure the close contact between the active material and the electrolyte, and improve the cycle performance and the processability of the battery. However, sulfide all-solid batteries face a prominent problem in solution processing that solvents and binders are difficult to cooperate. On one hand, sulfide SE is easy to degrade in polar solvent, so that only nonpolar solvent can be selected, the selection range of binder is greatly limited, and on the other hand, the low-polarity binder which can be dissolved in nonpolar solvent has weak interaction with active material and sulfide SE, so that good contact between solids is difficult to maintain, and the battery performance is affected. These problems seriously hamper commercialization of sulfide ASSB by scalable solution processes, and thus an innovative approach to break through this technical bottleneck is urgently needed. Disclosure of Invention Based on the above problems, the present invention provides a method for preparing a cathode film with low reactivity and high adhesiveness, which reduces the reactivity of the cathode film and improves the adhesiveness by improving the method for preparing the cathode film. The invention provides a positive electrolyte membrane slurry, which comprises a slurry I, a slurry II and an emulsifying agent, wherein the slurry I is a polar phase and contains a binder, a conductive agent and a polar organic solvent, the efficient dispersion of the binder is realized by utilizing the dissolution characteristic of the polar organic solvent, a plurality of adaptive polar organic solvents and binder combination forms can be configured, the application scene of a system is expanded, the slurry II is a nonpolar phase and contains electrolyte, active substances and nonpolar organic solvents, the problem of structural instability of the sulfide electrolyte caused by contact with a polar system can be effectively reduced by the aid of the suitability of the nonpolar organic solvents and the sulfide electrolyte, the emulsifying agent comprises one or more of sorbitol esters, glyceride esters, fatty acid esters, polyoxyethylene ethers, block copolymer emulsifying agents and anionic emulsifying agents, the electrolyte is the sulfide electrolyte, and the active substances are at least one selected from LiFePO 4、LiCoO2、NCM、NCA、LiMn2O4. In a preferred embodiment, the mass ratio of the binder to the conductive agent to the polar organic solvent is 1 (0.1-0.5): 8-20; As a preferred embodiment, the mass ratio of the electrolyte, the active substance and the nonpolar organic solvent is 1 (1-4): 1-8 As a preferable implementation mode, the mass ratio of the emulsifier to the slurry I to the slurry II is 1 (50-150) to 20-80. As a preferred embodiment, the sulfide electrolyte is selected from at least one of LGPS (lithium germanium phosphorus sulfur), LPSC (lithium phosphorus sulfur chlorine), LPSI (lithium phosphorus sulfur iodine). As a preferred embodiment, the polar organic solvent is at least one selected from NMP (N-methylpyrrolidone), DMF (N, N-dimethylformamide), DMSO (dimethyl sulfoxide), acetone, THF (tetrahydrofuran), ethyl acetate, dichloromethane, isopropanol. As a preferred embodiment, the nonpolar organic solvent includes, but is not limited to, one or more of toluene, xylene, cyclohexane, and n-hexane. As a preferred embodiment, the binder is at least one selected from PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), SBR (styrene butadiene rubber), CMC (sodium carboxymethyl cellulose), PAA (polyacrylic acid), PVA (polyvinyl alcohol). The conductive agent includes, but is not limited to, one or more of Super P, acetylene black, carbon Nanotubes (CNTs), graphene, and carbon fibers as a preferred embodiment. As a preferred embodiment, the active material is one or both of LiFePO 4、LiCoO2、NCM、NCA、LiMn2O4. In a second aspect, the present invention provides a method for preparing a cathode film having low reactivity and high adhesion, comprising the steps of: S1, uniformly mixing a binder, a conducti