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CN-121983654-A - Preparation method of ultrathin sulfide solid electrolyte dry film

CN121983654ACN 121983654 ACN121983654 ACN 121983654ACN-121983654-A

Abstract

The invention discloses a preparation method of an ultrathin sulfide solid electrolyte dry film, relates to the technical field of solid electrolyte dry films, and solves the problems that an electrolyte film is subjected to hole and crack generation in transfer printing after rolling of a traditional solid electrolyte dry film, and the thickness of the electrolyte film is difficult to reach below 30 mu m. The method comprises the following steps of S1, preparing a positive electrode thick film, S2, preparing an electrolyte thick film, S3, sequentially stacking a release film, the positive electrode thick film and the electrolyte thick film to form a laminated structure, S4, carrying out multistage rolling on the laminated structure by using a roller press by adopting a differential temperature multistage composite rolling method, synchronously thinning and compositing the positive electrode thick film and the electrolyte thick film to form a composite film, and S5, stripping the release film from the composite film to obtain the ultrathin sulfide solid electrolyte dry film. The invention solves the problem that the traditional electrolyte thick film generates holes and cracks in the transfer printing link after rolling.

Inventors

  • Lv Fengzheng

Assignees

  • 深圳固丰硅科新材料有限公司

Dates

Publication Date
20260505
Application Date
20260225

Claims (10)

  1. 1. The preparation method of the ultrathin sulfide solid electrolyte dry film is characterized by comprising the following steps of: s1, preparing a positive thick film by adopting a positive material, a conductive agent, sulfide solid electrolyte and a binder; S2, preparing an electrolyte thick film; S3, stacking the release film, the positive electrode thick film and the electrolyte thick film in sequence to form a laminated structure; s4, carrying out multistage rolling on the laminated structure by using a roller press by adopting a differential temperature multistage composite rolling method, and synchronously thinning and compositing the positive thick film and the electrolyte thick film to form a composite film; and S5, stripping the release film from the composite film to obtain the ultrathin sulfide solid electrolyte dry film.
  2. 2. The method for preparing an ultrathin sulfide solid electrolyte dry film according to claim 1, wherein the positive electrode thick film is obtained by rolling a positive electrode material, a conductive agent, a sulfide solid electrolyte and a binder, and has a thickness of 150-250 μm.
  3. 3. The method for preparing the ultrathin sulfide solid state electrolyte dry film according to claim 2, wherein the positive electrode material comprises one or more of ternary materials, lithium-rich manganese-based materials, lithium cobaltates and lithium iron phosphates, the sulfide solid state electrolyte comprises one or more of sulfur silver germanium ore type Li 6 PS 5 Cl, sulfide glass ceramic type Li 7 P 3 S 11 and lithium-free sulfide type Na 3 PS 4 , and the binder comprises polytetrafluoroethylene or polyvinylidene fluoride.
  4. 4. The method for preparing an ultrathin sulfide solid electrolyte dry film as claimed in claim 3, wherein the addition amount of sulfide solid electrolyte in the preparation process of the positive electrode thick film is 0.5-5% of the total mass of the positive electrode material, the conductive agent and the binder.
  5. 5. The method for preparing an ultrathin sulfide solid electrolyte dry film as claimed in claim 4, wherein the electrolyte thick film in the step S2 is prepared by mixing sulfide solid electrolyte and a binder as raw materials, fibrillating the mixture, and rolling the mixture to obtain the electrolyte thick film with the thickness of 80-120 μm.
  6. 6. The method for preparing the ultrathin sulfide solid electrolyte dry film as claimed in claim 5, wherein the roller press in the step S4 comprises at least five groups of rollers, at least five stages of rolling processes are carried out, the roller gap of each stage of rolling process is independently controllable, the roller gap from the feeding end to the discharging end is gradually decreased, and the thinning amplitude of each stage is 10-30 μm.
  7. 7. The method for preparing an ultrathin sulfide solid electrolyte dry film according to claim 6, wherein each group of rollers comprises an upper roller shaft and a lower roller shaft, the temperatures of the upper roller shaft and the lower roller shaft are set to be 75-130 ℃, and the temperature difference between the upper roller shaft and the lower roller shaft is 10-50 ℃; The upper roll shaft and the lower roll shaft of the roller rotate in a differential mode on the basis of differential temperature setting.
  8. 8. The method for preparing an ultrathin sulfide solid electrolyte dry film as claimed in claim 7, wherein the temperature of the upper roller is set to 125 ℃, the temperature of the lower roller is set to 80 ℃, and the upper roller and the lower roller rotate at a constant speed.
  9. 9. The method for preparing an ultrathin sulfide solid electrolyte dry film according to claim 7, wherein the temperature of the upper roller is set to 125 ℃, the temperature of the lower roller is set to 125 ℃, and the upper roller and the lower roller rotate at a constant speed.
  10. 10. The method for preparing a dry film of an ultrathin sulfide solid electrolyte according to claim 7, wherein the temperature of the upper roller is set to 80 ℃, the temperature of the lower roller is set to 80 ℃, and the upper roller and the lower roller rotate at a constant speed.

Description

Preparation method of ultrathin sulfide solid electrolyte dry film Technical Field The invention relates to the technical field of solid electrolyte dry films, in particular to a preparation method of an ultrathin sulfide solid electrolyte dry film. Background The solid electrolyte is a functional material which keeps solid state at normal temperature or high temperature and has high ion conduction capability, is mainly used for replacing liquid electrolyte and a diaphragm in the traditional lithium battery so as to improve the safety and energy density of the battery, plays a core role in the solid battery, can conduct cations such as lithium ions (Li +) and the like, and can prevent electrons from passing through, thereby realizing the storage and release of electric energy; the solid electrolyte dry hair film is a solid electrolyte film prepared by using solid electrolyte as a material through a dry process, and is characterized in that solvent is not used, solid electrolyte powder and a binder are directly mixed and then pressed for forming, so that a compact film with an ion conduction function is formed. The traditional solid electrolyte dry film needs to be transferred after rolling, the electrolyte film has the problems of generating holes and cracks in the transfer, and the thickness of the electrolyte film is difficult to reach below 30 mu m, so that the existing requirements are not met, and the preparation method of the ultrathin sulfide solid electrolyte dry film is provided. Disclosure of Invention The invention aims to provide a preparation method of an ultrathin sulfide solid electrolyte dry film, which aims to solve the problems that the conventional solid electrolyte dry film proposed in the background art needs to be transferred after being rolled, holes and cracks are generated in an electrolyte film during transfer, and the thickness of the electrolyte film is difficult to be less than 30 mu m. In order to achieve the purpose, the invention provides the following technical scheme that the preparation method of the ultrathin sulfide solid electrolyte dry film comprises the following steps: s1, preparing a positive electrode thick film; S2, preparing an electrolyte thick film; S3, stacking the release film, the positive electrode thick film and the electrolyte thick film in sequence to form a laminated structure; s4, carrying out multistage rolling on the laminated structure by using a roller press by adopting a differential temperature multistage composite rolling method, and synchronously thinning and compositing the positive thick film and the electrolyte thick film to form a composite film; and S5, stripping the release film from the composite film to obtain the ultrathin sulfide solid electrolyte dry film. Preferably, the positive electrode thick film in S1 is formed by rolling a positive electrode material, a conductive agent, a sulfide solid electrolyte and a binder, including but not limited to raw materials, to obtain a positive electrode thick film with a thickness of 150-250 μm. Preferably, the positive electrode material includes, but is not limited to, one or more of ternary materials, lithium-rich manganese-based materials, lithium cobaltate, lithium iron phosphate, sulfide solid state electrolytes including, but not limited to, one or more of silver-sulfur germanium ore type Li 6PS5 Cl, sulfide glass ceramic type Li 7P3S11, lithium-free sulfide type Na 3PS4, and binders including, but not limited to, polytetrafluoroethylene or polyvinylidene fluoride. Preferably, in the preparation process of the positive electrode thick film, the addition amount of the sulfide solid electrolyte accounts for 0.5-5% of the total mass of the positive electrode material, the conductive agent and the binder. Preferably, the electrolyte thick film in the step S2 is prepared by mixing sulfide solid electrolyte and binder as raw materials, fibrillating the mixture, and rolling to obtain the electrolyte thick film with the thickness of 80-120 mu m. Preferably, the roller press in the step S4 comprises at least five groups of rollers, at least five stages of rolling processes are performed, the roller shaft gap of each stage of rolling process is independently controllable, the roller shaft gap from the feeding end to the discharging end is gradually decreased, and the thinning amplitude of each stage is 10-30 μm; The upper roll shaft and the lower roll shaft of the roller rotate in a differential mode on the basis of differential temperature setting. Preferably, each set of rolls comprises an upper roll shaft and a lower roll shaft, the temperatures of the upper roll shaft and the lower roll shaft are set to be 75-130 ℃, and the temperature difference between the upper roll shaft and the lower roll shaft is 10-50 ℃. Preferably, the temperature of the upper roller shaft is set to 125 ℃, the temperature of the lower roller shaft is set to 80 ℃, and the upper roller shaft and the lower roller shaft ro