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CN-122000433-A - Electrolyte and preparation method thereof

CN122000433ACN 122000433 ACN122000433 ACN 122000433ACN-122000433-A

Abstract

The invention relates to the technical field of lithium battery electrolyte, in particular to an electrolyte and a preparation method thereof, wherein the method comprises the steps of preparing local high-concentration electrolyte; the method comprises the steps of providing epoxy resin and a curing agent thereof, mixing local high-concentration electrolyte, the epoxy resin and the curing agent thereof to obtain pouring liquid, providing glass fibers, infiltrating the pouring liquid into the glass fibers, and curing the infiltrated glass fibers in situ to obtain the electrolyte. The electrolyte and the preparation method thereof can solve the technical problems of poor mechanical strength and low conductivity of the solid electrolyte.

Inventors

  • XIANG YONG
  • LIU HAO
  • LUO ZHENJUN
  • ZHANG WEILI

Assignees

  • 电子科技大学
  • 清华大学合肥公共安全研究院

Dates

Publication Date
20260508
Application Date
20240724

Claims (10)

  1. 1. A method of preparing an electrolyte, the method comprising: Preparing local high-concentration electrolyte; Providing epoxy resin and a curing agent thereof, blending local high-concentration electrolyte, epoxy resin and the curing agent thereof, and inducing microphase separation of the epoxy resin by using the local high-concentration electrolyte to obtain pouring liquid; And providing glass fibers, soaking the pouring liquid into the glass fibers, and carrying out in-situ solidification on the soaked glass fibers to obtain the electrolyte.
  2. 2. The method of preparing an electrolyte according to claim 1, wherein the local high concentration electrolyte comprises 1, 2-tetrafluoroethyl-2, 3-tetrafluoropropyl ether (TT E), ethylene glycol dimethyl ether (DM E) and lithium salt.
  3. 3. The method for preparing an electrolyte according to claim 2, wherein the volume ratio of the ethylene glycol dimethyl ether to the 1, 2-tetrafluoroethyl-2, 3-tetrafluoropropyl ether is (80% -20%) (20% -80%).
  4. 4. The method for preparing an electrolyte according to claim 2, wherein the lithium salt is LiTF SI or LiF SI and the concentration of the lithium salt is 0.5M to 1.5M.
  5. 5. The method for preparing an electrolyte according to claim 1, wherein the mass ratio of the local high-concentration electrolyte to the epoxy resin to the curing agent is 1-10 to 1 (0.1-0.5).
  6. 6. The method of claim 1, wherein the epoxy resin is E54 and the curing agent is a diethylenetriamine curing agent specific for E54.
  7. 7. The method for preparing an electrolyte according to claim 1, wherein the glass fiber has a thickness of 100 μm to 500. Mu.m, and a cross-sectional diameter of 19mm.
  8. 8. The method for preparing the electrolyte according to claim 1, wherein the step of impregnating the glass fiber with the casting solution and curing the impregnated glass fiber in situ to obtain the electrolyte comprises the steps of impregnating the glass fiber with the casting solution to obtain a wet film, carrying out constant temperature treatment on the wet film at a first temperature for a first duration, and carrying out constant temperature treatment at a second temperature for a second duration to complete curing to obtain the electrolyte, wherein the second temperature is higher than the first temperature.
  9. 9. The method for producing an electrolyte according to claim 8, wherein the wet film is heated to 30 to 60℃at 0.2 to 2℃per minute on a hot press, cured at a constant temperature for 2 to 8 hours, and then heated to 80 to 100℃at 1 to 3℃per minute, and kept at a constant temperature for 30 to 150 minutes.
  10. 10. An electrolyte characterized by being prepared by the method for preparing an electrolyte according to any one of claims 1 to 9.

Description

Electrolyte and preparation method thereof [ Field of technology ] The invention relates to the technical field of lithium battery electrolyte, in particular to electrolyte and a preparation method thereof. [ Background Art ] Lithium ion batteries play an important role in the storage of renewable energy sources, but current lithium ion batteries are difficult to meet the requirements of large-scale energy storage on energy density, safety and cost. Current research into lithium ion batteries is divided into two approaches, one is to continue to optimize the traditional lithium ion batteries, and the other is to improve the core components of the batteries in a large scale to develop next generation batteries. Among them, solid-state batteries are attracting attention because of higher safety, energy density and longer cycle life. The greatest advantage of solid-state batteries over conventional lithium-ion batteries is their higher safety, since solid-state batteries do not contain flammable organic electrolytes and solid-state electrolytes themselves are not flammable. Solid-state batteries have a longer cycle life because of their slower side reactions than liquids themselves. In addition, many aging factors in conventional lithium ion batteries have little effect on solid state batteries, such as problems with dissolution of transition metals. However, the solid electrolyte is capable of withstanding the impact of dendrites for a short period of time as compared with the liquid electrolyte, but the solid electrolyte is deformed by being continuously subjected to external force during long-time cycling of the battery, residual stress inside the membrane is gradually accumulated, and finally the material is disabled, so that the problem of mechanical deterioration is more serious in the solid battery. Notably, in solid electrolytes, the electrical conductivity between the electrolyte and the electrode is greatly impaired because of the presence of polymer organic components or the difficulty in solving the problem of the inorganic electrolyte interface, and the electrical resistance of the overall electrolyte is inevitably increased. Therefore, when the requirements of mechanical strength and conductivity are simultaneously met, it is important to find a new design method and thought to simultaneously meet the requirements of the solid electrolyte. [ Invention ] The invention provides an electrolyte and a preparation method thereof, which aim to solve the technical problems of poor mechanical strength and low conductivity of solid electrolyte. The invention provides a technical scheme for solving the technical problems, and the method comprises the steps of preparing local high-concentration electrolyte, providing epoxy resin and a curing agent thereof, blending the local high-concentration electrolyte, the epoxy resin and the curing agent thereof, inducing microphase separation of the epoxy resin by using the local high-concentration electrolyte to obtain casting solution, providing glass fibers, infiltrating the casting solution into the glass fibers, and curing the infiltrated glass fibers in situ to obtain the electrolyte. Preferably, the local high concentration electrolyte composition comprises 1, 2-tetrafluoroethyl-2, 3-tetrafluoropropyl ether (tte), ethylene glycol dimethyl ether (DM E) and lithium salt. Preferably, the volume ratio of the ethylene glycol dimethyl ether to the 1, 2-tetrafluoroethyl-2, 3-tetrafluoropropyl ether is (80% -20%) (20% -80%). Preferably, the lithium salt is Li TF S I or LiF S I, and the concentration of the lithium salt is 0.5M-1.5M. Preferably, the mass ratio of the local high-concentration electrolyte to the epoxy resin to the curing agent is (1-10) 1 (0.1-0.5). Preferably, the epoxy resin is epoxy resin E54, and the curing agent is a diethylenetriamine curing agent special for the epoxy resin E54. Preferably, the thickness of the glass fiber is 100-500 mu m, and the diameter of the cross section is 19mm. Preferably, the step of impregnating the glass fiber with the casting solution, and the step of in-situ curing the impregnated glass fiber to obtain the electrolyte comprises the steps of impregnating the glass fiber with the casting solution to obtain a wet film, carrying out constant temperature treatment on the wet film at a first temperature for a first duration, and carrying out constant temperature treatment at a second temperature for a second duration to complete curing to obtain the electrolyte, wherein the second temperature is higher than the first temperature. Preferably, the wet film is heated to 30-60 ℃ at 0.2-2 ℃ per min on a hot press, cured at constant temperature for 2-8 hours, and then heated to 80-100 ℃ at 1-3 ℃ per min, and maintained at constant temperature for 30-150min. The invention provides another technical scheme for solving the technical problems, namely an electrolyte prepared by the method for preparing the electrolyte. Compared with the