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CN-122025778-A - Preparation method of composite polymer quasi-solid electrolyte

CN122025778ACN 122025778 ACN122025778 ACN 122025778ACN-122025778-A

Abstract

The invention belongs to the field of solid lithium ion battery materials, and particularly relates to a preparation method of a composite polymer quasi-solid electrolyte, which comprises the following steps of 1) taking trimesic acid and aluminum nitrate nonahydrate as raw materials, performing solvothermal reaction, and washing and drying; 2) modifying the product of the step 1) by using magnesium salt ethanol solution, washing and drying, mixing with PVDF and LiTFSI, mixing and stirring in a solvent to obtain a suspension, 3) casting the suspension into a film, and uncovering the film after vacuum drying to obtain a finished product. The preparation method has the advantages of simple process and good compatibility with the existing battery electrode processing process (such as a coating method). The prepared electrolyte membrane has good flexibility, is easy to integrate with an electrode, and has considerable application potential in the fields of quasi-solid lithium metal batteries, flexible electronic equipment and the like.

Inventors

  • ZENG DONGQING
  • HU HAIJUN
  • XU SAIQIN
  • SUN YONG
  • WANG KUN
  • ZHOU WEIMIN
  • XU GUIYING
  • LIU YUE

Assignees

  • 安徽晖阳新能源材料有限公司
  • 辽宁科技大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. A method for preparing a composite polymer quasi-solid electrolyte, which is characterized by comprising the following steps: 1) Dissolving trimesic acid in ethanol solution, adding aluminum nitrate nonahydrate, stirring uniformly, adding the uniformly mixed solution into a reaction kettle, placing the reaction kettle in a constant-temperature drying oven, keeping the temperature of 150-200 ℃ for 10-13 hours, centrifugally washing, respectively washing with ethanol and deionized water to be neutral, and vacuum drying the product at 50-70 ℃ for 10-12 hours; 2) Dissolving magnesium salt in ethanol solution, adding the material obtained in the step 1), carrying out ultrasonic and magnetic stirring, centrifugally washing the reacted solution, washing the solution to be neutral by ethanol and deionized water respectively, and carrying out vacuum drying on the product at 50-70 ℃ for 10-12 h; 3) Uniformly mixing 0.01-0.05 g of the sample obtained in the step 2), 0.4-0.8 g of PVDF and 0.1-0.5 g of LiTFSI, then adding the mixture into 10-30 ml of solvent, and mixing and stirring for 4-9 hours to obtain suspension; 4) Casting the suspension obtained in the step 3) into a die, vacuum drying the suspension in a vacuum drying oven at 50-60 ℃ for 12-36 hours, and removing the formed film after cooling to room temperature to obtain the composite polymer quasi-solid electrolyte material.
  2. 2. The method for preparing the composite polymer quasi-solid electrolyte according to claim 1, wherein in the step 1), 20-40 ml of ethanol and 20-40 ml of deionized water are mixed in a beaker to obtain an ethanol solution, 0.3-0.6 g of trimesic acid is added, and 6-10 g of aluminum nitrate nonahydrate is added after the trimesic acid is dissolved.
  3. 3. The method for preparing a quasi-solid electrolyte of a composite polymer according to claim 1, wherein in the step 1), stirring is carried out uniformly at 200-300 rpm, and the stirring is maintained for 10-15 min.
  4. 4. The method for preparing the quasi-solid electrolyte of the composite polymer according to claim 1, wherein in the step 2), 40-60 ml of ethanol and 40-60 ml of deionized water are mixed in a beaker, 0.3-1.2 g of magnesium salt is added, after magnesium sulfate is dissolved, 0.1-0.3 g of the material obtained in the step 1) is added, and the ultrasonic treatment is carried out for 10-15 min, and the magnetic stirring is carried out for more than 24 hours.
  5. 5. The method of claim 1 or 4, wherein the magnesium salt is magnesium sulfate, magnesium nitrate or magnesium chloride.
  6. 6. The method for preparing a quasi-solid electrolyte of a composite polymer according to claim 1, wherein the centrifugal washing speed is 8000-10000 rpm, and the centrifugal washing time is kept for 12-15 min.
  7. 7. The method for preparing a quasi-solid electrolyte of composite polymer according to claim 1, wherein the solvent in the step 3) is DMF or NMP.
  8. 8. The method for preparing the quasi-solid electrolyte of the composite polymer according to claim 1, wherein PVDF and LiTFSI in the step 3) are dried in vacuum at 50-70 ℃ for 12-36 hours in a vacuum drying oven before use.
  9. 9. The method for preparing a quasi-solid electrolyte of composite polymer according to claim 1, wherein the molecular weight of the PVDF is 400000 to 600000.
  10. 10. The method for preparing a quasi-solid electrolyte of composite polymer according to claim 1, wherein in the step 4), the mold is a glass culture dish circular mold with a diameter of 40-70 mm.

Description

Preparation method of composite polymer quasi-solid electrolyte Technical Field The invention belongs to the field of solid lithium ion battery materials, and particularly relates to a preparation method of a composite polymer quasi-solid electrolyte. Background Lithium ion batteries have been widely used in the fields of portable electronic devices, electric vehicles, large-scale energy storage systems, and the like due to their advantages of high energy density, long cycle life, and the like. The traditional lithium ion battery adopts liquid electrolyte (organic electrolyte and lithium salt), although the basic ion transmission requirement can be met, potential safety hazards such as liquid leakage, inflammability, explosiveness and the like exist, side reactions are easy to occur at the interface of the liquid electrolyte and an electrode, so that the battery cycle stability is reduced, and the development requirement of next-generation energy storage equipment with high energy density and high safety is difficult to adapt. The solid electrolyte can be divided into three types of inorganic solid electrolyte, polymer solid electrolyte and composite solid electrolyte according to materials, wherein the inorganic solid electrolyte (such as sulfide and oxide) has the characteristics of high ionic conductivity, excellent mechanical strength and the like, but has the problems of high brittleness, high interface contact resistance, high processing cost and the like, the composite solid electrolyte combines the advantages of inorganic and polymer systems, the inorganic filler is introduced into a polymer matrix to improve ion transmission and mechanical properties, the polymer solid electrolyte takes the polymer as a matrix, lithium salt as an ion source, an organic solvent is not needed, the flexible and large-scale preparation (such as solution casting and hot press molding) can be realized, good interface contact with an electrode can be formed, and the like, and the solid electrolyte is particularly suitable for flexible energy storage equipment, can further optimize the performance through molecular design or composite modification, and becomes one of the solid electrolyte systems with the most industrialization potential. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a preparation method of a composite polymer quasi-solid electrolyte, which solves the problem of low lithium ion mobility caused by high crystallinity of a single polymer electrolyte membrane at room temperature, and can prepare the composite polymer quasi-solid electrolyte by well dispersing a filler in a polar solvent through chemical modification of the surface of MOF, thereby well inhibiting the crystallization phase of the polymer and promoting the dissolution of lithium salt to improve the lithium ion mobility. In order to achieve the above purpose, the present invention is realized by the following technical scheme: a method for preparing a composite polymer quasi-solid electrolyte, comprising the steps of: 1) Dissolving trimesic acid in ethanol solution, adding aluminum nitrate nonahydrate, stirring uniformly, adding the uniformly mixed solution into a reaction kettle, placing the reaction kettle in a constant-temperature drying oven, keeping the temperature of 150-200 ℃ for 10-13 hours, centrifugally washing, respectively washing with ethanol and deionized water to be neutral, and vacuum drying the product at 50-70 ℃ for 10-12 hours; 2) Dissolving magnesium salt in ethanol solution, adding the material obtained in the step 1), carrying out ultrasonic and magnetic stirring, centrifugally washing the reacted solution, washing the solution to be neutral by ethanol and deionized water respectively, and carrying out vacuum drying on the product at 50-70 ℃ for 10-12 h; 3) Uniformly mixing 0.01-0.05 g of the sample obtained in the step 2), 0.4-0.8 g of PVDF and 0.1-0.5 g of LiTFSI, then adding the mixture into 10-30 ml of solvent, and mixing and stirring for 4-9 hours to obtain suspension; 4) Casting the suspension obtained in the step 3) into a die, vacuum drying the suspension in a vacuum drying oven at 50-60 ℃ for 12-36 hours, and removing the formed film after cooling to room temperature to obtain the composite polymer quasi-solid electrolyte material. In the step 1), 20-40 ml of ethanol and 20-40 ml of deionized water are taken and mixed in a beaker to obtain an ethanol solution, then 0.3-0.6 g of trimesic acid is added, and after the trimesic acid is dissolved, 6-10 g of aluminum nitrate nonahydrate is added. In the step 1), stirring uniformly, stirring at 200-300 rpm, and keeping for 10-15min. In the step 2), 40-60 ml of ethanol and 40-60 ml of deionized water are taken and mixed in a beaker, then 0.3-1.2 g of magnesium salt is added, after magnesium sulfate is dissolved, 0.1-0.3 g of the material obtained in the step 1) is added, ultrasonic treatment is carried out for 10-15