Search

CN-121983505-A - Zinc powder composite pole piece with cyclized polyacrylonitrile self-assembled protective layer and preparation method and application thereof

CN121983505ACN 121983505 ACN121983505 ACN 121983505ACN-121983505-A

Abstract

The invention relates to the technical field of zinc cathodes, in particular to a zinc powder composite pole piece with a cyclized polyacrylonitrile self-assembled protective layer, and a preparation method and application thereof. The preparation method comprises the steps of dispersing cyclized polyacrylonitrile in water, adding zinc powder, stirring for 2-5 hours, standing for self-assembly, collecting dark precipitates, vacuum drying to obtain a zinc powder composite material cPAN@ZnP with a cyclized polyacrylonitrile self-assembly protective layer, dissolving the cPAN@ZnP, a conductive material and an adhesive in a solvent to prepare slurry, and coating the slurry on a current collector copper foil to obtain the zinc powder composite pole piece. The water-based zinc ion symmetric battery with the zinc powder composite pole piece with the cyclized polyacrylonitrile self-assembled protective layer prepared by the invention has long cycle life. The zinc-iodine full-cell battery also has good performance, high rate performance and long service life.

Inventors

  • ZHU YUNHAI
  • FU XIAONA
  • YANG YINGKUI
  • WANG MEIFANG
  • YANG ZIXUAN
  • Jiang yalong
  • CHENG YU

Assignees

  • 武汉纺织大学

Dates

Publication Date
20260505
Application Date
20260204

Claims (10)

  1. 1. The preparation method of the zinc powder composite pole piece with the cyclized polyacrylonitrile self-assembled protective layer is characterized by comprising the following steps: Dispersing cyclized polyacrylonitrile in water, adding zinc powder, stirring, standing for self-assembly, collecting dark precipitates, and vacuum drying to obtain a zinc powder composite material cPAN@ZnP with a cyclized polyacrylonitrile self-assembly protective layer; and dissolving cPAN@ZnP, a conductive material and an adhesive in a solvent to prepare slurry, and coating the slurry on a current collector copper foil to obtain the zinc powder composite pole piece.
  2. 2. The method of claim 1, wherein the cyclized polyacrylonitrile is produced by placing polyacrylonitrile powder in a tube furnace and heating at 300 to 400 ℃ for 1 to 2 hours.
  3. 3. The preparation method of claim 1, wherein the mass ratio of the cyclized polyacrylonitrile to the zinc powder in the cPAN@ZnP is 1-5:1-4.
  4. 4. The method of claim 1, wherein the mixture is stirred for 2 to 5 hours and then allowed to stand at room temperature for self-assembly for 30 to 120 minutes.
  5. 5. The method of claim 1, wherein the drying is performed at 40-90 ℃ for 8-16 hours.
  6. 6. The preparation method of claim 1, wherein the mass ratio of cPAN@ZnP, conductive material and adhesive is 6-8:1-2:1-4.
  7. 7. The method of claim 1, wherein the conductive material is conductive carbon black, the binder is polyvinylidene fluoride, and the solvent is 1-methyl-2-pyrrolidone.
  8. 8. The process of claim 1 wherein the zinc powder has a particle size of no greater than 50 μm; The thickness of the current collector copper foil is 50 mu m; and respectively ultrasonically washing the current collector copper foil in water and ethanol, and drying.
  9. 9. A zinc powder composite pole piece with a cyclized polyacrylonitrile self-assembled protective layer prepared by the preparation method of any one of claims 1 to 8.
  10. 10. Use of the zinc powder composite pole piece of claim 9 in a water-based zinc ion symmetric battery or a zinc-iodine full battery.

Description

Zinc powder composite pole piece with cyclized polyacrylonitrile self-assembled protective layer and preparation method and application thereof Technical Field The invention relates to the technical field of zinc cathodes, in particular to a zinc powder composite pole piece with a cyclized polyacrylonitrile self-assembled protective layer, and a preparation method and application thereof. Background The Aqueous Zinc Ion Battery (AZIBs) is widely regarded as a powerful candidate for future large-scale energy storage due to the advantages of high safety, low cost, environmental protection and the like. Currently, zinc foil is the most studied of aqueous zinc metal batteries. However, zinc foil is fixed in shape, and it is difficult to meet the demands of zinc-based electronic devices of complex shapes. In contrast, zinc powder (ZnP) has the advantages of low cost, good workability, good adjustability and the like, which is very attractive for large-scale production. However, the practical application of zinc powder cathodes still faces serious problems of polarization, hydrogen Evolution Reaction (HER), corrosion, inherent dendrite growth, etc. These problems not only lead to performance degradation of zinc powder cathodes, but also can significantly reduce battery capacity, coulombic efficiency, rate capability and cycle life, thereby limiting the wide application of aqueous zinc ion batteries. The root causes of these problems in the zinc powder negative electrode during the operation of the battery are the spherical structure of the high specific surface area of the zinc powder and the complex pore structure of the zinc powder negative electrode. On one hand, the huge specific surface area increases the contact area of zinc powder and electrolyte, so that hydrogen evolution reaction and corrosion are more severe. On the other hand, the complex pore structure makes the current distribution and zinc ion flux extremely uneven, and zinc ions are preferentially deposited on the surfaces and contact points of zinc powder particles during the charging process, so that dendrites are formed. The unavoidable volume shrinkage caused by zinc dissolution during the discharge phase consumes electrical contact between the powders and even produces complete contact loss, eventually leading to collapse of the electrode from the internal structure. In order to solve these problems, various technical solutions have been proposed, including structural modification of zinc powder, compounding with other materials, modification of binder, etc., but the existing protective layer design fails to fully solve the linkage effects of the problems of inherent dendrite growth, severe polarization, corrosion, hydrogen evolution, etc. Therefore, there is a need to develop a new, simple and efficient negative electrode protection scheme. Disclosure of Invention The invention aims at providing a zinc powder composite pole piece with a cyclized polyacrylonitrile self-assembled protective layer, and a preparation method and application thereof. The first object of the invention is to provide a preparation method of a zinc powder composite pole piece with a cyclized polyacrylonitrile self-assembled protective layer, which comprises the following steps: Dispersing cyclized polyacrylonitrile in water, adding zinc powder, stirring, standing for self-assembly, collecting dark precipitates, and vacuum drying to obtain a zinc powder composite material cPAN@ZnP with a cyclized polyacrylonitrile self-assembly protective layer; and dissolving cPAN@ZnP, a conductive material and an adhesive in a solvent to prepare slurry, and coating the slurry on a current collector copper foil to obtain the zinc powder composite pole piece. Further, placing the polyacrylonitrile powder into a tube furnace, and heating at 300-400 ℃ for 1-2 hours to obtain the cyclized polyacrylonitrile. Further, the mass ratio of the cPAN@ZnP to the zinc powder is 1-5:1-4. Further, stirring for 2-5 hours, and standing at room temperature for self-assembly for 30-120 minutes. Further, vacuum drying is carried out at 40-90 ℃ for 8-16 h. Further, the mass ratio of the cPAN@ZnP, the conductive material and the adhesive is 6-8:1-2:1-4. Further, the conductive material is conductive carbon black, the adhesive is polyvinylidene fluoride, and the solvent is 1-methyl-2-pyrrolidone. Further, the zinc powder has a particle size of not more than 50 μm; The thickness of the current collector copper foil is 50 mu m; and respectively ultrasonically washing the current collector copper foil in water and ethanol, and drying. The second purpose of the invention is to provide a zinc powder composite pole piece with a cyclized polyacrylonitrile self-assembled protective layer, which is prepared by the preparation method. The third object of the invention is to provide an application of the zinc powder composite pole piece in a water system zinc ion symmetrical battery or a zinc-iodine full battery. Accor