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CN-121790409-B - Composite polymer current collector, preparation method and application thereof

CN121790409BCN 121790409 BCN121790409 BCN 121790409BCN-121790409-B

Abstract

The invention relates to the technical field of electrochemical energy storage equipment components, in particular to a composite polymer current collector, a preparation method and application thereof, wherein the composite polymer current collector comprises a polymer base film and a metal layer arranged on at least one side surface of the polymer base film, the material of the polymer base film comprises polyarylether resin containing a phthalazinone structure, and the polyarylether resin containing the phthalazinone structure has the chemical structure shown as follows: Wherein n is a positive integer. According to the composite polymer current collector provided by the invention, the polyarylether resin containing the phthalazinone structure is used as the base material, and the metal layer is arranged on the base material, so that the surface density of the current collector is lower, the mass ratio of the current collector in the battery core is reduced, and the mass energy density of the sodium-based energy storage device is improved.

Inventors

  • HU FANGYUAN
  • JIAN XIGAO
  • LIU DONGMING
  • WANG JINYAN
  • ZHANG SHOUHAI
  • LIU CHENG
  • WENG ZHIHUAN

Assignees

  • 大连理工大学

Dates

Publication Date
20260508
Application Date
20260306

Claims (10)

  1. 1. A composite polymer current collector comprising a polymer base film (1) and a metal layer (2) provided on at least one side surface of the polymer base film (1), wherein the material of the polymer base film (1) comprises a polyarylether resin containing a phthalazinone structure having the chemical structure shown below: wherein n is a positive integer.
  2. 2. The composite polymeric current collector according to claim 1, wherein the material of the metal layer (2) comprises at least one of aluminum, copper.
  3. 3. The composite polymeric current collector according to claim 1, wherein the polymeric base film (1) has a thickness of 1-15 μm; And/or the thickness of the metal layer (2) is 100nm-2000nm; and/or the number average molecular weight of the polyarylether resin containing the phthalazinone structure is 20000 to 50000g/mol.
  4. 4. A method of preparing a composite polymeric current collector according to any one of claims 1 to 3, comprising the steps of: the metal layer (2) is formed on at least one side surface of the polymer base film (1).
  5. 5. The method for preparing a composite polymeric current collector according to claim 4, characterized in that it does not comprise a pretreatment step of the polymeric base film (1) aimed at increasing the surface energy, before forming the metal layer (2); and/or the forming mode of the metal layer (2) comprises at least one of evaporation, magnetron sputtering, ion plating and electroplating.
  6. 6. The method for preparing a composite polymer current collector according to claim 4, wherein the method for preparing the polymer base film (1) comprises the steps of: s1, preparing polyarylether resin slurry containing a phthalazinone structure: dissolving polyarylether resin powder containing a phthalazinone structure in a polar solvent, and stirring until the polyarylether resin powder is completely dissolved to obtain polyarylether resin slurry containing the phthalazinone structure; s2, film forming: and (3) carrying out film forming treatment and post-treatment on the polyarylether resin slurry containing the phthalazinone structure to obtain the polymer base film (1).
  7. 7. The method for preparing a composite polymer current collector according to claim 6, wherein in step S1, the mass ratio of the polyarylether resin powder containing a phthalazinone structure to the polar solvent is 1:5-15; And/or, in step S1, the polar solvent includes one of N-methylpyrrolidone, N-dimethylacetamide, chloroform; And/or, in step S1, the temperature of the stirring is 80-120 ℃; and/or in the step S2, the film forming treatment comprises the steps of coating the slurry on the surface of a substrate, and drying to volatilize the polar solvent to form a solid film, wherein the drying adopts a gradient heating method; And/or, in step S2, the post-treatment includes immersing the substrate with the solid film in water, separating the film from the substrate, and then drying.
  8. 8. The method of preparing a composite polymer current collector according to claim 7, wherein in step S2, the coating is performed by a doctor blade method, and a gap between a bottom of a doctor blade and a surface of the substrate is 25 μm to 500 μm; and/or the substrate comprises a glass plate; And/or, before the slurry is coated on the surface of the substrate, the film forming treatment further comprises pretreatment of the substrate, wherein the pretreatment comprises the steps of cleaning the surface of the substrate by using deionized water and ethanol in sequence, and then drying for 10-60 minutes at 50-120 ℃; And/or, in the step S2, the gradient heating method comprises the steps of firstly preserving heat at 60-80 ℃ for 6-12 hours, and then heating to 130-200 ℃ at a heating rate of 2-10 ℃ per minute, and preserving heat for 12-24 hours.
  9. 9. The preparation method of the composite polymer current collector according to claim 5, wherein the magnetron sputtering is vacuum magnetron sputtering, the specific parameters of the magnetron sputtering comprise one of a copper target and an aluminum target, the background vacuum degree is 0.00001-0.01Pa, the temperature of a magnetron sputtering cavity is 25-100 ℃, the sputtering atmosphere is one of nitrogen and argon, the working pressure is 0.3-10 Pa, the sputtering time is 100-3000 s, the flow of nitrogen or argon is 20-70sccm, and the sputtering power is 20-250W.
  10. 10. Use of a composite polymer current collector according to any one of claims 1-3 or prepared by a preparation method according to any one of claims 4-9 in a sodium-based energy storage device, a lithium-based energy storage device or a potassium-based energy storage device.

Description

Composite polymer current collector, preparation method and application thereof Technical Field The invention relates to the technical field of electrochemical energy storage equipment components, in particular to a composite polymer current collector, a preparation method and application thereof. Background Under the push of the global double-carbon target, the energy structure has become a necessary trend towards clean and low-carbonization transformation, and the installed capacity of renewable energy sources such as wind energy, solar energy and the like is continuously increased. However, the energy is greatly influenced by natural conditions, the output power has obvious intermittence and fluctuation, and the energy is required to be stored in real time by means of an efficient energy storage technology, so that the stable operation of a power grid is ensured. Sodium-based energy storage devices rely on abundant reserves of sodium resources, extremely low cost and excellent low-temperature performance, and become one of core candidate technologies in the field of large-scale energy storage (such as power grid peak shaving, base station standby power supply and new energy automobile low-voltage energy storage system). In recent years, sodium-based energy storage devices are rapidly broken through in the fields of material research and development, device assembly and the like, however, core performance indexes of the sodium-based energy storage devices still have the problems of obvious short plates, particularly relatively low energy density, and the sodium-based energy storage devices become key bottlenecks for restricting the penetration of the sodium-based energy storage devices into high-end energy storage scenes (such as long-endurance portable energy storage and high-end new energy automobile auxiliary energy storage). Currently, research on the improvement of energy density of sodium-based energy storage devices in the industry is mostly focused on the development and optimization of active substances in battery cells. Scientific researchers continuously improve the specific capacity and the electron conduction efficiency of the active substances by regulating and controlling the crystal structure of the active substances (such as constructing layered oxides and polyanion compounds), optimizing the morphology (such as preparing nanoscale and porous particles), doping modification (such as introducing alien metal ions) and the like, so that the bottleneck of energy density is broken through. It is worth noting that the energy density improvement of the battery cell is not only dependent on the performance of the active substance, but also is closely related to the ratio and performance of inactive components in the battery cell. However, there is currently very little interest in the industry in the development of inactive components (e.g., current collectors, separators, electrolyte additives). The current collector is used as a key inactive component of the sodium-based energy storage device, and has the functions of bearing active substances, building an electronic transmission path, maintaining the stability of the cell structure and the like. Its performance and design directly determine the energy density, cycle life and safety of the device. The traditional pure metal current collector (mainly comprising aluminum foil and copper foil) commonly adopted by the current sodium-based energy storage device has larger surface density and accounts for 15% -25% of the total mass of the battery core. Because the current collector does not participate in electrochemical reaction, the current collector belongs to 'invalid mass', the high proportion of the current collector directly compresses the mass space of active substances, and on the premise of fixed total mass of the battery core, the mass proportion of the current collector is reduced by 5%, the mass proportion of the active substances can be improved by about 4% -6%, and the energy density of the device is further improved by 8% -12%. Therefore, the high mass ratio of the traditional metal current collector has become an important factor for restricting the weight reduction and the mass energy density improvement of the sodium-based energy storage device. Therefore, developing a current collector with low areal density, so as to reduce the mass ratio of the current collector in the battery core and improve the mass energy density of the sodium-based energy storage device is a technical problem to be solved in the field. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a composite polymer current collector, a preparation method and application thereof, and the composite polymer current collector provided by the invention has the advantages that the polyaromatic ether resin containing a phthalazinone structure is used as a base material, and a metal layer is arranged on the base material, so that th