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CN-121975165-A - Ion exchange membrane and preparation method and application thereof

CN121975165ACN 121975165 ACN121975165 ACN 121975165ACN-121975165-A

Abstract

The invention discloses an ion exchange membrane, a preparation method and application thereof, wherein the volume swelling rate of the ion exchange membrane is less than 20 percent at 20 ℃, the electrochemical parameter alpha 1 is less than 2.5, and the electrochemical parameter alpha 1 is the ratio of the volume swelling rate and the ion conductivity.

Inventors

  • YANG ZEZHOU
  • WANG YANJIE
  • SUN HUA
  • LIN XIAOYIN
  • GAO LONGHUI

Assignees

  • 深圳市科新创界新材料有限公司

Dates

Publication Date
20260505
Application Date
20260114

Claims (10)

  1. 1. An ion exchange membrane, characterized in that at 20 ℃, the volume swelling ratio of the ion exchange membrane is <20%, and the electrochemical parameter α1 is the ratio of the volume swelling ratio and the ion conductivity is less than 2.5.
  2. 2. The ion exchange membrane of claim 1, wherein the electrochemical parameters of the ion exchange membrane at 60 ℃ are denoted as α2, α1 and α2 satisfy the following relationship: (α2-α1)/α2<0.2。
  3. 3. The ion exchange membrane according to claim 1 or 2, wherein the ion exchange membrane is operated continuously at a voltage decay rate of 1000 h <50 μv/h in a constant current test at 80 ℃ and 10000A/m 2 current density.
  4. 4. An ion exchange membrane according to any one of claims 1 to 3, wherein the ion exchange membrane is a sulphonated polymer ion exchange membrane.
  5. 5. A method for producing an ion exchange membrane according to any one of claims 1 to 4, comprising: And coating the polymer slurry to obtain a wet film, carrying out gradient heating drying forming on the wet film, and finally carrying out biaxial stretching to obtain the ion exchange film.
  6. 6. The method of claim 5, wherein the gradient heating method comprises: S21, heating from room temperature to 35-45 ℃ at 0.1-0.3 ℃ per min, and simultaneously heating and drying at the interval temperature to be more than or equal to 60 min; s22, heating to 60-70 ℃ at 0.4-0.8 ℃ per minute, and simultaneously heating and drying at the interval temperature to be more than or equal to 30 min; S23, heating to be more than 80 ℃ at the temperature of 0.9-1.2 ℃ per minute, and simultaneously heating and drying to be more than or equal to 60 min at the temperature of more than 80 ℃.
  7. 7. The method according to claim 6, wherein step S21 is performed under vacuum; and/or, in step S23, the final heating and drying temperature is equal to or less than 140 ℃.
  8. 8. The preparation method according to claim 5-7, wherein the temperature of the biaxial stretching is not less than 120 ℃, preferably 120-140 ℃ for 30-60 min; and/or the stretching multiplying power of the biaxial stretching is 1-10%.
  9. 9. The method according to any one of claims 5 to 8, wherein the wet film has a thickness of 30 to 1000 μm; And/or the polymer comprises any one or a combination of at least two of sulfonated polysulfone materials, sulfonated polyether sulfone materials, sulfonated polyarylethersulfone materials, sulfonated polyamide materials, sulfonated polyimide materials, sulfonated polyether imide materials, sulfonated polyether ether ketone materials, sulfonated polyaryletherketone materials, sulfonated polyphenylene sulfide materials, sulfonated polyphenylene ether materials, sulfonated polybenzimidazole materials or sulfonated polyphosphazene materials; And/or the solid content of the polymer slurry is 20-40 wt%.
  10. 10. Use of the ion exchange membrane according to any one of claims 1 to 4 in a fuel cell, a flow cell or an electrolyzed water hydrogen production membrane.

Description

Ion exchange membrane and preparation method and application thereof Technical Field The invention belongs to the technical field of ion exchange membranes, and particularly relates to an ion exchange membrane and a preparation method and application thereof. Background The following statements are merely to provide background information related to the present disclosure and may not necessarily constitute prior art. The ion exchange membrane is one of important components in fuel cells, flow batteries and the like, needs to have physical isolation and ion conduction dual functions, is one of key technologies for restricting the development and application of the batteries, and has an important role in improving the comprehensive performance of the batteries. The existing ion exchange membrane has the problems of higher swelling degree, lower mechanical strength, poor stability, membrane rupture and the like in the actual use process, and has safety risk. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide an ion exchange membrane and a preparation method and application thereof. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the present invention provides an ion exchange membrane having a volume swell ratio of <20% at 20 ℃ and an electrochemical parameter α1<2.5, the electrochemical parameter α1 being the ratio of the volume swell ratio to the ionic conductivity. In a second aspect, the present invention provides a method for preparing an ion exchange membrane according to the first aspect, the method comprising: And (3) casting the polymer slurry into a wet film, drying and forming the wet film by gradient heating, and finally, carrying out biaxial stretching to obtain the ion exchange film. In a third aspect, the present invention provides the use of an ion exchange membrane as described in the first aspect in a fuel cell, flow cell or electrolyzed water hydrogen production membrane. The ion exchange membrane provided by the invention has high ionic conductivity and low swelling rate, and is excellent in dimensional stability and good in mechanical property. When the ion exchange membrane is prepared, the crystallization behavior of the chain segment in the drying process is controlled in a gradient heating mode, so that the chain segment is slowly crystallized, the crystallinity of the ion exchange membrane is improved, the swelling rate of the ion exchange membrane is reduced, meanwhile, the mechanical strength of the ion exchange membrane is improved, and a biaxially stretching step is introduced after the ion exchange membrane is dried to form a membrane, so that the orientation of a high molecular chain segment is facilitated, the ion conduction capacity of the ion exchange membrane is improved, and the crystallinity of the ion exchange membrane is improved by biaxially stretching, so that the swelling rate of the ion exchange membrane is further reduced, and the mechanical property of the ion exchange membrane is improved. Detailed Description The present invention will be described in further detail below for the purpose of better understanding of the aspects of the present invention by those skilled in the art. The following detailed description is merely illustrative of the principles and features of the present invention, and examples are set forth for the purpose of illustration only and are not intended to limit the scope of the invention. All other embodiments, which can be made by those skilled in the art based on the examples of the invention without making any inventive effort, are intended to be within the scope of the invention. The terms "first," "second," and the like, as used herein, are used for distinguishing between different objects and not for describing a particular sequential or sub-relationship, unless otherwise indicated. Unless otherwise indicated, terms used in the present application have well-known meanings commonly understood by those skilled in the art. Unless otherwise indicated, the values of the parameters mentioned in the present application may be determined by various test methods commonly used in the art, for example, may be determined according to the test methods given in the examples of the present application. The test temperature for each parameter was 25 ℃ unless otherwise indicated. The embodiment of the invention provides an ion exchange membrane, wherein the volume swelling rate of the ion exchange membrane is less than 20% at 20 ℃, and the electrochemical parameter alpha 1 is less than 2.5, and the electrochemical parameter alpha 1 is the ratio of the volume swelling rate to the ion conductivity. The ion exchange membrane provided by the invention has a proper electrochemical parameter alpha 1, so that the ion exchange membrane has excellent dimensional stability and good mechanical property, has good attenuation performance, and can fully m