阅读说明：本技术 一种燃料电池用三维图形表面质子交换膜及其制备方法与应用 (Three-dimensional graph surface proton exchange membrane for fuel cell and preparation method and application thereof ) 是由 袁伟 柯育智 苏日鹏 方程 李锦广 于 2021-07-06 设计创作，主要内容包括：本发明公开了一种燃料电池用三维图形表面质子交换膜及其制备方法与应用。该质子交换膜的制备方法包括3D打印和热压印工艺；其中3D打印工艺用来打印精密图形热压印模具,热压印工艺用来制备具有三维图形的高比表面积质子交换膜。热压印模具原料采用高硬度聚合物材料,克服了传统基于金属模具的制备工艺缺陷。热压印工艺采用上下两层缓冲层结构,具有一步压印成型的特征。本发明制备成型的表面图形结构的质子交换膜具有高比表面积,可以提供快速质子传输通道并扩大燃料电池膜电极的三相边界,从而提高燃料电池的输出性能。具有该表面图形结构的质子交换膜能够有效改善氢燃料电池的水管理,实现高性能、长寿命质子交换膜燃料电池的构建。(The invention discloses a three-dimensional graph surface proton exchange membrane for a fuel cell and a preparation method and application thereof. The preparation method of the proton exchange membrane comprises 3D printing and hot stamping processes; the 3D printing process is used for printing a precise pattern hot stamping die, and the hot stamping process is used for preparing the proton exchange membrane with the three-dimensional pattern and the high specific surface area. The hot stamping die adopts high-hardness polymer material as raw material, and overcomes the defects of the traditional preparation process based on a metal die. The hot embossing process adopts an upper buffer layer structure and a lower buffer layer structure, and has the characteristic of one-step embossing molding. The proton exchange membrane with the surface pattern structure prepared and formed by the invention has high specific surface area, can provide a rapid proton transmission channel and enlarge the three-phase boundary of the membrane electrode of the fuel cell, thereby improving the output performance of the fuel cell. The proton exchange membrane with the surface pattern structure can effectively improve the water management of the hydrogen fuel cell and realize the construction of the proton exchange membrane fuel cell with high performance and long service life.)

1. A preparation method of a three-dimensional graph surface proton exchange membrane for a fuel cell comprises 3D printing and hot stamping processes, and is characterized in that: the 3D printing is used to make a mold structure and the hot embossing process is used to make a three-dimensional graphic surface film structure.

2. The method of claim 1, wherein: the feeding amount of the printing die support of the 3D printing process is 30-50 mu m per layer, the feeding amount of the printing die support layer is 30-50 mu m per layer, and the feeding amount of the printing working layer is 10-20 mu m per layer; the 3D printed material is a high-hardness brittle resin material.

3. The method of claim 2, wherein: the high-hardness brittle resin material is photosensitive resin, thermoplastic polyurethane elastomer rubber, polyvinyl chloride and engineering plastics.

4. The method of claim 1, wherein: the hot stamping process comprises the following steps: sequentially stacking the isolation layer, the buffer layer, the proton exchange membrane, the mold, the buffer layer and the isolation layer in a sequence from bottom to top to form an imprinting group, and then carrying out hot embossing to obtain a single-sided three-dimensional graph structure;

or the isolation layer, the buffer layer, the mold, the proton exchange membrane, the mold, the buffer layer and the isolation layer are sequentially stacked into an imprinting group from bottom to top, and then hot-imprinting is carried out to obtain the double-sided three-dimensional graph structure.

5. The method of claim 4, wherein: the proton exchange membrane is a perfluorinated sulfonic acid proton exchange membrane; the size of the buffer layer and the isolation layer is the same as that of the proton exchange membrane.

6. The method of claim 4, wherein: the temperature of the hot stamping is 100-150 ℃, the pressure is 1-3MPa, and the time is 3-5 min.

7. The proton exchange membrane with the three-dimensional graph surface prepared by the preparation method of any one of claims 1 to 6, which is characterized in that: the surface graph structure of the proton exchange membrane on the surface of the three-dimensional graph is a sine function curved surface, the amplitude range of the sine function is 0.05-0.15mm, the angular speed is 6-8rad/s, and the height of the surface graph of the proton exchange membrane is the amplitude height of the sine function.

8. The application of the proton exchange membrane with the three-dimensional graph surface as recited in claim 7 in the preparation of a cathode of a hydrogen fuel cell, which is characterized in that: the proton exchange membrane on the surface of the three-dimensional graph has a single-sided three-dimensional graph structure.

9. The application of the proton exchange membrane with the three-dimensional graph surface as recited in claim 7 in the preparation of the anode of the hydrogen fuel cell, which is characterized in that: the proton exchange membrane on the surface of the three-dimensional graph has a single-sided three-dimensional graph structure.

10. The application of the proton exchange membrane double-sided pattern structure with the three-dimensional graph surface of claim 7 in the preparation of a high-performance membrane electrode assembly, which is characterized in that: the proton exchange membrane on the surface of the three-dimensional graph has a double-sided three-dimensional graph structure.

Technical Field

The invention belongs to the technical field of fuel cells, and particularly relates to a three-dimensional graph surface proton exchange membrane for a fuel cell, and a preparation method and application thereof.

Background

As a novel environment-friendly energy technology, the proton exchange membrane fuel cell has very wide development potential and application prospect. Compared with other energy conversion devices, the fuel cell has the characteristics of high energy conversion efficiency, high power density and the like. At the same time, no greenhouse gas is emitted, and low-temperature starting is supported. The series of advantages make the fuel cell have wide application prospect in automobiles and portable power generation equipment. Therefore, the research and development of novel and efficient proton exchange membrane fuel cells become a hotspot in the field of new energy research, and the development of proton exchange membranes with excellent performance plays a significant role in promoting the development of the field.

The proton exchange membrane is used as a core component of the membrane electrode of the hydrogen fuel cell, provides a place for electrochemical reaction, and also provides a transmission channel for various substances in the cell. Therefore, the proton exchange membrane with excellent performance and high-efficiency substance transmission can greatly improve the performance of the fuel cell, prolong the service life and reduce the cost. Generally, a proton exchange membrane adopts a smooth surface structure, so that the proton exchange membrane has a smaller surface area, and further, the contact area between the membrane and substances such as a catalyst is smaller, and a reaction site and a substance transmission channel cannot be well provided. Therefore, the method for improving the specific surface area by manufacturing the surface patterned structure of the proton exchange membrane is an effective way for solving the problems of small three-phase interface and low performance of the fuel cell reaction.

Patent CN201810300304.8 discloses a three-dimensional proton exchange membrane with high specific surface area for fuel cell. According to the method, a pore-forming agent and a perfluorinated sulfonic acid resin solution are subjected to ultrasonic oscillation to form porous layer slurry, the porous layer slurry is covered on a pretreated proton exchange membrane in a coating mode, and then acid treatment is carried out to obtain the proton exchange membrane. The method adopts a mode of coating the porous slurry to form a three-dimensional structure, has longer flow and low efficiency, and is easy to excessively increase the film thickness. In addition, the traditional preparation method of the proton exchange membrane with high surface area mostly adopts a chemical preparation process. The process has the defects of complicated flow, long time consumption and easy environmental pollution caused by byproducts. Therefore, the invention provides a novel and efficient preparation method of the proton exchange membrane on the surface of the three-dimensional graph, which can effectively solve the problems.

Disclosure of Invention

In order to solve the problems that the surface area of a proton exchange membrane is small, a fuel cell is easy to be flooded by water and the like, the invention aims to provide a preparation method of the proton exchange membrane with the three-dimensional graph surface and application of the fuel cell based on the proton exchange membrane. The method comprises a 3D printing process and a hot stamping process, wherein the 3D printing process is used for manufacturing a mold structure, and the hot stamping process is used for manufacturing a surface pattern structure of the proton exchange membrane.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of a three-dimensional graph surface proton exchange membrane for a fuel cell comprises 3D printing and hot stamping processes, wherein the 3D printing is used for manufacturing a mould structure and can be used for rapidly printing a precise graph structure in one step; the hot stamping process is used for manufacturing the three-dimensional graphic surface film structure and has the characteristics of rapid forming, batch manufacturing and the like.

Preferably, the feeding amount of the printing mold support of the 3D printing process is 30-50 mu m per layer, the feeding amount of the printing mold support layer is 30-50 mu m per layer, and the feeding amount of the printing working layer is 10-20 mu m per layer; the 3D printed material is a high-hardness brittle resin material. And then carrying out post-treatment to remove the bracket to obtain a finished product of the mold. The bottom support has the functions of ensuring the flatness of the mold plane in the printing process and ensuring the printing precision; the purpose of the hierarchical printing is to improve printing efficiency while ensuring accuracy.

More preferably, the high-hardness brittle resin material is photosensitive resin, thermoplastic polyurethane elastomer rubber, polyvinyl chloride or engineering plastic. Overcomes the defects of the traditional preparation process based on metal molds, and has the characteristics of low cost, wide material sources and the like.

Preferably, the hot stamping process includes: sequentially stacking the isolation layer, the buffer layer, the proton exchange membrane, the mold, the buffer layer and the isolation layer in a sequence from bottom to top to form an imprinting group, and then carrying out hot embossing to obtain a single-sided three-dimensional graph structure;

or the isolation layer, the buffer layer, the mold, the proton exchange membrane, the mold, the buffer layer and the isolation layer are sequentially stacked into an imprinting group from bottom to top, and then hot-imprinting is carried out to obtain the double-sided three-dimensional graph structure. The impressing group structure has the functions of protecting the brittle die and the impressing head and ensuring the impressing smoothness of the proton exchange membrane.

Further preferably, the proton exchange membrane is a perfluorosulfonic acid proton exchange membrane; the size of the buffer layer and the isolation layer is the same as that of the proton exchange membrane.

Further preferably, the temperature of the hot stamping is 100-150 ℃, the pressure is 1-3MPa, and the time is 3-5 min. And after hot pressing, taking out the perfluorinated sulfonic acid proton exchange membrane, cooling at room temperature, separating the buffer layer and the isolation layer material from the die to obtain the proton exchange membrane with the three-dimensional graph.

The proton exchange membrane on the surface of the three-dimensional graph prepared by the preparation method has the advantages that the surface graph structure of the proton exchange membrane on the surface of the three-dimensional graph is a sine function curved surface, the amplitude range of the sine function is 0.05-0.15mm, the angular speed is 6-8rad/s, and the height of the surface graph of the proton exchange membrane is the amplitude height of the sine function.

The proton exchange membrane on the surface of the three-dimensional graph is applied to preparing a cathode of a hydrogen fuel cell, and has a single-sided three-dimensional graph structure. The sine function curved surface structure has a water management effect on the fuel cell, can drain water in time, enlarges a three-phase interface of the catalyst, the proton exchange membrane and the reactant, provides a reaction site with a high specific surface area, and is beneficial to transmitting oxygen to the surface of the cathode catalyst and improving the performance of the fuel cell.

The proton exchange membrane on the surface of the three-dimensional graph is applied to the preparation of the anode of the hydrogen fuel cell, and has a single-sided three-dimensional graph structure. The surface pattern structure has the functions of promoting water drainage in the reaction process of the fuel cell, reducing dead zones of the catalyst and reducing transmission resistance.

The proton exchange membrane on the surface of the three-dimensional graph is applied to the preparation of a high-performance membrane electrode assembly, and has a double-sided three-dimensional graph structure.

Compared with the prior art, the invention has the advantages that:

the invention applies 3D printing technology and hot stamping technology:

(1) the 3D printing is used for manufacturing the die, a precise graphical structure can be printed quickly in one step, the raw material is a high-hardness brittle polymer material, the die has the characteristics of high surface precision, small geometric scale, quick forming and the like, the defect that the traditional embossing process only adopts a metal die material is overcome, and the die has the characteristics of low cost, high efficiency, wide material source and the like.

(2) After the 3D printing process is optimized, a printing support is established at the bottom of the mold to ensure the flatness of the mold plane in the printing process and ensure the printing precision; the printing process adopts hierarchical layering printing to improve printing efficiency while guaranteeing the precision.

(3) The hot stamping mainly uses recyclable buffer layer and isolation layer materials, and the stamping temperature range is 100-150 ℃. The whole process is low in pollution and energy consumption, and the product is formed in one step. Because the pattern preparation mode of physical molding is adopted, no chemical residue exists. Pretreatment and post-treatment are not needed before and after the proton exchange membrane is processed, so that the risk of damaging the proton exchange membrane is greatly reduced.

(4) When the prepared perfluorinated sulfonic acid proton exchange membrane is applied to a cathode of a hydrogen fuel cell, the sine function curve has a water management effect on the fuel cell, water can be drained in time, a three-phase interface of a catalyst-proton exchange membrane-reactant is enlarged, a reaction site with a high specific surface area is provided, oxygen can be transmitted to the surface of a cathode catalyst, and the performance of the fuel cell is improved.

(5) The 3D printing and hot stamping processes are very safe and reliable, and the high-performance surface-patterned proton exchange membrane can be manufactured only by simple steps.

Drawings

FIG. 1 is an overall process flow diagram of the present invention.

FIG. 2 is a surface map of a mold model of example 1 with a sine function of 0.1mm sin8 x.

Fig. 3 is a graph comparing the performance of the batteries of example 1 and comparative example 1.

Detailed Description

The following embodiments are further described in detail with reference to examples, which are not repeated herein, but the present invention is not limited to the following embodiments. It is noted that the processes described below, if not specifically described in detail, are all realizable or understandable by those skilled in the art with reference to the prior art. The reagents or apparatus used are regarded as conventional products which can be purchased commercially without reference to the manufacturer.

Example 1

A preparation method of a three-dimensional graph surface proton exchange membrane for a fuel cell refers to figure 1 in the preparation process, and comprises the following steps:

firstly, a 2cm by 2mm mould model is established, the height of 2mm from the side surface of the graph is taken as an original point, the height of a bottom support is 1.5mm, the flatness of the mould plane in the printing process can be ensured, and the printing precision is ensured. The total height of the model is 3.5mm, and the surface sine function surface is 0.1mm sin8x (shown in figure 2). The structure has the functions of reducing dead zones of the catalyst and reducing transmission resistance. The raw material of the mold is photosensitive resin, so that the defect that the traditional imprinting process only adopts metal mold materials is overcome, and the method has the characteristics of low cost and wide material source.

In a second step, the mold is printed using digital light processing 3D printing technology (DLP). The printing die is regulated and controlled in a grading and layering mode, the feeding amount of the support and the supporting layer is 40 mu m/layer, and the feeding amount of the working layer is 10 mu m/layer. The hierarchical layered printing can improve the printing efficiency while ensuring the precision.

And thirdly, preparing a 2 cm-2 cm Nafion117 proton exchange membrane, taking out two pieces of weighing paper, two special silica gel pads and the mould printed in the second step. And stacking the weighing paper, the silica gel pad, the proton exchange membrane, the mold, the silica gel pad and the weighing paper into an impression group from bottom to top. The stamping group is single-sided stamping, and the processed proton exchange membrane has a single-sided three-dimensional graph structure. The impressing group structure has the functions of protecting the brittle die and the impressing head and ensuring the impressing smoothness of the proton exchange membrane.

And fourthly, debugging the hot press, setting the imprinting temperature to be 125 ℃ and the pressure value to be 1MPa, and completing pressure loading.

And fifthly, starting imprinting, wherein the imprinting time is 3 minutes, and waiting for the imprinting group to cool after imprinting is finished.

And sixthly, after the imprinting group is cooled for a period of time, removing the weighing paper, the silica gel pad and the mold to obtain an exchange membrane with the surface subjected to graphical imprinting treatment, wherein the sine curve parameter of the exchange membrane is 0.1mm sin8 x.

Example 2

The same procedure as in example 1 was repeated except that the mold sine function surface parameters were changed to 0.1mm sin6 x.

Example 3

The same procedure as in example 1 was repeated except that the mold sine function surface parameters were changed to 0.1mm sin4 x.

Example 4

The procedure of example 1 was repeated except that the proton exchange membrane and the mold were changed to 4cm by 4 cm.

Example 5

The structure of the impression group in the embodiment 1 is changed into the sequence of weighing paper, a silica gel pad, a mold, a proton exchange membrane, a mold, a silica gel pad and weighing paper, and the proton exchange membrane is placed between the two molds, so that the processed proton exchange membrane has a double-sided graph structure, and the conditions of other parameters are the same as those of the embodiment 1.

Comparative example 1

The perfluorinated sulfonic acid proton exchange membrane which is not subjected to the overprinting treatment is directly prepared into a membrane electrode, the hydrogen flow is 15ml/min, and the air side is self-breathing type with the membrane electrode in the embodiment 1. The catalyst adopts a commercial Pt/C catalyst, and the loading capacity of the cathode catalyst and the anode catalyst is 0.5mg/cm²The area of the membrane electrode is 2cm x 2 cm. After the fuel cell performance test, a cell performance comparison graph as shown in fig. 3 was obtained. Under the above conditions, the proton exchange membrane with the patterned surface can be seen at a current density of more than 20mA/cm²In the case of (2), the voltage and the power density are obviously superior to those of the proton exchange membrane with a smooth surface and without the patterned embossing treatment, and the power density is increased and then decreased along with the increase of the current density. The peak value of the power density of the proton exchange membrane on the surface of the three-dimensional graph appears at the current density of 60mA/cm²Nearby, the maximum value reaches 20.8mW/cm²And the peak value of the power density of the conventional proton exchange membrane fuel cell with a smooth surface is 13.8mW/cm². Therefore, the proton exchange membrane with the three-dimensional graph surface has better cell performance.

The above examples are only preferred embodiments of the present invention, which are intended to be illustrative and not limiting, and those skilled in the art should understand that they can make various changes, substitutions and alterations without departing from the spirit and scope of the invention.