CN1215580C - A kind of anti-methanol permeation proton exchange membrane preparation method - Google Patents

Abstract

The present invention discloses a method for preparing methanol penetration resisting proton exchange membranes, which is used for preparing proton exchange membranes for direct methanol fuel batteries by doping aromatic heterocyclic ring polymers containing sulfonic acid side groups, and inorganic material and belongs to the technical range of preparing fuel battery material. Aromatic heterocyclic ring polymers containing sulphonic acid side groups, which are used as membrane matrices, are added into solvent form a uniform mixture, and then, inorganic matter is added to form suspended matter. Nanometer breaking technology is utilized to break the suspended matter to obtain slurry dispersed uniformly, and a pouring method is adopted to prepare a membrane. A formed membrane has the advantages of uniform structure and favorable compactness and not only can well resist methanol penetration, but also has favorable chemical stability and proton conductivity, and the permeation rate of methanol is smaller than 5%. The present invention can be used for preparing proton exchange membranes for direct methanol fuel batteries to enhance the output characteristic of direct methanol fuel batteries. The present invention can widen the types of proton exchange membranes for direct methanol fuel batteries and promote the practicability and the commercialization of direct methanol fuel batteries.

Description

A kind of anti-methanol permeation proton exchange membrane preparation method

technical field

The invention belongs to the technical scope of fuel cell material preparation, and in particular relates to a kind of anti-methanol permeation proton exchange membrane used for direct methanol fuel cell by doping aromatic heterocyclic polymers containing sulfonic acid side groups and inorganic materials to prepare proton exchange membranes Preparation.

Background technique

The proton exchange membrane currently used in direct methanol fuel cells is a perfluorocarbon polymer sulfonic acid type ion exchange membrane. When this perfluorocarbon polymer sulfonic acid ion exchange membrane is used in direct methanol fuel cells, there is a problem that methanol permeates from the anode to the cathode to hinder the electrochemical reaction of the cathode, and its permeability is as high as 40%, which greatly affects the direct methanol fuel cell. Development and application of fuel cells.

Contents of the invention

The object of the present invention is to provide a kind of anti-methanol permeation proton exchange membrane preparation method, it is characterized in that: use the aromatic heterocyclic polymer containing sulfonic acid side group: the aromatic heterocyclic polymer containing sulfonic acid side group is containing sulfonic acid side group Any one of polyphenylquinoxaline containing sulfonic acid side groups, polypyrrolene containing sulfonic acid side groups, polyphenylene benzoxazole containing sulfonic acid side groups and polybenzimidazole containing sulfonic acid side groups is used as the proton exchange The base material of the film is dissolved in the solvent to obtain a homogeneous mixture, and inorganic substances are added to form a suspension. The suspension is crushed by nano-crushing technology to obtain a uniformly dispersed slurry, which is poured to form a membrane, solidified, and defilmed in water to obtain a methanol permeable proton exchange membrane; the preparation steps of the methanol permeable proton exchange membrane are as follows:

1) Polyphenylquinoxaline containing sulfonic acid side groups, polypyrrolene containing sulfonic acid side groups, polyphenylene benzoxazole containing sulfonic acid side groups and polybenzimidazole containing sulfonic acid side groups Any one of the organic solvents is dissolved in the organic solvent in a ratio of 1: (10-14) by weight to form a uniform mixture;

2) adding silicon dioxide or titanium oxide and the mixture to the mixture in a weight ratio of 1: (1-6) to form a suspension, and mixing the suspension with an ultra-high pressure of 60-380Mpa;

3) Ultrasonic waves are introduced, and the suspended matter is subjected to nano-crushing and whole-chain treatment of aromatic heterocyclic polymers containing sulfonic acid side groups in step 1 under the action of ultrasonic vibration force;

4) Cast the slurry formed above to form a film at room temperature, and then cure it at 100-300°C in an inert atmosphere or at 60-150°C for 2-8 hours in an inert atmosphere for 2-6 hours at room temperature, Cool to room temperature and defilm in water.

The solvent used is any one of dimethylformamide, dimethylacetamide, dimethylsulfoxide and N-methylpyrrolidone.

The beneficial effect of the present invention is that the aromatic heterocyclic polymer proton exchange membrane containing sulfonic acid side groups is different from the currently used perfluorosulfonic acid proton exchange membrane, and it not only can resist methanol penetration well, but also has good chemical stability and proton conductivity. Compared with the perfluorocarbon polymer sulfonic acid ion exchange membrane, the membrane structure formed by it is quite uniform and compact. The ability to resist methanol permeation has been greatly improved, and the methanol permeability is less than 5%. It can be used as a proton exchange membrane in direct methanol fuel cells to improve the methanol permeation resistance and electrochemical stability of proton exchange membranes used in direct methanol fuel cells, and improve battery performance. The electrochemical activity of the cathode increases the specific power of the fuel cell and improves the output characteristics of the fuel cell.

Description of drawings

Figure 1 shows the test results of methanol permeability.

Figure 2 shows the test results of the output characteristics of the direct methanol fuel cell

Specific implementation examples

The invention relates to a method for preparing a methanol-permeable proton exchange membrane. The aromatic heterocyclic polymer containing sulfonic acid side groups: polyphenylquinoxaline containing sulfonic acid side groups, polypyrrole containing sulfonic acid side groups, polyphenylene benzoxazole containing sulfonic acid side groups or After any one of the polybenzimidazoles containing sulfonic acid side groups is dissolved in a solvent to form a uniform mixture, silicon dioxide or titanium oxide is added to form a suspension. The suspension is crushed by nano-crushing technology to obtain a uniformly dispersed slurry, and the membrane is formed by casting method, solidified, and defilmed in water to obtain a methanol permeable proton exchange membrane; the preparation steps of the methanol permeable proton exchange membrane are as follows:

1) Dissolving the aromatic heterocyclic polymer containing sulfonic acid side groups in an organic solvent at a weight ratio of 1: (10-14) to form a homogeneous mixture;

2) adding silicon dioxide or titanium oxide and the mixture to the mixture in a weight ratio of 1: (1-6) to form a suspension, and mixing the suspension with an ultra-high pressure of 60-380Mpa;

3) Ultrasonic waves are introduced, and the suspended matter is subjected to nano-crushing and whole-chain treatment of aromatic heterocyclic polymers containing sulfonic acid side groups in step 1) under the action of ultrasonic vibration force;

4) Cast the slurry formed above into a film at room temperature, solidify at room temperature for 2-6 hours, then solidify at 100-300°C in an inert atmosphere or at 60-150°C in a vacuum of 100pa for 2-8 hours, and cool to Defilm in water at room temperature.

The aromatic heterocyclic polymer containing sulfonic acid side groups is

The solvent used is any one of dimethylformamide, dimethylacetamide, dimethylsulfoxide and N-methylpyrrolidone.

Give examples below to illustrate the present invention:

Example 1:

①Dissolve 1 part of polybenzimidazole containing sulfonic acid side groups in 10 parts of organic solvent dimethylformamide to form a uniform mixture;

② Add 8 parts of silicon dioxide to the mixture to form a suspension;

③ Mix the suspension with 180Mpa ultra-high pressure;

④Introduce ultrasonic waves, apply ultrasonic vibration force to suspended matter, and carry out nano-crushing of suspended matter and whole-chain treatment of aromatic heterocyclic polymers;

⑤ After casting the slurry formed above to form a film at room temperature, solidify at room temperature for 2 hours, then solidify at 100°C in an inert atmosphere for 4 hours, cool to room temperature, and remove the membrane in water to obtain a methanol permeation-resistant proton exchange membrane.

Example 2:

① Dissolving 1 part of polyphenylquinoxaline containing sulfonic acid side groups in 12 parts of organic solvent dimethylacetamide to form a uniform mixture;

② Add 6 parts of titanium dioxide to the mixture to form a suspension;

③ Mix the suspension with 120Mpa ultra-high pressure;

④Introduce ultrasonic waves, apply ultrasonic vibration force to suspended matter, and carry out nano-crushing of suspended matter and whole-chain treatment of aromatic heterocyclic polymers;

⑤ After casting the slurry formed above to form a film at room temperature, solidify at room temperature for 3 hours, then solidify at 140°C for 4 hours in an inert atmosphere, cool to room temperature, and remove the membrane in water to obtain a methanol permeation-resistant proton exchange membrane.

Example 3:

① 1 part of polypyrrolone containing sulfonic acid side groups is dissolved in 14 parts of organic solvent dimethyl sulfoxide to form a homogeneous mixture;

② Add 10 parts of silicon dioxide to the mixture to form a suspension;

③ Mix the suspension with 160Mpa ultra-high pressure;

④Introduce ultrasonic waves, apply ultrasonic vibration force to suspended matter, and carry out nano-crushing of suspended matter and whole-chain treatment of aromatic heterocyclic polymers;

⑤ After casting the slurry formed above to form a film at room temperature, solidify at room temperature for 4 hours, then solidify at 170°C in an inert atmosphere for 4 hours, cool to room temperature, and remove the film in water to obtain a methanol permeation-resistant proton exchange membrane.

Example 4:

① 1 part of polyphenylene benzoxazole containing sulfonic acid side groups is dissolved in 13 parts of organic solvent N-methylpyrrolidone to form a uniform mixture;

② Add 6 parts of silicon dioxide to the mixture to form a suspension;

③ Mix the suspension with 100Mpa ultra-high pressure;

④Introduce ultrasonic waves, apply ultrasonic vibration force to suspended matter, and carry out nano-crushing of suspended matter and complete chain treatment of aromatic heterocyclic polymers;

⑤ After casting the slurry formed above to form a film at room temperature, solidify at room temperature for 2 hours, then solidify at 160°C for 5 hours in an inert atmosphere, cool to room temperature, and remove the membrane in water to obtain a methanol permeation-resistant proton exchange membrane.

Just to mention the above four examples, using the aromatic heterocyclic polymers containing sulfonic acid side groups, the process is basically the same and the results are the same. From the test results of the methanol permeability shown in Figure 1 and the test results of the output characteristics of the direct methanol fuel cell shown in Figure 2, it can be known that the aromatic heterocyclic polymer proton exchange membrane containing sulfonic acid side groups is more effective than the perfluorosulfonic acid type The anti-methanol permeation ability of the proton exchange membrane of the proton exchange membrane is increased by more than 2 times; the output power of the direct methanol fuel cell is increased by more than one time.

(In Figure 2: 1-instance 1; 2-instance 2; 3-instance 3; 4-instance 4; 5-perfluorosulfonic acid type)

Claims (2)

1. a methanol tolerance permeates the proton exchange membrane preparation method, it is characterized in that: use the aromatic heterocyclic polymer that contains sulfonic acid lateral group: the polyphenylene quinoxaline that contains sulfonic acid lateral group, the poly-pyrrole throat that contains sulfonic acid lateral group, contain the polyhenylene benzoxazole of sulfonic acid lateral group or contain that any one base-material as proton exchange membrane of polybenzimidazoles of sulfonic acid lateral group is molten to obtain uniform mixture in solvent, add inorganic matter and form suspended matter, by the nanometer crushing technology this suspended matter is carried out fragmentation, obtain finely dispersed slurry, cast system film, solidify, demoulding promptly obtains methanol tolerance infiltration proton exchange membrane in the water; Its methanol tolerance infiltration proton exchange membrane preparation process is:

1) will contain the polyphenylene quinoxaline of sulfonic acid lateral group, the poly-pyrrole throat that contains sulfonic acid lateral group, any one and the organic solvent of polybenzimidazoles that contain the polyhenylene benzoxazole of sulfonic acid lateral group and contain sulfonic acid lateral group with weight ratio 1: ratio (10-14) is dissolved in the organic solvent, forms uniform mixture;

2) with inorganic matter silicon dioxide or titanium oxide and mixture with weight ratio 1: ratio (1-6) adds in the mixture and forms suspended matter, with the superhigh pressure mix suspending thing of 60-380Mpa;

3) import ultrasonic wave, suspended matter is under the effect of vibration of ultrasonic wave power, and it is broken and the whole chain of the aromatic heterocyclic polymer that contains sulfonic acid lateral group in the step 1) handled to carry out nanometer;

4) slurry of above formation is at room temperature poured into a mould film forming, at room temperature solidify after 2-6 hour and in inert atmosphere, solidified 2-8 hour under 60-150 ℃ under 100-300 ℃ or in the 100pa vacuum, be cooled to room temperature, demoulding in the water.

2. according to the described methanol tolerance infiltration of claim 1 proton exchange membrane preparation method, it is characterized in that: solvent for use is any one in dimethyl formamide, dimethylacetylamide, dimethyl sulfoxide (DMSO), the N-methyl pyrrolidone.

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