阅读说明：本技术 一种燃料电池用碳碳纤维纸的制备方法 (Preparation method of carbon fiber paper for fuel cell ) 是由 褚慎 褚卫丰 于 2020-11-27 设计创作，主要内容包括：本发明公开了一种燃料电池用碳碳纤维纸的制备方法：先把碳纤维原丝切成1～15mm的碳纤维短丝；将碳纤维短丝高温提纯后形成碳纤维短切纤维,再将提纯后的碳纤维短切纤维和酚醛树脂搅拌均匀形成碳纤维浆料；将碳纤维浆料涂布在PET膜或离型纸的一面得到预处理纤维纸；涂布完成后将预处理纤维纸放在烘箱内至碳纤维浆料升至固化的临界温度得到初步纤维纸；将初步纤维纸进行压力固化,压力固化后剥离PET膜或离型纸得到碳纤维纸;将碳纤维纸碳化,碳化后形成碳碳纤维纸。本发明中碳碳纤维纸为单层结构,碳碳纤维纸中前期纤维短切纤维和酚醛树脂均匀分布,后期孔隙更为均匀,透气效果更优。(The invention discloses a preparation method of carbon fiber paper for a fuel cell, which comprises the following steps: firstly, cutting carbon fiber precursors into 1-15 mm short carbon fiber filaments; purifying the carbon fiber short filaments at high temperature to form carbon fiber chopped fibers, and uniformly stirring the purified carbon fiber chopped fibers and phenolic resin to form carbon fiber slurry; coating the carbon fiber slurry on one surface of a PET film or release paper to obtain pretreated fiber paper; after coating, placing the pretreated fiber paper in an oven until the carbon fiber slurry is heated to the curing critical temperature to obtain primary fiber paper; and carbonizing the carbon fiber paper to form the carbon-carbon fiber paper. The carbon-carbon fiber paper is of a single-layer structure, the chopped fibers and the phenolic resin in the early stage of the carbon-carbon fiber paper are uniformly distributed, the pores in the later stage are more uniform, and the ventilation effect is better.)

1. A preparation method of carbon fiber paper for fuel cells is characterized by comprising the following steps:

(1) firstly, cutting carbon fiber precursors into 1-15 mm short carbon fiber filaments;

(2) purifying the carbon fiber short filaments at high temperature to form carbon fiber chopped fibers, and uniformly stirring the purified carbon fiber chopped fibers and phenolic resin to form carbon fiber slurry;

(3) coating the carbon fiber slurry on one surface of a PET film or release paper to obtain pretreated fiber paper, wherein the coating thickness is 0.1-1 mm;

(4) after coating, placing the pretreated fiber paper in an oven until the carbon fiber slurry is heated to the curing critical temperature to obtain primary fiber paper;

(5) carrying out pressure curing on the preliminary fiber paper, and stripping the PET film or the release paper after the pressure curing to obtain carbon fiber paper;

(6) carbonizing the carbon fiber paper to form the carbon-carbon fiber paper.

2. The method for producing carbon fiber paper for fuel cells according to claim 1, wherein the carbon fiber precursor specification is one or a combination of 3K, 6K, 12K, 24K, and 48K.

3. The method for producing carbon fiber paper for fuel cells according to claim 1, wherein the temperature at the time of the high-temperature purification in the step (2) is 2000 to 3000 ℃.

4. The method for producing carbon fiber paper for fuel cells according to claim 1, wherein the content of the phenolic resin in the carbon fiber slurry is 30 to 60%.

5. The method for preparing carbon fiber paper for fuel cells according to claim 1, wherein the oven baking in step (4) is divided into four stages, the first stage has a residence time of 15 minutes and a temperature of 50 ℃, the second stage has a residence time of 15 minutes and a temperature of 50 ℃, the third stage has a residence time of 30 minutes and a temperature of 120 ℃, and the fourth stage has a residence time of 30 minutes and a temperature of 150 ℃.

6. The method for preparing carbon fiber paper for fuel cells according to claim 1, wherein the carbonization time in the step (6) is divided into four stages, the first stage residence time is 15 minutes, the temperature is 400 ℃, the second stage residence time is 30 minutes, the temperature is 600 ℃, the third stage residence time is 30 minutes, the temperature is 800 to 950 ℃, the fourth stage residence time is 30 minutes, and the temperature is 1200 ℃.

7. The method for preparing carbon-carbon fiber paper for fuel cells according to claim 1, wherein the carbon-carbon fiber paper is cooled, then coated with a hydrophobic material on one side and a hydrophobic conductive material on the other side, then sintered at 400 ℃, and then cooled and molded after sintering.

8. The method for preparing carbon fiber paper for fuel cells according to claim 7, wherein the amount of the hydrophobic material is 1 to 20g/m²SaidThe amount of the hydrophobic conductive material to be coated is 1-50 g/m²。

9. The method for producing carbon fiber paper for fuel cells according to claim 8, wherein the hydrophobic material is polytetrafluoroethylene.

10. The method for preparing carbon fiber paper for fuel cells according to claim 8, wherein the coating hydrophobic conductive material comprises polytetrafluoroethylene and carbon powder, and the amount of the carbon powder is 60-90% of the amount of the coating hydrophobic conductive material.

Technical Field

The invention relates to the field of preparation methods of battery materials, in particular to a preparation method of carbon fiber paper for a fuel cell.

Background

The performance of the carbon fiber paper for the fuel cell is mainly realized through four indexes, namely 1, tensile strength 2, air permeability 3, pore uniformity 4 and conductivity, the carbon fiber paper for the fuel cell in the prior art is prepared by firstly preparing carbon fiber paper through a dry method or a wet method, and then the carbon fiber paper is subjected to deep processing to obtain the carbon fiber paper for the fuel cell, so that the steps are large, and the manufacturing cost is high. Due to the dry method and wet method processes, the length of carbon fibers is generally controlled to be 1-3 mm in the manufacturing process, the tensile strength of the carbon fiber paper for the fuel cell can be influenced due to the excessively short carbon fibers, and the carbon fiber paper manufactured by the dry method and the wet method is of a multilayer structure, so that the air holes are unevenly distributed and the air permeability is poor.

Disclosure of Invention

The invention aims to provide a preparation method of carbon fiber paper for a fuel cell.

The carbon fiber paper has the innovation points that the carbon fiber chopped fibers and the phenolic resin are uniformly stirred to form carbon fiber slurry, the carbon fiber slurry is coated on the PET film or the release paper, and the PET film or the release paper is peeled off after the later-stage curing.

In order to achieve the purpose, the technical scheme of the invention is as follows: the preparation method of the carbon fiber paper for the fuel cell comprises the following steps:

(1) firstly, cutting carbon fiber precursors into 1-15 mm short carbon fiber filaments;

(2) purifying the carbon fiber short filaments at high temperature to form carbon fiber chopped fibers, and uniformly stirring the purified carbon fiber chopped fibers and phenolic resin to form carbon fiber slurry;

(3) coating the carbon fiber slurry on one surface of a PET film or release paper to obtain pretreated fiber paper, wherein the coating thickness is 0.1-1 mm;

(4) after coating, placing the pretreated fiber paper in an oven until the carbon fiber slurry is heated to the curing critical temperature to obtain primary fiber paper;

(5) carrying out pressure curing on the preliminary fiber paper, and stripping the PET film or the release paper after the pressure curing to obtain carbon fiber paper;

(6) carbonizing the carbon fiber paper to form the carbon-carbon fiber paper.

Form carbon fiber slurry through with carbon fiber chopped fiber and phenolic resin stirring, with carbon fiber slurry coating at the PET membrane or from type paper, after the later stage solidification peeling off the PET membrane or from type paper, because coating process does not have the requirement to fiber length, so carbon fiber length can suitably put long, the overlap joint nature is just better like this, tensile strength is stronger, electric conductive property is more excellent, and the carbon fiber paper after peeling off is single-layer construction, and carbon fiber paper middle and early stage fibre chopped fiber and phenolic resin evenly distributed, later stage hole is more even, ventilation effect is more excellent.

Further, the carbon fiber precursor specification is one or more of 3K, 6K, 12K, 24K and 48K.

Further, the temperature of the high-temperature purification in the step (2) is 2000-3000 ℃. High-temperature purification is carried out on the carbon fiber short filaments in the earlier stage, so that the energy consumption is saved.

Further, the content of the phenolic resin in the carbon fiber slurry is 30-60%.

Further, the baking time of the oven is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 50 ℃, the residence time of the second section is 15 minutes, the temperature is 50 ℃, the residence time of the third section is 30 minutes, the temperature is 120 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 150 ℃.

Further, the carbonization is divided into four sections, wherein the residence time of the first section is 15 minutes, the temperature is 400 ℃, the residence time of the second section is 30 minutes, the temperature is 600 ℃, the residence time of the third section is 30 minutes, the temperature is 800-950 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 1200 ℃.

The temperature is slowly increased and the resin is gradually carbonized, so that the resin is convenient to shape and solidify.

Further, after the carbon-carbon fiber paper is cooled, a hydrophobic material is coated on one surface of the carbon-carbon fiber paper, a hydrophobic conductive material is coated on the other surface of the carbon-carbon fiber paper, then sintering is carried out at the temperature of 400 ℃, and cooling forming is carried out after sintering is finished. The hydrophobicity can prolong the service life of the product, and the material of the lead can increase the conductivity of the carbon-carbon fiber paper.

Furthermore, the dosage of the hydrophobic material is 1-20 g/m²The amount of the coating hydrophobic conductive material is 1-50 g/m²。

Further, the hydrophobic material is polytetrafluoroethylene.

Further, the coating hydrophobic conductive material comprises polytetrafluoroethylene and carbon powder, and the amount of the carbon powder is 60-90% of the amount of the coating hydrophobic conductive material.

The invention has the beneficial effects that:

1. according to the invention, the carbon fiber chopped fibers and the phenolic resin are uniformly stirred to form the carbon fiber slurry, the carbon fiber slurry is coated on the PET film or the release paper, and the PET film or the release paper is peeled off after the later-stage curing, because the coating process has no requirement on the fiber length, the carbon fiber length can be properly lengthened, so that the lap joint performance is better, the tensile strength is stronger, the electric conductivity is better, the peeled carbon fiber paper is of a single-layer structure, the carbon fiber paper is uniformly distributed with the chopped fibers and the phenolic resin at the former stage, the later-stage pores are more uniform, and the ventilation effect is better.

2. Compared with carbon-carbon fiber paper manufactured by wet and dry processes, the carbon-carbon fiber paper manufactured by the method has the advantages of few processes, low cost, basically no sewage discharge, environmental protection and energy conservation.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below.

Example 1: a preparation method of carbon fiber paper for fuel cell comprises cutting carbon fiber precursor into 1mm carbon fiber short filaments; the specification of the carbon fiber precursor is 3K. Purifying the carbon fiber short filaments at high temperature to form carbon fiber chopped fibers, and uniformly stirring the purified carbon fiber chopped fibers and phenolic resin to form carbon fiber slurry, wherein the content of the phenolic resin in the carbon fiber slurry is 30%; the temperature for high temperature purification was 2000 ℃. And coating the carbon fiber slurry on one surface of the PET film to obtain pretreated fiber paper, wherein the coating thickness is 0.1 mm. After coating, placing the pretreated fiber paper in an oven until the carbon fiber slurry is heated to the curing critical temperature to obtain primary fiber paper; the baking time of the oven is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 50 ℃, the residence time of the second section is 15 minutes, the temperature is 50 ℃, the residence time of the third section is 30 minutes, the temperature is 120 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 150 ℃. And (3) carrying out pressure curing on the preliminary fiber paper, and stripping the PET film after the pressure curing to obtain the carbon fiber paper. Carbonizing the carbon fiber paper to form the carbon-carbon fiber paper. The carbonization time is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 400 ℃, the residence time of the second section is 30 minutes, the temperature is 600 ℃, the residence time of the third section is 30 minutes, the temperature is 800 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 1200 ℃. After the carbon-carbon fiber paper is cooled, coating a hydrophobic material on one surface of the carbon-carbon fiber paper, coating a hydrophobic conductive material on the other surface of the carbon-carbon fiber paper, sintering at the temperature of 400 ℃, and cooling and forming after sintering; the dosage of the hydrophobic material is 1g/m2, the dosage of the coating hydrophobic conductive material is 1g/m2, the hydrophobic material is polytetrafluoroethylene, the coating hydrophobic conductive material comprises polytetrafluoroethylene and carbon powder, and the amount of the carbon powder is 60% of the amount of the coating hydrophobic conductive material.

Example 2: a preparation method of carbon fiber paper for fuel cell comprises cutting carbon fiber precursor into carbon fiber short filaments with a diameter of 10 mm; the specification of the carbon fiber precursor is 12K. Purifying the carbon fiber short filaments at high temperature to form carbon fiber chopped fibers, and uniformly stirring the purified carbon fiber chopped fibers and phenolic resin to form carbon fiber slurry, wherein the content of the phenolic resin in the carbon fiber slurry is 40%; the temperature for high temperature purification was 2500 ℃. And coating the carbon fiber slurry on one surface of release paper to obtain pretreated fiber paper, wherein the coating thickness is 0.5 mm. After coating, placing the pretreated fiber paper in an oven until the carbon fiber slurry is heated to the curing critical temperature to obtain primary fiber paper; the baking time of the oven is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 50 ℃, the residence time of the second section is 15 minutes, the temperature is 50 ℃, the residence time of the third section is 30 minutes, the temperature is 120 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 150 ℃. Pressure fixing is carried out on the preliminary fiber paperAnd (4) curing, and peeling off the release paper after pressure curing to obtain the carbon fiber paper. Carbonizing the carbon fiber paper to form the carbon-carbon fiber paper. The carbonization time is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 400 ℃, the residence time of the second section is 30 minutes, the temperature is 600 ℃, the residence time of the third section is 30 minutes, the temperature is 900 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 1200 ℃. After the carbon-carbon fiber paper is cooled, coating a hydrophobic material on one surface of the carbon-carbon fiber paper, coating a hydrophobic conductive material on the other surface of the carbon-carbon fiber paper, sintering at the temperature of 400 ℃, and cooling and forming after sintering; the amount of hydrophobic material is 10g/m²The amount of the coated hydrophobic conductive material is 25g/m²The hydrophobic material is polytetrafluoroethylene, the coated hydrophobic conductive material comprises polytetrafluoroethylene and carbon powder, and the amount of the carbon powder is 80% of the amount of the coated hydrophobic conductive material.

Example 3: a preparation method of carbon fiber paper for fuel cell comprises cutting carbon fiber precursor into carbon fiber short filaments of 15 mm; the specification of the carbon fiber precursor is 6K. Purifying the carbon fiber short filaments at high temperature to form carbon fiber chopped fibers, and uniformly stirring the purified carbon fiber chopped fibers and phenolic resin to form carbon fiber slurry, wherein the content of the phenolic resin in the carbon fiber slurry is 60%; the temperature for high temperature purification is 3000 ℃. And coating the carbon fiber slurry on one surface of the PET film to obtain pretreated fiber paper, wherein the coating thickness is 1 mm. After coating, placing the pretreated fiber paper in an oven until the carbon fiber slurry is heated to the curing critical temperature to obtain primary fiber paper; the baking time of the oven is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 50 ℃, the residence time of the second section is 15 minutes, the temperature is 50 ℃, the residence time of the third section is 30 minutes, the temperature is 120 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 150 ℃. And carbonizing the carbon fiber paper to form the carbon-carbon fiber paper. The carbonization time is divided into four sections, the residence time of the first section is 15 minutes, the temperature is 400 ℃, the residence time of the second section is 30 minutes, the temperature is 600 ℃, the residence time of the third section is 30 minutes, the temperature is 950 ℃, the residence time of the fourth section is 30 minutes, and the temperature is 1200 ℃. After carbon-carbon fiber paper is cooled, the carbon isCoating a hydrophobic material on one surface of the carbon fiber paper and a hydrophobic conductive material on the other surface of the carbon fiber paper, sintering at the temperature of 400 ℃, and cooling and forming after sintering; the amount of hydrophobic material is 20g/m²The amount of the coated hydrophobic conductive material is 50g/m²The hydrophobic material is polytetrafluoroethylene, the coated hydrophobic conductive material comprises polytetrafluoroethylene and carbon powder, and the amount of the carbon powder is 90% of the amount of the coated hydrophobic conductive material.

Example 4: referring to examples 1, 2 and 3, the carbon fiber precursor specification is one or more combinations of 3K, 6K, 12K, 24K and 48K.

The described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.