Carbon fiber paper with runner and preparation method thereof

Abstract

The invention discloses carbon fiber paper with a runner and a preparation method of the carbon fiber paper. The method comprises the following steps: obtaining initial carbon fiber raw paper; the initial carbon fiber raw paper is placed in the dipping solution for dipping treatment, and intermediate carbon fiber paper is obtained; placing the intermediate carbon fiber paper between the flat plate and the runner plate to form a hot-pressing treatment intermediate; a bulge with a preset shape is arranged on one surface, close to the middle carbon fiber paper, of the runner plate; carrying out hot-pressing treatment on the hot-pressing treatment intermediate at 120-180 DEG C to obtain a carbon fiber paper precursor with a runner in a preset shape; the time corresponding to the hot pressing treatment is 60-120 minutes, and the pressure is 1-3 MPa; and sequentially performing carbonization treatment and graphitization treatment on the carbon fiber paper precursor to obtain the target carbon fiber paper. The runner plate is prepared in advance, and the runner is directly prepared in the carbon fiber paper forming process, so that the complex runner preparation process of the bipolar plate is omitted, and the preparation cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of proton exchange membrane fuel cells, and in particular to a carbon fiber paper with flow channels and a preparation method thereof. Background Art

[0002] One of the keys to fuel cells is the management of water and gas. Based on the management of water and gas, the goal is to improve the reaction efficiency of fuel cells and reduce the cost of fuel cells. The flow channel of the bipolar plate is used for the conduction of water and gas. The flow channel processing of the bipolar plate generally adopts the stamping process, which requires expensive die cutting to stamp the metal sheet to form the flow channel.

[0003] The cost of bipolar plates in existing battery stacks accounts for a high proportion. For example, metal bipolar plates need to be imported and then processed through a series of complex processes such as stamping, welding, plating and sealing. At present, there are still technical bottlenecks in the processing of bipolar plates, such as too deep flow channels, easy to break during stamping, and highly dense flow fields are difficult to stamp. Because the substrate of the bipolar plate includes metal or graphite, the substrate itself is relatively brittle, the thickness reduction is limited, and the processing is very difficult, resulting in high costs. Summary of the invention

[0004] In order to reduce the cost of bipolar plates without affecting the conduction of water and gas in the fuel cell reaction, the present application conducts composite design and processing of carbon fiber paper, and provides a carbon fiber paper with flow channels and a preparation method thereof. By pre-preparing the flow channel plate, the flow channel is directly prepared during the carbon paper molding process, eliminating the complex flow channel preparation process of the bipolar plate and effectively reducing the preparation cost.

[0005] In one aspect, the present application provides a method for preparing carbon fiber paper having a flow channel, the method comprising:

[0006] Obtaining initial carbon fiber base paper;

[0007] placing the initial carbon fiber base paper in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper;

[0008] The intermediate carbon fiber paper is placed between the flat plate and the flow channel plate to form a hot pressing treatment intermediate; the flow channel plate has a bulge of a preset shape on one side close to the intermediate carbon fiber paper;

[0009] The hot pressing intermediate is subjected to hot pressing treatment at 120-180° C. to obtain a carbon fiber paper precursor having a flow channel of the preset shape; the hot pressing treatment corresponds to a time of 60-120 min and a pressure of 1-3 MPa;

[0010] The carbon fiber paper precursor is subjected to carbonization treatment and graphitization treatment in sequence to obtain the target carbon fiber paper.

[0011] Furthermore, the initial carbon fiber base paper is placed in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper, comprising:

[0012] Placing the initial carbon fiber base paper in the impregnation solution, and performing the impregnation treatment at room temperature to obtain an impregnated product; the impregnation time corresponding to the impregnation treatment is 60-120 minutes;

[0013] The impregnated product is dried at 60-120° C. to obtain the intermediate carbon fiber paper; the drying time is 2-5 hours.

[0014] Furthermore, the carbon fiber paper precursor is subjected to carbonization treatment and graphitization treatment in sequence to obtain the target carbon fiber paper, comprising:

[0015] The carbon fiber paper precursor is subjected to the carbonization treatment to obtain a carbonized product; the carbonization temperature corresponding to the carbonization treatment is 800-1200° C., and the carbonization time is 60-120 min;

[0016] The carbonized product is subjected to the graphitization treatment to obtain the target carbon fiber paper; the graphitization temperature corresponding to the graphitization treatment is 2000-3000° C., and the graphitization time is 60-120 min.

[0017] Further, the hot pressing treatment of the hot pressing intermediate at 120-180° C. to obtain a carbon fiber paper precursor having a flow channel of the preset shape comprises:

[0018] Performing a heat-pressing treatment on the heat-pressing intermediate at 120-180° C. to obtain a heat-pressing treatment product;

[0019] The product between the flat plate and the flow channel plate is separated from the hot pressing product to obtain the carbon fiber paper precursor.

[0020] Furthermore, the method further comprises:

[0021] Obtaining an initial flow channel plate; the thickness of the initial flow channel plate is greater than 10 cm;

[0022] Laser cutting the initial flow channel plate so that a protrusion of the preset shape is formed on one surface of the initial flow channel plate to obtain an intermediate flow channel plate;

[0023] The intermediate flow channel plate is cleaned to remove residual impurities on the surface of the intermediate flow channel plate to obtain the flow channel plate.

[0024] Furthermore, the flow channel plate is one of a parallel flow channel, a serpentine flow channel, a wavy flow channel, and a variable diameter flow channel.

[0025] Furthermore, the surface density of the initial carbon fiber base paper is 50-100 g / m 2 , thickness is 300-600μm.

[0026] Furthermore, the impregnation solution is one of a phenolic resin solution, an alkyd resin solution, an epoxy resin solution, and a polyurethane resin solution, and the concentration of the impregnation solution is 5-20wt%.

[0027] Furthermore, the target carbon fiber paper has a thickness of 150-250 μm and a surface density of 55-110 g / m 2 ; The width of the flow channel is 1-2mm and the depth is 30-125μm.

[0028] On the other hand, a carbon fiber paper with flow channels is provided. The carbon fiber paper with flow channels is prepared by the above-mentioned preparation method. Flow channels of preset shapes are distributed on the carbon fiber paper with flow channels. The ratio of the thickness of the carbon fiber paper to the depth of the flow channels is 1:(0.2-0.5).

[0029] On the other hand, a fuel cell is provided. The fuel cell includes the carbon fiber paper with flow channels. The carbon fiber paper with flow channels is prepared by the above-mentioned preparation method.

[0030] The carbon fiber paper with flow channels and the preparation method thereof provided in the present application have the following technical effects:

[0031] The present application obtains the initial carbon fiber base paper; the initial carbon fiber base paper is placed in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper; the intermediate carbon fiber paper is placed between a flat plate and a flow channel plate to form a hot pressing intermediate; the flow channel plate has a bulge of a preset shape on one side close to the intermediate carbon fiber paper; the hot pressing intermediate is hot pressed at 120-180°C to obtain a carbon fiber paper precursor with a flow channel of a preset shape; the corresponding time for hot pressing treatment is 60-120min, and the pressure is 1-3MPa; the carbon fiber paper precursor is sequentially carbonized and graphitized to obtain the target carbon fiber paper. The present application introduces a flow channel design on the carbon fiber paper, eliminating the complex flow channel preparation process on the bipolar plate and reducing the preparation cost; by pre-preparing the flow channel mold plate, a deep flow channel and a high-density flow channel design can be achieved, and the flow channel can be directly prepared during the carbon fiber paper forming process, effectively improving the preparation accuracy and preparation efficiency; the flow channel on the carbon fiber paper can improve the gas conduction in the plane direction of the carbon fiber paper, improve the overall performance of the carbon fiber paper, simplify the battery design, and further reduce the preparation cost.

[0032] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions and advantages of the embodiments of this specification or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic flow chart of a method for preparing a carbon fiber paper with a flow channel provided in an embodiment of this specification;

[0035] Figure 2 It is a schematic diagram of an impregnation process provided in an embodiment of this specification;

[0036] Figure 3 This is a schematic diagram of a process for obtaining a carbon fiber paper precursor provided in an embodiment of this specification;

[0037] Figure 4 This is a schematic diagram of a process for preparing a target carbon fiber material from a carbon fiber paper precursor provided in an embodiment of this specification;

[0038] Figure 5 It is a structural schematic diagram of a carbon fiber paper with flow channels provided in an embodiment of this specification. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] The following describes a method for preparing a carbon fiber paper having a flow channel of the present application, specifically as follows Figure 1 As shown, the method may include:

[0041] S1: Obtaining initial carbon fiber base paper.

[0042] Furthermore, the surface density of the initial carbon fiber base paper is 50-100 g / m 2 , thickness is 300-600μm.

[0043] In the embodiment of the present application, before preparing the carbon fiber paper with flow channels, it is necessary to select a suitable base paper. The base paper is mainly composed of carbon fibers, and the surface density can be selected to be 50-100 g / m 2, carbon fiber base paper with a thickness of 300-600μm is used as the preparation raw material.

[0044] The embodiment of the present application selects carbon fiber base paper with suitable surface density and thickness as the preparation raw material, and introduces a flow channel design on the carbon fiber base paper, which can avoid the complicated flow channel preparation process of the bipolar plate and effectively reduce the preparation cost.

[0045] S2: placing the initial carbon fiber base paper in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper.

[0046] Furthermore, the step of placing the initial carbon fiber base paper in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper may include:

[0047] S21: placing the initial carbon fiber base paper in the impregnation solution, and performing the impregnation treatment at room temperature to obtain an impregnated product; the impregnation time corresponding to the impregnation treatment is 60-120 minutes;

[0048] S22: drying the impregnated product at 60-120° C. to obtain the intermediate carbon fiber paper; the drying time is 2-5 hours.

[0049] In the embodiment of the present application, the carbon fiber base paper is treated by an impregnation method, the initial carbon fiber base paper is completely immersed in the impregnation solution, and the impregnation is carried out at room temperature for 60-120 minutes. After the impregnation is completed, the impregnation product obtained is dried to obtain the impregnation product after drying, that is, the intermediate carbon fiber paper. The drying temperature can be 60-120°C, and the drying time can be 2-5 hours.

[0050] The embodiment of the present application processes the initial carbon fiber base paper by an impregnation method, which can improve the overall mechanical properties of the material, such as strength, toughness, etc., and make it have good processing performance, which is convenient for subsequent molding and processing. It can also improve the pore structure on the surface of the initial carbon fiber paper to meet its gas diffusion application.

[0051] Furthermore, the impregnation solution is one of a phenolic resin solution, an alkyd resin solution, an epoxy resin solution, and a polyurethane resin solution, and the concentration of the impregnation solution is 5-20wt%.

[0052] In the embodiment of the present application, a binder is used for impregnation treatment, and a 5-20wt% impregnation solution can be used. The impregnation solution can be one of a phenolic resin solution, an alkyd resin solution, an epoxy resin solution, and a polyurethane resin solution.

[0053] In the embodiment of the present application, the above-mentioned immersion treatment process may also include:

[0054] The initial carbon fiber base paper is placed in a 5-10wt% impregnation solution and impregnated at room temperature to obtain an impregnated product; the impregnation time corresponding to the impregnation treatment is 60-120 minutes;

[0055] The impregnated product is dried at 60-120° C. to obtain intermediate carbon fiber paper; the corresponding time for the drying treatment is 2-5 hours.

[0056] In the embodiment of the present application, the above-mentioned immersion treatment process may also include:

[0057] The initial carbon fiber base paper is placed in a 10-20wt% impregnation solution, and is impregnated at room temperature to obtain an impregnated product; the impregnation time corresponding to the impregnation treatment is 60-120 minutes;

[0058] The impregnated product is dried at 60-120° C. to obtain intermediate carbon fiber paper; the corresponding time for the drying treatment is 2-5 hours.

[0059] In the embodiment of the present application, the above-mentioned immersion treatment process may also include:

[0060] The initial carbon fiber base paper is placed in a 15-20wt% impregnation solution, and is impregnated for 60 minutes at room temperature to obtain an impregnated product;

[0061] The impregnated product is dried at 60-120° C. for 2-5 hours to obtain an intermediate carbon fiber paper.

[0062] In an embodiment of the present application, the above-mentioned immersion treatment process may not be limited to a single immersion treatment, but may also be two or more immersion treatments. For two or more immersion treatments, the concentration of the immersion solution and the immersion time in each immersion process may be the same or different.

[0063] In an embodiment of the present application, the above-mentioned impregnation treatment may further include:

[0064] The initial carbon fiber base paper is placed in a 5-10wt% impregnation solution, and is impregnated for 30 minutes at room temperature to obtain a primary impregnation product;

[0065] The primary impregnation product is placed in a 5-20wt% impregnation solution and subjected to a secondary impregnation treatment for 30 minutes at room temperature;

[0066] The secondary impregnation product is dried at 60-120° C. to obtain intermediate carbon fiber paper; the corresponding time for the drying treatment is 2-5 hours.

[0067] In an embodiment of the present application, the above-mentioned impregnation treatment may further include:

[0068] The initial carbon fiber base paper is placed in a 5-10wt% impregnation solution, and is impregnated for 20 minutes at room temperature to obtain a primary impregnation product;

[0069] The primary impregnation product is placed in a 10-15wt% impregnation solution and subjected to a secondary impregnation treatment for 20 minutes at room temperature;

[0070] The secondary impregnation product is placed in a 15-20wt% impregnation solution and subjected to a third impregnation treatment for 25 minutes at room temperature;

[0071] The three-impregnation products are dried at 60-120° C. to obtain intermediate carbon fiber paper; the corresponding time for the drying treatment is 2-5 hours.

[0072] The embodiment of the present application selects a suitable resin solution as the impregnation solution, so that the impregnated product can have good processing characteristics and meet more usage requirements.

[0073] S3: placing the intermediate carbon fiber paper between the flat plate and the flow channel plate to form a hot pressing treated intermediate; the flow channel plate has a bulge of a preset shape on one side close to the intermediate carbon fiber paper.

[0074] In an embodiment of the present application, after the impregnation treatment is completed, the dried intermediate carbon fiber paper is placed between the flat plate and the flow channel plate to form a hot pressing treated intermediate, and the side of the flow channel plate with a protrusion of a preset shape is brought close to the intermediate carbon fiber paper so that one side of the intermediate carbon fiber paper forms a flow channel with a preset shape during the hot pressing process.

[0075] Furthermore, the method may also include:

[0076] Obtaining an initial flow channel plate; the thickness of the initial flow channel plate is greater than 10 cm;

[0077] Laser cutting the initial flow channel plate so that a protrusion of the preset shape is formed on one surface of the initial flow channel plate to obtain an intermediate flow channel plate;

[0078] The intermediate flow channel plate is cleaned to remove residual impurities on the surface of the intermediate flow channel plate to obtain the flow channel plate.

[0079] In the embodiment of the present application, before preparing the carbon fiber paper with flow channels, the flow channel mold plate can be prepared according to actual needs, and the flow channel plate can be processed according to the size tooling of the hot press. First, select a suitable initial flow channel plate, which can be a steel plate with a thickness greater than 10 cm; input the designed graphics (including processing width, processing depth, etc.) into the laser engraving machine, and then start the laser cutting for processing, so that a bulge with a preset shape is formed on one side of the initial flow channel plate, that is, a shape that matches the flow channel size, to obtain an intermediate flow channel plate; because after laser engraving, the surface of the intermediate flow channel plate will have residual impurities such as slag or oxide scale residues, so the intermediate flow channel plate obtained after laser cutting needs to be cleaned to remove these impurities, and dust blowing or washing with water can be used for cleaning.

[0080] In the embodiment of the present application, the size and shape of the flow channel plate match the shape of the flow channel finally prepared. If the width of the flow channel is 1-2mm and the depth is 30-125μm, then the width of the protrusion on the flow channel plate can be 1-2mm and the height can be 30-125μm, thereby improving the preparation accuracy and efficiency.

[0081] The embodiment of the present application prepares the flow channel plate in advance through laser cutting, and can flexibly customize flow channels of different sizes according to actual needs, thereby improving the preparation accuracy of the flow channel mold plate and the flow channel, and can meet the preparation requirements of flow channels of different sizes, thereby obtaining a higher density flow channel, avoiding the complicated process of preparing the flow channel on the bipolar plate, and reducing the processing difficulty and processing cost.

[0082] Furthermore, the flow channel plate is one of a parallel flow channel, a serpentine flow channel, a wavy flow channel, and a variable diameter flow channel.

[0083] In the embodiments of the present application, the shape, size, etc. of the flow channel plate can be designed and prepared according to actual needs to prepare carbon fiber paper with flow channels of different sizes. The flow channel plate can be one of a parallel flow channel, a serpentine flow channel, a wavy flow channel, and a variable diameter flow channel.

[0084] The embodiments of the present application can prepare carbon fiber paper with flow channels of different shapes and sizes through flow channel plates of different shapes and sizes, which can improve the preparation flexibility and preparation accuracy of the carbon fiber paper, obtain flow channels with more precise sizes, and meet different application requirements.

[0085] S4: performing hot pressing treatment on the hot pressing treated intermediate at 120-180° C. to obtain a carbon fiber paper precursor having a flow channel of the preset shape; the hot pressing treatment corresponds to a time of 60-120 min and a pressure of 1-3 MPa.

[0086] In the embodiment of the present application, a hot pressing treatment is performed at 120-180° C. to obtain a carbon fiber paper precursor having a flow channel of a preset shape. The curing and holding time can be 60-120 min, and the pressure can be 1-3 MPa.

[0087] Furthermore, the step of hot pressing the hot pressing intermediate at 120-180° C. to obtain the carbon fiber paper precursor having the flow channel of the preset shape may include:

[0088] S41: performing a heat pressing treatment on the heat pressing treatment intermediate at 120-180° C. to obtain a heat pressing treatment product;

[0089] S42: Separating the product between the flat plate and the flow channel plate from the hot pressing product to obtain the carbon fiber paper precursor.

[0090] In the embodiment of the present application, after the hot pressing intermediate is hot pressed at 120-180°C, a hot pressing product is obtained, and the product between the flat plate and the flow channel plate is separated from the hot pressing product to obtain a carbon fiber paper precursor with flow channels.

[0091] The embodiment of the present application can obtain a carbon fiber paper precursor with a flow channel by separating the carbon fiber paper precursor from between the flat plate and the flow channel plate, so as to perform subsequent carbonization and graphitization treatments to improve the overall performance of the carbon fiber paper.

[0092] S5: sequentially subjecting the carbon fiber paper precursor to carbonization treatment and graphitization treatment to obtain target carbon fiber paper.

[0093] Furthermore, the step of sequentially performing carbonization and graphitization on the carbon fiber paper precursor to obtain the target carbon fiber paper may include:

[0094] S51: performing the carbonization treatment on the carbon fiber paper precursor to obtain a carbonized product; the carbonization temperature corresponding to the carbonization treatment is 800-1200° C., and the carbonization time is 60-120 min;

[0095] S52: performing the graphitization treatment on the carbonized product to obtain the target carbon fiber paper; the graphitization temperature corresponding to the graphitization treatment is 2000-3000° C., and the graphitization time is 60-120 min.

[0096] In the embodiment of the present application, after obtaining the carbon fiber paper precursor, it is necessary to sequentially perform carbonization treatment and graphitization treatment on the carbon fiber paper precursor, so as to improve the overall performance of the target carbon fiber paper.

[0097] In the embodiment of the present application, the carbon fiber paper precursor is firstly carbonized to obtain a carbonized product, and the carbonization temperature corresponding to the carbonization treatment can be 800-1200°C, and the carbonization time can be 60-120 minutes. The carbonization treatment can improve the strength, stiffness, conductivity and other properties of the material, while optimizing its structure and performance, and removing unstable components, thereby improving the overall performance of the material.

[0098] In the embodiment of the present application, after the carbonization treatment is completed, the carbonization product is subjected to graphitization treatment, and the graphitization temperature corresponding to the graphitization treatment can be 2000-3000°C, and the graphitization time can be 60-120min. Since the higher the graphitization temperature, the higher the energy consumption, the preferred temperature for the graphitization treatment can be 2500°C, which can not only ensure the effect of the graphitization treatment, but also avoid unnecessary energy consumption. Graphitization treatment can increase the degree of crystallization of carbon fiber paper, reduce the particle spacing, and make the carbon fiber more fitted and uniform, thereby improving its mechanical properties and wear resistance.

[0099] The embodiments of the present application perform carbonization and graphitization on the carbon fiber paper precursor, thereby improving the conductivity, wear resistance and mechanical properties of the material and improving the overall performance of the finally obtained carbon fiber paper with flow channels.

[0100] Furthermore, the target carbon fiber paper has a thickness of 150-250 μm and a surface density of 55-110 g / m 2 ; The width of the flow channel is 1-2mm and the depth is 30-125μm.

[0101] In the embodiment of the present application, the thickness of the carbon fiber paper with flow channels finally prepared is 150-250 μm, and the surface density is 55-110 g / m 2 The width of the flow channel on the carbon fiber paper is 1-2mm, and the depth is 30-125μm. Among them, the depth of the flow channel is 20-50% of the thickness of the carbon fiber paper, realizing the design and preparation of deep flow channels and highly dense flow channels.

[0102] The embodiments of the present application improve the gas conduction in the plane direction of the carbon fiber paper by reasonably designing the width and depth of the flow channel, thereby obtaining carbon fiber paper with better overall performance and simplifying the overall design and preparation process of the battery.

[0103] The embodiment of the present application first obtains the initial carbon fiber base paper, and places it in an impregnation solution for impregnation treatment, and then places the product obtained by the impregnation treatment between a flat plate and a flow channel plate, and performs a hot pressing treatment to obtain a carbon fiber paper precursor with a flow channel of a specific shape, and then the carbon fiber paper precursor is successively carbonized and graphitized to obtain the target carbon fiber paper. By selecting carbon fiber base paper with appropriate surface density and thickness as the preparation raw material, it is impregnated to give it good processing characteristics to meet different needs; by pre-preparing the flow channel mold plate, a deep flow channel and high-density flow channel design can be achieved; by introducing the flow channel design on the carbon fiber paper, and directly preparing the flow channel during the carbon fiber paper forming process, the preparation accuracy and preparation efficiency are effectively improved, and the flow channel on the carbon fiber paper can improve the gas conduction in the plane direction of the carbon fiber paper, improve the overall performance of the carbon fiber paper, simplify the battery design, and reduce the preparation cost.

[0104] The embodiment of the present application also provides a carbon fiber paper with flow channels, which is prepared by the above-mentioned preparation method. The carbon fiber paper with flow channels has flow channels of preset shapes distributed on it, and the ratio of the thickness of the carbon fiber paper to the depth of the flow channels is 1:(0.2-0.5).

[0105] In the embodiments of the present application, carbon fiber paper with flow channels can be prepared by the preparation method in the above method embodiments. The flow channel distribution on the carbon fiber paper can be achieved by designing and preparing a flow channel mold plate in advance. The depth of the flow channel on the carbon fiber paper is 20-50% of the thickness of the carbon fiber paper.

[0106] In the embodiments of the present application, Figure 5 is a schematic diagram of the structure of a carbon fiber paper with flow channels provided in an embodiment of the present application, such as Figure 5 As shown, flow channels are distributed on the carbon fiber paper, and the flow channels on the carbon fiber paper can improve the gas conduction in the plane direction of the carbon fiber paper, improve the overall performance of the carbon fiber paper, and simplify the battery design.

[0107] The embodiment of the present application further provides a fuel cell, the fuel cell comprising the carbon fiber paper with flow channels, the carbon fiber paper with flow channels being prepared by the above-mentioned preparation method.

[0108] Embodiment 1:

[0109] This embodiment provides a method for preparing carbon fiber paper with flow channels, and the specific preparation method includes:

[0110] The surface density is 50-100g / m 2, a carbon fiber base paper with a thickness of 300-600 μm is placed in a 5-20wt% phenolic resin alcohol solution for 60-120 minutes of impregnation treatment, and then dried at 60-120° C. after the impregnation is completed, and then hot-pressed at 120-180° C. and 1-3 MPa for 60-120 minutes to obtain a carbon fiber paper precursor;

[0111] The carbon fiber paper precursor is carbonized at 800-1200° C. for 60-120 minutes, and then graphitized at 2000-3000° C. for 60-120 minutes to obtain carbon fiber paper with flow channels.

[0112] Embodiment 2:

[0113] This embodiment provides a method for preparing carbon fiber paper with flow channels, and the specific preparation method includes:

[0114] The surface density is 50g / m 2 , a carbon fiber base paper with a thickness of 300 μm is placed in a 5wt% phenolic resin alcohol solution for 60 minutes of impregnation treatment, and then dried at 60°C, and then hot-pressed at 120°C and 1MPa for 60 minutes to obtain a carbon fiber paper precursor;

[0115] The carbon fiber paper precursor is carbonized at 1000° C. for 80 minutes, and then graphitized at 2500° C. for 60-120 minutes to obtain a carbon fiber paper with flow channels.

[0116] Embodiment 3:

[0117] This embodiment provides a method for preparing carbon fiber paper with flow channels, and the specific preparation method includes:

[0118] The surface density is 100g / m 2 , a carbon fiber base paper with a thickness of 600 μm is placed in a 20wt% phenolic resin alcohol solution for 120 minutes of impregnation treatment, and then dried at 120°C, and then hot-pressed at 180°C and 3MPa for 120 minutes to obtain a carbon fiber paper precursor;

[0119] The carbon fiber paper precursor is carbonized at 1000° C. for 80 minutes, and then graphitized at 2500° C. for 60-120 minutes to obtain a carbon fiber paper with flow channels.

[0120] Embodiment 4:

[0121] This embodiment provides a method for preparing carbon fiber paper with flow channels, and the specific preparation method includes:

[0122] The surface density is 80g / m 2, a carbon fiber base paper with a thickness of 500 μm is placed in a 15wt% phenolic resin alcohol solution for 100 minutes of impregnation treatment, and then dried at 100°C, and then hot-pressed at 160°C and 2MPa for 100 minutes to obtain a carbon fiber paper precursor;

[0123] The carbon fiber paper precursor is carbonized at 1000° C. for 80 minutes, and then graphitized at 2500° C. for 60-120 minutes to obtain a carbon fiber paper with flow channels.

[0124] It can be seen from the embodiments provided by the present application that the present application obtains initial carbon fiber base paper; places the initial carbon fiber base paper in an impregnation solution for impregnation treatment to obtain intermediate carbon fiber paper; places the intermediate carbon fiber paper between a flat plate and a flow channel plate to form a hot pressing intermediate; the flow channel plate has a protrusion of a preset shape on one side close to the intermediate carbon fiber paper; the hot pressing intermediate is hot pressed at 120-180°C to obtain a carbon fiber paper precursor having a flow channel of a preset shape; the corresponding time for the hot pressing treatment is 60-120min, and the pressure is 1-3MPa; the carbon fiber paper precursor is sequentially carbonized and graphitized to obtain the target carbon fiber paper. The present application introduces a flow channel design on the carbon fiber paper, eliminating the complex flow channel preparation process on the bipolar plate and reducing the preparation cost; by pre-preparing the flow channel mold plate, a deep flow channel and a high-density flow channel design can be achieved, and the flow channel can be directly prepared during the carbon fiber paper molding process, effectively improving the preparation accuracy and preparation efficiency; the flow channel on the carbon fiber paper can improve the gas conduction in the plane direction of the carbon fiber paper, improve the overall performance of the carbon fiber paper, simplify the battery design, and further reduce the preparation cost.

[0125] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing carbon fiber paper with flow channels, characterized in that: The method comprises: Obtaining initial carbon fiber base paper; placing the initial carbon fiber base paper in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper; The intermediate carbon fiber paper is placed between the flat plate and the flow channel plate to form a hot pressing treatment intermediate; the flow channel plate has a bulge of a preset shape on one side close to the intermediate carbon fiber paper; The hot pressing intermediate is subjected to hot pressing treatment at 120-180° C. to obtain a carbon fiber paper precursor having a flow channel of the preset shape; the hot pressing treatment corresponds to a time of 60-120 min and a pressure of 1-3 MPa; The carbon fiber paper precursor is subjected to carbonization treatment and graphitization treatment in sequence to obtain the target carbon fiber paper.

2. The method according to claim 1, characterized in that The step of placing the initial carbon fiber base paper in an impregnation solution for impregnation treatment to obtain an intermediate carbon fiber paper comprises: Placing the initial carbon fiber base paper in the impregnation solution, and performing the impregnation treatment at room temperature to obtain an impregnated product; the impregnation time corresponding to the impregnation treatment is 60-120 minutes; The impregnated product is dried at 60-120° C. to obtain the intermediate carbon fiber paper; the drying time is 2-5 hours.

3. The method according to claim 1, characterized in that The method of sequentially subjecting the carbon fiber paper precursor to carbonization and graphitization to obtain the target carbon fiber paper comprises: The carbon fiber paper precursor is subjected to the carbonization treatment to obtain a carbonized product; the carbonization temperature corresponding to the carbonization treatment is 800-1200° C., and the carbonization time is 60-120 min; The carbonized product is subjected to the graphitization treatment to obtain the target carbon fiber paper; the graphitization temperature corresponding to the graphitization treatment is 2000-3000° C., and the graphitization time is 60-120 min.

4. The method according to claim 1, characterized in that: The step of subjecting the hot pressing intermediate to hot pressing at 120-180° C. to obtain a carbon fiber paper precursor having a flow channel of the preset shape comprises: Performing a heat-pressing treatment on the heat-pressing intermediate at 120-180° C. to obtain a heat-pressing treatment product; The product between the flat plate and the flow channel plate is separated from the hot pressing product to obtain the carbon fiber paper precursor.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Obtaining an initial flow channel plate; the thickness of the initial flow channel plate is greater than 10 cm; Laser cutting the initial flow channel plate so that a protrusion of the preset shape is formed on one surface of the initial flow channel plate to obtain an intermediate flow channel plate; The intermediate flow channel plate is cleaned to remove residual impurities on the surface of the intermediate flow channel plate to obtain the flow channel plate.

6. The method according to claim 5, characterized in that The flow channel plate is one of a parallel flow channel, a serpentine flow channel, a wavy flow channel, and a variable diameter flow channel.

7. The method according to claim 1, characterized in that The surface density of the initial carbon fiber base paper is 50-100 g / m 2 , thickness is 300-600μm.

8. The method according to claim 2, characterized in that: The impregnation solution is one of a phenolic resin solution, an alkyd resin solution, an epoxy resin solution, and a polyurethane resin solution, and the concentration of the impregnation solution is 5-20 wt %.

9. The method according to claim 1, characterized in that: The target carbon fiber paper has a thickness of 150-250 μm and a surface density of 55-110 g / m 2 ; The width of the flow channel is 1-2mm and the depth is 30-125μm.

10. A carbon fiber paper having a flow channel, characterized in that: The carbon fiber paper with flow channels is prepared by the preparation method according to any one of claims 1 to 9, and flow channels of preset shapes are distributed on the carbon fiber paper with flow channels, and the ratio of the thickness of the carbon fiber paper to the depth of the flow channels is 1:(0.2-0.5).

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