CN109802147B

CN109802147B - Gas diffusion layer for fuel cell using membrane electrode as collector and its preparing method

Info

Publication number: CN109802147B
Application number: CN201811465575.5A
Authority: CN
Inventors: 曹婷婷; 米新艳; 崔新然; 张克金; 朱雅男; 王茁; 李军泽; 苏中辉; 杨帅
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2018-12-03
Filing date: 2018-12-03
Publication date: 2021-10-01
Anticipated expiration: 2038-12-03
Also published as: CN109802147A

Abstract

The invention discloses a gas diffusion layer for a fuel cell, which takes a membrane electrode as a collector, and comprises a first composite non-woven layer, a second composite non-woven layer, a third composite non-woven layer, a fourth composite non-woven layer and an active carbon micro-pore layer, wherein the four non-woven layers respectively adopt different equivalent apertures, the four non-woven layers are sequentially laminated and bonded together according to the sequence of the equivalent apertures from large to small, and the active carbon micro-pore layer is uniformly dispersed on the outer surface of the non-woven layer with the smallest effective aperture. The gas diffusion layer is prepared by adopting the composite of the differential pore diameter structures of the multiple layers of porous materials, so that the gas transmission efficiency is improved, and the gas transmission resistance is reduced. The invention also provides a preparation method of the gas diffusion layer for the fuel cell, which takes the membrane electrode as the collector.

Description

Gas diffusion layer for fuel cell using membrane electrode as collector and its preparing method

Technical Field

The invention relates to the field of new energy fuel cells, in particular to a gas diffusion layer for a fuel cell with a membrane electrode as a collector and a preparation method thereof.

Background

With the continuous improvement of the requirements of environmental protection, energy conservation and emission reduction, the change of the driving force of the motor vehicle from the traditional energy to the new energy is a development direction for a long time in the future, and one of ten development directions in national manufacturing 2025 comprises a new energy development strategy. New energy sources include clean alternative fuels, secondary energy storage batteries, and fuel cell vehicles. The secondary energy storage battery has an influence on the large-scale application of the secondary energy storage battery in the aspect of a vehicle power system due to the limitation of theoretical energy density, safety problems, the problem that the charging efficiency and the service life are difficult to greatly improve and the difficulty of recycling. The fuel cell is used as a fuel supplement type power generation system, the limitation of volume and mass energy density is avoided, the energy utilization rate can reach more than 50%, the energy cleanliness is integrally higher than that of a secondary energy storage battery, the hydrogen source is wide, the hydrogenation speed is similar to that of gasoline filling, the once filling driving range is 400-700 kilometers, the operation life is long, and the overall performance is very suitable for being used as a vehicle-mounted power source. The biggest barrier to commercial promotion and application at present is the cost problem. The price of the platinum-containing catalyst can only increase gradually with the gradual reduction of platinum deposits, and the gas diffusion layer based on the carbon fiber papermaking structure can only depend on import due to the weak foundation of China in the aspect of carbon fiber materials. The substrate sheet of the metal bipolar plate is easily warped, so that the electron passing efficiency is reduced, and the internal resistance is increased. The materials of the components of the fuel cell are selected at present based on the traditional fuel cell structure, namely, the electronic transportation depends on the internal component channel, namely, all the components need to be good conductors of the electrons. Therefore, the material of each component is selected from metal of good electronic conductor or carbon-based material close to semiconductor, the material selection range is small, and the price is high.

Disclosure of Invention

In order to solve the problem of high cost caused by the defects of the traditional fuel cell structure, the invention adopts low-cost insulating materials to replace imported conductive carbon paper materials for preparation, and provides the gas diffusion layer of the fuel cell, which is used for taking a membrane electrode as a collector electrode. The gas diffusion layer only needs to take on the uniform transfer of the reaction gas while inhibiting the transfer of electrons perpendicular to the gas diffusion layer. The gas diffusion layer is prepared by adopting the composite of the differential pore diameter structures of the multiple layers of porous materials, so that the gas transmission efficiency is improved, and the gas transmission resistance is reduced. Especially, the application of the non-conductive material greatly reduces the component cost and has obvious practical value.

The technical scheme of the invention is as follows:

a gas diffusion layer for a fuel cell with a membrane electrode as a collector comprises a first composite non-woven layer, a second composite non-woven layer, a third composite non-woven layer, a fourth composite non-woven layer and an active carbon micro-pore layer, wherein the four non-woven layers respectively adopt different equivalent apertures, the four non-woven layers are sequentially laminated and bonded together according to the sequence of the equivalent apertures from large to small, and the active carbon micro-pore layer is uniformly dispersed on the outer surface of the non-woven layer with the smallest effective aperture.

The first composite non-woven layer is non-woven paper which is prepared by compounding single or multiple materials and has an equivalent aperture of 60-80 mu m; the second composite non-woven layer is non-woven paper which is prepared by compounding single or multiple materials and has an equivalent pore size of 50-70 um; the third non-woven layer is non-woven paper which has an equivalent pore size of 40-60um and is prepared by compounding single or multiple materials; the No. four non-woven layer is non-woven paper which is compounded by single or multiple materials and has the equivalent aperture of 20-40 um.

The invention also provides a method for preparing the gas diffusion layer for the fuel cell by taking the membrane electrode as the collector, which comprises the steps of laminating and bonding four non-woven layers together in sequence from large equivalent aperture to small equivalent aperture, uniformly dispersing an active carbon microporous layer on the outer surface of the non-woven layer with the smallest effective aperture, and respectively placing the non-woven layers on two sides of the membrane electrode assembly which is taken as the collector after heat treatment.

The invention has the beneficial effects that: the insulating non-woven composite layer with the gradually reduced pore diameter is used as the gas diffusion layer, so that the material cost is effectively reduced, the gas transmission resistance is reduced, and the power of the fuel cell is effectively improved.

Drawings

Fig. 1 is a schematic view of a gas diffusion layer for a fuel cell using a membrane electrode as a collector.

In the figure: 1-a composite non-woven layer, 2-a composite non-woven layer, 3-a composite non-woven layer, 4-a composite non-woven layer, 5-an active carbon microporous layer

Detailed Description

The technical scheme of the invention is described in detail in the following with reference to the accompanying drawings and embodiments:

as shown in fig. 1, the gas diffusion layer for a fuel cell using a membrane electrode as a collector includes four composite

nonwoven layers

1, 2, 3, 4 with different equivalent pore sizes and an activated carbon microporous layer 5. The four non-woven layers are laminated and bonded together in sequence from large equivalent aperture to small equivalent aperture, active carbon micro-porous layers (Super P)5 are uniformly dispersed on the outer surface of the non-woven layer with the smallest effective aperture, the non-woven layers are respectively placed on two sides of a membrane electrode assembly serving as a collector after heat treatment, in order to reduce the total weight of a fuel cell stack, molded phenolic resin powder is made into a gas introduction flow channel with the thickness of 0.5mm, a repeating unit is packaged into a short stack with the design of 1MPa by adopting a sealing ring, and the test result is that the peak power is 1.2 MPa. The cost is reduced by 60 percent compared with the traditional fuel cell with the same power.

Example 1

A gas diffusion layer for a fuel cell with a membrane electrode as a collector electrode is prepared by selecting a terylene composite non-woven paper with an equivalent aperture of 80um as a first composite non-woven layer 1, selecting a polypropylene insulating composite non-woven paper with an equivalent aperture of 60um as a second composite non-woven layer 2, selecting a terylene composite non-woven fabric with an equivalent aperture of 40um as a third composite non-woven layer 3, selecting a polyamide insulating composite non-woven paper with an equivalent aperture of 20um as a fourth composite non-woven layer 4, laminating and bonding the four non-woven layers together in sequence from large to small according to the equivalent aperture, uniformly dispersing an active carbon microporous layer 5(Super P) on the other surface of the non-woven layer with the smallest equivalent aperture, respectively placing the layers on two sides of a membrane electrode assembly as the collector electrode after heat treatment, preparing a gas introduction flow channel with the thickness of 0.5mm by molding phenolic resin powder in order to reduce the total weight of a fuel cell stack, the repeating units are packaged into a short pile with the design of 1MPa by adopting a sealing ring, and the test result is that the peak power is 1.2 MPa. The cost is reduced by 60 percent compared with the traditional fuel cell with the same power.

Example 2

The method comprises the steps of selecting vinylon composite non-woven paper with an equivalent pore diameter of 70 mu m as a first composite non-woven layer 1, selecting monofilament composite non-woven paper with an equivalent pore diameter of 65 mu m as a second composite non-woven layer 2, selecting vinylon composite non-woven fabric with an equivalent pore diameter of 50 mu m as a third composite non-woven layer 3, selecting terylene composite non-woven fabric with an equivalent pore diameter of 35 mu m as a fourth composite non-woven layer 4, laminating and bonding the four non-woven layers together, uniformly dispersing an active carbon microporous layer 5(Super P) on one side with a smaller gap, placing the activated carbon microporous layer 5(Super P) on two sides of a membrane electrode assembly serving as a collector electrode after heat treatment, preparing a gas introduction flow channel with the thickness of 0.8mm by using mould pressing reinforced polypropylene filled composite resin, packaging a repeating unit into a short stack with the design of 1MPa by using a sealing ring, and testing the peak power to be 1.1 MPa. The cost is reduced by 50% compared with the traditional fuel cell with the same power.

Example 3

Selecting a terylene composite non-woven fabric with an equivalent aperture of 70um as a first composite non-woven fabric layer 1, selecting a chinlon composite non-woven fabric with an equivalent aperture of 60um as a second composite non-woven fabric layer 2, selecting a polypropylene composite non-woven fabric with an equivalent aperture of 50um as a third composite non-woven fabric layer 3, selecting a vinylon composite non-woven fabric with an equivalent aperture of 40um as a fourth composite non-woven fabric layer 4, laminating and bonding the four non-woven fabrics together, uniformly dispersing an activated carbon microporous layer 5(Super P) on one side with a smaller gap, respectively placing the activated carbon microporous layer on two sides of a membrane electrode assembly serving as a collector after heat treatment, preparing a mould pressing reinforced polyamide ester into a gas introduction flow passage with a thickness of 0.8mm for reducing the total weight of a fuel cell stack, packaging a repeating unit into a short stack with a design of 1MPa by adopting a sealing ring, and testing the peak power of 1.1 MPa. The cost is reduced by 50% compared with the traditional fuel cell with the same power.

Claims

1. A gas diffusion layer for a fuel cell with a membrane electrode as a collector is characterized by comprising a first composite non-woven fabric layer, a second composite non-woven fabric layer, a third composite non-woven fabric layer, a fourth composite non-woven fabric layer and an active carbon micro-porous layer, wherein the first composite non-woven fabric layer, the second composite non-woven fabric layer, the third composite non-woven fabric layer and the fourth composite non-woven fabric layer are all insulating non-woven fabric composite layers; the four composite non-woven layers respectively adopt different equivalent apertures, the four composite non-woven layers are sequentially laminated and bonded together according to the sequence of the equivalent apertures from large to small, and the activated carbon microporous layer is uniformly dispersed on the outer surface of the non-woven layer with the smallest effective aperture.

2. The gas diffusion layer for a fuel cell with a membrane electrode as an electrode collector according to claim 1, wherein the first composite nonwoven layer is a nonwoven paper made of single or multiple materials with an equivalent pore size of 60-80 um; the second composite non-woven layer is non-woven paper which is prepared by compounding single or multiple materials and has an equivalent pore size of 50-70 um; the third non-woven layer is non-woven paper which has an equivalent pore size of 40-60um and is prepared by compounding single or multiple materials; the No. four non-woven layer is non-woven paper which is compounded by single or multiple materials and has the equivalent aperture of 20-40 um.

3. The method of manufacturing a gas diffusion layer for a fuel cell using a membrane electrode as a collector according to claim 1, wherein four nonwoven fabric layers are laminated and bonded in order of the equivalent pore size from the largest to the smallest, and activated carbon microporous layers are uniformly dispersed on the outer surface of the nonwoven fabric layer having the smallest effective pore size, and are disposed on both sides of the membrane electrode assembly as a collector after heat treatment.