CN1949567A

CN1949567A - Sealing device of three in one membreane electrode for energy-saving fuel cell

Info

Publication number: CN1949567A
Application number: CNA2005100304169A
Authority: CN
Inventors: 胡里清; 李丽; 郭伟良; 胡卓滔
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2005-10-12
Filing date: 2005-10-12
Publication date: 2007-04-18

Abstract

The invention relates to an energy-saving fuel cell three-in-one membrane electrode sealing device, comprising proton exchange membrane and three-in-one membrane electrodes of carbon diffused layer material on two sides of the proton exchange membrane, and sealing frame, where the membrane electrode is divided into middle effective part and peripheral sealing part, and the sealing part is divided into two regions (A) and (B); in the region (A), the proton exchange membrane and the carbon diffused layer material on the two sides have the same size, regular and smooth, and the sealing frame is coated on two sides of the membrane electrode in the region (A); in the region (B), the proton exchange membrane and the carbon-diffused layer material on the two sides do not have the same size, and a gap is formed on one side, and the sealing frame is arraned at the gap. As compared with the existing technique, the invention has good sealing property, and is uneasy to block.

Description

Three-in-one membrane electrode sealing device for energy-saving fuel cell

Technical Field

The invention relates to a fuel cell, in particular to a three-in-one membrane electrode sealing device of an energy-saving fuel cell.

Background

An electrochemical fuel cell is a device capable of converting hydrogen and an oxidant into electrical energy and reaction products. The inner core component of the device is a Membrane Electrode (MEA), which is composed of a proton exchange Membrane and two porous conductive materials sandwiched between two surfaces of the Membrane, such as carbon paper. The membrane contains a uniform and finely dispersed catalyst, such as a platinum metal catalyst, for initiating an electrochemical reaction at the interface between the membrane and the carbon paper. The electrons generated in the electrochemical reaction process can be led out by conductive objects at two sides of the membrane electrode through an external circuit to form a current loop.

At the anode end of the membrane electrode, fuel can permeate through a porous diffusion material (carbon paper) and undergo electrochemical reaction on the surface of a catalyst to lose electrons to form positive ions, and the positive ions can pass through a proton exchange membrane through migration to reach the cathode end at the other end of the membrane electrode. At the cathode end of the membrane electrode, a gas containing an oxidant (e.g., oxygen), such as air, forms negative ions bypermeating through a porous diffusion material (carbon paper) and electrochemically reacting on the surface of the catalyst to give electrons. The anions formed at the cathode end react with the positive ions transferred from the anode end to form reaction products.

In a pem fuel cell using hydrogen as the fuel and oxygen-containing air as the oxidant (or pure oxygen as the oxidant), the catalytic electrochemical reaction of the fuel hydrogen in the anode region produces hydrogen cations (or protons). The proton exchange membrane assists the migration of positive hydrogen ions from the anode region to the cathode region. In addition, the proton exchange membrane separates the hydrogen-containing fuel gas stream from the oxygen-containing gas stream so that they do not mix with each other to cause explosive reactions.

In the cathode region, oxygen gains electrons on the catalyst surface, forming negative ions, which react with the hydrogen positive ions transported from the anode region to produce water as a reaction product. In a proton exchange membrane fuel cell using hydrogen, air (oxygen), the anode reaction and the cathode reaction can be expressed by the following equations:

and (3) anode reaction:

and (3) cathode reaction:

in a typical pem fuel cell, a Membrane Electrode (MEA) is generally placed between two conductive plates, and the surface of each guide plate in contact with the MEA is die-cast, stamped, or mechanically milled to form at least one or more channels. The flow guide polar plates can be polar plates made of metal materials or polar plates made of graphite materials. The fluid pore channels and the diversion trenches on the diversion polar plates respectively guide the fuel and the oxidant into the anode area and the cathode area on two sides of the membrane electrode. In the structure of a single proton exchange membrane fuel cell, only one membrane electrode is present, and a guide plate of anode fuel and a guide plate of cathode oxidant are respectively arranged on two sides of the membrane electrode. The guide plates are used as current collector plates and mechanical supports at two sides of the membrane electrode, and the guide grooves on the guide plates are also used as channels for fuel and oxidant to enter the surfaces of the anode and the cathode and as channels for taking away water generated in the operation process of the fuel cell.

In order to increase the total power of the whole proton exchange membrane fuel cell, two or more single cells can be connected in series to form a battery pack in a straight-stacked manner or connected in a flat-laid manner to form a battery pack. In the direct-stacking and serial-type battery pack, two surfaces of one polar plate can be provided with flow guide grooves, wherein one surface can be used as an anode flow guide surface of one membrane electrode, and the other surface can be used as a cathode flow guide surface of another adjacent membrane electrode, and the polar plate is called a bipolar plate. A series of cells are connected together in a manner to form a battery pack. The battery pack is generally fastened together into one body by a front end plate, a rear end plate and a tie rod.

U.S. Pat. No. 4, 6,057,054 discloses a method for packaging a membrane electrode of a fuel cell, which has a structure shown in FIG. 1, wherein 1 'is a membrane electrode, 2' is a rubber frame, 3 'is an air inlet, 4' is a hydrogen inlet, 5 'is an air outlet, and 6' is a hydrogen outlet.

The method is characterized in that: wrap the one deck elasticity rubber frame around membrane electrode, this elasticity rubber frame extendsout from trinity electrode membrane electrode edge, and extension length is about 1 ~ 10mm, and thickness is greater than membrane electrode thickness, and two bipolar plate assembly back on the membrane electrode, the frame is corresponding with the seal groove on the bipolar plate to reach sealed effect.

However, the air guiding groove of the guiding plate in the Shenli company patent, an energy-saving fuel cell (patent number: 02279853.6), is of a straight-through type. If the membrane electrode sealing method of the U.S. patent is adopted, the rubber frame above the membrane electrode is extruded and enters the air guide groove to generate blockage, and the normal power generation of the fuel cell is directly influenced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide an energy-saving fuel cell three-in-one membrane electrode sealing device.

The purpose of the invention can be realized by the following technical scheme: the utility model provides an energy-saving trinity membrane electrode sealing device of fuel cell, includes trinity membrane electrode, the sealed frame that comprises the carbon diffusion layer material of proton exchange membrane and both sides, trinity membrane electrode divide into middle active part and sealed part all around, its characterized in that, the sealed part of trinity membrane electrode divide into A, B two regions, in the A region, the carbon diffusion layer material of proton exchange membrane and both sides is equal size, and neatly levels, sealed frame cladding in the both sides of A district membrane electrode, in the B region, the carbon diffusion layer material of proton exchange membrane and both sides is unequal size, and forms the position of lacking in one of them side, sealed frame establish and lack the position department at this.

In the area B, the carbon diffusion layer material on one side of the proton exchange membrane and the proton exchange membrane are in the same size, the carbon diffusion layer material on the other side is in a slightly shorter size to form a gap, and the sealing frame is arranged at the gap.

In the area B, the carbon diffusion layer material on one side of the proton exchange membrane and the proton exchange membrane are in the same size, the carbon diffusion layer material on the other side is slightly longer in size to form a gap, and the sealing frame is arranged at the gap.

The sealing frame is made of elastic rubber materials.

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

when the membrane electrode is matched with the energy-saving flow guide bipolar plate in Shanghai Shenli patent (patent number: 02279853.6), one side of the membrane electrode, which is provided with the edge of the rubber elastic material, corresponds to the sealing groove on the flow guide bipolar plate, so that the hydrogen fuel on the side of the flow guide bipolar plate is not leaked; the area B on the other side of the membrane electrode is made of rigid non-deformable carbon diffusion layer material, corresponds to the air groove of the flow guide bipolar plate, and does not deform after being compressed, so that the rubber frame is prevented from being sunk into the air flow guide groove.

Drawings

FIG. 1 is a schematic view of a conventional fuel cell membrane electrode sealing device;

FIG. 2 is a schematic sectional view of a fuel cell membrane electrode assembly of the present invention;

FIG. 3 is a side sectional view of the fuel cell membrane electrode seal assembly of the present invention in area A;

FIG. 4(a) is a sectional top view of a fuel cell membrane electrode sealing device B according to the present invention;

FIG. 4(B) is a sectional top view of another area B of the fuel cell membrane electrode sealing device of the present invention;

fig. 5 is a schematic view of a fuel cell stack integrated using an intermediate hydrogen-donating clamp plate.

Detailed Description

The invention is further described with reference to the following drawings and specific embodiments.

As shown in fig. 2 and 3, a three-in-one membrane electrode sealing device for energy-saving fuel cell comprises a three-in-one membrane electrode 1 and a sealing frame 4, wherein the three-in-one membrane electrode 1 is composed of a proton exchange membrane 3 and carbon diffusion layer materials 2 on two sides of the proton exchange membrane 3, the three-in-one membrane electrode 1 is divided into a middle effective part and a peripheral sealing part, the sealing part of the three-in-one membrane electrode 1 is divided into A, B two areas, the carbon diffusion layer materials 2 on the proton exchange membrane 3 and the two sides of the proton exchange membrane are equal in size in the area A and neat and flat, the sealing frame 4 is coated on the two sides of the membrane electrode in the area A, the carbon diffusion layer materials 2 on the proton exchange membrane 3 and the two sides of the proton exchange membrane are unequal in.

As shown in fig. 4(a), in the region B, the carbon diffusion layer material 2 on one side of the proton exchange membrane 3 and the proton exchange membrane 3 are equal in size, and the carbon diffusion layer material 2 on the other side is slightly shorter in size to form a defect, and the elastic rubber material frame 4 is provided at the defect. (example 1)

As shown in fig. 4(B), in the region (B), the carbon diffusion layer material 2 on one side of the proton exchange membrane 3 and the proton exchange membrane 3 have the same size, and the carbon diffusion layer material 2 on the other side has a slightly longer size to form a defect, and the elastic rubber material frame 4 is provided at the defect. (example 2)

As shown in FIG. 5, in the fuel cell stack integrated by the middle hydrogen supply clamping plate, the number of single cells is 80, the size of the fuel cell stack is 275 multiplied by 132 multiplied by 63mm, and the power is 100-300W.

Claims

1. The utility model provides an energy-saving trinity membrane electrode sealing device of fuel cell, includes trinity membrane electrode, the sealed frame that comprises the carbon diffusion layer material of proton exchange membrane and both sides, trinity membrane electrode divide into middle active part and sealed part all around, its characterized in that, the sealed part of trinity membrane electrode divide into (A), (B) two regions, in (A) region, the carbon diffusion layer material of proton exchange membrane and both sides is equal size, and neatly levels, sealed frame cladding in the both sides of (A) district membrane electrode, in (B) region, the carbon diffusion layer material of proton exchange membrane and both sides is the unequal size, and form the position of lacking in one side wherein, sealed frame establish and lack position department this.

2. The three-in-one membrane electrode sealing device for the energy-saving fuel cell as claimed in claim 1, wherein in the area (B), the carbon diffusion layer material on one side of the proton exchange membrane has the same size as the proton exchange membrane, and the carbon diffusion layer material on the other side has a slightly shorter size to form a gap, and the sealing frame is disposed at the gap.

3. The three-in-one membrane electrode sealing device for the energy-saving fuel cell as claimed in claim 1, wherein in the area (B), the carbon diffusion layer material on one side of the proton exchange membrane has the same size as the proton exchange membrane, and the carbon diffusion layer material on the other side has a slightly longer size to form a gap, and the sealing frame is disposed at the gap.

4. The sealing device of claim 1, 2 or 3, wherein the sealing frame is made of elastic rubber material.