CN2554806Y

CN2554806Y - High-efficient anti-corrosion compound flow collection mother board for fuel cell

Info

Publication number: CN2554806Y
Application number: CN02265853U
Authority: CN
Inventors: 胡里清
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2002-07-29
Filing date: 2002-07-29
Publication date: 2003-06-04
Anticipated expiration: 2012-07-29

Abstract

The utility model relates to a highly effective anticorrosive compound current collection motherboard used for a fuel battery, which comprises an electric conduction active block and at least a non-electric conduction opening block. The electric conduction active block and the end part of at least one non-electric conduction opening block form a current collection motherboard. Compared with the prior art, the utility model has the advantages that the cost is low, and the utility model is anticorrosive, etc.

Description

Efficient anti-corrosion composite current collecting mother board for fuel cell

Technical Field

The utility model relates to a fuel cell's component part especially relates to a high-efficient anticorrosion composite mass flow mother board for fuel cell.

Background

An electrochemical fuel cell is a device that is capable of converting hydrogen fuel 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 by permeating 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 guiding plate in contact with the MEA is die-cast, stamped, or mechanically milled to form at least one or more guiding grooves. The guide electrode plates can be plates made of metal materials or plates made of graphite materials. The diversion pore canals and the diversion grooves on the diversion electrode 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 arranged, and a flow guide polar plate of anode fuel and a flow guide polar plate of cathode oxidant are respectively arranged on two sides of the membrane electrode. The flow guide polar plates are used as a current flow collection mother plate and mechanical supports at two sides of the membrane electrode, and flow guide grooves on the flow guide polar 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.

A typical battery pack generally includes: (1) the fuel (such as hydrogen, methanol or hydrogen-rich gas obtained by reforming methanol, natural gas and gasoline) and the oxidant (mainly oxygen or air) are uniformly distributed in the diversion trenches of the anode surface and the cathode surface; (2) cooling fluid (such as water) is uniformly distributed into cooling channels in each battery pack through an inlet and an outlet of the cooling fluid and a flow guide channel, and heat generated by electrochemical exothermic reaction of hydrogen and oxygen in the fuel cell is absorbed and taken out of the battery pack for heat dissipation; (3) the outlets of the fuel gas and the oxidant gas and the corresponding flow guide channels can carry out liquid and vapor water generated in the fuel cell when the fuel gas and the oxidant gas are discharged. Typically, all fuel, oxidant, and cooling fluid inlets and outlets are provided in one or both end plates of the fuel cell stack.

The proton exchange membrane fuel cell can be used as a power system of vehicles such as vehicles and ships, and can also be used as a mobile or fixed power station.

The pem fuel cell is generally composed of several single cells, which are connected in series or in parallel to form a pem fuel cell stack, and the pem fuel cell stack is combined with other operation support systems to form the whole pem fuel cell power generation system.

Fig. 1 shows a membrane electrode in a single cell of a conventional proton exchange membrane fuel cell, which includes an air inlet 1a, a water inlet 2a, a hydrogen inlet 3a, an electrode active region 4a, an air outlet 5a, a water outlet 6a, and a hydrogen outlet 7 a; fig. 2 shows a flow guide plate in a single cell of a conventional proton exchange membrane fuel cell, which includes an air inlet 1a, a water inlet 2a, a hydrogen inlet 3a, a flow channel 8a, an air outlet 5a, a water outlet 6a, and a hydrogen outlet 7 a; fig. 3 shows a fuel cell stack in which a plurality of unit cells are connected in series, and the fuel cell stack includes a panel 9a, a first current collecting mother plate 10a, a cell stack 11a, a second current collecting mother plate 12a, a load 13 a; the proton exchange membrane fuel cell stack can be composed of a plurality of single cells in series connection, or a plurality of single cells in series connection to form a unit, and then a plurality of units are connected in parallel to form the fuel cell stack shown in fig. 4, wherein the fuel cell stack comprises a first current collecting mother plate 10a, a cell stack 11a, a second current collecting mother plate 12a and an insulating plate 14 a; the pem fuel cell stacks of fig. 3 and 4 refer to two or more collector motherboards, which are positive, negative or negative and positive collector motherboards in the fuel cell stack. The two collecting mother boards have the following two functions:

1. the current of a plurality of fuel cell monocells connected in series or in parallel or the whole fuel cell stack is led out to form a positive electrode and a negative electrode which conduct the current of an external circuit;

2. as shown in fig. 5, the flow collecting mother plate has various fluid passage holes for allowing various fluids of the fuel cell to freely pass through, and 1a, 2a, 3a, 5a, 6a and 7a are fluid holes, 15ais an ear of a current leading-out terminal, and 10a is the flow collecting mother plate, so that the size of the flow collecting mother plate except the ears of the two current leading-out terminals is basically the same as that of the flow guiding plate in the fuel cell stack, and the fluid holes on the flow collecting mother plate are also the same as that of the flow guiding holes on the flow guiding plate, so as to form various flow guiding passages of the whole fuel cell stack.

At present, the current collecting mother plates in various fuel cell stacks adopt very special materials for achieving the above two functions, for example, metal gold, metal platinum or methods adopting other metals such as stainless steel, copper, aluminum, gold plating and platinum. With these materials, the electrical conductivity is excellent and no electrochemical corrosion reactions occur when various fluids pass through the current collector mother plate to generate metal ions that are harmful to the fuel cell. However, these materials, such as gold and platinum, are expensive, and are inconvenient to electroplate on other metals, such as copper, stainless steel and aluminum.

If stainless steel, metallic copper, aluminum materials are used directly as the collector motherboards, electrochemical corrosion can occur as various fluids pass through the collector motherboards, and metal ions that can be harmful to the fuel cell can be generated.

Disclosure of Invention

The utility model aims to overcome the defects of the prior art and provide a cheap and corrosion-resistant efficient anti-corrosion composite current collecting mother plate for a fuel cell.

The purpose of the utility model can be realized through the following technical scheme: the high-efficiency anti-corrosion composite current collecting mother board for the fuel cell is characterized by comprising a conductive active block and at least one non-conductive pore channel block, wherein the conductive active block and the end part of the at least one non-conductive pore channel block are compounded to form the current collecting mother board.

The conductive active block is rectangular, the non-conductive pore channel blocks are two, and the two non-conductive pore channel blocks are also rectangular and are respectively arranged at the upper end and the lower end of the conductive active block to form a current collecting mother board close to a square.

The conductive active block is rhombus, the non-conductive pore channel blocks are four, the four non-conductive pore channel blocks are right-angled triangles and are respectively arranged at the upper end and the lower end of the conductive active block and are butted in pairs to form a current collecting mother board close to a square.

The left end and the right end of the conductive active block are symmetrically provided with current leading-out lugs, and the current leading-out lugs are provided with connecting holes.

The non-conductive pore block is provided with a hydrogen inlet and outlet pore, an air inlet and outlet pore and a cooling water inlet and outlet pore.

The non-conductive pore passage block is made of corrosion-resistant non-metallic materials, including plastics, epoxy resin or glass.

The thickness of the conductive active block is the same as that of each non-conductive pore block.

The sealing groove is arranged at the connecting part of the conductive active block and each non-conductive pore channel block.

The utility model discloses owing to adopted above technical scheme, adopt low-priced, corrosion-resistant non-metallic material in the non-conductive pore part of mass flow mother board promptly, replace metal material such as expensive gold, platinum like plastics, epoxy board, glass etc. consequently, the utility model has the advantages of with low costs, corrosion-resistant.

Drawings

FIG. 1 is a schematic structural diagram of a membrane electrode in a single cell of a conventional PEM fuel cell;

FIG. 2 is a schematic structural diagram of a current-guiding plate in a single cell of a conventional PEM fuel cell;

FIG. 3 is a schematic diagram of a fuel cell stack in which a plurality of single cells are connected in series;

FIG. 4 is a schematic diagram of a conventional fuel cell stack in which several cells are connected in parallel;

FIG. 5 is a schematic structural diagram of a current collecting mother plate in a single cell of a conventional PEM fuel cell;

fig. 6 is a schematic structural diagram of embodiment 1 of the present invention;

FIG. 7 is a cross-sectional view A-A of FIG. 6;

fig. 8 is a schematic structural view of embodiment 2 of the present invention;

fig. 9 is a left side view of fig. 8.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

As shown in fig. 6-9, an inexpensive, corrosion resistant current collector master can be divided into a number of basic zones: the materials on the area A and the area C of the current collecting mother board are corrosion-resistant non-conductive materials, such as plastic, epoxy resin boards, glass and the like, the materials on the area B are excellent conductive materials, such as aluminum, copper, zinc and titanium, the area A, the area C and the area B are bonded together in a certain mode and can be isolated from each other through a sealing material, so that various fluids cannot leak to the area B when passing through the area A and the area C, the area B can be completely isolated from media such as air and water, the current collecting conduction cannot generate electrochemical corrosion reaction, and generated ions cannot leak into various fluid channels to pollute a fuel cell in case of corrosion. The regions of this composite collector mother plate are equal in thickness.

Example 1

As shown in fig. 6 and 7, the high-efficiency anti-corrosion composite current collecting mother plate for the fuel cell comprises a conductive active block 1 and two non-conductive pore channel blocks 2, wherein the conductive active block 1 is rectangular and is arranged in the middle of the current collecting mother plate, and the two non-conductive pore channel blocks are also rectangular and are respectively arranged at the upper end and the lower end of the conductive active block 1 to form a nearly square current collecting mother plate. The left end and the right end of the conductive active block 1 are symmetrically provided with current leading-out lugs 11, and the current leading-out lugs are provided with connecting holes 111. The non-conductive pore channel block 2 is provided with an air inlet channel 21, a cooling water inlet channel 22, a hydrogen inlet channel 23, an air outlet channel 25, a cooling water outlet channel 26 and a hydrogen outlet channel 27; the non-conductive pore block 2 is made of corrosion-resistant plastic. The thickness of the conductive active block 1 is the same as that of each non-conductive pore block 2. The connecting part of the conductive active block 1 and each non-conductive pore channel block 2 is provided with a sealing groove 3, and a sealing ring is arranged in the sealing groove.

Example 2

As shown in fig. 8 and 9, the high-efficiency anti-corrosion composite current collecting mother board for the fuel cell comprises a conductive active block 1 and four non-conductive pore channel blocks 2, wherein the conductive active block 1 is in a diamond shape and is arranged in the middle of the current collecting mother board, and the four non-conductive pore channel blocks 2 are in a right-angled triangle shape and are respectively arranged at the upper end and the lower end of the conductive active block 1 and are butted in pairs to form a current collecting mother board close to a square. The left end and the right end of the conductive active block are symmetrically provided with current leading-out lugs 11, and the current leading-out lugs are provided with connecting holes 111. The non-conductive pore channel block 2 is provided with an air inlet channel 21, a cooling water inlet channel 22, a hydrogen inlet channel 23, an air outlet channel 25, a cooling water outlet channel 26 and a hydrogen outlet channel 27; the non-conductive pore block 2 is made of corrosion-resistant epoxy resin. The thickness of the conductive active block 1 is the same as that of each non-conductive pore block 2. The connecting part of the conductive active block 1 and each non-conductive pore channel block 2 is provided with a sealing groove 3, and a sealing ring is arranged in the sealing groove.

Claims

1. The high-efficiency anti-corrosion composite current collecting mother board for the fuel cell is characterized by comprising a conductive active block and at least one non-conductive pore channel block, wherein the conductive active block and the end part of the at least one non-conductive pore channel block are compounded to form the current collecting mother board.

2. The efficient corrosion-resistant composite current collecting mother plate for a fuel cell according to claim 1, wherein the conductive active block is rectangular, the non-conductive pore passage blocks are also rectangular, and the two non-conductive pore passage blocks are respectively arranged at the upper end and the lower end of the conductive active block to form a nearly square current collecting mother plate.

3. The efficient corrosion-resistant composite current collecting mother plate for a fuel cell according to claim 1, wherein the conductive active blocks are diamond-shaped, the non-conductive pore passage blocks are four, the four non-conductive pore passage blocks are right-angled triangles, and the four non-conductive pore passage blocks are respectively arranged at the upper end and the lower end of the conductive active blocks and are butted in pairs to form a nearly square current collecting mother plate.

4. The high-efficiency anti-corrosion composite current collecting mother plate for the fuel cell according to claim 1, 2 or 3, wherein the left and right ends of the conductive active block are symmetrically provided with current leading lugs, and the current leading lugs are provided with connecting holes.

5. The high-efficiency anti-corrosion composite current collecting mother plate for the fuel cell according to claim 1, 2 or 3, wherein the non-conductive pore block is provided with a hydrogen inlet and outlet pore, an air inlet and outlet pore and a cooling water inlet and outlet pore.

6. The high efficiency corrosion resistant composite current collecting mother plate for a fuel cell according to claim 1, wherein the non-conductive porous block is made of a corrosion resistant non-metallic material including plastic, epoxy resin or glass.

7. The high efficiency corrosion resistant composite current collecting mother plate for a fuel cell according to claim 1, wherein the thickness of the conductive active blocks is the same as the thickness of each non-conductive via block.

8. The efficient corrosion-proof composite current collecting mother plate for the fuel cell according to claim 1, further comprising a sealing groove provided with a sealing ring, wherein the sealing groove is arranged at the connecting part of the conductive active block and each non-conductive pore channel block.