CN2624412Y

CN2624412Y - A diverting double polar plate for highly effective fuel battery

Info

Publication number: CN2624412Y
Application number: CNU032318669U
Authority: CN
Inventors: 胡里清; 李拯; 夏建伟
Original assignee: Shanghai Shen Li High Tech Co Ltd
Current assignee: Shanghai Shenli Technology Co Ltd
Priority date: 2003-06-04
Filing date: 2003-06-04
Publication date: 2004-07-07
Anticipated expiration: 2013-06-04

Abstract

The utility model relates to a high efficient bipolar flow baffle plate for fuel battery, which comprises an air baffler and a hydrogen baffler assembled, the cooling liquid guide channel of the back of the air baffler or a shallow sealing channel arranged around the smooth surface, the cooling liquid guide channel of the back side of the hydrogen baffler or shallow wide sealing channels corresponding to the air baffler arranged around the smooth surface, the shallow wide sealing channel has an adhesion agent fully filled the sealing groove after the air baffler pressed together with the hydrogen baffler, both plates shall be adhered with zero clearance. Compared with the existing technology, the utility model has the advantages of high conductive efficiency, high mechanical strength, and low cost, etc.

Description

High-efficiency fuel cell flow guide bipolar plate

Technical Field

The utility model relates to a fuel cell especially relates to a high-efficient fuel cell water conservancy diversion bipolar plate.

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 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 conductive plate in contact with the MEA is die-cast, stamped, or mechanically milled to form at least one or more channels. The conductive film 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 membrane electrode guiding 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 attwo 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.

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) the inlet and outlet of cooling fluid (such as water) and the flow guide channel uniformly distribute the cooling fluid into the cooling channels in each battery pack, and the heat generated by the 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 has wide application, can be used as a power system of all vehicles, ships and other vehicles, and can also be used as a power generation system as a ground fixed power station, a movable power source and the like.

The flow guide plate in a proton exchange membrane fuel cell is one of the most critical components that make up a fuel cell stack. The fuel cell flow guiding bipolar plate is generally formed by combining two plates, wherein the two plates have the functions of an air guiding groove surface and a hydrogen guiding groove surface respectively, and cooling fluid is formed between the two plates after combination. For example: the jacket smooth plate surface of the cooling fluid, the groove surface for guiding the cooling fluid and six diversion holes (air inlet and air outlet, hydrogen inlet and hydrogen outlet, cooling fluid inlet and cooling fluid outlet). For example: fig. 1, 2 and 3 described in US Patent 5,521,018, in fig. 1, the hydrogen groove 1 ', the hydrogen guiding hole 2', the sealing groove 3 ', the guiding plate 4', the air guiding flow hole 5 ', the cooling guiding flow hole 6' are included, fig. 2 is a diagram of a light panel and a guiding hole on the reverse side of the air guiding groove surface or the hydrogen guiding groove surface, fig. 3 is a diagram of a flow field and a guiding hole of a cooling fluid guided on the reverse side of the air guiding groove surface or the hydrogen guiding groove surface; thus, the front side of the air guide groove is a smooth plate surface; and a hydrogen guide groove surface on the front surface and a cooling fluid guide groove surface on the back surface; or the front surface of the hydrogen guide groove is a hydrogen guide groove surface, and the back surface of the hydrogen guide groove is a smooth plate surface; and a bipolar plateconsisting of two plates with an air-guiding groove on the front surface and a cooling fluid-guiding groove on the back surface. The bipolar plate has the characteristics that: (1) is formed by combining two plates; (2) the middle of the two plates is used for guiding cooling fluid. Such a composite bipolar plate has the following technical drawbacks:

1. one of the two plates is a smooth plate surface, but the other plate corresponding to the smooth plate surface is required to be provided with a sealing groove and a sealing ring is arranged, and after combination, the flow of cooling fluid can be limited in the cooling splint groove, so that the cooling fluid does not flow into air and hydrogen channels or leak to the outer surface of the fuel cell stack. This sealing difficulty is greater, increasing the design and manufacturing difficulties of fuel cell engineering.

2. The technique of combining two plates into a bipolar plate must ensure the mechanical strength of each plate, that is, the thickness of each plate, which seriously increases the difficulty of reducing the thickness of the whole bipolar plate, and severely limits the weight-volume ratio power of the fuel cell stack.

The prior art of EP1009051, which is incorporated by reference, substantially overcomes the above-mentioned drawbacks. However, the patent must adopt conductive adhesive, the whole surface of the two combined plates is uniformly coated with the conductive adhesive, and the two combined plates are bonded under certain temperature and pressure to form a bipolar plate, the technology has the defects that the conductive adhesive with high conductivity is not good in bonding effect, and the conductive function of the bipolar plate is seriously influenced after the conductive adhesive with low conductivity is coated on the corresponding surface of the two combined plates, so that the internal resistance of a fuel cell stack is very large; in addition, the uniform coating technology of the conductive adhesive has certain difficulty.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a high-efficient fuel cell water conservancy diversion bipolar plate that electrically conducts efficient, mechanical strength is big, with low costs in order to overcome the defect that above-mentioned prior art exists.

The purpose of the utility model can be realized through the following technical scheme:

a high-efficient fuel cell diversion bipolar plate, this bipolar plate is formed by air guide flow plate and hydrogen guide flow plate combination, the said air guide flow plate includes setting up the air guide flow trough on the front, set up and lead the cooling fluid trough or be the plain noodles on the reverse side, the said hydrogen guide flow plate includes setting up the hydrogen guide flow trough on the front, also set up and lead the cooling fluid trough or be the plain noodles on the reverse side, said air guide flow plate and hydrogen guide flow plate have air guide hole, hydrogen guide hole and lead the cooling fluid hole; the hydrogen guide plate is characterized in that a shallow and wide sealing groove is formed in the periphery of the cooling fluid guide groove or the smooth surface of the reverse side of the air guide flow plate, a shallow and wide sealing groove corresponding to the reverse side of the air guide flow plate is formed in the periphery of the cooling fluid guide groove or the smooth surface of the reverse side of the hydrogen guide flow plate, an adhesive is arranged in the shallow and wide sealing groove, after the air guide flow plate and the hydrogen guide flow plate are pressed together, the adhesive just fills the sealing groove, and the two plates are attached to each other in a zero gap mode.

The adhesive can be one selected from epoxy glue, silicon sealant and solid ribbon glue.

The air flow guiding plate or the hydrogen flow guiding plate can be selected from a thin graphite plate or a metal plate.

The utility model adopts the technical proposal that one side or two sides of the corresponding surface of two plates to be combined are both provided with a shallower and wider sealing groove, then a manipulator is used for uniformly coating an adhesive with a thickness larger than the depth of the sealing groove on the sealing groove, but with a width larger than the pressing width of the sealing groove, such as epoxy glue, silicon sealant, solid banded adhesive and the like, when the two plates are combined, the two plates are pressed at a certain temperature and pressure, so that the adhesive on the two plates is just spread out on the sealing groove on one or two plates, and the two plates are bonded together, and the contact between the two plates is zero clearance; therefore, the method has the following characteristics:

(1) the adhesive for the combined bonding of the two plates does not need a conductive adhesive, but uses an adhesive which is cheap and has very good bonding effect, such as: epoxy glue, silicon sealant, solid tape glue, and the like.

(2) The adhesive after the two combined plates are glued is filled in the whole sealing groove, but the two combined plates cannot be laid on the plate surface, and the gap between the two combined plates is zero, so that the good conductivity of the bipolar plate is not influenced.

(3) The two plates to be combined can be made of a very thin one-step molded plate or a metal plate made of graphite, the mechanical strength of the bipolar plate after being glued is greatly increased, and the specific power density of the volume and the weight of thefuel cell stack can be greatly improved.

Drawings

FIG. 1 is a schematic structural view of an air guide groove surface or a hydrogen guide groove surface and a flow guide hole;

FIG. 2 is a schematic structural view of a reverse optical plate and a flow guide hole of an air guide groove surface or a hydrogen guide groove surface;

fig. 3 is a schematic structural view of a flow field and a flow guide hole for guiding cooling fluid on the reverse side of an air guide groove surface or a hydrogen guide groove surface;

FIG. 4 is a schematic structural view of a hydrogen-guiding groove surface of a bipolar plate according to the present invention;

FIG. 5 is a schematic view of the reverse structure of the hydrogen-guiding groove surface of the bipolar plate of the present invention;

FIG. 6 is a schematic structural view of the air-guiding groove surface of the bipolar plate of the present invention;

fig. 7 is a schematic view of the reverse structure of the air-guiding groove surface of the bipolar plate of the present invention.

Detailed Description

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

The embodiment is a high-efficiency fuel cell flow guiding bipolar plate, as shown in fig. 4 and 5, which is composed of two graphite plates to be combined, and the size of the graphite plate is 100 × 200 × 1 mm.

As shown in fig. 4, which is a schematic structural view of the front hydrogen groove surface of the hydrogen guiding flow plate 11 to be assembled, in the figure, 1a and 1b are hydrogen inlet and outlet guiding holes, 2a and 2b are cooling fluid guiding holes, 3a and 3b are air inlet and outlet guiding holes, a hydrogen guiding flow groove 4 is provided between the hydrogen inlet and outlet guiding holes 1a and 1b, and a sealing groove 5 is provided at the periphery of the groove hole; referring to fig. 5, which is a schematic structural view of a smooth surface of a reverse side of a hydrogen flow guiding plate to be combined, 6 shown in the figure is a sealing groove for laying an adhesive, the width of the sealing groove is 15mm, the depth of the sealing groove is 0.5mm, the adhesive is coated by a mechanical arm respectively, the adhesive is epoxy glue, the width of the epoxy glue is 10mm, the height of the epoxy glue is 0.75mm, and the surface is further provided with a hydrogen flow guiding hole, a cooling fluid guiding hole and an air flow guiding hole corresponding to the front side of the hydrogen flow guiding plate.

As shown in fig. 6, which is a schematic structural view of the front air groove surface of the air guide plate 12 to be assembled, in the figure, 1a and 1b are hydrogen inlet and outlet guide holes, 2a and 2b are cooling fluid guide holes, 3a and 3b are air inlet and outlet guide holes, an air guide flow groove 7 is provided between the air inlet and outlet guide holes 3a and 3b, and a sealing groove 8 is provided around the groove hole; referring to fig. 7, which is a schematic structural view of a cooling fluid guiding groove on the reverse side of the air flow guiding plate to be assembled, 9 is a sealing groove for laying an adhesive, the width of the sealing groove is 15mm, the depth of the sealing groove is 0.5mm, the adhesive is coated by a manipulator respectively, the adhesive uses an epoxy adhesive, the width of the epoxy adhesive is 10mm, the height of the epoxy adhesiveis 0.75mm, 10 is a cooling fluid guiding groove arranged between cooling fluid guiding holes 2a and 2b, and the cooling fluid guiding groove is further provided with a hydrogen guiding airflow hole, a cooling fluid guiding hole and an air guiding airflow hole corresponding to the front side of the cooling fluid guiding groove.

The back surface of the hydrogen guide flow plate 11 and the back surface of the air guide flow plate 12 are pressed at 120 ℃ and 0.1MPa, the adhesive is just paved in the sealing groove and is cured and glued together, and the two plates are jointed in a zero gap manner to form a flow guide bipolar plate.

Claims

1. A high-efficient fuel cell diversion bipolar plate, this bipolar plate is formed by air guide flow plate and hydrogen guide flow plate combination, the said air guide flow plate includes setting up the air guide flow trough on the front, set up and lead the cooling fluid trough or be the plain noodles on the reverse side, the said hydrogen guide flow plate includes setting up the hydrogen guide flow trough on the front, also set up and lead the cooling fluid trough or be the plain noodles on the reverse side, said air guide flow plate and hydrogen guide flow plate have air guide hole, hydrogen guide hole and lead the cooling fluid hole; the hydrogen guide plate is characterized in that a shallow and wide sealing groove is formed in the periphery of the cooling fluid guide groove or the smooth surface of the reverse side of the air guide flow plate, a shallow and wide sealing groove corresponding to the reverse side of the air guide flow plate is formed in the periphery of the cooling fluid guide groove or the smooth surface of the reverse side of the hydrogen guide flow plate, an adhesive is arranged in the shallow and wide sealing groove, after the air guide flow plate and the hydrogen guide flow plateare pressed together, the adhesive just fills the sealing groove, and the two plates are attached to each other in a zero gap mode.

2. The bipolar plate for high efficiency fuel cell flow guiding of claim 1, wherein the adhesive is selected from the group consisting of epoxy glue, silicone sealant, and solid tape glue.

3. The high efficiency fuel cell bipolar plate of claim 1, wherein said air or hydrogen flow directing plates are selected from the group consisting of thin graphite plates and metal plates.