CN203932175U - A kind of fuel cell electricity getting device - Google Patents

Abstract

The utility model discloses a power-taking device for a fuel cell, which comprises a power-taking plate and an electrode column. A plurality of electrode columns are arranged on the power-taking plate, and a positioning hole is opened on the power-taking plate. The positioning hole is a hollow structure, and the electrode column passes through the positioning The holes are vertically arranged on the power-taking plate, and the electrode columns are parallel to each other and the distance is equal; the end of the power-taking plate in contact with the electrode column is provided with a shoulder, the length of which is slightly smaller than the thickness of the power-taking plate, and the shoulder is brazed on the A local brazing layer is formed on the positioning hole, and a gold-plated layer is arranged on the side of the electric plate away from the electrode column. The fuel cell power-taking plate device provided by the utility model adopts a uniformly distributed electrode column and the power-taking plate are connected by brazing to form a fuel cell power-taking device, which can not only provide a uniform power-taking effect, but also prevent the occurrence of Large surface potential difference; and can effectively use the surrounding space of the fuel cell stack, which is conducive to improving the volume power density of the cell stack, especially for high-power stacks.

Description

A fuel cell electric device

technical field

The utility model relates to a battery power-taking device, in particular to a fuel cell power-taking device, which belongs to the technical field of fuel cells.

Background technique

The proton exchange membrane hydrogen fuel cell (PEMFC) is an important member of the fuel cell (FC) family. When forming a loop with an external circuit, the two reaction gases, hydrogen and air (oxygen), undergo redox in a catalytic state. React and generate directional movement of electrons, thereby directly converting the chemical energy contained in the reactant gas into electrical energy. The basic unit of a fuel cell stack is a single cell. For a PEMFC stack, the single cell consists of a membrane electrode, a diffusion layer on both sides of the membrane electrode, and an electrode plate adjacent to the diffusion layer. The electrode plate on the same side as the hydrogen gas It is called the anode, and the electrode plate on the same side as the air (oxygen) is called the cathode. Membrane electrodes are composed of proton exchange membranes and catalysts coated on both sides. The area occupied by the catalyst is called the active area. The effective voltage of a single cell is very low, the highest open circuit voltage is only 1.229V, and the unit area per square centimeter generally can only provide a current of about 1A, so a single cell with too small area is not practical. Usually the single cell is manufactured as a thin-layer structure with a large area. The loop current of the external circuit is the parallel sum of the current per unit area. The larger the area, the greater the current supplied to the external circuit; then many single cells are used in series. To obtain the required high enough voltage, at this point, the anode of one cell is combined with the cathode of the other cell and is called a bipolar plate. There is also a sealing ring between the bipolar plate and the membrane electrode to isolate the atmosphere. This stacked structure composed of multi-layer single cells with a sealing ring is the core part of the stack. Encapsulation structure, in the encapsulation structure, there are two power-taking boards located on both sides of the above-mentioned multi-layer single-cell stacked structure, which respectively form the positive pole and negative pole of the entire fuel cell stack, and are used for power-taking connection of external circuits.

With continuous breakthroughs in the key technologies of fuel cells, the scope of application of fuel cells is becoming wider and wider. In particular, fuel cell stacks are used as vehicle power batteries, and their demand will not be lower than that of traditional fuel engines. The development trend of fuel cell technology is that the power density of the stack is getting higher and higher. The basic condition of the realization method is that on the aforementioned active area, its unit area can emit a larger current, and the external output current of the fuel cell is equal to the current per unit area and The product of the active area, the current of the high-power stack has reached about 400A, and there will be a possibility of a larger current in the future.

The power-taking board device is an important part of the fuel cell stack, and it is a connecting device for the external output of the electric energy generated by the stack. For fuel cells, the uniform power generation on the active area and the uniform power generation of each single cell are very important conditions to ensure the healthy operation of the stack. This uniformity is also reflected in the consistency of the surface potential. In addition to the power generation status of the single cell itself will affect this consistency, the way the power is taken from the external circuit will also have a significant impact, which will interact with the power generation reaction: When there is a potential difference in the area of the electric plate itself, it will affect the surface potential of the single cell layer by layer, resulting in a lateral current on the active surface of the single cell. The normal progress of the power generation reaction, especially when the membrane electrode reaction itself is uneven, the surface potential difference caused by the way of taking electricity will aggravate the uneven state, increase the probability of the reaction tending to reverse, and cause damage to the membrane electrode .

At present, the common power-taking methods generally include centralized power-taking methods such as the side lead-out of the power-taking plate and the use of large poles on the surface. The actual measurement of the potential difference between the various parts of the power-taking plate will reach about 0.3V. The potential difference should not exceed 0.05V. It can be seen that the voltage difference of the power-taking board will have a large adverse effect.

On the other hand, the centralized power-taking method will cause a significant increase in the temperature of the place where the current of the power-taking plate is concentrated. This temperature will affect the temperature of the membrane electrode in the adjacent area and change its hydrothermal state, which is not conducive to the stability of the reaction. At the same time, it may burn membrane electrode.

Utility model content

In view of this, the purpose of the utility model is to propose a fuel cell power-taking device that is feasible to manufacture, low in cost and uniform in power taking.

Based on the above purpose, the utility model provides a fuel cell power-taking device, which includes a power-taking plate and an electrode column, a plurality of electrode columns are arranged on the power-taking plate, positioning holes are opened on the power-taking plate, and the positioning The hole is a hollow structure, and the electrode columns are vertically arranged on the power-taking plate through the positioning holes, and the electrode columns are parallel to each other and the distance is equal; A shaft shoulder is set, the length of the shaft shoulder is slightly smaller than the thickness of the power-taking plate, the shoulder is brazed on the positioning hole and forms a local brazing layer, and the power-taking plate is away from a side of the electrode column. The side is provided with a gold-plated layer.

In some embodiments, the power-taking plates are respectively arranged at both ends of the fuel cell stack, and the side of the power-taking plate in contact with the electrode column is connected with an insulating plate and a clamping end plate, and the clamping The end plate is arranged on the outside of the insulating plate, and the end of the power-taking plate which is not in contact with the electrode column is provided with a gold-plated layer and connected to the bipolar plate in the fuel cell stack.

In some embodiments, when the power-taking board is a PCB board, a copper-clad board is added, and the copper-clad board is the first copper-clad board arranged at the end of the power-taking board in contact with the electrode column and the power-taking board. The second copper-clad plate at the other end where the plate is not in contact with the electrode column; the PCB board forms conductive vias through uniform via-hole copper coating, and deposits copper at the conductive vias to electrically connect the copper clad layers on both sides.

In some embodiments, the cross-sectional area of the end of the electrode column that is in contact with the power-taking plate is not greater than the cross-sectional area of the end of the electrode post that is not in contact with the power-taking plate.

In some embodiments, the active area of the fuel cell is the corresponding area where electrode posts are arranged on the power-taking plate, and one electrode post is arranged on every active area of 30 cm ² -40 cm ² in the corresponding area.

In some embodiments, the diameter of the shoulder is not greater than 3 mm, and the diameter of the electrode post is not greater than 12 mm.

In some embodiments, there are 6 electrode columns and they are evenly arranged on the power-taking board according to the area of the power-taking board.

In some embodiments, the positioning holes are hollow structures with equal diameters.

The utility model evenly welds a plurality of electrode columns in the area corresponding to the electric plate and the active area. The diameter and quantity of the electrode columns are determined according to the size of the active area and the current intensity. The active area of the membrane electrode corresponding to each electrode column should be approximately The same, that is, the electrode columns should be evenly distributed. In this way, after the external circuit is connected, the current generated on the active area can pass through the nearest electrode column, avoiding the uneven problem of centralized or biased electricity collection. At the same time, because the surface potential on the electrode plate will be very uniform, there will be no concentrated overheating of large currents, which better solves the aforementioned problem of centralized power collection. For high-power stacks, its effect advantages will be more obvious.

In terms of the fuel cell stack device, there must be an insulating plate on the outer surface of the power-taking plate, and a clamping end plate on the outside of the insulating plate, so that the electrode column welded on the power-taking plate must pass through the insulating plate and the clamping end plate to insulate The plate and the clamping end plate are processed with through holes at the place where the electrode column of the power-taking plate passes through. In this way, there are high requirements on the positional accuracy of the electrode column welding of the power-taking plate, so as to ensure that the power-taking device meets the assembly requirements of the fuel cell stack, which is conducive to normal reaction and reduces power consumption.

From the above, it can be seen that the fuel cell power-taking plate device provided by the utility model adopts a uniformly distributed electrode column and the power-taking plate is connected by brazing to form a fuel cell power-taking device, which has the following advantages:

1) Since a plurality of electrode columns are arranged on the power-taking plate, the electrode columns are arranged in parallel and vertically arranged on the power-taking plate. Therefore, for the fuel cell, it can provide a uniform power-taking effect and prevent a large surface potential difference on the area of the power-taking plate;

2) The distance between the electrode columns is set according to the active area of the fuel cell, and the power-taking plate is uniformly provided with installation positioning holes. It can prevent overheating due to current concentration. By dispersing the current, the diameter of the external lead wire of the fuel cell can be thinner, which can effectively use the surrounding space of the fuel cell stack, and is conducive to improving the volumetric power density of the cell stack, especially for high-power stacks. .

Description of drawings

Fig. 1 is a schematic diagram of a fuel cell power-taking board device (the power-taking board is a red copper plate) in an embodiment of the present invention;

Fig. 2 is a schematic diagram of the power-taking board device of the fuel cell (the power-taking board is a PCB board) in the embodiment of the utility model.

Detailed ways

In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

Please refer to FIG. 1 , a fuel cell power-taking device, including a power-taking plate 102 and an electrode column 101, a plurality of electrode columns 101 are arranged on the power-taking plate 102, and a positioning hole 103 is opened on the power-taking plate 102, The positioning hole 103 is a hollow structure, and the electrode column 101 is vertically arranged on the power-taking plate 102 through the positioning hole 103, and the electrode columns 101 are parallel to each other and have equal spacing distances; the power-taking plate 102 One end in contact with the electrode column 101 is provided with a shoulder 104, the length of the shoulder 104 is slightly smaller than the thickness of the power-taking plate 102, and the shoulder 104 is brazed on the positioning hole 103 to form a The local brazing layer 105 is provided with a gold-plated layer on the side of the power-taking plate 102 away from the electrode post 101 . Since the power-taking board 102 is provided with a positioning hole 103 , and the positioning hole 103 is a hollow structure, the power-taking board 102 is divided into a plurality of smaller power-taking board structures. Since the electrode columns 101 are vertically arranged on the power-taking plate 102 through the positioning holes 103, the electrode columns 101 are parallel and spaced at equal distances, which can prevent large surface potentials from appearing on the area of the power-taking plate 102 Poor, it can also prevent overheating due to current concentration, which is beneficial to the stability of the reaction, and at the same time reduces the possibility of burning the membrane electrode. Since the end of the power-taking plate 102 in contact with the electrode column 101 is provided with a shoulder 104, the length of the shoulder 104 is slightly smaller than the thickness of the power-taking plate 102, and the electrode column 101 can be facilitated by setting the shoulder 104. It is fixed on the power-taking board 102. At the same time, since the shoulder 104 is brazed on the positioning hole 103 to form a local brazing layer 105 , the brazing temperature is low, so that the thermal deformation of the power-taking plate 102 is small, and the shape and position accuracy is easy to maintain. Since the side of the power-taking plate 102 away from the electrode column 101 is provided with a gold-plated layer, after welding, the other side of the power-taking surface away from the electrode column 101 needs to be plated with gold to reduce the contact between the power-taking plate 102 and the bipolar plate. resistance. Gold plating is common, and gold-tin solder can generally be used. This side needs to have a material with good electrical conductivity and strong resistance to electrochemical corrosion. Because gold is more common, other materials generally do not work as well.

There is a high requirement for the welding position accuracy of the electrode column 101 of the power-taking plate 102, so as to ensure that the power-taking device meets the assembly requirements of the fuel cell stack, which is conducive to the normal reaction and reduces power consumption. The manufacturing process of plate 102 welding electrode column 101 is optimized.

Specifically, the optimization method of the manufacturing process is as follows:

Taking the copper plate 102 as an example, a number of positioning holes 103 with a diameter of 3 mm can be processed on the copper plate, and the number can be selected to process one positioning hole per 40 square centimeters according to the current technical level of the fuel cell membrane electrode. hole 103, so that the current passing through each electrode column 101 is about 40A, and the diameter of the electrode column 101 is about 12mm. The processing method adopted should ensure that the power-taking plate 102 is clamped once, and after a reference positioning, the positions of all the round holes are automatically positioned by the processing equipment and the round holes are processed to prevent the expansion of the position error of the round holes. This round hole is used as the electrode column 101 The positioning hole 103 is installed. After brazing, the side of the red copper plate that is not welded with the electrode post 101 is plated with gold to form the power-taking device for the fuel cell.

In this way, in the packaging device of the fuel cell, there are two power-taking plates 102 located on both sides of the multi-layer single-cell stacked device body, which respectively form the positive pole and the negative pole of the entire fuel cell stack, and are used for power-taking connections of external circuits. It further reduces the uneven power generation of the fuel cell caused by the surface potential difference caused by the way of taking electricity, and reduces the probability of the reaction tending to go in the opposite direction and the damage of the membrane electrode.

In this embodiment, optionally, the electrode post 101 is made of red copper, and other materials with good conductivity, such as silver, may also be used.

In this embodiment, optionally, the power-taking board 102 is a red copper board. The copper plate has good electrical conductivity and is cheap outside the copper plate. It is a widely used variety of copper materials. In addition, it has good mechanical properties, good plasticity in hot state, fair plasticity in cold state, and good machinability.

Please refer to FIG. 1 and FIG. 2 , when the power-taking board 102 is a PCB board, a copper-clad board on both sides is added, and the copper-clad board is the first cladding board arranged at the end of the power-taking board 102 in contact with the electrode column 101. Copper plate 207 and the second copper-clad plate 208 at the other end of the power-taking plate 102 that is not in contact with the electrode column 101; the PCB board forms conductive vias 206 through uniform via-hole copper coating, and at the conductive vias 206 Depositing copper makes the two copper layers electrically connected. Since a PCB board is used, it is necessary to form a conductive via hole 206 by using a copper-clad via hole method to ensure the electrical connection between the first copper-clad board 207 and the second copper-clad board 208, and facilitate conduction when the power-taking board 102 is working. current in the battery stack.

When a PCB board is used, the boards on both sides should be coated with bare copper. The first copper-clad board 207 and the second copper-clad board 208 on both sides of the board refer to the upper and lower boards of the PCB, and the two boards between the two sides Connections should be made through evenly spaced copper vias. Specifically, the optimization method of the manufacturing process is as follows:

Specifically, a number of through holes with a diameter of 3 mm are processed on the PCB to form the positioning holes 103. According to the current technical level of fuel cell membrane electrodes, one positioning hole 103 can be processed within every 30 to 40 square centimeters. , so that the current passing through each electrode column 101 is about 30A-40A, and the diameter of the electrode column 101 is about 12mm. After the electrode posts 101 are brazed, one side of the power-taking plate 102 of the PCB without welding the electrode posts 101 is plated with gold to form the fuel cell power-taking device. Both sides of the used PCB board need to have copper clad layers, and via holes should be evenly distributed on the PCB board. The via holes are coated with copper to form conductive vias 206, and the conductive vias 206 electrically connect the copper clad layers on both sides.

In this embodiment, optionally, the power-taking board 102 is respectively arranged at both ends of the fuel cell stack, and the side of the power-taking board 102 in contact with the electrode column 101 is connected to the insulating plate and the clamping end. The clamping end plate is arranged on the outside of the insulating plate, and the end of the power-taking plate 102 that is not in contact with the electrode column 101 is provided with a gold-plated layer and connected to the bipolar plate in the fuel cell stack. The power-taking board 102 is a connecting device for external output of electric energy generated by the fuel cell stack. For a fuel cell stack, the uniform power generation on the active area and the uniform power generation of each single cell can ensure the healthy operation of the stack. When there is no potential difference in the area of the power-taking plate 102 itself, it will not affect the surface potential of the single cell, so that the generation of lateral current on the active surface of the single cell is reduced.

In this embodiment, optionally, the cross-sectional area of the end of the electrode column 101 that is in contact with the power-taking plate 102 is not larger than that of the end of the electrode column 101 that is not in contact with the power-taking plate 102 cross-sectional area. For the convenience of processing, the electrode column 101 is a cylinder, and the solid area of the diameter of the top of the electrode column 101 should be adapted to the magnitude of the current passed by the electrode column 101 . When a cone is used, the diameter of one end assembled with the power-taking plate 102 should be greater than the diameter of the top, so that the bottom area of the cone is larger and the circumference is longer. If manual welding is used, only its outer circumference may be welded. In this way, the conductivity of the longer outer circumference is more guaranteed.

In this embodiment, optionally, the active area of the fuel cell is the corresponding area where the electrode column 101 is arranged on the power-taking plate 102, and the corresponding area is provided with an electrode column for every active area of 30 cm ² -40 cm ² 101. Take the copper plate 102 as an example, process a number of positioning holes 103 with a diameter of 3 mm on the copper plate, and the number can be selected to process one positioning hole per 40 square centimeters according to the current technical level of the fuel cell membrane electrode 103, so that the current passing through each electrode column 101 is about 40A, and the diameter of the electrode column 101 is about 12mm. After brazing, the side of the red copper plate that is not welded with the electrode post 101 is plated with gold to form the power-taking device for the fuel cell.

In this embodiment, optionally, the diameter of the shaft shoulder 104 is not greater than 3 mm, that is, the nominal diameters of the positioning holes 103 on the power-taking plate 102 are uniformly not greater than 3 mm, but the diameter of the shaft shoulder 104 should take a negative tolerance To facilitate insertion into the positioning hole 103 of the power-taking board 102 . The diameter of the electrode column 101 is not greater than 12mm.

In this embodiment, optionally, there are six electrode columns 101 and they are evenly arranged on the power-taking plate 102 according to the area of the power-taking plate 102 . If one electrode column 101 is installed on the active area of 30cm ² to 40cm ² according to the corresponding area, it is the most preferred case to install 6 battery power-taking plates 102 devices. And any number of electrode columns 101 need to be arranged. The output potential differences between the electrode columns 101 are equal, because the electrode columns 101 are parallel and have the same spacing distance, and the volume of the electrode columns 101 is the same, so the current passing through them in the same time is the same, and the output potential difference is also the same. equal.

In this embodiment, optionally, the positioning hole 103 is a hollow structure with the same diameter. Since the power-taking plate 102 is a hollow structure with the same diameter, the positioning hole 103 and the corresponding area of the active area are evenly spaced. A plurality of electrode columns 101 are welded. The diameter and number of the electrode columns 101 are determined according to the active area and the current intensity. The active area of the membrane electrode corresponding to each electrode column 101 should be roughly the same, that is, the electrode columns 101 can be evenly distributed. In this way, after the external circuit is connected, the current generated on the active area can pass through the nearest electrode column 101, avoiding the uneven problem of centralized or biased electricity collection.

Those of ordinary skill in the art should understand that: the above descriptions are only specific embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications made within the spirit and principles of the present utility model, equivalent Replacement, improvement, etc. should all be included in the protection scope of the present utility model.

Claims (8)

1. a fuel cell electricity getting device, it is characterized in that, comprise power taking plate and electrode column, on described power taking plate, multiple electrode columns are set, on described power taking plate, offer location hole, described location hole is hollow structure, and described electrode column is vertically set on described power taking plate by described location hole, and described electrode column between two parallel and spacing distance equates; Described power taking plate arranges the shaft shoulder with one end that described electrode column contacts, the length of the described shaft shoulder is slightly less than the thickness of described power taking plate, described shaft shoulder soldering is on described location hole and form a local brazing layer, and a side of described power taking backboard ionization electrode post arranges Gold plated Layer.

2. fuel cell electricity getting device according to claim 1, it is characterized in that, described power taking plate is separately positioned on the two ends of fuel cell pack, the side that described power taking plate contacts with described electrode column is connected with insulation board and clamping end plate, described clamping end plate is arranged on the outside of described insulation board, and one end that described power taking plate does not contact with electrode column arranges Gold plated Layer and is connected with the bipolar plates in this fuel cell pack.

3. fuel cell electricity getting device according to claim 1, it is characterized in that, when described power taking plate is pcb board, set up copper clad plate, described copper clad plate is to be arranged on first copper clad plate of one end and the second copper clad plate of the other end that described power taking plate does not contact with electrode column that described power taking plate contacts with described electrode column; Described pcb board applies copper by even via hole and forms conductive via, and at described conductive via place, deposited copper makes two sides copper-clad electrical communication.

4. according to the fuel cell electricity getting device described in claim 1-3 any one, it is characterized in that, the cross-sectional area of one end that described electrode column contacts with described power taking plate is not more than the cross-sectional area of one end that described electrode column do not contact with described power taking plate.

5. fuel cell electricity getting device according to claim 1, is characterized in that, described fuel cell active area is the corresponding region that electrode column is set on power taking plate, and described corresponding region is according to every 30cm ²～40cm ²active area on an electrode column is set.

6. fuel cell electricity getting device according to claim 1, is characterized in that, the diameter of the described shaft shoulder is not more than 3mm, and the diameter of described electrode column is not more than 12mm.

7. fuel cell electricity getting device according to claim 1, is characterized in that, described electrode column is 6 and is evenly arranged on described power taking plate according to the area of power taking plate.

8. fuel cell electricity getting device according to claim 1, is characterized in that, described location hole is the hollow structure that diameter all equates.