CN215220768U

CN215220768U - Bipolar plate structure of fuel cell

Info

Publication number: CN215220768U
Application number: CN202022645362.XU
Authority: CN
Inventors: 陈矛
Original assignee: Guangzhou Hezhiyuan Hydrogen Technology Co ltd
Current assignee: Guangzhou Hezhiyuan Hydrogen Technology Co ltd
Priority date: 2020-11-16
Filing date: 2020-11-16
Publication date: 2021-12-17
Anticipated expiration: 2030-11-16

Abstract

The utility model discloses a fuel cell bipolar plate structure, including the base plate to and set up upper panel and the lower panel of laminating at the base plate two sides respectively, upper panel and lower panel all are provided with many parallel penetrating flow path slot that supplies the gas flow, the rib portion that two adjacent flow path slots formed still is provided with the short channel groove that spanes the flow path slot, the short channel groove communicates with each other with the flow path slot and forms communicating cavity flow path with great ease, one side that upper panel, lower panel have the short channel groove is laminated respectively on the two sides of base plate. The utility model discloses simple structure can disperse the water droplet of one of them some condensation of flow path slot rapidly to other flow path slots through the short channel groove on, prevents to block up the flow path slot on the bipolar plate because of the comdenstion water, has avoided gas composition to take place the deviation and has influenced the electricity generation reaction.

Description

Bipolar plate structure of fuel cell

Technical Field

The utility model relates to a fuel cell technical field, specific is a fuel cell bipolar plate structure.

Background

A fuel cell is a chemical device that directly converts chemical energy of fuel into electrical energy, and is also called an electrochemical generator. The bipolar plate is also called as a current collecting plate, is one of the important components of the fuel cell, and is used for providing a gas flow channel, preventing the hydrogen in a cell gas chamber from communicating with air, and establishing a current path between a cathode and an anode which are connected in series.

The current fuel cell system is mainly a solid polymer fuel cell (PEFC), and the main components of a PEFC stack are an electrolyte membrane, an electrode catalyst, and a bipolar plate (including a gas flow path). The electrolyte membrane used in the PEFC has a function of sulfonating a part of the fluorocarbon polymer, and causes proton transfer due to the coexistence of water. The bipolar plate functions to distribute fuel gas (anode) and gas (cathode) and collect electrons generated on the catalyst by contacting the electrolyte membrane and the electrode catalyst. Since the function of the bipolar plate is to transport electrons to an external circuit (anode) and from the outside to the catalyst (cathode), it requires a high electrical conductivity and a function of uniformly flowing fuel (hydrogen gas) and air.

As the power generation reaction proceeds inside the fuel cell, hydrogen in the entire fuel gas decreases, the flow velocity downstream of the gas flow path of the bipolar plate decreases, the partial pressure of water vapor becomes high, and the flow path through which a part of water vapor condenses becomes narrow or blocked. Since the gas flow rate becomes low, it is difficult to blow condensed water droplets on the gas flow path. In the gas flow path of the bipolar plate, if the flow path is narrowed or clogged by water droplets, the amount of gas supplied to the catalyst layer around the flow path is reduced, hydrogen gas proceeds by the power generation reaction, and the hydrogen concentration in some places inside the fuel cell is lower than that in other places, thereby causing unstable power generation. Therefore, it may be difficult to continue power generation; further, water droplets accumulated in the bipolar plate gas flow channels cause deterioration of the electrolyte membrane, deterioration of the electrode catalyst, and corrosion of the separator, which greatly shortens the life of the fuel cell stack.

SUMMERY OF THE UTILITY MODEL

The utility model provides a simple structure, reducible runner blocks, avoids gaseous composition to take place the fuel cell bipolar plate structure of deviation.

Fuel cell bipolar plate structure, including the base plate to and set up upper panel and the lower panel of laminating at the base plate two sides respectively, upper panel and lower panel all are provided with many parallel penetrating flow path slot that supplies the gas flow, adjacent two the rib portion that flow path slot formed still is provided with the short channel groove that spanes flow path slot, short channel groove communicates with each other with flow path slot and forms communicating cavity flow path with great ease, one side that upper panel, lower panel had the short channel groove is laminated respectively on the two sides of base plate.

The fuel cell bipolar plate structure is characterized in that short channel grooves are arranged on rib parts formed by two adjacent flow channel grooves, the short channel grooves are distributed on the flow channel grooves in a criss-cross mode and form a hollow flow channel in the same mode as the flow channel grooves, water formed in the power generation process is condensed in one part of the flow channel grooves and then quickly dispersed into other flow channel grooves through the short channel grooves, the situation that gas cannot pass through the flow channel grooves due to the fact that the water is condensed and blocked at one section of the flow channel grooves is avoided, the hydrogen concentration ratio of the bipolar plate is maintained, the contact area between the rib parts of the flow channel grooves and the adjacent bipolar plate can be increased due to the fact that one side, provided with the short channel grooves, of the two bipolar plates is attached to the two sides of the base plate respectively, the contact area between an electrode catalyst and the surface of the bipolar plate is increased, and power generation reaction of a fuel cell is facilitated. The utility model discloses simple structure can disperse the water droplet of one of them some condensation of flow path slot rapidly to other flow path slots through the short channel groove on, prevents to block up the flow path slot on the bipolar plate because of the comdenstion water, has avoided gas composition to take place the deviation and has influenced the electricity generation reaction.

Drawings

Fig. 1 is a schematic structural view of a bipolar plate of a fuel cell.

Fig. 2 is a schematic diagram of the upper panel structure.

Fig. 3 is a structural view of a fuel cell bipolar plate stack.

Detailed Description

As shown in fig. 1-3, the gas-liquid separator comprises a substrate 1, and an upper panel 2 and a lower panel 3 which are respectively arranged on two sides of the substrate and are jointed, wherein the upper panel and the lower panel are respectively provided with a plurality of parallel and through flow channel grooves 4 for gas to flow, the rib part formed by two adjacent flow channel grooves is also provided with a short channel groove 5 crossing the flow channel grooves, the short channel grooves are communicated with the flow channel grooves to form a cavity flow channel which is communicated in a longitudinal and transverse mode, and one sides of the upper panel and the lower panel with the short channel grooves are respectively jointed on two sides of the substrate.

The fuel cell bipolar plate structure, the bipolar plate having a cavity flow path formed by the substrate, and the upper and lower face plates attached to both sides of the substrate, may be stacked with an MEA (membrane electrode) 10 to form a fuel cell reactor.

The fuel cell bipolar plate structure can respectively sinter the upper panel and the lower panel to the two sides of the substrate through a high-temperature high-pressure device. The high pressure and high temperature can inhibit the grain growth of the material, form compact sintered body or compact bonding interface, combine the flow channel grooves of the upper and lower panels and the substrate tightly, prevent the leakage current between the flow channel grooves and the edge of the substrate, and the bipolar plate after high temperature combination has high flatness.

In the fuel cell bipolar plate structure, the flow channel grooves 4 arranged on the upper panel 2 and the lower panel 3 are parallel serpentine flow channels. The serpentine flow channel groove can not only increase the length of the flow channel, but also increase the communication area with the short channel groove in the vertical direction, even if the condensed water blocks part of the serpentine flow channel groove, the gas can also enter other parts of the serpentine flow channel groove through the short channel groove from other places, and the problem of the gas supply amount of the catalyst layer around the flow channel is effectively solved.

In the fuel cell bipolar plate structure, the flow channel groove (4) and the short channel groove (5) of which the rib crosses the flow channel groove form a hollow shape. Further increasing the water drop to be rapidly dispersed to other flow path grooves.

In the fuel cell bipolar plate structure, the flow channel area of the flow channel grooves 4 of the upper panel 2 and the lower panel 3 is rectangular, wherein the width of the flow channel groove is 1-2mm, the rib interval of two adjacent flow channel grooves is 1-2mm, the depth of the flow channel groove serving as a fuel electrode is 0.2-0.4 mm, the depth of the flow channel groove serving as an air electrode is 0.4-0.8 mm, the interval of the short channel groove is 4-6mm, the width of the short channel groove is 4-6mm, the depth of the short channel groove serving as the fuel electrode is 0.1-0.3mm, and the depth of the short channel groove serving as the air electrode is 0.3-0.7 mm. Since the flow rate of air is twice or more of that of fuel (hydrogen gas) during power generation, it is necessary to provide different depths of the flow channel grooves between the fuel electrode and the air electrode, and to increase the cross-sectional area of the flow channel to ensure that the air electrode has sufficient air and no pressure loss occurs.

The fuel cell bipolar plate structure, the corresponding air inlet 6, gas outlet 7 are equally divided on the left and right sides of the base plate 1, the upper panel 2 and the lower panel 3, grooves 8 for gas distribution are arranged between the air inlet 6 and the flow channel grooves 4 and between the gas outlet 7 and the flow channel grooves 4. In order to enable the gas to flow into the flow channel grooves from the gas inlet or the gas outlet, the gas flow-dividing device also has a flow-dividing effect on the gas, and the gas is uniformly buffered and divided into the flow channel grooves.

The bipolar plate structure of the fuel cell is made of heat-resistant alloys such as Ti (titanium) or Ti alloy (titanium alloy) or stainless steel or nickel-chromium-iron alloy. Further, Ti (titanium) or a Ti alloy (titanium alloy) is preferable, and has advantages of corrosion resistance, light weight, and the like.

Claims

1. The utility model provides a fuel cell bipolar plate structure, its characterized in that includes base plate (1) to and set up respectively in top panel (2) and lower panel (3) of the laminating of base plate both sides, top panel and lower panel all are provided with many and run-through flow path slot (4) that supply gas to flow in parallel, adjacent two the rib that flow path slot formed still is provided with and crosses short channel groove (5) of flow path slot, short channel groove communicates with each other with the flow path slot and forms the communicating cavity flow path of vertically and horizontally, one side that upper panel, lower panel have the short channel groove is laminated respectively on the both sides of base plate.

2. The fuel cell bipolar plate structure of claim 1, wherein the upper and lower face plates are sintered to both sides of the base plate by a high temperature and high pressure apparatus, respectively.

3. The fuel cell bipolar plate structure according to claim 1, wherein the flow channel grooves (4) provided in the upper and lower face plates (2, 3) are parallel serpentine flow channels.

4. The fuel cell bipolar plate structure according to claim 1, wherein said flow path groove (4) and the short passage groove (5) whose rib crosses the flow path groove form a hollow shape.

5. The fuel cell bipolar plate structure according to claim 4, wherein the flow path regions of the flow path grooves (4) of the upper and lower face plates (2, 3) are rectangular, wherein the width of the flow path groove is 1 to 2mm, the rib pitch of two adjacent flow path grooves is 1 to 2mm, the depth of the flow path groove as the fuel electrode is 0.2mm to 0.4mm, the depth of the flow path groove as the air electrode is 0.4mm to 0.8mm, the pitch of the short passage groove is 4 to 6mm, the width is 4 to 6mm, the depth of the short passage groove as the fuel electrode is 0.1 to 0.3mm, and the depth of the short passage groove as the air electrode is 0.3 to 0.7 mm.

6. The fuel cell bipolar plate structure according to claim 1, wherein the left and right sides of the base plate (1), the upper plate (2) and the lower plate (3) are respectively provided with a corresponding gas inlet (6) and a corresponding gas outlet (7), and grooves (8) for gas shunting are arranged between the gas inlet (6) and the flow channel groove (4) and between the gas outlet (7) and the flow channel groove (4).

7. The fuel cell bipolar plate structure of claim 1 wherein said bipolar plate is made of a material that is a nickel-chromium-iron alloy.

8. The fuel cell bipolar plate structure of claim 1, wherein said bipolar plate is made of stainless steel.

9. The fuel cell bipolar plate structure of claim 1, wherein said bipolar plate is made of Ti (titanium).

10. The fuel cell bipolar plate structure of claim 1, wherein said bipolar plate is made of a Ti alloy (titanium alloy).