A metal bipolar plate hydrogen fuel cell

Abstract

The utility model provides a kind of metal bipolar plate hydrogen fuel cell, including metal bipolar plate hydrogen fuel single battery group, first end plate, second end plate, the first end plate and the second end plate pass through fastener and fix the metal bipolar plate hydrogen fuel single battery group between the first end plate and the second end plate, first current collector is equipped between the first end plate and the metal bipolar plate hydrogen fuel single battery group, second current collector is equipped between the second end plate and the metal bipolar plate hydrogen fuel single battery group, the metal bipolar plate hydrogen fuel single battery group includes multiple single cell of sequentially superposed;So in multiple traffic field application scenarios, the metal bipolar plate hydrogen fuel cell of the application has higher volume power density and mass power density.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen fuel cell technology, specifically to a metal bipolar plate hydrogen fuel cell. Background Technology

[0002] Hydrogen fuel's greatest advantages as an energy source are its pollution-free nature, high efficiency, and recyclability, making it a future direction for new energy development and one of the main energy development directions for fuel cell vehicles.

[0003] In clean energy power applications, hydrogen fuel cell stacks have become one of the most promising, commercially viable, green, low-carbon, and widely applicable technological development directions, and the commercialization process of hydrogen fuel cell stacks is gradually accelerating. The electrochemical reaction of a hydrogen fuel cell occurs in the core of the fuel cell. Each hydrogen fuel cell stack consists of multiple fuel cell cells, which convert the chemical energy of the fuel into electrical energy.

[0004] Existing hydrogen fuel cells require high volumetric power density and mass power density in various transportation applications. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a metal bipolar plate hydrogen fuel cell with high volumetric power density and high mass power density.

[0006] The technical solution adopted by this utility model to solve its technical problem is: A metal bipolar plate hydrogen fuel cell includes a metal bipolar plate hydrogen fuel cell assembly, a first end plate, and a second end plate. The first end plate and the second end plate are fastened together to fix the metal bipolar plate hydrogen fuel cell assembly between the first end plate and the second end plate. A first current collector is provided between the first end plate and the metal bipolar plate hydrogen fuel cell assembly, and a second current collector is provided between the second end plate and the metal bipolar plate hydrogen fuel cell assembly. The metal bipolar plate hydrogen fuel cell assembly includes a plurality of single cells stacked sequentially.

[0007] In one embodiment, the single cell includes a metal bipolar plate body and a membrane electrode assembly. The metal bipolar plate body includes a cathode plate and an anode plate. The cathode plate and the anode plate are bonded together to form the bipolar plate body. A first flow field is provided on the outer side of the cathode plate, a second flow field is provided on the outer side of the anode plate, and a third flow field is formed by bonding the inner sides of the cathode plate and the anode plate together.

[0008] In one embodiment, the first flow field includes a first through hole, a first bridge channel, a first distribution zone, a first gas reaction zone, a first sub-collection zone, a second bridge channel, and a second through hole through which gas flows from left to right in sequence. The flow channel length on the first distribution zone is the same as the flow channel length on the first sub-collection zone. The second flow field includes the sixth through hole, the sixth bridge channel, the third distribution zone, the third gas reaction zone, the third sub-collection zone, the fifth bridge channel, and the fifth through hole through which the gas flows from right to left in sequence. The flow channel length in the third sub-collection zone is the same as the flow channel length in the third distribution zone. The third flow field includes the third through hole, the third bridge channel, the second sub-collection zone, the second gas reaction zone, the second distribution zone, the fourth bridge channel, and the fourth through hole through which the liquid flows from left to right in sequence. The flow channel length in the second distribution zone is the same as the flow channel length in the second sub-collection zone.

[0009] In one embodiment, the first distribution area includes a plurality of first distribution channels, which are fan-shaped and have a gradually increasing length from top to bottom. The first sub-collection area includes a plurality of first sub-collection channels, which are fan-shaped and have a gradually decreasing length from top to bottom. The third sub-collection area includes several third sub-collection channels, which are fan-shaped and gradually increase in length from top to bottom. The third distribution area includes several third distribution channels, which are fan-shaped and gradually decrease in length from top to bottom.

[0010] In one embodiment, the first gas reaction zone, the second gas reaction zone, and the third gas reaction zone each include a plurality of gas flow channels, and the cross-sectional area of ​​each gas flow channel varies periodically along the gas flow direction.

[0011] In one embodiment, each cross-sectional area change cycle of the gas flow channel includes a first wide diameter region, a first gradient region, a first narrow diameter region, a second gradient region, a second wide diameter region, a third gradient region, a second narrow diameter region, and a fourth gradient region connected in sequence. The cross-sectional area of ​​the first narrow diameter region is inclined downward along the gas flow direction and its diameter remains constant, while the cross-sectional area of ​​the second narrow diameter region is inclined upward along the gas flow direction and its diameter remains constant.

[0012] In one embodiment, the first gradient region, the first narrow diameter region, the second gradient region, and the third gradient region, the second narrow diameter region, and the fourth gradient region are mirror images of each other.

[0013] In one embodiment, the cross-sectional area of ​​the first wide-diameter region is a direct-flow channel along the gas flow direction; the cross-sectional area of ​​the first gradient region is arc-shaped and its diameter gradually decreases along the gas flow direction; the cross-sectional area of ​​the second gradient region is arc-shaped and its diameter gradually increases along the gas flow direction; the cross-sectional area of ​​the second wide-diameter region is a direct-flow channel along the gas flow direction; the cross-sectional area of ​​the third gradient region is arc-shaped and its diameter gradually decreases along the gas flow direction; and the cross-sectional area of ​​the fourth gradient region is arc-shaped and its diameter gradually increases along the gas flow direction.

[0014] In one embodiment, the first end plate is provided with an air inlet communicating with the first through hole, an air outlet communicating with the second through hole, a hydrogen inlet communicating with the fifth through hole, and a hydrogen outlet communicating with the sixth through hole; the second end plate is provided with a coolant inlet communicating with the third through hole and a coolant outlet communicating with the fourth through hole.

[0015] In one embodiment, the first end plate and the second end plate are further fixedly connected by a balance block. The first end plate and the second end plate are provided with symmetrical mounting notches. The two ends of the balance block are set on the mounting notches on the first end plate and the second end plate and are flush with the first end plate and the second end plate.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention utilizes a metal bipolar plate hydrogen fuel cell stack, a first end plate, and a second end plate. The first end plate and the second end plate are fastened together to fix the metal bipolar plate hydrogen fuel cell stack between the first end plate and the metal bipolar plate hydrogen fuel cell stack. A first current collector is provided between the first end plate and the metal bipolar plate hydrogen fuel cell stack, and a second current collector is provided between the second end plate and the metal bipolar plate hydrogen fuel cell stack. The metal bipolar plate hydrogen fuel cell stack comprises multiple stacked cells. Therefore, the metal bipolar plate hydrogen fuel cell of this application has high volumetric power density and mass power density in various transportation applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This utility model Figure 1 A schematic diagram of the exploded structure; Figure 3 This utility model Figure 1 A schematic diagram of the front structure of the first end plate; Figure 4 This utility model Figure 1 Schematic diagram of the reverse structure of the first end plate; Figure 5 This utility model Figure 1 A schematic diagram of the front structure of the second end plate; Figure 6 This utility model Figure 1 Schematic diagram of the reverse structure of the second end plate; Figure 7 This is a top view schematic diagram of the metal bipolar plate structure of Embodiment 1 of this utility model; Figure 8 For the purpose of this utility model Figure 7 A schematic diagram of the structure viewed from below; Figure 9 This utility model Figure 7 A magnified diagram of part A in the middle; Figure 10 This utility model Figure 7 Schematic diagram of the flow channel structure of the first gas reaction zone, the second gas reaction zone, and the third gas reaction zone; Figure 11 This utility model Figure 10 A schematic diagram of the structure of a single flow channel.

[0018] In the diagram: 10. Gas flow channel, 11. First wide diameter region, 12. First gradient region, 13. First narrow diameter region, 14. Second gradient region, 15. Second wide diameter region, 16. Third gradient region, 17. Second narrow diameter region, 18. Fourth gradient region; 100. Metal bipolar plate hydrogen fuel cell pack; 101. First end plate; 102. Second end plate; 103. Fastener; 104. Air inlet; 105. Air outlet; 106. Hydrogen inlet; 107. Hydrogen outlet; 108. Coolant inlet; 109. Coolant outlet; 1011. Balance block; 1012. Mounting notch; 110. First through hole; 111. First bridging channel; 112. First distribution zone; 113. First gas reaction zone; 120. Second through hole; 121. Second bridging channel; 122. First sub-collection zone; 130. Third through hole, 131. Third bridge passage, 132. Second sub-collection area, 140. Fourth through hole, 141. Fourth bridge passage, 142. Second distribution area; 150. Fifth through hole, 151. Fifth bridge channel, 152. Third sub-collection zone, 153. Third gas reaction zone, 160. Sixth through hole, 161. Sixth bridge channel, 162. Third distribution zone. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1 like Figure 1-6 As shown, this embodiment includes a metal bipolar plate hydrogen fuel cell pack 100, a first end plate 101, and a second end plate 102. The first end plate 101 and the second end plate 102 are fixed between the first end plate 101 and the second end plate 102 by a connecting rod 103.

[0021] A first current collector is provided between the first end plate 101 and the metal bipolar plate hydrogen fuel cell pack 100, and a second current collector is provided between the second end plate 102 and the metal bipolar plate hydrogen fuel cell pack 100. In this embodiment, the first current collector is located in the middle of the side of the first end plate 101 facing the metal bipolar plate hydrogen fuel cell pack, and the second current collector is located in the middle of the side of the second end plate 102 facing the metal bipolar plate hydrogen fuel cell pack 100. The size of the first current collector is smaller than that of the first end plate 101, and the size of the second current collector is smaller than that of the second end plate 102, so as to ensure that an effective conductive path is formed between the current collector and the end plate.

[0022] The first current collector is fixedly connected to the top of the first end plate via a first U-shaped block, and the second current collector is fixedly connected to the top of the second end plate via a second U-shaped block. In this embodiment, both the first and second current collectors are made of highly conductive materials to ensure efficient current transmission in the fuel cell stack.

[0023] In this embodiment, the first end plate 101 and the second end plate 102 are both made of modified nylon and resin materials, which have good insulation properties and mechanical strength, effectively preventing current from being conducted to the external environment, while ensuring the structural stability of the entire fuel cell stack.

[0024] The metal bipolar plate hydrogen fuel cell pack 100 includes multiple single cells stacked sequentially. Each single cell includes a bipolar plate body and a membrane electrode assembly. The bipolar plate body includes a cathode plate and an anode plate. The cathode plate and the anode plate are bonded together to form the bipolar plate body. A first flow field is provided on the outer side of the cathode plate, a second flow field is provided on the outer side of the anode plate, and a third flow field is formed by the inner sides of the cathode plate and the anode plate being bonded together.

[0025] like Figure 7-11As shown, the first flow field includes a first through-hole 110, a first bridge channel 111, a first distribution zone 112, a first gas reaction zone 113, a first sub-collection zone 122, a second bridge channel 121, and a second through-hole 120, through which gas flows from left to right and passes sequentially. Thus, the first through-hole 110, the first bridge channel 111, the first distribution zone 112, the first gas reaction zone 113, the second sub-collection zone 122, the second bridge channel 121, and the second through-hole 120 constitute an oxidant flow field or a fuel flow field. That is, the oxidant or fuel enters from the first through-hole 110, enters the first distribution zone 112 through the first bridge channel 111, flows to the first gas reaction zone 113 in the first distribution zone 112 and reacts, then enters the first sub-collection zone 122 and converges, and enters the second through-hole 120 through the second bridge channel 121, thus realizing the flow of the oxidant flow field or the fuel flow field.

[0026] The flow channel length on the first distribution area 112 is the same as the flow channel length on the first sub-collection area 122, and the first through hole 110 and the second through hole 120 are diagonally arranged on the bipolar plate body; that is, in this embodiment, the first distribution area 112 and the first sub-collection area 122 have the same size and are arranged oppositely.

[0027] The first distribution zone 112 includes several first distribution channels, which are fan-shaped and gradually increase in length from top to bottom. The first sub-collection zone 122 includes several first sub-collection channels, which are fan-shaped and gradually decrease in length from top to bottom.

[0028] In this embodiment, several flow channels in the first distribution area 112 are arc-shaped flow channels, with the length of the flow channels gradually increasing from top to bottom; several flow channels in the first sub-collection area 122 are arc-shaped flow channels, with the length of the flow channels gradually decreasing from bottom to top.

[0029] That is, the longest flow channel in the first distribution zone 112 is connected to the shortest flow channel in the first sub-collection zone 122 through the first gas reaction zone 113; the shortest flow channel in the first distribution zone 112 is connected to the longest flow channel in the first sub-collection zone 122 through the first gas reaction zone 113; and so on, the second longest flow channel in the first distribution zone 112 is connected to the second shortest flow channel in the first sub-collection zone 122 through the first gas reaction zone 113; and the second shortest flow channel in the first distribution zone 112 is connected to the second longest flow channel in the first sub-collection zone 122 through the first gas reaction zone 113. This ensures that the length of each flow channel from the inlet to the outlet is equal. This makes the gas reaction time in each flow channel within the reaction zone tend to be consistent, resulting in consistent power generation throughout the reaction zone, ultimately leading to stable fuel cell power output and improved performance and lifespan.

[0030] The second flow field includes the sixth through-hole 160, the sixth bridge channel 161, the third distribution zone 162, the third gas reaction zone 153, the third sub-collection zone 152, the fifth bridge channel 151, and the fifth through-hole 150, through which gas flows from right to left. Thus, the fifth through-hole 150, the fifth bridge channel 151, the third sub-collection zone 152, the third gas reaction zone 153, the third distribution zone 162, the sixth bridge channel 161, and the sixth through-hole 160 constitute the oxidant flow field or the fuel flow field. That is, the oxidant or fuel enters from the sixth through-hole 160, enters the third distribution zone 162 through the sixth bridge channel 161, flows to the third gas reaction zone 153 in the third distribution zone 162 and reacts, then enters the third sub-collection zone 152 and converges, and enters the fifth through-hole 150 through the fifth bridge channel 151, thus realizing the flow of the oxidant flow field or the fuel flow field.

[0031] The flow channel length on the third sub-collection area 152 is the same as the flow channel length on the third distribution area 162. The fifth through hole 150 and the sixth through hole 160 are diagonally arranged on the bipolar plate body. In this embodiment, the third sub-collection area 152 and the third distribution area 162 have the same size and are arranged oppositely.

[0032] In this embodiment, the flow channel of the third distribution area 162 is an arc-shaped flow channel, which gradually lengthens from top to bottom; the flow channel of the third sub-collection area 152 is an arc-shaped flow channel, which gradually lengthens from bottom to top.

[0033] The third sub-gathering zone 152 includes several third sub-gathering channels, which are fan-shaped and gradually increase in length from top to bottom. The third distribution zone 162 includes several third distribution channels, which are fan-shaped and gradually decrease in length from top to bottom. That is, the longest flow channel in the third sub-collection zone 152 is connected to the shortest flow channel in the third distribution zone 162 through the third gas reaction zone 153; the shortest flow channel in the third sub-collection zone 152 is connected to the longest flow channel in the third sub-collection zone 162 through the third gas reaction zone 153; and so on, the second longest flow channel in the third sub-collection zone 152 is connected to the second shortest flow channel in the third distribution zone 162 through the third gas reaction zone 153; and the second shortest flow channel in the third sub-collection zone 152 is connected to the second longest flow channel in the third distribution zone 162 through the third gas reaction zone 153. This ensures that the length of each flow channel from the inlet to the outlet is equal. This makes the gas reaction time in each flow channel within the reaction zone tend to be consistent, resulting in consistent power generation throughout the reaction zone, ultimately leading to stable fuel cell power output and improved performance and lifespan.

[0034] The third flow field includes the third through-hole 130, the third bridge channel 131, the second sub-collection zone 132, the second gas reaction zone, the second distribution zone 142, the fourth bridge channel 141, and the fourth through-hole 140, through which the liquid flows from left to right in sequence. Thus, the third through-hole 130, the third bridge channel 131, the second distribution zone 142, the second gas reaction zone, the second sub-collection zone 132, the fourth bridge channel 141, and the fourth through-hole 140 constitute the coolant flow field; that is, the coolant enters from the third through-hole 130, passes through the third bridge channel 131, enters the second distribution zone 142, flows to the second gas reaction zone in the second distribution zone 142 and reacts there, then enters the second sub-collection zone 132 to collect, and finally flows through the fourth bridge channel 141 to the fourth through-hole 140, thus realizing the flow of the coolant.

[0035] In this embodiment, the third flow field is the coolant flow field in the bipolar plate body, and the coolant flow field is the third flow field formed by the inner surfaces of the cathode plate and the anode plate being attached to each other; the flow structure of the coolant flow field in the bipolar plate body is the prior art.

[0036] The flow channel length on the second distribution area 142 is the same as the flow channel length on the second sub-collection area 132. In this embodiment, the second distribution area 142 and the second sub-collection area 132 have the same size but are arranged oppositely.

[0037] The second distribution zone 142 includes several second distribution channels, which are fan-shaped and gradually increase in length from top to bottom. The second sub-collection zone 132 includes several second sub-collection channels, which are fan-shaped and gradually decrease in length from top to bottom.

[0038] The flow channel of the second distribution zone 142 is an arc-shaped flow channel, which gradually becomes longer from top to bottom; the flow channel of the second sub-collection zone 132 is an arc-shaped flow channel, which gradually becomes shorter from bottom to top.

[0039] That is, the longest flow channel in the second distribution zone 142 is connected to the shortest flow channel in the second sub-collection zone 132 through the second gas reaction zone; the shortest flow channel in the second distribution zone 142 is connected to the longest flow channel in the second sub-collection zone 132 through the second gas reaction zone, and so on. The second longest flow channel in the second distribution zone 142 is connected to the second shortest flow channel in the second sub-collection zone 132 through the second gas reaction zone; the second shortest flow channel in the second distribution zone 142 is connected to the second longest flow channel in the second sub-collection zone 132 through the second gas reaction zone. This ensures that the length of each flow channel from the inlet to the outlet is equal. This makes the gas reaction time in each flow channel within the reaction zone more consistent, resulting in more consistent power generation throughout the reaction zone, ultimately stabilizing the fuel cell's output power and improving its performance and lifespan.

[0040] In this embodiment, the first through hole 110, the third through hole 130, and the fifth through hole 150 are all disposed at the first end 101 of the bipolar plate body; the second through hole 120, the fourth through hole 140, and the sixth through hole 160 are all disposed at the second end 102 of the bipolar plate body.

[0041] The third through hole 130 is disposed between the first through hole 110 and the fifth through hole 150, and the fourth through hole 140 is disposed between the sixth through hole 160 and the second through hole 120.

[0042] In this embodiment, the first through hole 110 and the second through hole 120 have the same size; the third through hole 130 and the fourth through hole 140 have the same size; and the fifth through hole 150 and the sixth through hole 160 have the same size. In one embodiment, the dimensions of the first through hole 110 and the second through hole 120 are larger than the dimensions of the fifth through hole 150 and the sixth through hole 160; that is, the first through hole 110 and the second through hole 120 are hexagonal through holes, the fifth through hole 150 and the sixth through hole 160 are also hexagonal through holes, and thus the aperture of the first through hole 110 and the second through hole 120 is larger than the aperture of the fifth through hole 150 and the sixth through hole 160.

[0043] The first gas reaction zone 113, the second gas reaction zone, and the third gas reaction zone 153 each include a plurality of gas flow channels 10. The cross-sectional area of ​​each gas flow channel 10 changes periodically along the gas flow direction. Each cross-sectional area change period of the gas flow channel 10 includes a first wide diameter zone 11, a first gradient zone 12, a first narrow diameter zone 13, a second gradient zone 14, a second wide diameter zone 15, a third gradient zone 16, a second narrow diameter zone 17, and a fourth gradient zone 18 connected in sequence. In this embodiment, the first gradient zone 12, the first narrow diameter zone 13, and the second gradient zone 14 are mirror images of the third gradient zone 16, the second narrow diameter zone 17, and the fourth gradient zone 18. The first wide diameter zone 11 and the second wide diameter zone 15 are not on the same horizontal line. That is, from the perspective of cross-sectional area, the first wide diameter zone 11 is located above one end of the second wide diameter zone 15.

[0044] The cross-sectional area of ​​the first wide diameter region 11 is a direct flow channel along the gas flow direction. In this embodiment, the first wide diameter region 11 is cylindrical. It should be noted that under the same operating conditions (same pressure / flow rate and temperature), the larger the flow channel area, the lower the flow velocity. When the gas passes through the first wide diameter region 11, its flow velocity is the lowest because the first wide diameter region 11 is in the range with the largest flow channel area in the entire flow channel cycle.

[0045] The cross-sectional area of ​​the first gradient region 12 is arc-shaped along the gas flow direction and the diameter gradually decreases; in this embodiment, the cross-sectional area of ​​the first gradient region 12 is arc-shaped along the gas flow direction and the diameter gradually decreases; and the maximum diameter end of the first gradient region 12 is connected to the first wide diameter region 11, and the minimum diameter of the first gradient region 12 is one-half the diameter of the first wide diameter region 11.

[0046] Therefore, after the gas from the first wide diameter region 11 enters the first gradual transition region 12, the flow velocity begins to increase. As the diameter of the first wide diameter region 11 gradually decreases, the gas flow velocity increases, and the force exerted on the two side walls of the first wide diameter region 11 also increases accordingly, until it enters the narrow diameter region 13.

[0047] The cross-sectional area of ​​the first narrow diameter region 13 is inclined downward along the gas flow direction and the diameter remains unchanged; in this embodiment, the front end of the first narrow diameter region 13 is connected to the minimum diameter in the first gradient region 12, that is, the diameter of the first narrow diameter region 13 is one-half the diameter of the first wide diameter region 11.

[0048] Therefore, when the gas in the first gradient zone 12 enters the first narrow diameter zone 13, the gas velocity in the first narrow diameter zone 13 reaches its maximum because the cross-sectional area of ​​the first narrow diameter zone 13 is inclined downward along the gas flow direction and the diameter remains unchanged; at the same time, the diameter of the first narrow diameter zone 13 is also the smallest.

[0049] The cross-sectional area of ​​the second gradient region 14 is arc-shaped along the gas flow direction and the diameter gradually increases. In this embodiment, the cross-sectional area of ​​the second gradient region 14 is arc-shaped along the gas flow direction and the diameter gradually increases; and the smallest diameter end of the first gradient region 12 is connected to the first narrow diameter region 13, and the smallest diameter of the second gradient region 14 is one-half the diameter of the first wide diameter region 11.

[0050] The cross-sectional area of ​​the second wide-diameter region 15 is a direct-flow channel along the gas flow direction; in this embodiment, the second wide-diameter region 15 is cylindrical; the front end of the second wide-diameter region 15 is connected to the maximum diameter end of the second gradient region 14; thus, after passing through the second gradient region 14, the gas enters the second wide-diameter region 15; since the gas enters the second gradient region 14 of the same diameter after passing through the first narrow-diameter region 13 for a short period of time, the gas flow velocity also decreases as the area of ​​the second gradient region 14 increases. After passing through the second gradient region 14, the gas enters the same second gradient region 14 as the first gradient region 11, at which point the gas flow velocity reaches its minimum.

[0051] The cross-sectional area of ​​the third gradient region 16 is arc-shaped along the gas flow direction and the diameter gradually decreases; in this embodiment, the cross-sectional area of ​​the third gradient region 16 is arc-shaped along the gas flow direction and the diameter gradually decreases; and the end of the third gradient region 16 with the largest diameter is connected to the end of the second wide diameter region 15, and the minimum diameter of the third gradient region 16 is half the diameter of the second wide diameter region 15.

[0052] Therefore, after the gas enters the third gradient region 16 from the second wide diameter region 15, the flow velocity begins to increase. As the diameter of the third gradient region 16 gradually decreases, the gas flow velocity becomes larger and larger, and the force on the two side walls of the third gradient region 16 also increases accordingly, until it enters the second narrow diameter region 17.

[0053] The cross-sectional area of ​​the second narrow diameter region 17 is inclined upward along the gas flow direction and the diameter remains unchanged; in this embodiment, the front end of the second narrow diameter region 17 is connected to the minimum diameter in the third gradient region 16; the diameter of the second narrow diameter region 17 is half the diameter of the second wide diameter region 15.

[0054] Therefore, when the gas in the third gradient zone 16 enters the second narrow diameter zone 17, the cross-sectional area of ​​the second narrow diameter zone 17 is inclined downward along the gas flow direction and the diameter remains unchanged; at the same time, the diameter of the second narrow diameter zone 17 is also the smallest. Therefore, the gas flow velocity entering the second narrow diameter zone 17 reaches the maximum.

[0055] The cross-sectional area of ​​the fourth gradient region 18 is arc-shaped along the gas flow direction and the diameter gradually increases; in this embodiment, the cross-sectional area of ​​the fourth gradient region 18 is arc-shaped along the gas flow direction and the diameter gradually increases; and the minimum diameter end of the fourth gradient region 18 is connected to the end of the second narrow diameter region 17, and the minimum diameter of the second narrow diameter region 17 is half the diameter of the first wide diameter region 11.

[0056] After passing through the short-length second narrow-diameter zone 17, the gas enters the same fourth gradual transition zone 18 connected to it. At this time, the flow channel area increases from small to large, and the gas flow velocity also decreases from high to low.

[0057] Thus, the entire flow channel circulates continuously, with the gas flow rate fluctuating between fast and slow. Consequently, the flow channel of this application can change the gas flow rate within the flow channel, enhancing the gas diffusion rate to the diffusion layer, which is beneficial for the gas to be evenly distributed and diffused to the gas diffusion layer of the membrane electrode to react with the catalyst. This allows for more efficient and full utilization of the reactants in the gas, while also enhancing the drainage performance within the flow channel.

[0058] The first end plate 101 is provided with an air inlet 104 communicating with the first through hole 110, an air outlet 105 communicating with the second through hole 120, a hydrogen inlet 106 communicating with the fifth through hole 150, and a hydrogen outlet 107 communicating with the sixth through hole 160; the second end plate 102 is provided with a coolant inlet 108 communicating with the third through hole 130 and a coolant outlet 109 communicating with the fourth through hole 140.

[0059] In this embodiment, air inlet 104, hydrogen inlet 106, air outlet 105, and hydrogen outlet 107 are each connected by a first connecting pipe; wherein, the first connecting pipes on air outlet 105 and hydrogen outlet 107 are tapered pipes; thereby facilitating the removal of water generated at the cathode and anode of the fuel cell, reducing flooding during fuel cell operation, and improving fuel cell stability.

[0060] The coolant inlet 108 and coolant outlet 109 are respectively connected by a second connecting pipe; in this embodiment, the second connecting pipe is a stepped connecting pipe, which enables the coolant surface to be evenly distributed, thus ensuring effective thermal management of the battery pack inside the fuel cell.

[0061] The first end plate 101 and the second end plate 102 are also fixedly connected by a balance block 1011. Symmetrical mounting notches 1012 are provided on the first end plate 101 and the second end plate 102. The two ends of the balance block 1011 are set on the mounting notches 1012 on the first end plate 101 and the second end plate 102 and are flush with the first end plate 101 and the second end plate 102.

[0062] In this embodiment, there are four balance blocks 1011. The top of the first end plate 101 and the second end plate 102 have two sets of symmetrically arranged mounting notches 1012, and the bottom also has two sets of symmetrically arranged mounting notches 1012. This allows the four balance blocks 1011 to be fixedly installed within the four sets of mounting notches 1012, thereby effectively improving the structural balance and seismic resistance of the entire fuel cell stack. This structural design not only enhances the connection strength between the end plates but also effectively absorbs vibration and stress during fuel cell operation, reducing performance degradation caused by mechanical deformation, thus improving the overall stability and service life of the fuel cell system.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the technical solutions of this utility model have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of this utility model.

Claims

1. A metal bipolar plate hydrogen fuel cell, characterized in that: The device includes a metal bipolar plate hydrogen fuel cell pack (100), a first end plate (101), and a second end plate (102). The first end plate (101) and the second end plate (102) are fastened together by fasteners (103) to fix the metal bipolar plate hydrogen fuel cell pack (100) between the first end plate (101) and the second end plate (102). A first current collector is provided between the first end plate (101) and the metal bipolar plate hydrogen fuel cell pack (100), and a second current collector is provided between the second end plate (102) and the metal bipolar plate hydrogen fuel cell pack (100). The metal bipolar plate hydrogen fuel cell pack (100) includes a plurality of single cells stacked in sequence.

2. The metal bipolar plate hydrogen fuel cell according to claim 1, characterized in that: The single cell includes a bipolar plate body and a membrane electrode assembly. The bipolar plate body includes a cathode plate and an anode plate. The cathode plate and the anode plate are bonded together to form the bipolar plate body. A first flow field is provided on the outer side of the cathode plate, a second flow field is provided on the outer side of the anode plate, and a third flow field is formed by the inner sides of the cathode plate and the anode plate being bonded together.

3. The metal bipolar plate hydrogen fuel cell according to claim 2, characterized in that: The first flow field includes a first through hole (110), a first bridge channel (111), a first distribution zone (112), a first gas reaction zone (113), a first sub-collection zone (122), a second bridge channel (121), and a second through hole (120) through which gas flows from left to right in sequence. The length of the flow channel on the first distribution zone (112) is the same as the length of the flow channel on the first sub-collection zone (122). The second flow field includes the sixth through hole (160), the sixth bridge channel (161), the third distribution zone (162), the third gas reaction zone (153), the third sub-collection zone (152), the fifth bridge channel (151), and the fifth through hole (150) through which the gas flows from right to left in sequence. The length of the flow channel on the third sub-collection zone (152) is the same as the length of the flow channel on the third distribution zone (162). The third flow field includes the third through hole (130), the third bridge channel (131), the second sub-collection zone (132), the second gas reaction zone, the second distribution zone (142), the fourth bridge channel (141), and the fourth through hole (140) through which the liquid flows from left to right in sequence. The flow channel length on the second distribution zone (142) is the same as the flow channel length on the second sub-collection zone (132).

4. The metal bipolar plate hydrogen fuel cell according to claim 3, characterized in that: The first distribution area (112) includes several first distribution channels, which are fan-shaped and gradually increase in length from top to bottom. The first sub-collection area (122) includes several first sub-collection channels, which are fan-shaped and gradually decrease in length from top to bottom. The third sub-collection area (152) includes several third sub-collection channels, which are fan-shaped and gradually increase in length from top to bottom. The third distribution area (162) includes several third distribution channels, which are fan-shaped and gradually decrease in length from top to bottom.

5. The metal bipolar plate hydrogen fuel cell according to claim 4, characterized in that: The first gas reaction zone (113), the second gas reaction zone, and the third gas reaction zone (153) each include several gas flow channels (10), and the cross-sectional area of ​​each gas flow channel (10) changes periodically along the gas flow direction.

6. The metal bipolar plate hydrogen fuel cell according to claim 5, characterized in that: Each cross-sectional area change cycle of the gas flow channel (10) includes a first wide diameter region (11), a first gradient region (12), a first narrow diameter region (13), a second gradient region (14), a second wide diameter region (15), a third gradient region (16), a second narrow diameter region (17), and a fourth gradient region (18) connected in sequence. The cross-sectional area of ​​the first narrow diameter region (13) is inclined downward along the gas flow direction and its diameter remains unchanged. The cross-sectional area of ​​the second narrow diameter region (17) is inclined upward along the gas flow direction and its diameter remains unchanged.

7. The metal bipolar plate hydrogen fuel cell according to claim 6, characterized in that: The first gradient area (12), the first narrow diameter area (13), the second gradient area (14) are mirror images of the third gradient area (16), the second narrow diameter area (17), and the fourth gradient area (18).

8. The metal bipolar plate hydrogen fuel cell according to claim 7, characterized in that: The cross-sectional area of ​​the first wide diameter region (11) is a direct current channel along the gas flow direction; the cross-sectional area of ​​the first gradient region (12) is arc-shaped along the gas flow direction and its diameter gradually decreases; the cross-sectional area of ​​the second gradient region (14) is arc-shaped along the gas flow direction and its diameter gradually increases; the cross-sectional area of ​​the second wide diameter region (15) is a direct current channel along the gas flow direction; the cross-sectional area of ​​the third gradient region (16) is arc-shaped along the gas flow direction and its diameter gradually decreases; the cross-sectional area of ​​the fourth gradient region (18) is arc-shaped along the gas flow direction and its diameter gradually increases.

9. The metal bipolar plate hydrogen fuel cell according to claim 3, characterized in that: The first end plate (101) is provided with an air inlet (104) communicating with the first through hole (110), an air outlet (105) communicating with the second through hole (120), a hydrogen inlet (106) communicating with the fifth through hole (150), and a hydrogen outlet (107) communicating with the sixth through hole (160); the second end plate (102) is provided with a coolant inlet (108) communicating with the third through hole (130) and a coolant outlet (109) communicating with the fourth through hole (140).

10. The metal bipolar plate hydrogen fuel cell according to claim 1, characterized in that: The first end plate (101) and the second end plate (102) are also fixedly connected by a balance block (1011). The first end plate (101) and the second end plate (102) are provided with symmetrical mounting notches (1012). The two ends of the balance block (1011) are set on the mounting notches (1012) on the first end plate (101) and the second end plate (102) and are flush with the first end plate (101) and the second end plate (102).

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