A high specific power cathode closed air-cooled fuel cell stack

Abstract

The present invention provides a high specific power cathode closed air-cooled fuel cell stack, which includes an air inlet end plate and a current collector insulating plate stacked in sequence; a composite honeycomb cooling fin is arranged between every several single cell module groups, and sealing components are connected to the left and right sides of the composite honeycomb cooling fin; the single cell module group includes an anode single panel, an anode sealing line, a membrane electrode, a cathode sealing line, a bipolar plate, an anode sealing line, a membrane electrode, a cathode sealing line, and a cathode single panel stacked in sequence from the air inlet end plate to the air outlet end plate; a cathode flow field is arranged on the bipolar plate and the cathode single panel, the cathode flow channel of the cathode flow field is a multi-stage branched flow channel, and several diaphragm structures are arranged in the cathode flow channel; the diaphragm structure protrudes along the air flow direction, and a hole is arranged in the middle of the diaphragm structure. The present invention adopts a fin design with high heat dissipation efficiency and a high-efficiency water management flow field structure, which can greatly reduce the temperature difference of the fuel cell stack and improve the specific power of the fuel cell stack.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular, to a high specific power cathode closed air-cooled fuel cell stack. Background Art

[0002] Traditional air-cooled fuel cells mostly have an open cathode structure. The air on the cathode serves as both a reaction gas and a cooling gas. In order to remove the heat generated during the reaction of the fuel cell stack and maintain the operating temperature of the fuel cell stack within an appropriate range, on the one hand, a large amount of air is required for heat dissipation, which also causes an excessive stoichiometric ratio of the cathode during the reaction of the membrane electrode, resulting in excessive dryness of the membrane electrode; on the other hand, the flow rate of the cooling fan is limited, and the heat dissipation efficiency of the open fuel cell stack is limited, and it cannot generate electricity under high current density conditions. In addition, the flow field design of the open cathode structure is limited, and it cannot balance the requirements of gas distribution and cooling heat dissipation, and the uniformity of the battery cannot be guaranteed, and the current density is limited. Therefore, it is difficult to balance the heat dissipation effect and the internal humidity of the open cathode air-cooled fuel cell during high current density discharge, which limits the power generation efficiency and service life of the fuel cell stack.

[0003] The prior art provides a cathode closed air-cooled fuel cell stack. This solution realizes the isolation of the cathode reaction air flow channel and the cooling air flow channel, but there are still two problems of poor thermal consistency and difficult water management, which limit the high performance and long life of the battery.

[0004] In the existing technology, for air-cooled fuel cells with different power levels and area sizes, the temperature difference between the inlet and outlet of the cooling medium air is about 10-20°C. The traditional open air-cooled fuel cell cathode has the same structure as the heat dissipation, and its heat dissipation efficiency is limited. In addition, the large air volume for heat dissipation causes the membrane electrode to dry, making it difficult to maintain high current density discharge, and the power density is limited. The existing closed air-cooled fuel cells are also limited by the heat dissipation efficiency and the water management problem of high current density discharge. Using the design of section-by-section cooling, it is difficult to improve the specific power of the fuel cell stack.

[0005] In view of the problems existing in the thermal consistency of the prior art, the structure of the cooling channel needs to be further optimized to improve the heat dissipation efficiency of the fuel cell stack and enhance the thermal consistency of the fuel cell stack; for the wide temperature range operating conditions of air-cooled fuel cells, the water management of the fuel cell stack is a difficult point. The existing flow field design is difficult to balance low flow resistance, high drainage capacity and efficient heat dissipation, resulting in a decline in battery performance or a shortening of the service life, and there is currently no good solution. Summary of the Invention

[0006] In view of the performance and life problems caused by the difficulties in water and heat management of air-cooled fuel cells mentioned above, a high specific power cathode closed air-cooled fuel cell stack is provided.

[0007] The technical means adopted by the present invention are as follows:

[0008] A high specific power cathode closed air-cooled fuel cell stack, comprising an air inlet end plate, a current collector insulating plate, a plurality of single cell module groups stacked in sequence, and an air outlet end plate; a composite honeycomb cooling fin is arranged between every several single cell module groups, and sealing components are connected to the left and right sides of the composite honeycomb cooling fin;

[0009] Each single cell module group has n single cells, n≥2. Two single cells include an anode single panel, an anode sealing line, a membrane electrode, a cathode sealing line, a bipolar plate, an anode sealing line, a membrane electrode, a cathode sealing line, and a cathode single panel stacked in sequence from the air inlet end plate to the air outlet end plate;

[0010] A cathode flow field is arranged on the bipolar plate and the cathode single panel. The cathode flow channels of the cathode flow field are multi-stage branched flow channels, and several diaphragm structures are arranged in the cathode flow channels; the diaphragm structures bulge along the air flow direction, and a hole is arranged in the middle of the diaphragm structures.

[0011] Further, along the direction of the cathode flow channel, the spacing of the diaphragm structures is distributed in a gradient with sparse in the middle and dense at both ends; the width of the cathode flow channel is proportional to the spacing of the diaphragm structures, and the ratio is 5 to 10 times the width of the cathode flow channel; the diaphragm structures on adjacent cathode flow channels are arranged in a staggered manner.

[0012] Further, the anode single panel is of a rectangular structure. An anode flow field is arranged on the surface of the anode single panel facing the membrane electrode. A cathode air inlet and an anode fuel outlet are arranged at one short side of the anode single panel, and a cathode air outlet and an anode fuel inlet are arranged at the other short side of the anode single panel; the cathode single panel is of a rectangular structure. A cathode flow field is arranged on the surface of the cathode single panel facing the membrane electrode. A cathode air inlet and an anode fuel outlet are arranged at one short side of the cathode single panel, and a cathode air outlet and an anode fuel inlet are arranged at the other short side of the cathode single panel; the bipolar plate is of a rectangular structure. An anode flow field and a cathode flow field are arranged on both sides of the bipolar plate respectively. A cathode air inlet and an anode fuel outlet are arranged at one short side of the bipolar plate, and a cathode air outlet and an anode fuel inlet are arranged at the other short side of the bipolar plate.

[0013] Further, the anode fuel inlet and the anode fuel outlet are arranged diagonally on the rectangular structure, and the cathode air inlet and the cathode air outlet are arranged diagonally on the rectangular structure;

[0014] Fuel enters from the anode fuel inlet and is discharged from the anode fuel outlet; air enters from the cathode air inlet and is discharged from the cathode air outlet; the flow directions of the fuel and the air are opposite, forming a countercurrent.

[0015] Further, the shape of the hole is one of a rectangle, a semicircle, an ellipse or a trapezoid, and the diameter range of the hole is 0.1 to 1.0 mm.

[0016] Furthermore, honeycomb channels are provided through the composite honeycomb cooling fin in the up-and-down direction, and the honeycomb channels are of single-layer honeycomb or honeycomb structure with more than one layer; along the cooling air inlet direction, the number of internal layers of the honeycomb channels gradually increases, and the air flow channels gradually increase.

[0017] Furthermore, the cross-section of the honeycomb channel is one of a circle, an ellipse, a triangle, a trapezoid or a rectangle, and the aperture range of the honeycomb channel is 0.5 mm to 5 mm.

[0018] Furthermore, the material of the composite honeycomb cooling fin is aluminum alloy, titanium alloy or stainless steel, and the surface of the composite honeycomb cooling fin is subjected to surface treatment of gold plating or carbon plating.

[0019] Furthermore, the thickness of the sealed component after compression matches the thickness of the composite honeycomb cooling fin.

[0020] Furthermore, the inlet end plate and the outlet end plate are fixed by disc springs and bolts.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] For the composite honeycomb cooling fin provided by the present invention, in terms of thermal management, the honeycomb structure realizes uniform heat dissipation, and the branched and hierarchical veins accelerate local heat conduction. In terms of mechanical properties, the honeycomb matrix bears the main load, and the branched and hierarchical veins realize stress dispersion, so that the whole fin has both high heat dissipation capacity and sufficient compressive strength.

[0023] In the flow channel of the cathode flow field provided by the present invention, a diaphragm structure is provided, which induces turbulence through local flow resistance change, enhances mass transfer at the interface of the gas diffusion layer, and promotes drainage. Moreover, the diaphragm structures on adjacent flow channels are arranged in a staggered manner to form a staggered mesh bamboo joint arrangement, so as to form a pressure difference between adjacent flow channels, and promote mass transfer and drainage under the ridge of the battery.

[0024] The present invention adopts a fin design with high heat dissipation efficiency and a high-efficiency water management flow field structure, which can greatly reduce the temperature difference of the stack, optimize the water management effect of the stack through water-heat coupling, and a one-to-many thermal management scheme and stack integrated structure can greatly improve the specific power of the stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 This is the explosion diagram of the device of the present invention.

[0027] Figure 2 This is the schematic diagram of the integrated fastening structure of the stack of the present invention.

[0028] Figure 3 This is the schematic diagram of the assembly of multiple single cell groups and honeycomb fins of the present invention.

[0029] Figure 4 This is the structure diagram of the cathode flow field of the present invention.

[0030] Figure 5 This is the structure diagram of the anode flow field of the present invention.

[0031] Figure 6 This is the vertical diagram of the diaphragm of the present invention.

[0032] Figure 7 This is the flat diagram of the diaphragm of the present invention.

[0033] Figure 8 This is the overall structure diagram of the composite honeycomb cooling fin of the present invention.

[0034] Figure 9 This is the schematic diagram of the stepped end face change of the composite honeycomb cooling fin of the present invention.

[0035] In the figure: 1. intake end plate; 2. outlet end plate; 3. current collecting insulating plate; 4. anode single-sided plate; 5. anode sealing line; 6. membrane electrode; 7. cathode sealing line; 8. bipolar plate; 9. cathode single-sided plate; 10. sealing assembly; 11. composite honeycomb cooling fin; 12. bolt; 13. disc spring; 81. cathode air intake port; 82. anode fuel outlet port; 83. anode fuel intake port; 84. cathode air outlet port; 85. diaphragm structure; 86. anode flow field. Detailed implementation manners

[0036] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0037] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way restrictive of the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0038] It should be noted that the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] Unless otherwise specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be construed as limiting the protection scope of the present invention: the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0041] For ease of description, spatial relative terms, such as "above", "over", "on the upper surface", "upper", etc., may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "beneath" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations of the spatial relative descriptions used herein will be made.

[0042] As Figure 1 and Figure 2 shown, the present invention provides a high specific power cathode closed air-cooled fuel cell stack, which includes an intake end plate 1, a current collector insulating plate 3, a plurality of single cell module groups stacked in sequence, and an exhaust end plate 2; a composite honeycomb cooling fin 11 is arranged between every several single cell module groups, and sealing components 10 are connected to the left and right sides of the composite honeycomb cooling fin 11. Adjacent multiple single cell module groups are stacked together by the composite honeycomb cooling fin 11 and the sealing components 10, as Figure 3 shown. The composite honeycomb cooling fin dissipates heat from adjacent multiple single cell modules, and the compression ratio of the sealing component 10 is designed so that the thickness after compression matches the thickness of the composite honeycomb cooling fin.

[0043] Honeycomb channels are arranged vertically through the composite honeycomb cooling fin 11. The honeycomb channels are of a single-layer honeycomb or a honeycomb structure of more than one layer, as Figure 8 and Figure 9 shown; along the cooling air intake direction, the number of internal layers of the honeycomb channels gradually increases, and the air flow channels gradually increase. The cross-section of the honeycomb channels is one of a circle, an ellipse, a triangle, a trapezoid or a rectangle, and the aperture range of the honeycomb channels is 0.5 mm to 5 mm. The material of the composite honeycomb cooling fin 11 is aluminum alloy, titanium alloy or stainless steel, and the surface of the composite honeycomb cooling fin 11 is subjected to surface treatment of gold plating or carbon plating. This is to reduce the contact resistance between the composite honeycomb cooling fin and the electrode plate and play an anti-corrosion role. The composite honeycomb cooling fin 11 can be a single-layer honeycomb, a two-layer honeycomb or a honeycomb fin of more layers. The number of honeycomb layers is determined by the heat dissipation requirements of the fuel cell stack. In terms of thermal management, the honeycomb structure realizes uniform heat dissipation, and the branched and hierarchical veins accelerate local heat conduction. In terms of mechanical properties, the honeycomb matrix bears the main load, and the branched and hierarchical veins realize stress dispersion, enabling the entire fin to have both high heat dissipation capacity and sufficient compressive strength;

[0044] The single battery pack module has n single batteries, where n≥2. Two single batteries include an anode single panel, an anode sealing line, a membrane electrode, a cathode sealing line, a bipolar plate, an anode sealing line, a membrane electrode, a cathode sealing line, and a cathode single panel stacked in sequence from the air inlet end plate to the air outlet end plate;

[0045] A cathode flow field is provided on the bipolar plate 8 and the cathode single panel 9, as Figure 4 shown. The cathode flow field is designed based on bionics, mimicking the fractal structure of the vascular bundles of bamboo stems. The cathode flow channels are designed as multi-stage branched channels, and convex "bamboo node" diaphragm structures 85 are periodically arranged in the channels, as Figure 6 and Figure 7 shown. Turbulence is induced by local flow resistance changes to enhance mass transfer at the gas diffusion layer interface and promote drainage. There are holes in the middle of the bamboo node diaphragm, and the hole shape can be any shape within the diameter range of 0.1~1.0 mm, such as rectangular, semi-circular, elliptical or trapezoidal; for the distribution law of the bamboo node structure, along the flow channel direction, the bamboo node spacing shows a gradient distribution that is sparse in the middle and dense at both ends. Moreover, the wider the flow channel width, the wider the bamboo node spacing, and its ratio is 5~10 times the flow channel width. Also, the diaphragm structures on adjacent flow channels are arranged in a staggered manner to form an interlaced network of bamboo nodes, creating a pressure difference between adjacent flow channels to promote mass transfer and drainage under the ridge of the battery;

[0046] The anode single panel 4 is a rectangular structure, as Figure 5As shown in the figure. On the side of the anode single panel 4 facing the membrane electrode 6, there is an anode flow field 86. At one short side of the anode single panel 4, there are a cathode air inlet 81 and an anode fuel outlet 82. At the other short side of the anode single panel 4, there are a cathode air outlet 84 and an anode fuel inlet 83; the cathode single panel 9 is a rectangular structure. On the side of the cathode single panel 9 facing the membrane electrode 6, there is a cathode flow field. At one short side of the cathode single panel 9, there are a cathode air inlet 81 and an anode fuel outlet 82. At the other short side of the cathode single panel 9, there are a cathode air outlet 84 and an anode fuel inlet 83; the bipolar plate 8 is a rectangular structure. On both sides of the bipolar plate 8, there are an anode flow field 86 and a cathode flow field respectively. At one short side of the bipolar plate 8, there are a cathode air inlet 81 and an anode fuel outlet 82. At the other short side of the bipolar plate 8, there are a cathode air outlet 84 and an anode fuel inlet 83. The anode fuel inlet 83 and the anode fuel outlet 82 are diagonally arranged in the rectangular structure. The cathode air inlet 81 and the cathode air outlet 84 are diagonally arranged in the rectangular structure; the fuel enters from the anode fuel inlet 83 and is discharged from the anode fuel outlet 82; the air enters from the cathode air inlet 81 and is discharged from the cathode air outlet 84; the flow directions of the fuel and the air are opposite, forming a countercurrent. The reaction heat of the stack is transferred from the plates to the composite honeycomb cooling fins, and then the heat is exported by the cooling air passing through the composite honeycomb cooling fins.

[0047] The stack is fastened by the disc springs 13 and bolts 12. The disc springs 13 can compensate for the deformation of the stack during the high and low temperature cycling process, reduce the impact vibration of the stack and the stress attenuation of the elastic components during the high and low temperature cycling process, and ensure the reliability of the stack assembly and fastening.

[0048] In the cathode closed air-cooled fuel cell in the following embodiments, a fin design with high heat dissipation efficiency and a high-efficiency water management flow field structure are adopted, which can greatly reduce the temperature difference of the stack, optimize the water management effect of the stack through water-thermal coupling, and a one-to-many heat management scheme and the stack integrated structure can greatly improve the specific power of the stack.

[0049] Embodiment

[0050] A cathode-closed air-cooled fuel cell stack, comprising an intake end plate 1, an exhaust end plate 2, a current collector insulating plate 3, and a plurality of single cell modules stacked between two current collector insulating plates 3; the single cell modules have two combination modes of 2 single cells and 3 single cells. The 2-single-cell module is stacked by an anode single-sided plate 4, an anode seal line 5, a membrane electrode 6, a cathode seal line 7, a bipolar plate 8, an anode seal line 5, a membrane electrode 6, a cathode seal line 7, and a cathode single-sided plate 9. The 3-single-cell module is stacked by an anode single-sided plate 4, an anode seal line 5, a membrane electrode 6, a cathode seal line 7, a bipolar plate 8, an anode seal line 5, a membrane electrode 6, a cathode seal line 7, a bipolar plate 8, an anode seal line 5, a membrane electrode 6, a cathode seal line 7, and a cathode single-sided plate 9. The plurality of single cell modules are stacked in an alternating order of 3, 2, 3, 2, 3. They are matched by a sealing assembly 10 and a composite honeycomb cooling fin 11. The compression ratio of the sealing assembly 10 is 25%, and the thickness tolerance with the composite honeycomb cooling fin is controlled within ±0.05 mm. The primary pore diameter of the main flow channel of the composite honeycomb cooling fin is 1.3 mm, the secondary pore diameter is 1.0 mm, and the tertiary pore diameter is 0.7 mm. The heat dissipation area is increased by 3-5 times. During the operation of the battery, a fan is installed on one side of the pore channel of the composite honeycomb cooling fin. The composite honeycomb cooling fin combines with a forced convection fan to achieve active-passive composite heat dissipation, and the temperature difference of the single cell < 5°C;

[0051] Meanwhile, in this embodiment, the gas flow channels of the anode and cathode plates are independent of the cooling air flow channels; the cathode flow field adopts a one-into-two hierarchical branch flow channel design. Five diaphragm structures are arranged on each branch flow channel, and the relative positions of adjacent diaphragm structures are staggered with each other, forming a reticular diaphragm structure distribution in the entire flow field area to promote the discharge of liquid water under the ridge, and the drainage efficiency is increased by 38%; the anode fuel enters from the short-side air inlet, and the cathode air enters from the short-side air inlet on the other side. The two flow in a countercurrent direction, and self-balanced humidity control is achieved by using the temperature difference, so that the fluctuation of the water content of the membrane electrode 6 ≤ ±3%;

[0052] In addition, the M3 bolt 12 and the Ф3.2 disc spring 13 used in this embodiment have a pre-tightening force of 5000 N, can compensate for thermal deformation of -30~80°C, and the deformation amount ≤ 0.08 mm, and can ensure that the contact resistance remains stable in a 30 Hz vibration environment (the fluctuation ≤ 1 mΩ·cm 2 )

[0053] The air-cooled fuel cell stack assembled with this structural design has a single-stack specific power of up to 1300 W / kg, and the operating current density is increased to 1500 mA / cm 2 , much higher than the 700 W / kg specific power and 500~600 mA / cm 2 operating current density of conventional open-type air-cooled fuel cell stacks.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A high specific power cathode closed air-cooled fuel cell stack, characterized in that: It includes an air intake end plate, a current collecting insulating plate, a plurality of single battery group modules and an air outlet end plate stacked in sequence; a composite honeycomb cooling fin is arranged between each plurality of single battery group modules, and a sealing component is connected to the left and right sides of the composite honeycomb cooling fin; The composite honeycomb cooling fins are provided with honeycomb channels in the up and down directions, and the honeycomb channels are single-layer honeycomb structures or honeycomb structures with more than single layers; along the cooling air inlet direction, the number of layers inside the honeycomb channels gradually increases, and the airflow channels gradually increase; The single battery module has n single batteries, n≥2, and the two single batteries include an anode single panel, an anode sealing line, a membrane electrode, a cathode sealing line, a bipolar plate, an anode sealing line, a membrane electrode, a cathode sealing line and a cathode single panel stacked in sequence from an air inlet end plate to an air outlet end plate; A cathode flow field is arranged on the bipolar plate and the cathode single plate. The cathode flow channel of the cathode flow field is a multi-stage branch flow channel. A plurality of diaphragm structures are arranged in the cathode flow channel. The diaphragm structure is convex along the air flow direction, and a hole is arranged in the middle of the diaphragm structure. Along the cathode flow channel, the spacing of the diaphragm structures is distributed in a gradient manner, with sparse spacing in the middle and dense spacing at both ends; the width of the cathode flow channel is proportional to the spacing of the diaphragm structures, and the ratio is 5 to 10 times the width of the cathode flow channel; the diaphragm structures on adjacent cathode flow channels are arranged in an alternating manner.

2. The high specific power cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The anode single panel is a rectangular structure, and an anode flow field is arranged on the side of the anode single panel facing the membrane electrode, a cathode air inlet and an anode fuel outlet are arranged on one short side of the anode single panel, and a cathode air outlet and an anode fuel inlet are arranged on the other short side of the anode single panel; the cathode single panel is a rectangular structure, and a cathode flow field is arranged on the side of the cathode single panel facing the membrane electrode, a cathode air inlet and an anode fuel outlet are arranged on one short side of the cathode single panel, and a cathode air outlet and an anode fuel inlet are arranged on the other short side of the cathode single panel; the bipolar plate is a rectangular structure, and an anode flow field and a cathode flow field are respectively arranged on both sides of the bipolar plate, a cathode air inlet and an anode fuel outlet are arranged on one short side of the bipolar plate, and a cathode air outlet and an anode fuel inlet are arranged on the other short side of the bipolar plate.

3. The high specific power cathode closed air-cooled fuel cell stack according to claim 2, characterized in that: The anode fuel inlet and the anode fuel outlet are arranged diagonally on the rectangular structure, and the cathode air inlet and the cathode air outlet are arranged diagonally on the rectangular structure; The fuel enters from the anode fuel inlet and is discharged from the anode fuel outlet; Air enters from the cathode air inlet and is discharged from the cathode air outlet; the flow directions of fuel and air are opposite, forming a countercurrent.

4. The high specific power cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The shape of the hole is one of rectangle, semicircle, ellipse or trapezoid, and the diameter of the hole ranges from 0.1 to 1.0 mm.

5. The high specific power cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The cross section of the honeycomb channel is one of circular, elliptical, triangular, trapezoidal or rectangular, and the aperture range of the honeycomb channel is 0.5mm~5mm.

6. The high specific power cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The material of the composite honeycomb cooling fin is aluminum alloy, titanium alloy or stainless steel, and the surface of the composite honeycomb cooling fin is subjected to gold plating or carbon plating.

7. The high specific power cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The thickness of the sealing component after compression matches the thickness of the composite honeycomb cooling fin.

8. The high specific power cathode closed air-cooled fuel cell stack according to claim 1, characterized in that: The air inlet end plate and the air outlet end plate are fixed by disc springs and bolts.

Images