Closed cathode pure oxygen fuel cell

Abstract

The invention discloses a closed cathode pure oxygen fuel cell, which comprises a fuel cell stack, the fuel cell stack comprises a gas inlet end plate, a positive electrode collector plate arranged close to one side of the gas inlet end plate, a blind end plate and a blind end collector plate arranged close to one side of the blind end plate, and a plurality of stacked bipolar plates and membrane electrode assemblies are arranged between the gas inlet end plate and the blind end plate; the gas inlet end plate is provided with a hydrogen inlet, a hydrogen outlet, an oxygen inlet and an oxygen outlet, the positive electrode collector plate, the bipolar plate and the membrane electrode assembly are provided with an oxygen common channel and a hydrogen common channel, and the bipolar plate is provided with an oxygen flow channel and a hydrogen flow channel; the oxygen inlet and the oxygen outlet are communicated through the oxygen common channel and the oxygen flow channel to form an oxygen flow path; and the hydrogen inlet and the hydrogen outlet are communicated through the hydrogen public channel and the hydrogen flow channel to form a hydrogen flow path. Compared with a traditional fuel cell, the fuel cell provided by the invention has the advantages that the stability and the endurance are greatly improved, and the problem of poor performance of the traditional fuel cell is improved.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, and in particular to a closed cathode pure oxygen fuel cell. Background Art

[0002] In recent years, fuel cells have attracted the attention of many countries due to their high efficiency and pollution-free nature, and have been widely used in many fields. Among them, proton exchange membrane fuel cells have a simple structure, low operating temperature, and fast startup speed, making them the most popular fuel cells on the market. Proton exchange membrane fuel cells are divided into water-cooled stacks and air-cooled stacks according to the cooling method. In the application of power products below 5KW, air-cooled stacks have an absolute advantage. In the power range of 5KW to 10kW, air-cooled stacks are also more suitable for applications with higher lightweight requirements.

[0003] The air-cooled fuel cell in the prior art closes the anode cavity and supplies hydrogen fuel gas through the gas port, while the cathode cavity is open. The surrounding air is driven by the rotation of the fan blades to flow along the guide cover through the cathode flow channel of the stack for oxygen supply and forced convection heat dissipation of the stack. Although the above method can meet the gas supply and heat dissipation required for the fuel cell reaction, the open structure makes it impossible to pressurize the air, and the power density of the fuel cell is low; the air cannot be pre-treated, and the power attenuation is serious in environments such as environmental pollution and low temperature; and the dryness and wetness of the proton exchange membrane cannot be guaranteed. It was found in actual tests that after long-term use or testing, the proton exchange membrane of the fuel cell stack frequently dried out or was flooded, and was greatly affected by adverse factors such as ambient temperature, resulting in limited overall efficiency of the fuel cell.

[0004] In view of this, the existing technology still needs to be improved and enhanced. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a closed cathode pure oxygen fuel cell to solve the problem of poor performance of the fuel cell in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A closed cathode pure oxygen fuel cell, comprising a fuel cell stack, the fuel cell stack comprising an air intake end plate, a positive current collector plate, a blind end current collector plate and a blind end plate, the positive current collector plate being arranged close to one side of the air intake end plate, the blind end current collector plate being arranged close to one side of the blind end plate, and a plurality of bipolar plates and membrane electrode assemblies being stacked between the air intake end plate and the blind end plate;

[0008] The air inlet end plate is provided with a hydrogen inlet, a hydrogen outlet connected to the hydrogen inlet, an oxygen inlet, and an oxygen outlet connected to the oxygen inlet; the positive electrode current collecting plate, the bipolar plate and the membrane electrode assembly are provided with an oxygen common channel and a hydrogen common channel; the bipolar plate is provided with an oxygen flow channel and a hydrogen flow channel; the oxygen common channel and the oxygen flow channel connect the oxygen inlet and the oxygen outlet to form an oxygen flow path; the hydrogen common channel and the hydrogen flow channel connect the hydrogen inlet and the hydrogen outlet to form a hydrogen flow path.

[0009] The bipolar plate includes an anode plate and a cathode plate, the hydrogen flow channel includes an anode hydrogen flow channel arranged on one side of the anode plate, a cooling air flow channel is arranged on the other side of the anode plate, the oxygen flow channel includes a cathode oxygen flow channel arranged on one side of the cathode plate, and the other side of the cathode plate is a plane.

[0010] The anode hydrogen flow channel and the cathode oxygen flow channel are serpentine flow channels, and the flow channel width of the anode hydrogen flow channel and the cathode oxygen flow channel is 0.5-2.5mm, the ridge width is 0.2-2.5mm, the flow channel depth is 0.2-2.5mm, and the flow channel inclination angle θ is 0°-60°.

[0011] The fuel cell stack further comprises a positioning liner, and bipolar plate sealing strips are arranged between the positioning liner and the anode plate and the cathode plate on both sides thereof, and the bipolar plate sealing strips are conductive adhesive.

[0012] The hydrogen flow channel also includes a hydrogen flow channel inlet arranged on the anode plate, which connects the hydrogen common channel with the anode hydrogen flow channel. The oxygen flow channel also includes an oxygen flow channel inlet arranged on the cathode plate, which connects the oxygen common channel with the cathode oxygen flow channel.

[0013] The bipolar plate is a graphite bipolar plate or a metal bipolar plate, and the surface of the bipolar plate is subjected to gold spraying treatment.

[0014] The total heat generated by the fuel cell stack is: Q 总 =n·(1.25VV 平均电压 )I 电堆电流 , where Q 总 is the total heat generated by the fuel cell stack reaction, n is the number of bipolar plates in the fuel cell stack, V 平均电压 is the output voltage of the fuel cell stack, I 电堆电流 is the output current of the fuel cell stack; the water output is: W = V 平均电压 I 电堆电流 / η / Q H2 , where η is the stack efficiency, Q H2 is the calorific value of hydrogen.

[0015] The membrane electrode assembly comprises a proton exchange membrane, and the thickness of the proton exchange membrane is not less than 50 μm.

[0016] The closed cathode pure oxygen fuel cell also includes a screw and a shell, wherein the screw connects the air intake end plate and the blind end plate to fix the fuel cell stack, and the fuel cell stack is mounted on the shell, a cooling fan is arranged on the shell, and the cooling fan is located on the side of the fuel cell pair.

[0017] The oxygen common channel includes an oxygen inlet common channel and an oxygen outlet common channel, and the oxygen inlet common channel and the oxygen outlet common channel are of the same size; the hydrogen common channel includes a hydrogen inlet common channel and a hydrogen outlet common channel, and the hydrogen inlet common channel and the hydrogen outlet common channel are of the same size; the cross-sectional area of ​​the oxygen common channel is greater than the cross-sectional area of ​​the hydrogen common channel.

[0018] Compared with the prior art, the present invention provides a closed cathode pure oxygen fuel cell, comprising a fuel cell stack, wherein the fuel cell stack comprises an air intake end plate, a positive current collector plate, a blind end current collector plate and a blind end plate, wherein the positive current collector plate is arranged close to one side of the air intake end plate, the blind end current collector plate is arranged close to one side of the blind end plate, and a plurality of bipolar plates and membrane electrode assemblies are stacked between the air intake end plate and the blind end plate;

[0019] The air inlet end plate is provided with a hydrogen inlet, a hydrogen outlet connected to the hydrogen inlet, an oxygen inlet, and an oxygen outlet connected to the oxygen inlet. The positive current collecting plate, the bipolar plate and the membrane electrode assembly are provided with an oxygen common channel and a hydrogen common channel. The bipolar plate is provided with an oxygen flow channel and a hydrogen flow channel. The oxygen common channel and the oxygen flow channel connect the oxygen inlet and the oxygen outlet to form an oxygen flow path; the hydrogen common channel and the hydrogen flow channel connect the hydrogen inlet and the hydrogen outlet to form a hydrogen flow path. Compared with traditional fuel cells, the closed cathode pure oxygen fuel cell in this application has greatly improved stability and endurance, which improves the problem of poor performance of traditional fuel cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a cell fuel stack in a closed cathode pure oxygen fuel cell provided by the present invention.

[0021] Figure 2 An exploded view of a cell fuel stack in a closed cathode pure oxygen fuel cell provided by the present invention.

[0022] Figure 3 An exploded view of a bipolar plate in a closed cathode pure oxygen fuel cell provided by the present invention at one angle.

[0023] Figure 4This is an exploded view from another angle of the bipolar plate in the closed cathode pure oxygen fuel cell provided by the present invention.

[0024] Figure 5 This is a schematic structural diagram of the anode plate on the side where the anode hydrogen flow channel is located in the closed cathode pure oxygen fuel cell provided by the present invention.

[0025] Figure 6 This is a schematic structural diagram of the anode plate on the side where the cooling air flow channel is located in the closed cathode pure oxygen fuel cell provided by the present invention.

[0026] Figure 7 This is a schematic structural diagram of the cathode plate on the side where the cathode oxygen flow channel is located in the closed cathode pure oxygen fuel cell provided by the present invention.

[0027] Figure 8 This is a schematic structural diagram of one side of the cathode plate plane in the closed cathode pure oxygen fuel cell provided by the present invention.

[0028] Fig. 9 A cross-sectional view at one angle of a bipolar plate in a closed cathode pure oxygen fuel cell provided by the present invention.

[0029] Fig.10 for Fig. 9 Enlarged view of part A in the middle.

[0030] Fig.11 A cross-sectional view from another angle of the bipolar plate in the closed cathode pure oxygen fuel cell provided by the present invention.

[0031] Fig.12 for Fig.11 Enlarged view of part B in the middle.

[0032] Fig.13 This is a schematic structural diagram of a positioning liner in a closed cathode pure oxygen fuel cell provided by the present invention.

[0033] Fig.14 This is a schematic structural diagram of the closed cathode pure oxygen fuel cell provided by the present invention.

[0034] Fig.15 Test data for existing fuel cells.

[0035] Fig.16 Test data of a closed cathode pure oxygen fuel cell provided for this application.

[0036] Reference Numbers

[0037] Fuel cell stack 1, air intake end plate 11, positive electrode current collecting plate 12, blind end current collecting plate 13, blind end plate 14, hydrogen inlet 15, hydrogen outlet 16, oxygen inlet 17, oxygen outlet 18, bipolar plate 2, anode plate 21, cooling air flow channel 210, first longitudinal groove 211, first transverse groove 212, second longitudinal groove 213, cathode plate 22, third longitudinal groove 221, second transverse groove 222, guide groove 223, membrane electrode assembly 31, positioning liner 32, oxygen inlet common channel 41, oxygen outlet common channel 42, hydrogen inlet common channel 51, hydrogen outlet common channel 52, cathode oxygen flow channel 61, oxygen flow channel inlet 62, oxygen flow channel outlet 63, anode hydrogen flow channel 71, hydrogen flow channel inlet 72, hydrogen flow channel outlet 73, bipolar plate sealing strip 81, sealing strip 82, screw 91, housing 92, cooling fan 93. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] It should be noted that when a component is referred to as being "mounted on", "fixed on" or "disposed on" another component, it may be directly on the other component or there may be a central component at the same time. When a component is referred to as being "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time.

[0040] It should also be noted that the directional terms such as left, right, up, and down in the embodiments of the present invention are merely relative concepts or are based on the normal use status of the product and should not be considered as restrictive.

[0041] The present invention provides a closed cathode pure oxygen fuel cell, see Figure 1-Figure 14 , comprising a fuel cell stack 1, the fuel cell stack 1 comprising an air intake end plate 11, a positive current collector plate 12, a blind end current collector plate 13 and a blind end plate 14, the positive current collector plate 12 is arranged close to one side of the air intake end plate 11, the blind end current collector plate 13 is arranged close to one side of the blind end plate 14, and a plurality of bipolar plates 2 and a membrane electrode assembly 31 are stacked between the air intake end plate 11 and the blind end plate 14;

[0042] The air inlet end plate 11 is provided with a hydrogen inlet 15, a hydrogen outlet 16 connected to the hydrogen inlet 15, an oxygen inlet 17, and an oxygen outlet 18 connected to the oxygen inlet 17. The positive current collector 12, the bipolar plate 2 and the membrane electrode assembly 31 are provided with an oxygen common channel (not marked in the figure) and a hydrogen common channel (not marked in the figure). The bipolar plate 2 is provided with an oxygen flow channel (not marked in the figure) and a hydrogen flow channel (not marked in the figure). The oxygen common channel and the oxygen flow channel connect the oxygen inlet 17 and the oxygen outlet 18 to form an oxygen flow path; the hydrogen common channel and the hydrogen flow channel connect the hydrogen inlet 15 and the hydrogen outlet 16 to form a hydrogen flow path. Compared with traditional fuel cells, the closed cathode pure oxygen fuel cell in the present application has greatly improved stability and endurance, which improves the problem of poor performance of traditional fuel cells.

[0043] For further information, see Figure 2-Figure 13 The oxygen common channel and the hydrogen common channel are through holes on the positive electrode current collecting plate 12, the bipolar plate 2 and the membrane electrode assembly 31. In the embodiment of the present application, the through holes are square holes. The purpose is to guide the oxygen and hydrogen entering the fuel cell stack 1 in a limited space, so that oxygen and hydrogen can quickly enter the oxygen flow channel and the hydrogen flow channel respectively, thereby reducing the start-up time of the reaction and improving the reaction efficiency.

[0044] The oxygen common channel includes an oxygen inlet common channel 41 and an oxygen outlet common channel 42. The oxygen inlet common channel 41 and the oxygen outlet common channel 42 are of the same size. On the one hand, it is conducive to ensuring the relative balance of the flow of the oxygen inlet 17 and the oxygen outlet 18 to ensure the stability of the operation of the fuel cell. On the other hand, it is conducive to the full reaction of the gas and timely removal of the heat generated by the gas reaction. Oxygen enters the fuel cell stack 1 through the oxygen inlet 17 and passes through the oxygen inlet common channel 41, the oxygen flow channel and the oxygen outlet common channel 42 in sequence and then flows out from the oxygen outlet 18. The entire flow process is conducive to increasing the flow path of oxygen. The oxygen flowing through the fuel cell stack 1 provides oxygen to participate in the reaction. At the same time, the reaction tail gas (that is, when the oxygen is output) can take away part of the heat, avoiding the safety hazard of heat accumulation inside the fuel cell.

[0045] The hydrogen common channel includes a hydrogen inlet common channel 51 and a hydrogen outlet common channel 52. The hydrogen inlet common channel 51 and the hydrogen outlet common channel 52 are of the same size, which can balance the flow of hydrogen entering and the discharge of waste gas and waste water, thereby ensuring the stability of the operation of the fuel cell. Hydrogen enters the fuel cell stack 1 through the hydrogen inlet 15 and passes through the hydrogen inlet common channel 51, the hydrogen flow channel and the hydrogen outlet common channel 52 in sequence before flowing out from the hydrogen outlet 16, thereby allowing the hydrogen to react as fully as possible and reducing the waste of hydrogen.

[0046] In the present application, the cross-sectional area of ​​the oxygen common channel is larger than the cross-sectional area of ​​the hydrogen common channel. On the one hand, it can ensure that the incoming oxygen takes away the heat generated by the reaction in time after participating in the reaction, thereby avoiding internal heat accumulation of the fuel cell. On the other hand, it can allow more oxygen to enter the interior of the fuel cell to avoid waste and incomplete combustion of hydrogen and improve reaction efficiency.

[0047] In the embodiment of the present application, the oxygen inlet 17 and the hydrogen outlet 16 are located on the same side of the intake end plate 11, and the oxygen outlet 18 and the hydrogen inlet 15 are located on the same side of the intake end plate 11. This method effectively balances the pressure of the inlet and outlet, making the flow rate of oxygen and hydrogen more uniform. In the present application, the oxygen inlet 17 and the oxygen outlet 18 can also be located on the same side of the intake plate, and similarly, the hydrogen inlet 15 and the hydrogen outlet 16 are located on the same side of the intake plate. The channels and flow channels inside the fuel cell need to be adaptively modified, and the above modifications are foreseeable.

[0048] For further information, see Figure 2 , Fig. 9 and Fig.11 The bipolar plate 2 is a graphite bipolar plate 2 or a metal bipolar plate 2, the metal bipolar plate 2 is stainless steel or titanium, and the surface of the bipolar plate 2 is subjected to gold spraying. A graphite plate or a metal plate is used, and gold spraying is performed on the surface of the bipolar plate 2. On the one hand, a metal conductive layer is formed on the surface of the bipolar plate 2 to improve the conductivity of the bipolar plate 2, thereby reducing the internal resistance of the fuel cell and improving the performance and efficiency of the fuel cell. On the other hand, a corrosion-resistant metal protective layer is formed on the surface of the bipolar plate 2 to reduce the corrosion effect of pure oxygen, thereby increasing the service life of the bipolar plate 2.

[0049] Further, please refer again to Figure 2-Figure 13 The bipolar plate 2 includes an anode plate 21 and a cathode plate 22, the hydrogen flow channel includes an anode hydrogen flow channel 71 arranged on one side of the anode plate 21, a cooling air flow channel 210 is arranged on the other side of the anode plate 21, and the oxygen flow channel includes a cathode oxygen flow channel 61 arranged on one side of the cathode plate 22, and the other side of the cathode plate 22 is a plane.

[0050] The cooling air flow channel 210 on the anode plate 21 of the same bipolar plate 2 is arranged opposite to the plane on the cathode plate 22. The cooling air flow channel 210 is composed of a plurality of parallel guide grooves (not marked in the figure) arranged at equal intervals. The guide grooves are arranged parallel to the short sides of the anode plate 21, and the two ends of the guide grooves are opened for cooling air circulation to achieve uniform heat dissipation of the bipolar plate 2. Furthermore, the setting of the cooling air flow channel 210 enables the fuel cell to use an external cooling fan 93 to blow the air in the cooling air flow channel 210, and take away the reaction heat of the fuel cell through the circulating air, thereby accelerating the discharge of heat in the fuel cell and ensuring that the fuel cell works at the optimal temperature. The setting of the cathode oxygen flow channel 61 guides the subsequent oxygen to enter the bipolar plate 2, thereby improving the reaction efficiency of the fuel cell.

[0051] The hydrogen flow channel also includes a hydrogen flow channel inlet 72 and a hydrogen flow channel outlet 73 arranged on the anode plate 21, the hydrogen flow channel inlet 72 and the hydrogen flow channel outlet 73 are respectively located at two diagonal positions on the anode plate 21, the hydrogen flow channel inlet 72 connects the hydrogen common channel with the anode hydrogen flow channel 71, and the anode hydrogen flow channel 71 is connected to the hydrogen common channel through the hydrogen flow channel outlet 73; the oxygen flow channel also includes an oxygen flow channel inlet 62 and an oxygen flow channel outlet 63 arranged on the cathode plate 22, the oxygen flow channel inlet 62 and the oxygen flow channel outlet 63 are respectively located at two diagonal positions on the cathode plate 22, the oxygen flow channel inlet 62 connects the oxygen common channel with the cathode oxygen flow channel 61, and the cathode oxygen flow channel 61 is connected to the oxygen common channel through the oxygen flow channel outlet 63; the oxygen flow channel inlet 62 guides the oxygen entering the oxygen common channel, so that the oxygen can flow through the inside of the cathode oxygen flow channel 61 through the oxygen flow channel inlet 62, provide the oxygen required for the fuel cell reaction and take away the reaction product water. In the embodiment of the present application, there are 6 oxygen flow channel inlets 62 and 63, and the number of oxygen flow channel inlets 62 can be adaptively adjusted according to the size of the oxygen common channel. For example, the larger the opening of the oxygen common channel, the more oxygen flow channel inlets 62 can be increased, and conversely, the smaller the opening of the oxygen common channel, the less oxygen flow channel inlets 62 can be reduced, thereby ensuring the stability and smoothness of oxygen entering the fuel cell stack 1 and improving the reaction efficiency of the fuel cell. Similarly, in the embodiment of the present application, there are 3 hydrogen flow channel inlets 72 and 73, and the number of hydrogen flow channel inlets 72 can be adaptively adjusted according to the size of the hydrogen common channel.

[0052] The fuel cell stack 1 also includes a positioning liner 32, which is an insulating plastic polymer. A groove (not marked in the figure) is provided on the positioning liner 32 for quickly and accurately stacking the cathode plate 22 and the membrane electrode assembly 31 to ensure the relative position of the membrane electrode assembly 31 and the cathode plate 22. At the same time, it plays a supporting role to ensure that the membrane electrode assembly 31 is compressed to the optimal height without over-pressurization, thereby improving the assembly quality.

[0053] A bipolar plate sealing strip 81 is provided between each positioning liner 32 and the anode plate 21 and cathode plate 22 on both sides thereof. The bipolar plate sealing strip 81 is a conductive adhesive. The bipolar plate sealing strip 81 makes the cathode plate 22 and the anode plate 21 fully fit on both sides of the positioning liner 32, ensuring that oxygen smoothly enters the cathode oxygen flow channel 61 through the oxygen inlet common channel 41 and the oxygen flow channel inlet 62, and ensures that hydrogen smoothly enters the anode hydrogen flow channel 71 through the hydrogen inlet common channel 51 and the hydrogen flow channel inlet 72, thereby avoiding leakage of oxygen and hydrogen during the circulation process; the bipolar plate 2 also includes a sealing strip located on the outside of the anode plate 21 and the cathode plate 22 A membrane electrode assembly 31 is arranged between two adjacent bipolar plates 2, and the two side surfaces of the membrane electrode assembly 31 are sealed respectively by the sealing strip 82 on the anode plate 21 side of one bipolar plate 2 and the sealing strip 82 on the cathode plate 22 side of another adjacent bipolar plate 2 to prevent gas leakage, ensure that oxygen and hydrogen flow along a preset path and react at a preset position, improve reaction efficiency, and avoid waste due to inability to fully react gas; oxygen inlet common channel 41, oxygen outlet common channel 42, hydrogen inlet common channel 51 and hydrogen outlet common channel 52 are also arranged on the bipolar plate sealing strips 81 and the sealing strips 82.

[0054] In the present application, two first longitudinal grooves 211 are arranged on the side where the anode hydrogen flow channel 71 of the anode plate 21 is located, and the two first longitudinal grooves 211 are arranged on both sides of the short side of the anode hydrogen flow channel 71, and two first transverse grooves 212 are connected between the two first longitudinal grooves 211. The first longitudinal grooves 211 and the first transverse grooves 212 are located on the periphery of the anode hydrogen flow channel 71 to install the sealing strip 82 on the outside of the anode plate 21. The sealing strip 82 on the outside of the anode plate 21 is against the oxygen anode on the anode plate 21. The common channel, the hydrogen common channel and the surrounding side of the anode hydrogen flow channel 71 are sealed to prevent hydrogen leakage during the circulation process; two second longitudinal grooves 213 are arranged on the side where the cooling air flow channel 210 of the anode plate 21 is located, for installing the bipolar plate sealing strip 81, and the setting direction of the two second longitudinal grooves 213 is parallel to the setting direction of the cooling air flow channel 210, and the two second longitudinal grooves 213 are located on both sides of the cooling air flow channel 210, and the long side of the cooling air flow channel 210 is flush with the long side of the anode plate 21;

[0055] The width of the second longitudinal groove 213 is greater than that of the first longitudinal groove 211. The purpose is to reserve an opening of the hydrogen flow channel inlet 72 in the spherical region formed by the second longitudinal groove 213. The opening of the hydrogen flow channel inlet 72 is arranged close to the side of the hydrogen inlet common channel 51. On the one hand, the opening of the hydrogen flow channel inlet 72 is close to the hydrogen inlet common channel 51, and hydrogen can be quickly guided to the anode hydrogen flow channel 71 through the hydrogen flow channel inlet 72. On the other hand, the bipolar plate sealing strip 81 is installed in the second longitudinal groove 213 to seal When the hydrogen inlet 15 is connected to the channel periphery, the periphery of one opening of the hydrogen flow channel inlet 72 can also be sealed at the same time; the other opening of the hydrogen flow channel inlet 72 is arranged close to the air inlet port of the anode hydrogen flow channel 71, so that the hydrogen can quickly enter the anode hydrogen flow channel 71 after passing through the hydrogen flow channel inlet 72. Furthermore, the sealing strip 82 on the outside of the anode plate 21 can seal the periphery of the other opening of the hydrogen flow channel inlet 72 while sealing the periphery of the anode hydrogen flow channel 71, ensuring that hydrogen will not leak during the circulation of the anode hydrogen flow channel 71.

[0056] The cooling air flow channel 210 is composed of a plurality of fins (the fins are cubes, and a plurality of cubes are arranged in an equidistant array, and the space between adjacent cubes is a cooling air flow channel 210). In order to allow the hydrogen to smoothly enter an opening of the hydrogen flow channel inlet 72 from the hydrogen inlet common channel 51, there is a height difference between the plane where the opening of the hydrogen flow channel inlet 72 is located and the raised end surface of the fin. The existence of the height difference forms a guiding space between the end surface where the opening of the hydrogen flow channel inlet 72 is located and the plane of the cathode plate 22 when the cathode plate 22 and the anode plate 21 are assembled, so that the hydrogen flow channel 210 can be easily connected to the anode plate 21. The hydrogen enters the guide space through the hydrogen inlet common channel 51, and enters the anode hydrogen flow channel 71 through the hydrogen flow channel inlet 72 under the guidance of an opening of the hydrogen flow channel inlet 72. The above structure is conducive to quickly guiding hydrogen into the anode hydrogen flow channel 71, thereby improving the reaction speed of the fuel cell, and also makes the assembly of the cathode plate 22 and the anode plate 21 tighter, avoiding safety hazards caused by gas leakage; the hydrogen or other products after the reaction in the anode hydrogen flow channel 71 then flow out from the hydrogen flow channel outlet 73, which has the same principle and structure as hydrogen entering the anode hydrogen flow channel 71, and will not be repeated here.

[0057] In the present application, two third longitudinal grooves 221 are arranged on the side where the cathode oxygen flow channel 61 of the cathode plate 22 is located, and the two third longitudinal grooves 221 are relatively arranged on both sides of the short side of the cathode oxygen flow channel 61, and two second transverse grooves 222 are also connected between the two third longitudinal grooves 221. The third longitudinal grooves 221 and the second transverse grooves 222 are located on the periphery of the cathode oxygen flow channel 61 to install the sealing strip 82 on the outside of the cathode plate 22. The sealing strip 82 on the outside of the cathode plate 22 seals the oxygen common channel, the hydrogen common channel and the surrounding side of the cathode oxygen flow channel 61 on the cathode plate 22 to prevent oxygen leakage during the circulation process; the other side of the cathode plate 22 is a plane, and a guide groove 223 is arranged on the side where it is located, and the oxygen flow channel enters An opening of the inlet 62 on one side of the plane of the cathode plate 22 is connected to the guide groove 223, and another opening of the oxygen channel inlet 62 on the side where the cathode oxygen channel 61 is located is connected to the cathode oxygen channel 61. The guide groove 223 can guide oxygen from the oxygen inlet common channel 41 into the oxygen channel inlet 62; further, the other opening of the oxygen channel inlet 62 is arranged close to the air inlet port of the cathode oxygen channel 61, so that oxygen can quickly enter the cathode oxygen channel 61 after passing through the oxygen channel inlet 62. The sealing strip 82 on the outside of the cathode plate 22 can seal the surrounding side of the cathode oxygen channel 61 while also sealing the surrounding side of the other opening of the oxygen channel inlet 62, ensuring that oxygen will not leak during the circulation process on one side of the cathode oxygen channel 61. The oxygen or other products after the reaction in the cathode oxygen channel 61 then flow out from the oxygen channel outlet 63, which has the same principle and structure as oxygen entering the cathode oxygen channel 61, and will not be repeated here. The plane side of the cathode plate 22 in the same bipolar plate 2 is arranged opposite to the cooling air flow channel 210 side of the anode plate 21, and the end face of the cooling air flow channel 210 is in contact with the plane of the cathode plate 22, so as to guide the air to flow through the bipolar plate 2 and reduce the temperature of the fuel cell stack 1 during the reaction process.

[0058] For further information, see Figure 1 , Figure 2 , Figure 5 and Figure 8 , the total heat generated by the fuel cell stack 1 is: Q 总 =n·(1.25VV 平均电压 )I 电堆电流 , where Q 总 is the total heat generated by the reaction of the fuel cell stack 1, n is the number of bipolar plates 2 in the fuel cell stack 1, V 平均电压 is the output voltage of the fuel cell stack 1, I 电堆电流 is the output current of the fuel cell stack 1; the water output is: W = V 平均电压 I 电堆电流 / η / Q H2 , where η is the stack efficiency, Q H2is the calorific value of hydrogen. The anode hydrogen flow channel 71 and the cathode oxygen flow channel 61 are serpentine flow channels, and the flow channel width of the anode hydrogen flow channel 71 and the cathode oxygen flow channel 61 is 0.5-2.5 mm, the ridge width is 0.2-2.5 mm, the flow channel depth is 0.2-2.5 mm, and the flow channel inclination angle θ is 0°-60°. The anode hydrogen flow channel 71 on the anode plate 21 and the cathode oxygen flow channel 61 on the cathode plate 22 are both arranged in a serpentine shape, which guides oxygen and hydrogen to enter the bipolar plate 2, and prolongs the reaction time of both to ensure sufficient reaction. The current density is greatly increased, so that the heat production and water production per unit area increase linearly. In order to facilitate the discharge of water heat, the anode hydrogen flow channel 71 and the cathode oxygen flow channel 61 are set as serpentine flow channels.

[0059] See also Figure 2 , the membrane electrode assembly 31 includes a proton exchange membrane, and the thickness of the proton exchange membrane is not less than 50μm. The membrane electrode assembly 31 includes a proton exchange membrane, a catalyst layer, a diffusion layer and an outer frame. Compared with the existing fuel cell, the thickness of the proton exchange membrane in the present application is not less than 50μm, which can ensure that the proton exchange membrane is less likely to be damaged structurally, reduce the risk of violent hydrogen and oxygen reaction caused by proton exchange membrane damage, and ensure that the leakage value between hydrogen and oxygen during the operation of the fuel cell becomes smaller.

[0060] For further information, see Figure 1 , Figure 6-Figure 14 The closed cathode pure oxygen fuel cell also includes a screw 91 and a shell 92, wherein the screw 91 connects the air intake end plate 11 and the blind end plate 14 to fix the fuel cell stack 1, and the fuel cell stack 1 is mounted on the shell 92, and a cooling fan 93 is provided on the shell 92, and the cooling fan 93 is located on the side of the fuel cell pair.

[0061] The screw 91 passes through the air intake end plate 11, a plurality of positioning linings 32 and the blind end plate 14 to clamp and fix the fuel cell stack 1, minimize the gap between the fuel cell stack 1, and further ensure that the gas fully reacts. In addition, the fuel cell stack 1 is mounted on the housing 92. On the one hand, the housing 92 can position the fuel cell stack 1 as a whole, which is conducive to improving the stability of the overall assembly of the fuel cell stack 1. On the other hand, the cooling fan 93 provided on the housing 92 increases the circulation rate of the air in the cooling air flow channel 210, thereby improving the heat dissipation efficiency of the fuel cell.

[0062] In the present application, oxygen is guided into the cathode oxygen flow channel 61 on the cathode plate 22 through the oxygen inlet 17, the oxygen inlet common channel 41, and the oxygen flow channel inlet 62, and hydrogen is guided into the anode hydrogen flow channel 71 on the anode plate 21 through the hydrogen inlet 15, the hydrogen inlet common channel 51, and the hydrogen flow channel inlet 72. The flow channel on the bipolar plate 2 allows the gas to be evenly distributed on both sides of the membrane electrode assembly 31. Hydrogen and oxygen undergo an electrochemical reaction under the action of the catalyst of the membrane electrode assembly 31, and the generated electrical energy is transmitted to the load through the positive electrode current collecting plate 12 and the blind end current collecting plate 13 at both ends of the fuel cell.

[0063] The current density of the closed cathode pure oxygen stack in this application can be greatly improved compared to the current density of the traditional air-cooled stack. At the same time, because the catalyst is not in contact with the air, the stability and durability of the stack are greatly improved. During the 100-hour test time, no obvious power attenuation was observed. Therefore, this product shows good performance in extreme environments, especially suitable for long-endurance power supply and high-stability power supply scenarios, so it has good application value in the fields of long-endurance drones, yachts, etc.

[0064] Fig.15 The test data of the fuel cell in the prior art, the rated power of the fuel cell stack is 50W, with 24 bipolar plates, Fig.16 These are the test data for the closed cathode pure oxygen fuel cell in this application, with a stack rated power of 600W and 13 bipolar plates.

[0065] In summary, the present invention provides a closed cathode pure oxygen fuel cell, including a fuel cell stack, wherein the fuel cell stack includes an air intake end plate, a positive current collector plate, a blind end current collector plate and a blind end plate, wherein the positive current collector plate is arranged close to one side of the air intake end plate, the blind end current collector plate is arranged close to one side of the blind end plate, and a plurality of bipolar plates and membrane electrode assemblies are stacked between the air intake end plate and the blind end plate;

[0066] The air inlet end plate is provided with a hydrogen inlet, a hydrogen outlet connected to the hydrogen inlet, an oxygen inlet, and an oxygen outlet connected to the oxygen inlet. The positive current collecting plate, the bipolar plate and the membrane electrode assembly are provided with an oxygen common channel and a hydrogen common channel. The bipolar plate is provided with an oxygen flow channel and a hydrogen flow channel. The oxygen common channel and the oxygen flow channel connect the oxygen inlet and the oxygen outlet to form an oxygen flow path; the hydrogen common channel and the hydrogen flow channel connect the hydrogen inlet and the hydrogen outlet to form a hydrogen flow path. Compared with traditional fuel cells, the closed cathode pure oxygen fuel cell in this application has greatly improved stability and endurance, which improves the problem of poor performance of traditional fuel cells.

[0067] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A closed cathode pure oxygen fuel cell, characterized in that: The fuel cell stack includes an air intake end plate, a positive current collector plate, a blind end current collector plate and a blind end plate, wherein the positive current collector plate is arranged close to one side of the air intake end plate, the blind end current collector plate is arranged close to one side of the blind end plate, and a plurality of bipolar plates and membrane electrode assemblies are stacked between the air intake end plate and the blind end plate; The air inlet end plate is provided with a hydrogen inlet, a hydrogen outlet connected to the hydrogen inlet, an oxygen inlet, and an oxygen outlet connected to the oxygen inlet; the positive electrode current collecting plate, the bipolar plate and the membrane electrode assembly are provided with an oxygen common channel and a hydrogen common channel; the bipolar plate is provided with an oxygen flow channel and a hydrogen flow channel; the oxygen common channel and the oxygen flow channel connect the oxygen inlet and the oxygen outlet to form an oxygen flow path; the hydrogen common channel and the hydrogen flow channel connect the hydrogen inlet and the hydrogen outlet to form a hydrogen flow path.

2. The closed cathode pure oxygen fuel cell according to claim 1, characterized in that: The bipolar plate includes an anode plate and a cathode plate, the hydrogen flow channel includes an anode hydrogen flow channel arranged on one side of the anode plate, a cooling air flow channel is arranged on the other side of the anode plate, the oxygen flow channel includes a cathode oxygen flow channel arranged on one side of the cathode plate, and the other side of the cathode plate is a plane.

3. The closed cathode pure oxygen fuel cell according to claim 2, characterized in that: The anode hydrogen flow channel and the cathode oxygen flow channel are serpentine flow channels, and the flow channel width of the anode hydrogen flow channel and the cathode oxygen flow channel is 0.5-2.5mm, the ridge width is 0.2-2.5mm, the flow channel depth is 0.2-2.5mm, and the flow channel inclination angle θ is 0°-60°.

4. The closed cathode pure oxygen fuel cell according to claim 2, characterized in that: The fuel cell stack further comprises a positioning liner, and bipolar plate sealing strips are arranged between the positioning liner and the anode plate and the cathode plate on both sides thereof, and the bipolar plate sealing strips are conductive adhesive.

5. The closed cathode pure oxygen fuel cell according to claim 2, characterized in that: The hydrogen flow channel also includes a hydrogen flow channel inlet arranged on the anode plate, which connects the hydrogen common channel with the anode hydrogen flow channel. The oxygen flow channel also includes an oxygen flow channel inlet arranged on the cathode plate, which connects the oxygen common channel with the cathode oxygen flow channel.

6. The closed cathode pure oxygen fuel cell according to claim 1, characterized in that: The bipolar plate is a graphite bipolar plate or a metal bipolar plate, and the surface of the bipolar plate is subjected to gold spraying treatment.

7. The closed cathode pure oxygen fuel cell according to claim 1, characterized in that: The total heat generated by the fuel cell stack is: Q 总 =n·(1.25VV 平均电压 )I 电堆电流 , where Q 总 is the total heat generated by the fuel cell stack reaction, n is the number of bipolar plates in the fuel cell stack, V 平均电压 is the output voltage of the fuel cell stack, I 电堆电流 is the output current of the fuel cell stack; the water output is: W = V 平均电压 I 电堆电流 / η / Q H2 , where η is the stack efficiency, Q H2 is the calorific value of hydrogen.

8. The closed cathode pure oxygen fuel cell according to claim 1, characterized in that: The membrane electrode assembly comprises a proton exchange membrane, and the thickness of the proton exchange membrane is not less than 50 μm.

9. The closed cathode pure oxygen fuel cell according to claim 1, characterized in that: It also includes a screw and a shell, wherein the screw connects the air intake end plate and the blind end plate to fix the fuel cell stack, and the fuel cell stack is mounted on the shell, a cooling fan is arranged on the shell, and the cooling fan is located on the side of the fuel cell pair.

10. The closed cathode pure oxygen fuel cell according to claim 1, characterized in that: The oxygen common channel includes an oxygen inlet common channel and an oxygen outlet common channel, and the oxygen inlet common channel and the oxygen outlet common channel are of the same size; the hydrogen common channel includes a hydrogen inlet common channel and a hydrogen outlet common channel, and the hydrogen inlet common channel and the hydrogen outlet common channel are of the same size; the cross-sectional area of ​​the oxygen common channel is greater than the cross-sectional area of ​​the hydrogen common channel.

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