Bipolar plate with harp-shaped flow field structure in liquid fuel cell and design method thereof

Abstract

The present invention belongs to the technical field of fuel cells, and discloses a bipolar plate with a harp-shaped flow field structure in a liquid fuel cell and a design method. The flow channel structure of the fuel cell adopts the bionic principle, and uses the body shape of a harp-shaped creature to make the flow channels of the anode and cathode plates, so that the fuel and oxidant of the fuel cell are in contact with the membrane electrode over a large area, stabilize the flow of the fuel and oxidant in the flow channel, reduce the flow resistance of the fuel and oxidant in the flow channel, increase the pressure drop, and make the fuel and oxidant evenly distributed on the surface of the membrane electrode. The present invention can solve the problem of improving the performance of fuel cells from a technical principle, provide theoretical and technical support for the commercial application of fuel cells, and accelerate the commercial application of fuel cells. The present invention reduces the flow resistance of the fuel and oxidant in the flow channel, reasonably increases the pressure drop, and promotes the uniform distribution of the fuel and oxidant on the surface of the electrode, thereby improving the performance of the battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and in particular relates to a bipolar plate with a harp-shaped flow field structure in a liquid fuel cell and a design method thereof. Background Art

[0002] Currently, the closest existing technologies are:

[0003] Since the industrial revolution, with the large-scale exploitation and utilization of traditional energy such as fossil energy, energy depletion and environmental pollution problems have begun to emerge one after another, and have become two major challenging issues facing the world today. Scientists from all over the world have begun to devote themselves to the research and development and promotion of green and clean energy to replace traditional energy in order to alleviate the energy crisis and protect the environment. With the development of science and technology, portable electronic products have become popular around the world, but the increasingly short and light appearance of products and the increasingly complex functions have also brought serious challenges to the batteries of electronic products. Existing battery technology can no longer meet the growing energy consumption needs of portable electronic products, and solar energy, wind energy, hydropower, bioenergy, geothermal power generation and other electric energy cannot be used in mobile and portable electronic devices. Therefore, it is urgent to develop new energy and batteries to replace traditional energy and power sources.

[0004] Fuel cells are environmentally friendly and highly efficient power generation devices that can directly convert chemical energy in fuel and oxidant into electrical energy. They are not restricted by the Carnot cycle and have high energy conversion efficiency, are pollution-free to the environment, and can be miniaturized. Therefore, they are favored by scientists from all over the world and have become one of the important energy sources that can replace traditional energy, protect the ecological environment, solve the energy crisis, and be applied to small electronic devices in the 21st century. Therefore, the study of fuel cells has important ecological significance for protecting the ecological environment and has important strategic significance for ensuring the country's energy security.

[0005] Fuel cells consist of an anode containing a catalyst, a cathode and an ion-conducting electrolyte. According to the type of electrolyte, they can be divided into phosphoric acid fuel cells, solid oxide fuels, alkaline fuel cells, molten carbonate fuel cells and proton exchange membrane fuel cells. Proton exchange membrane fuel cells have broad application prospects due to their higher energy conversion rate, greater energy ratio, simple structure, good mobility, durability, environmental friendliness and modularity. They have been recognized as the preferred energy source for electric vehicles, regional power stations, spacecraft and various small mobile devices. According to the type of fuel used, proton exchange membrane fuel cells are divided into two categories: hydrogen fuel cells using hydrogen as fuel and liquid fuel cells using alcohols, acids, etc. as fuel.

[0006] In liquid fuel cells, the bipolar plate is one of the key components of the fuel cell. It is responsible for distributing the fuel and oxidant required by the battery, and its flow field structure characteristics directly affect the performance of the fuel cell. Whether the flow field structure design of the bipolar plate in the fuel cell is reasonable will not only affect the power generation performance of the battery, but also affect the stability, reliability and life of the fuel cell operation. The ideal flow field design of the bipolar plate of the fuel cell should make the fuel in the entire flow field and the oxygen in the air transfer to the electrode uniformly, and can also take out the product water generated by the electrode reaction in time. Otherwise, it will lead to uneven distribution of current density, power density and heat generation of the entire bipolar plate, causing local overheating and water loss, which directly affects the operation performance of the battery. In addition, the design of the bipolar plate groove, from the perspective of gas or liquid distribution alone, the smaller the flow resistance in the groove, the better. The traditional flow field structure of liquid fuel cells mainly includes point flow field, mesh flow field, straight parallel flow field, serpentine flow field and interdigital flow field. Point flow fields are prone to short circuits when fluid passes through the flow field, and the fluid is unevenly distributed, which is not conducive to the discharge of liquid water and will affect battery performance; the mesh flow field has a more uniform fluid distribution, which is conducive to the mass transfer of the reaction gas and reduces concentration polarization, but the anti-corrosion process of the metal mesh is difficult and the resistance drop is relatively high; the interdigitated flow field greatly improves the battery power ratio, enhances the mass transfer capacity of the diffusion layer and the discharge of water in the diffusion layer, but the reactants are unevenly distributed throughout the electrode; the electrolyte flow path in the straight parallel flow channel is shorter and the flow resistance is smaller, but the electrolyte distribution is uneven, which affects the battery performance; the serpentine flow field is currently the most popular flow field structure, and the electrolyte is evenly distributed, but its flow path is longer and the flow resistance is larger, which also has an adverse effect on battery performance.

[0007] Therefore, there is an urgent need to invent a new flow field structure to overcome the defects of the above flow field structure from the working principle.

[0008] In summary, the problems existing in the prior art are:

[0009] (1) In the prior art, the flow field design of the bipolar plate in the fuel cell causes uneven mass transfer of the fuel in the entire flow field and the oxygen in the air to the electrode, and fails to promptly remove the product water generated by the electrode reaction, resulting in uneven distribution of current density, power density and heat generation of the entire bipolar plate, causing local overheating and water loss, which directly affects the operating performance of the battery.

[0010] (2) In the prior art, short circuits are prone to occur in point flow fields when fluid passes through the flow field, and the fluid is unevenly distributed, which is not conducive to the discharge of liquid water and will affect battery performance; the anti-corrosion process of the metal mesh of the mesh flow field fluid is difficult, and the resistance drop is relatively high; the reactants in the interdigitated flow field are unevenly distributed at various locations on the electrode; the electrolyte is unevenly distributed in the straight parallel flow channel, which affects the performance of the battery; the serpentine flow field has a longer flow process and a larger flow resistance, which also has an adverse effect on battery performance.

[0011] Difficulty in solving the above technical problems:

[0012] In order to improve the performance of fuel cells with point flow field, mesh flow field, straight parallel flow field, serpentine flow field and cross-finger flow field structure, the current solution is to optimize the flow field structure parameters to achieve the purpose of improving battery performance. Although the performance of fuel cells can be improved by optimizing the flow field structure, it is very difficult to continue to improve the performance of fuel cells from a technical point of view. Therefore, a new fuel cell flow field structure must be invented to solve the problem of fuel cells being unable to improve performance from a technical principle.

[0013] The significance of solving the above technical problems:

[0014] The present invention can solve the problem of improving the performance of fuel cells from a technical principle, provide theoretical and technical support for the commercial application of fuel cells, and accelerate the commercial application of fuel cells. Summary of the invention

[0015] In view of the problems existing in the prior art, the present invention provides a bipolar plate with a harp-shaped flow field structure in a liquid fuel cell and a design method thereof.

[0016] The present invention is implemented as follows: a design method for a flow field structure bipolar plate, the design method for a flow field structure bipolar plate comprising:

[0017] The flow channel structure of the fuel cell adopts the bionic principle and uses the body shape of a harp-like creature to make the flow channels of the anode and cathode plates, so that the fuel and oxidant of the fuel cell are in contact with the membrane electrode over a large area, stabilizing the flow of the fuel and oxidant in the flow channel, reducing the flow resistance of the fuel and oxidant in the flow channel, increasing the pressure drop, and making the fuel and oxidant evenly distributed on the surface of the membrane electrode.

[0018] Further, when stabilizing the flow of fuel and oxidant in the flow channel, the anode flow channel fuel distribution stabilizer and the cathode flow channel oxidant distribution stabilizer both redistribute the fuel and oxidant, and both force the reactants to convect through the fuel and oxidant diffusion layers, so that the fuel and oxidant are close to the catalyst layer.

[0019] Further, the anode plate and the cathode plate are shaped like a square or a rectangle, and the working area in the middle is shaped like a square or a rectangle;

[0020] The size of the flow channel width, depth, radiation angle, stabilizer and ridge width parameters are designed according to the size and performance of the battery. The flow channel width is 0.5-4.5mm, the flow channel depth is 0.5-2mm, the flow channel ridge width is 0.5-2.5mm, the radiation angle is 30-60°, and the diameter of the stabilizer is 1-10mm; the size of the radiation angle determines the shape of the positive and negative bipolar plates and the shape of the working area in the middle. When the radiation angle is 45°, the shape of the positive and negative bipolar plates and the shape of the working area in the middle is a square; when the radiation angle is an angle other than 45°, the shape of the positive and negative bipolar plates and the shape of the working area in the middle is a rectangle;

[0021] The substrates of the anode plate and cathode plate are polycarbonate plate, polyethylene, organic glass PMMA or stainless steel plate;

[0022] The base materials are polycarbonate sheets, polyethylene and organic glass, and the auxiliary materials are metal plating liquid and carbon nanotubes;

[0023] The base material is stainless steel plate, and the auxiliary materials are silver, platinum or titanium nitride;

[0024] Metal plating solutions include aluminum, titanium, nickel plating solutions and silver plating solutions.

[0025] Another object of the present invention is to provide a flow field structure bipolar plate, the flow field structure bipolar plate comprising an anode plate and a cathode plate; the flow field structures of the anode plate and the cathode plate are harp-shaped;

[0026] The anode plate includes a fuel inflow channel, an anode plate fixing pin hole, a fuel outflow channel outlet, a fuel return branch, a fuel outflow channel, an anode flow channel, an anode flow channel fuel distribution stabilizer and a fuel inflow channel inlet;

[0027] The cathode plate includes an oxidant outflow channel outlet, a cathode channel, an oxidant inflow channel, a cathode channel oxidant distribution stabilizer, an oxidant inflow channel inlet, an oxidant outflow channel, an oxidant reflux branch and a cathode plate pin hole.

[0028] The fuel inlet of the anode plate is connected to the anode channel fuel distribution stabilizer through the fuel inlet channel; the adjacent symmetrical anode channels are connected to the anode channel fuel distribution stabilizer; the fuel outlet is connected to the anode channel fuel distribution stabilizer through the fuel outflow channel; the fuel return branch connects the anode channel fuel distribution stabilizer and the anode channel together; the fixing pin connects the outer shells of multiple anode plates through the anode plate fixing pin hole; the fuel outflow channel transports the fuel to the fuel inlet of the next anode plate;

[0029] The oxidant inflow channel inlet of the cathode plate is connected to the cathode channel oxidant distribution stabilizer through the oxidant inflow channel; the adjacent symmetrical cathode channel is connected to the cathode channel oxidant distribution stabilizer; the oxidant outflow channel outlet is connected to the cathode channel oxidant distribution stabilizer through the oxidant outflow channel; the oxidant reflux branch connects the cathode channel oxidant distribution stabilizer and the cathode channel together;

[0030] The fixing pins connect the outer shells of the plurality of cathode plates through the fixing pin holes of the cathode plates; the oxidant outflow channel transports the oxidant to the oxidant inflow channel inlet of the next cathode plate.

[0031] Furthermore, the bipolar plate fuel distribution stabilizer is the intersection of two adjacent symmetrical flow channels, and its cross section is circular.

[0032] Another object of the present invention is to provide a single cell equipped with the bipolar plate of the flow field structure, the single cell comprising: a fuel cell anode plate, a fuel cell cathode plate, a first membrane electrode fixing plate, a membrane electrode and a second membrane electrode fixing plate; the fuel cell anode plate and the fuel cell cathode plate are harp-shaped;

[0033] The first membrane electrode fixing plate is provided with a first membrane electrode fixing plate front plate and a first membrane electrode fixing plate back plate;

[0034] The second membrane electrode fixing plate is provided with a second membrane electrode fixing plate front plate and a second membrane electrode fixing plate back plate;

[0035] The second membrane electrode fixing plate includes a fifth fixing pin shaft, a sixth fixing pin shaft, a second square through opening, a first fixing pin hole, a second fixing pin hole, and a second membrane electrode fixing opening;

[0036] The first membrane electrode fixing plate comprises a first fixing pin, a second fixing pin, a first membrane electrode fixing opening, a third fixing pin, a first square opening and a fourth fixing pin.

[0037] The membrane electrode is placed between the first membrane electrode fixing plate and the second membrane electrode fixing plate, and is fixed by the second membrane electrode fixing port and the first membrane electrode fixing port; the first membrane electrode fixing plate and the second membrane electrode fixing plate are positioned and connected together by the first fixing pin hole, the second fixing pin hole, the first fixing pin shaft, and the second fixing pin shaft.

[0038] The anode plate is positioned and fixedly connected to the second membrane electrode fixing plate through the anode plate fixing pin hole, the third fixing pin shaft and the fourth fixing pin shaft; the cathode plate is positioned and fixedly connected to the first membrane electrode fixing plate through the cathode plate fixing pin hole, the fifth fixing pin shaft and the sixth fixing pin shaft.

[0039] Furthermore, the second membrane electrode fixing plate and the materials of the second membrane electrode fixing plate are polycarbonate plates, polyethylene and organic glass with insulating functions, and the shape is square or rectangular.

[0040] Another object of the present invention is to provide a green energy vehicle equipped with the single battery.

[0041] Another object of the present invention is to provide a mobile and portable electronic device equipped with the single battery.

[0042] Another object of the present invention is to provide a mobile communication terminal equipped with the single battery.

[0043] In summary, the advantages and positive effects of the present invention are:

[0044] The flow field structure of the cathode and anode plates of the fuel cell designed in the present invention is based on the body shape of the harp-shaped carnivorous sponge on the seabed. It is a new type of battery flow field invented through bionic design of its appearance. The purpose is to enable the fuel and oxidant of the fuel cell to contact the electrodes as much as possible, reduce the flow resistance of the fuel and oxidant in the flow channel, reasonably increase the pressure drop, promote the uniform distribution of the fuel and oxidant on the surface of the electrode, and improve the performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a three-dimensional diagram of the anode plate provided by an embodiment of the present invention.

[0046] Figure 2 It is a plan view of the anode plate provided by an embodiment of the present invention.

[0047] Figure 3 It is a three-dimensional diagram of the cathode plate provided by an embodiment of the present invention.

[0048] Figure 4 It is a plan view of the cathode plate provided by an embodiment of the present invention.

[0049] Figure 5 It is a structural diagram of a single battery provided in an embodiment of the present invention.

[0050] Figure 6 It is a reverse side view of the second membrane electrode fixing pair provided in an embodiment of the present invention.

[0051] Figure 7 It is a front view of the second membrane electrode fixing pair provided in an embodiment of the present invention.

[0052] Figure 8 It is a reverse side view of the first membrane electrode fixing pair provided in an embodiment of the present invention.

[0053] Fig. 9 It is a front view of the first membrane electrode fixing pair provided in an embodiment of the present invention.

[0054] In the figure: 1, anode plate; 2, fuel inflow channel; 3, anode plate fixing pin hole; 4, fuel outflow channel outlet; 5, fuel return branch; 6, fuel outflow channel; 7, anode channel; 8, anode channel fuel distribution stabilizer; 9, fuel inflow channel inlet; 10, cathode plate; 11, oxidant outflow channel outlet; 12, cathode channel; 13, fuel inflow channel; 14, cathode channel oxidant distribution stabilizer; 15, oxidant inflow channel inlet; 16, oxidant outflow channel; 17, oxidant Agent reflux branch; 18, cathode plate fixing pin hole; 19, first membrane electrode fixing plate; 20, membrane electrode; 21, second membrane electrode fixing plate; 22, fifth fixing pin shaft; 23, sixth fixing pin shaft; 24, second square opening; 25, first fixing pin hole; 26, second fixing pin hole; 27, second membrane electrode fixing port; 28, first fixing pin shaft; 29, second fixing pin shaft; 30, first membrane electrode fixing port; 31, third fixing pin shaft; 32, first square opening; 33, fourth fixing pin shaft. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. 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.

[0056] In the prior art, the bipolar plate flow field design in the fuel cell makes the fuel in the entire flow field and the oxygen in the air transfer to the electrode unevenly, and the product water generated by the electrode reaction cannot be taken out in time, resulting in uneven distribution of current density, power density and heat generation of the entire bipolar plate, causing local overheating and water loss, which directly affects the operating performance of the battery. In the prior art, the point flow field is prone to short circuit when the fluid passes through the flow field, and the fluid distribution is uneven, which is not conducive to the discharge of liquid water and affects the battery performance; the anti-corrosion process of the mesh flow field fluid metal mesh is difficult, and the resistance drop is high; the reactants in the cross-finger shape flow field are unevenly distributed at various locations of the electrode; the electrolyte is unevenly distributed in the straight parallel flow channel, which affects the performance of the battery; the serpentine flow field has a longer flow process and greater flow resistance, which also has an adverse effect on the battery performance.

[0057] To solve the above problems, the present invention is described in detail below with reference to the accompanying drawings.

[0058] The design method of the flow field structure bipolar plate provided by the embodiment of the present invention includes:

[0059] The flow channel structure of the fuel cell adopts the bionic principle and uses the body shape of a harp-like creature to make the flow channels of the anode and cathode plates, so that the fuel and oxidant of the fuel cell are in contact with the membrane electrode over a large area, stabilizing the flow of the fuel and oxidant in the flow channel, reducing the flow resistance of the fuel and oxidant in the flow channel, increasing the pressure drop, and making the fuel and oxidant evenly distributed on the surface of the membrane electrode.

[0060] In an embodiment of the present invention, when stabilizing the flow of fuel and oxidant in the flow channel, the anode flow channel fuel distribution stabilizer and the cathode flow channel oxidant distribution stabilizer both redistribute the fuel and oxidant, and both force the reactants to convect through the fuel and oxidant diffusion layers, so that the fuel and oxidant are close to the catalyst layer.

[0061] In the embodiment of the present invention, the anode plate and the cathode plate are shaped like a square or a rectangle, and the working area in the middle is shaped like a square or a rectangle;

[0062] The size of the flow channel width, depth, radiation angle, stabilizer and ridge width parameters are designed according to the size and performance of the battery. The flow channel width is 0.5-4.5mm, the flow channel depth is 0.5-2mm, the flow channel ridge width is 0.5-2.5mm, the radiation angle is 30-60°, and the diameter of the stabilizer is 1-10mm; the size of the radiation angle determines the shape of the positive and negative bipolar plates and the shape of the working area in the middle. When the radiation angle is 45°, the shape of the positive and negative bipolar plates and the shape of the working area in the middle is a square; when the radiation angle is an angle other than 45°, the shape of the positive and negative bipolar plates and the shape of the working area in the middle is a rectangle;

[0063] The substrates of the anode plate and cathode plate are polycarbonate plate, polyethylene, organic glass PMMA or stainless steel plate;

[0064] The base materials are polycarbonate sheets, polyethylene and organic glass, and the auxiliary materials are metal plating liquid and carbon nanotubes;

[0065] The base material is stainless steel plate, and the auxiliary materials are silver, platinum or titanium nitride;

[0066] Metal plating solutions include aluminum, titanium, nickel plating solutions and silver plating solutions.

[0067] The bipolar plate with a harp-shaped flow field structure in the liquid fuel cell provided by the embodiment of the present invention includes an anode plate and a cathode plate, such as Figure 1-Figure 4 shown.

[0068] The anode plate 1 is composed of a fuel inlet channel 2, an anode plate fixing pin hole 3, a fuel outflow channel outlet 4, a fuel return branch 5, a fuel outflow channel 6, an anode channel 7, an anode channel fuel distribution stabilizer 8 and a fuel inlet channel inlet 9.

[0069] The cathode plate 10 is composed of an oxidant outflow channel outlet 11, a cathode channel 12, an oxidant inflow channel 13, a cathode channel oxidant distribution stabilizer 14, an oxidant inflow channel inlet 15, an oxidant outflow channel 16, an oxidant reflux branch 17 and a cathode plate fixing pin hole 18.

[0070] Two adjacent symmetrical flow channels are connected together through a bipolar plate fuel (or oxidant) distribution stabilizer, and the fuel (or oxidant) distribution stabilizer distributes the fuel (or oxidant) to the next set of symmetrical flow channels or fuel (or oxidant) distribution stabilizers;

[0071] The fuel return branch connects the fuel (or oxidant) distribution stabilizer with the flow channel, and returns the fuel (or oxidant) in the fuel (or oxidant) distribution stabilizer closest to the fuel inflow channel and the fuel outflow channel to the flow channel connected thereto, and is discharged through the fuel (or oxidant) outflow channel outlet.

[0072] Specifically, it includes: the fuel inlet 9 of the anode plate 1 is connected to the anode channel fuel distribution stabilizer 8 through the fuel inlet channel 2; the adjacent symmetrical anode channel 7 is connected to the anode channel fuel distribution stabilizer 8; the fuel outflow channel outlet 4 is connected to the anode channel fuel distribution stabilizer 8 through the fuel outflow channel; the fuel return branch 5 connects the anode channel fuel distribution stabilizer 8 and the anode channel 7 together. The fixing pin connects the outer shells of multiple anode plates 1 through the anode plate fixing pin hole 3; the fuel outflow fuel outflow channel 6 transports the fuel to the fuel inlet 9 of the next anode plate 1;

[0073] The oxidant inlet 15 of the cathode plate 10 is connected to the cathode channel oxidant distribution stabilizer 14 through the oxidant inlet channel 13; the adjacent symmetrical cathode channel 12 is connected to the cathode channel oxidant distribution stabilizer 14; the oxidant outlet 11 is connected to the cathode channel oxidant distribution stabilizer 14 through the oxidant outlet channel; the oxidant reflux branch 17 connects the cathode channel oxidant distribution stabilizer 14 and the cathode channel 12 together.

[0074] The fixing pins connect the outer shells of the plurality of cathode plates 10 through the cathode plate fixing pin holes 18 ; the oxidant outflow channel 16 transports the oxidant to the oxidant inflow channel inlet 15 of the next cathode plate 10 .

[0075] The present invention is further described below in conjunction with the working principle.

[0076] The flow field structure of the positive and negative plates of a single cell is harp-shaped. The harp sponge lives at a depth of 10,800-11,500 feet on the seabed. In order to adapt to the harsh deep-sea environment, it has evolved carnivorous characteristics and formed a unique branch-like structure, thereby increasing the body area in contact with the ocean current, allowing the ocean current to flow evenly over its body surface, reducing the resistance to flow, and increasing the probability of capturing prey. The structure of the fuel cell flow channel of the present invention adopts the bionic principle and utilizes the body shape of the harp-shaped organism to form the flow channel of the positive and negative plates. The purpose is to enable the fuel and oxidant of the fuel cell to contact the membrane electrode as much as possible, stabilize the flow of the fuel and oxidant in the flow channel, reduce the flow resistance of the fuel and oxidant in the flow channel, increase the pressure drop, and promote the uniform distribution of the fuel and oxidant on the surface of the membrane electrode to improve the performance of the battery.

[0077] In the embodiment of the present invention, the bipolar plate fuel distribution stabilizer (buffer) is the intersection of two adjacent symmetrical flow channels, and the cross section is circular. The functions of the anode flow channel fuel distribution stabilizer 8 and the cathode flow channel oxidant distribution stabilizer 14 are:

[0078] (1) The function of secondary distribution of fuel and oxidant is to ensure that the fuel and oxidant are stable and evenly distributed in each branch;

[0079] (2) It can increase the forced convection of reactants through the fuel and oxidant diffusion layers, bringing the fuel and oxidant closer to the catalyst layer, accelerating the electrochemical reaction rate and improving battery performance.

[0080] In the embodiment of the present invention, the shape and main parameters of the bipolar plate include:

[0081] The shape of the positive and negative bipolar plates is square or rectangular, and the working area in the middle is also square or rectangular (flow channel area). The main structural parameters include flow channel width (section width), depth, radiation angle, stabilizer (buffer) and ridge width (shoulder width). The size of the parameters is mainly determined by the size and performance of the battery. The specific value range is: flow channel width (section width) is 0, 5-4, 5mm, flow channel depth is 0, 5-2mm, flow channel ridge width (shoulder width) is 0, 5-2, 5mm, radiation angle is 30-60°, and the diameter of the stabilizer (buffer) is 1-10mm. The size of the radiation angle also determines the shape of the positive and negative bipolar plates and the shape of the working area in the middle. When the radiation angle is 45°, the shape of the positive and negative bipolar plates and the shape of the working area in the middle is square, and it is rectangular at other angles.

[0082] In the embodiment of the present invention, the materials used to make the bipolar plates of fuel cells are mainly graphite materials, metal materials and composite materials. Although graphite materials have the advantages of excellent electrical and thermal conductivity, good corrosion resistance and low thermal expansion coefficient, the brittleness of graphite materials causes considerable processing difficulty, which limits the reduction of the thickness of the entire bipolar plate and also increases the weight of the fuel cell; although metal materials have excellent electrical conductivity, good thermal conductivity, high mechanical strength, good air tightness and are easy to process, their surfaces are easily corroded by acidic fuels and must be electroplated with a protective film; composite materials require special processing during processing and have high processing costs. The substrates of the positive and negative plates of the single cell of the present invention are selected from polycarbonate sheets, polyethylene, organic glass (PMMA) or stainless steel sheets. For polycarbonate sheets, polyethylene and organic glass, auxiliary materials are selected from metal plating solutions and carbon nanotubes; for stainless steel plates, auxiliary materials are selected from silver, platinum or titanium nitride. Metal plating solutions include aluminum, titanium, nickel plating solutions and silver plating solutions.

[0083] The present invention is further described below in conjunction with a single cell having a harp-shaped flow field structure.

[0084] The single cell with harp-shaped flow field structure of the present invention is as follows Figure 5 As shown, it is mainly composed of a fuel cell anode plate 1, a fuel cell cathode plate 10, a first membrane electrode fixing plate 19, a membrane electrode 20 and a second membrane electrode fixing plate 21.

[0085] The membrane electrode 20 fixing pair is composed of a second membrane electrode fixing plate 21 and a first membrane electrode fixing plate 19, each fixing plate including a fixing plate front side and a fixing plate back side. The second membrane electrode fixing plate 21 is composed of a fifth fixing pin 22, a sixth fixing pin 23, a second square opening 24, a first fixing pin hole 25, a second fixing pin hole 26, a second membrane electrode fixing opening 27, etc.

[0086] The membrane electrode is placed between the first membrane electrode fixing plate 19 and the second membrane electrode fixing plate 21, and fixed by the second membrane electrode fixing port 27 and the first membrane electrode fixing port; the first membrane electrode fixing plate 19 and the second membrane electrode fixing plate 21 are positioned and connected together by the first fixing pin hole 25, the second fixing pin hole 26, the first fixing pin shaft 28, and the second fixing pin shaft 29.

[0087] The anode plate is positioned and fixedly connected to the second membrane electrode fixing plate 21 through the anode plate fixing pin hole 3, the third fixing pin shaft 31 and the fourth fixing pin shaft 33; the cathode plate is positioned and fixedly connected to the first membrane electrode fixing plate 19 through the cathode plate fixing pin hole 18, the fifth fixing pin shaft 22 and the sixth fixing pin shaft 23.

[0088] The first membrane electrode fixing plate 19 is composed of a first fixing pin 28 , a second fixing pin 29 , a first membrane electrode fixing opening 30 , a third fixing pin 31 , a first square opening 32 and a fourth fixing pin 33 .

[0089] The materials used to make the second membrane electrode fixing plate 21 and the second membrane electrode fixing plate 19 are polycarbonate sheets, polyethylene and organic glass with insulating functions. The thickness is 2mm, the shape is square or rectangular, and the outer dimensions are equal to the dimensions of the anode and cathode plates. A square or rectangular through-hole 24 and 32 are opened in the middle of the membrane electrode fixing pair. The length × width of the through-hole is 2-3mm smaller than the membrane electrode 20. A square or rectangular opening 27 and 30 are opened in the middle of the plane front of the membrane electrode fixing pair. The length × width of the opening is equal to the size of the membrane electrode 20. The depth of the opening is 0.2-0.3mm. On the membrane electrode fixing pair 21, two φ2×0.5mm pin holes are symmetrically opened on the front, and two φ2×0.5mm pin shafts are symmetrically provided on the back. On the first membrane electrode fixing plate 19, two φ2×0.5mm pin shafts are symmetrically provided on the front and back. The pin holes and pin shafts on the two membrane electrode fixing pairs cooperate symmetrically to play the role of fixing, tightening and positioning. See details. Figures 6 to 9 .

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A design method for a flow field structure bipolar plate, characterized in that: The design method of the flow field structure bipolar plate includes: The flow channel structure of the fuel cell adopts the bionic principle, using the body shape of a harp-like creature to make the flow channels of the anode and cathode plates, so that the fuel and oxidant of the fuel cell are in contact with the membrane electrode over a large area, stabilizing the flow of the fuel and oxidant in the flow channel, reducing the flow resistance of the fuel and oxidant in the flow channel, increasing the pressure drop, and making the fuel and oxidant evenly distributed on the surface of the membrane electrode; When stabilizing the flow of fuel and oxidant in the flow channel, the anode flow channel fuel distribution stabilizer and the cathode flow channel oxidant distribution stabilizer both redistribute the fuel and oxidant, and both force the reactants to convect through the fuel and oxidant diffusion layers, so that the fuel and oxidant are close to the catalyst layer; Adjacent symmetrical anode channels are connected to the anode channel fuel distribution stabilizer, and adjacent symmetrical cathode channels are connected to the cathode channel oxidant distribution stabilizer. The bipolar plate fuel distribution stabilizer is the intersection of the two adjacent symmetrical channels, and has a circular cross section.

2. The design method of the flow field structure bipolar plate according to claim 1, characterized in that: The anode plate and cathode plate are square or rectangular in shape, and the working area in the middle is square or rectangular; The size of the flow channel width, depth, radiation angle, stabilizer and ridge width parameters are designed according to the size and performance of the battery. The flow channel width is 0.5-4.5mm, the flow channel depth is 0.5-2mm, the flow channel ridge width is 0.5-2.5mm, the radiation angle is 30-60°, and the diameter of the stabilizer is 1-10mm; the size of the radiation angle determines the shape of the positive and negative bipolar plates and the shape of the middle working area. When the radiation angle is 45°, the shape of the positive and negative bipolar plates and the shape of the middle working area are square; when the radiation angle is an angle other than 45°, the shape of the positive and negative bipolar plates and the shape of the middle working area are rectangular; The substrates of the anode plate and cathode plate are polycarbonate plate, polyethylene, organic glass PMMA or stainless steel plate; The base materials are polycarbonate sheets, polyethylene and organic glass, and the auxiliary materials are metal plating liquid and carbon nanotubes; The base material is stainless steel plate, and the auxiliary materials are silver, platinum or titanium nitride; Metal plating solutions include aluminum, titanium, nickel plating solutions and silver plating solutions.

3. A flow field structure bipolar plate designed using the design method of the flow field structure bipolar plate according to claim 1, characterized in that: The flow field structure bipolar plate comprises an anode plate and a cathode plate; the flow field structures of the anode plate and the cathode plate are harp-shaped; The anode plate includes a fuel inflow channel, an anode plate fixing pin hole, a fuel outflow channel outlet, a fuel return branch, a fuel outflow channel, an anode flow channel, an anode flow channel fuel distribution stabilizer and a fuel inflow channel inlet; The cathode plate includes an oxidant outflow channel outlet, a cathode channel, an oxidant inflow channel, a cathode channel oxidant distribution stabilizer, an oxidant inflow channel inlet, an oxidant outflow channel, an oxidant return branch and a cathode plate pin hole; the fuel inflow channel inlet of the anode plate is connected to the anode channel fuel distribution stabilizer through the fuel inlet channel; the adjacent symmetrical anode channels are connected to the anode channel fuel distribution stabilizer; the fuel outflow channel outlet is connected to the anode channel fuel distribution stabilizer through the fuel outflow channel; the fuel return branch connects the anode channel fuel distribution stabilizer and the anode channel together; the fixing pin connects the outer shells of multiple anode plates through the anode plate fixing pin hole; the fuel outflow channel transports the fuel to the fuel inflow channel inlet of the next anode plate; The oxidant inflow channel inlet of the cathode plate is connected to the cathode channel oxidant distribution stabilizer through the oxidant inflow channel; The adjacent symmetrical cathode flow channels are connected to the cathode flow channel oxidant distribution stabilizer; the oxidant outflow channel outlet is connected to the cathode flow channel oxidant distribution stabilizer through the oxidant outflow channel; the oxidant reflux branch connects the cathode flow channel oxidant distribution stabilizer and the cathode flow channel together; The fixing pins connect the outer shells of the plurality of cathode plates through the fixing pin holes of the cathode plates; the oxidant outflow channel transports the oxidant to the oxidant inflow channel inlet of the next cathode plate.

4. A single cell equipped with the bipolar plate with the flow field structure according to claim 3, characterized in that: The single cell comprises: a fuel cell anode plate, a fuel cell cathode plate, a first membrane electrode fixing plate, a membrane electrode and a second membrane electrode fixing plate; the fuel cell anode plate and the fuel cell cathode plate are in the shape of a harp; The first membrane electrode fixing plate is provided with a first membrane electrode fixing plate front plate and a first membrane electrode fixing plate back plate; The second membrane electrode fixing plate is provided with a second membrane electrode fixing plate front plate and a second membrane electrode fixing plate back plate; The second membrane electrode fixing plate includes a fifth fixing pin shaft, a sixth fixing pin shaft, a second square through opening, a first fixing pin hole, a second fixing pin hole, and a second membrane electrode fixing opening; The first membrane electrode fixing plate comprises a first fixing pin, a second fixing pin, a first membrane electrode fixing opening, a third fixing pin, a first square opening and a fourth fixing pin; The membrane electrode is placed between the first membrane electrode fixing plate and the second membrane electrode fixing plate, and is fixed by the second membrane electrode fixing opening and the first membrane electrode fixing opening; the first membrane electrode fixing plate and the second membrane electrode fixing plate are positioned and connected together by the first fixing pin hole, the second fixing pin hole, the first fixing pin shaft, and the second fixing pin shaft; The anode plate is positioned and fixedly connected to the second membrane electrode fixing plate through the anode plate fixing pin hole, the third fixing pin shaft and the fourth fixing pin shaft; the cathode plate is positioned and fixedly connected to the first membrane electrode fixing plate through the cathode plate fixing pin hole, the fifth fixing pin shaft and the sixth fixing pin shaft.

5. The single cell according to claim 4, characterized in that: The second membrane electrode fixing plate is made of a polycarbonate plate, polyethylene and organic glass with an insulating function, and is square or rectangular in shape.

6. A green energy vehicle equipped with the single battery according to claim 4.

7. A mobile and portable electronic device equipped with the single battery according to claim 4.

8. A mobile communication terminal equipped with the single battery according to claim 4.

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