Liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell integrated with porous titanium water transport plate and method

Abstract

The application discloses a liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell integrated with a porous titanium water transfer plate and a method. The cell comprises, from top to bottom, an anode end plate, an anode plate, a membrane electrode, a cathode composite plate and a cathode end plate which are tightly stacked in sequence. The cathode composite plate is provided with a porous titanium water transfer plate for water transfer. The porous titanium water transfer plate is provided with a symmetrical cathode flow field for uniform distribution and discharge of reaction gas. Liquid water is generated through the cathode composite plate, the porous titanium water transfer plate and the cathode flow field and is reversely diffused to maintain the humidity of the membrane electrode. The application integrates the porous titanium water transfer plate in the single cell, realizes the cathode water flooding alleviation and the membrane electrode humidity maintenance through autonomous water management, meets the requirements of the single cell compactness, high air tightness and high power density in a water-tight environment, and significantly improves the working condition adaptability and working stability of the fuel cell.

Description

Technical Field

[0001] This invention relates to a single-cell structure in the field of underwater fuel cell technology, and more particularly to a proton exchange membrane fuel cell structure and method based on a porous titanium water transport plate. Background Technology

[0002] Since the beginning of the 21st century, the energy crisis and environmental degradation have intensified. Dual-carbon policies have driven the transformation of social development towards green and low-carbon practices. Hydrogen energy, as a clean energy source with zero emissions, high calorific value, and wide availability, has become an ideal alternative to fossil fuels. Proton exchange membrane fuel cells, due to their advantages of low operating temperature, high power density, and rapid start-stop, are widely used in underwater unmanned equipment, aerospace, and new energy vehicles. Among these, underwater fuel cells, with their high fuel efficiency, have become the core choice for powering underwater confined environments.

[0003] Underwater, fuel cell systems cannot obtain air from the environment, so they use pure oxygen as the oxidant. These systems typically employ a dead-end anode-cathode strategy, resulting in almost zero gas flow at the cell outlet, which greatly improves fuel and oxidant utilization. However, this presents a challenge: low-speed pure oxygen cannot blow away droplets at the interface between the flow channel and the gas diffusion layer, causing liquid to accumulate at this interface, leading to severe overflow problems and rapid performance degradation.

[0004] To address the water management requirements of underwater fuel cell systems, there is an urgent need to design an integrated and compact single-cell internal structure that can mitigate cathode flooding and maintain membrane electrode humidity through autonomous water management, while simultaneously meeting the requirements for airtightness, corrosion resistance, and low energy consumption in underwater confined environments. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes a liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell and method integrating a porous titanium water transport plate. Based on the single-cell structure of the fuel cell with the porous titanium water transport plate, the invention achieves a bidirectional function of autonomous drainage of the cathode and autonomous humidification of the membrane electrode by integrating a hydrophilic porous titanium water transport plate inside the single cell.

[0006] The technical solution adopted in this invention is: I. A liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate: It includes a positive electrode plate, an anode plate, a membrane electrode, a cathode composite plate, and a cathode plate that are stacked tightly in sequence from top to bottom; an anode insulating sheet and an anode current collector are stacked in sequence between the positive electrode plate and the anode plate from top to bottom, and a cathode current collector and a cathode insulating sheet are stacked in sequence between the cathode composite plate and the cathode plate from top to bottom. The cathode composite plate is equipped with a porous titanium water transport plate for water conveyance, and the porous titanium water transport plate is provided with a symmetrically arranged cathode flow field for uniform distribution and discharge of reaction gas.

[0007] Heating holes are provided on the sides of both the anode and cathode end plates, and heating rods are installed in the heating holes. Temperature measuring holes are provided on the sides of both the anode and cathode composite plates, and thermocouples are installed in the temperature measuring holes.

[0008] The cathode composite plate mainly consists of a porous titanium water transport plate, a cathode cooling plate, and a cooling chamber cover plate. The top surface of the cathode cooling plate has a groove, which is sequentially divided into three parts along the flow direction: an inlet distribution area, a main reaction area, and an outlet confluence area. The bottom of the groove where the main reaction area is located has a strip-shaped through-groove group, and the bottom surface of the grooves where the inlet distribution area and the outlet confluence area are located has a set of oblique strip protrusions. The porous titanium water transport plate is placed on the groove of the cathode cooling plate and covers the main reaction area. The bottom surface of the cathode cooling plate has a cavity as a cooling chamber, which is connected to the groove through the strip-shaped through-groove group. The bottom of the cavity is sealed with a cooling chamber cover plate.

[0009] The cathode cooling plate of the cathode composite plate has oxygen inlet and outlet holes on both sides, which are connected to the groove through the internal channel of the cathode cooling plate; the cathode cooling plate of the cathode composite plate has cooling water inlet and outlet holes on both sides, which are connected to the cooling chamber through the internal channel of the cathode cooling plate.

[0010] The main reaction zone consists of multiple parallel strip channels evenly spaced along the flow direction on the surface of the cathode cooling plate, with each strip channel arranged along the flow direction. The inlet distribution zone and outlet confluence zone consist of multiple parallel oblique protrusions evenly spaced along the flow direction on the surface of the cathode cooling plate, with each oblique protrusion arranged at an angle not parallel to the flow direction. The bottom surface of the porous titanium water transfer plate is flat, and the top surface is provided with a strip protrusion group, which consists of multiple parallel strip protrusions evenly spaced along the flow direction, with each strip protrusion arranged along the flow direction. The gaps between all adjacent strip protrusions form parallel flow channels toward the membrane electrode, and all parallel flow channels constitute the main reaction zone.

[0011] The anode plate has parallel flow channels on the surface facing the membrane electrode to form an anode flow field. The layout of the anode flow field is the same as that of the cathode flow field, which is also composed of three parts: an inlet distribution area, a main reaction area, and an outlet confluence area. Hydrogen inlet and outlet holes are opened on both sides of the anode plate, and the hydrogen inlet and outlet holes on both sides are respectively connected to the anode flow field.

[0012] The porous titanium water transport plate is made of hydrophilic porous titanium sheet formed by powder sintering.

[0013] The cathode cooling plate has a cathode sealing ring on the outer edge of the groove for sealing connection with the bottom surface of the membrane electrode. The bottom surface of the porous titanium water transfer plate and the main reaction area of ​​the cathode cooling plate are sealed and connected by a cooling chamber sealing ring, so that the cooling chamber is not directly connected to the groove, but is connected to the groove through the porous titanium water transfer plate. The cooling chamber cover plate and the surrounding wall of the cooling water cavity are sealed and connected by a cooling chamber cover plate sealing ring.

[0014] The membrane electrode is mainly composed of an anode diffusion layer, an anode PET frame, a catalyst-coated proton exchange membrane, a cathode PET membrane, and a cathode diffusion layer connected sequentially from top to bottom; The anode PET frame, cathode PET film, and cathode diffusion layer are all annular shapes with a hollowed-out slot in the middle. The size of the anode diffusion layer and the cathode diffusion layer is larger than the hollowed-out slot in the anode PET frame and the hollowed-out slot in the cathode PET film, respectively. The catalyst loading area of ​​the catalyst-coated proton exchange membrane is smaller than the inner frame of the anode PET frame; thermosetting adhesive is provided at the edges of the catalyst-coated proton exchange membrane, the anode PET frame, and the cathode PET membrane.

[0015] II. A liquid-cooled hydrogen-oxygen proton exchange method for a liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell, the method comprising: S1. Initially, cooling water is introduced into the cooling chamber of the cathode composite plate. The cooling water circulates through the cooling chamber, and the porous titanium water transport plate of the cathode composite plate originally contains water. S2. Hydrogen gas is introduced into the anode flow field of the anode plate. The hydrogen gas is distributed through the anode flow field and reaches the anode catalyst layer to undergo an oxidation reaction to generate hydrogen ions. The hydrogen ions migrate through the proton exchange membrane in the membrane electrode to the cathode catalyst layer and react with oxygen to generate liquid water. S3. At the same time, oxygen is introduced into the groove of the cathode composite plate. Under the action of the cathode flow field in the groove, hydrogen ions and oxygen are fully mixed to produce oxygen and react to generate liquid water and generate heat. The liquid water is adsorbed by the pores of the hydrophilic porous titanium water transport plate under capillary action. S4. The generated liquid water is directionally transported to the cooling chamber through the pores of the porous titanium water transfer plate under the pressure difference between the cathode flow field and the cooling chamber, thereby continuously draining the cathode-generated water. Part of the water in the cooling water vaporizes to form water vapor, which is driven by the concentration gradient and diffuses in the opposite direction to the cathode flow field through the pores of the water transfer plate, thereby achieving effective humidification of the membrane electrode.

[0016] The single cell of this invention is mainly composed of an anode plate, an anode electrode, a membrane electrode, a porous titanium water transport plate, a cathode composite plate, and a cathode plate bonded together from top to bottom. The porous titanium water transport plate is a porous titanium sheet that has undergone hydrophilic treatment and is sandwiched between the cathode composite plate and the membrane electrode. Under the combined action of pressure difference and capillary pressure, it can realize the passive discharge of liquid water from the cathode reaction chamber to the cooling chamber and the bidirectional transfer of water vapor from the cooling chamber to the cathode reaction chamber through autonomous humidification.

[0017] This invention integrates a porous titanium water transport plate inside a single cell, and achieves cathode flooding mitigation and membrane electrode humidity maintenance through autonomous water management. This meets the requirements of compactness, high airtightness, and high power density of single cells in underwater sealed environments, and significantly improves the adaptability and operational stability of fuel cells.

[0018] The beneficial effects of this invention are: 1) The integrated hydrophilic porous titanium water transfer plate enables passive drainage of the cathode at 100%RH, significantly extending the working time in dead-end mode; it also enables autonomous humidification at 0%RH, avoiding performance degradation at low humidity and breaking through the limitations of traditional single-function water management.

[0019] 2) Water management is achieved through the optimization of the internal structure of a single cell, eliminating the need for additional external gas-liquid separators, humidifiers and other components, which greatly simplifies the system structure, reduces parasitic energy consumption, and meets the core requirements of "compact and low power consumption" for closed environments such as underwater and aerospace.

[0020] 3) The present invention adopts a parallel flow channel design to reduce the processing difficulty of bipolar plates; the porous titanium water transport plate is prepared by powder sintering process, which has strong parameter controllability, is compatible with existing fuel cell manufacturing processes, and is convenient for large-scale production and engineering application.

[0021] 4) After hydrophilic treatment, the porous titanium water transfer plate has good hydrophilicity and stability. The titanium material has excellent corrosion resistance, mechanical strength and thermal and electrical conductivity, and can adapt to extreme working conditions. Attached Figure Description

[0022] Figure 1 This is an isometric exploded view of the single cell of the present invention.

[0023] Figure 2 This is an isometric exploded view of the cathode composite plate of the present invention.

[0024] Figure 3 This is a front view of the cathode composite plate of the present invention.

[0025] Figure 4 This is a cross-sectional view of the cathode composite electrode plate of the present invention.

[0026] Figure 5 This is a front view of the anode plate of the present invention.

[0027] Figure 6 This is an isometric view of the cathode cooling plate of the present invention.

[0028] Figure 7 This is an isometric exploded view of the membrane electrode of the present invention.

[0029] The figure shows: 1. Anode end plate, 2. Heating hole, 3. Anode insulating sheet, 4. Anode current collector, 5. Anode electrode plate, 6. Temperature measuring hole, 7. Membrane electrode, 8. Cathode composite electrode plate, 9. Cathode current collector, 10. Cathode insulating sheet, 11. Positioning pin, 12. Cathode end plate, 13. Cathode sealing ring, 14. Porous titanium water transport plate, 15. Cathode cooling plate, 16. Cooling chamber sealing ring, 17. Oxygen inlet / outlet, 18. Cooling water inlet / outlet, 19. Cooling cover sealing ring, 20. Cooling chamber cover, 21. Inlet distribution area, 22. Main reaction area, 23. Outlet confluence area, 24. Cathode flow field, 25. Cooling chamber, 26. Anode flow field, 27. Anode diffusion layer, 28. Anode PET frame, 29. Catalyst-coated proton exchange membrane, 30. 31. Thermosetting adhesive; 32. Cathode PET film; 33. Cathode diffusion layer. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] like Figure 1 As shown, the battery structure includes an anode plate 1, an anode plate 5, a membrane electrode 7, a cathode composite plate 8, and a cathode plate 12, which are stacked tightly from top to bottom. An anode insulating sheet 3 and an anode current collector 4 are stacked between the anode plate 1 and the anode plate 5 from top to bottom. A cathode current collector 9 and a cathode insulating sheet 10 are stacked between the cathode composite plate 8 and the cathode plate 12 from top to bottom. The membrane electrode 7 is arranged between the anode plate 5 and the cathode composite plate 8. All components are sealed together by sealing rings.

[0032] The cathode composite plate 8 is equipped with a porous titanium water transport plate 14 for water conveyance. The porous titanium water transport plate 14 is provided with a symmetrically arranged cathode flow field 24 for uniform distribution and discharge of reaction gas. Through the porous titanium water transport plate 14, the liquid water generated by the cathode is discharged to the cooling chamber under the action of capillary action and pressure difference. At the same time, its porous structure is used to realize the reverse evaporation and humidification of coolant under low humidity conditions, which has the innovative feature of realizing the dual functions of passive drainage and autonomous humidification by using this structure.

[0033] Furthermore, positioning pins 11 perpendicular to the upper surface of the cathode end plate 12 are vertically installed at both opposite corners of the cathode end plate 12, so that the anode end plate 1, anode insulating sheet 3, anode current collector 4, anode electrode plate 5, membrane electrode 7, cathode composite electrode plate 8, cathode current collector 9, and cathode insulating sheet 10 are all tightly fixed to the cathode end plate 12 in sequence through the pin holes opened at their two opposite corners.

[0034] In practice, each of the anode end plate 1, anode insulating sheet 3, anode current collector 4, anode electrode 5, membrane electrode 7, cathode composite electrode 8, cathode current collector 9, and cathode insulating sheet 10 has a matching pin hole at its diagonal position. Each component is precisely positioned in the horizontal direction by the cooperation of the positioning pin 11 and the pin hole, ensuring the coaxiality and sealing of the single cell assembly. After assembly, a clamping pressure of 1.4 MPa is applied by an external clamping device to ensure that the contact resistance of each contact layer meets the conductivity requirements.

[0035] Heating holes 2 are provided on the sides of both the anode plate 1 and the cathode plate 12, and heating rods are installed in the heating holes 2. Temperature measuring holes 6 are provided on the sides of both the anode plate 5 and the cathode composite plate 8, and thermocouples are installed in the temperature measuring holes 6. The thermocouples and heating rods are used to detect the internal temperature of the battery and to heat the overall temperature of the battery, respectively.

[0036] like Figure 2 As shown, the cathode composite plate 8 is mainly composed of a porous titanium water transport plate 14, a cathode cooling plate 15, and a cooling chamber cover plate 20, which are tightly bonded together from top to bottom; the top surface of the cathode cooling plate 15 has a groove, such as... Figure 2 As shown, the groove is sequentially divided into three parts along the flow direction: an inlet distribution area 21, a main reaction area 22, and an outlet confluence area 23. A strip-shaped through-groove group is provided at the bottom of the groove where the main reaction area 22 is located. An oblique strip protrusion group is provided on the bottom surface of the groove where the inlet distribution area 21 and the outlet confluence area 23 are located. The porous titanium water transfer plate 14 is placed on the groove of the cathode cooling plate 15 and only covers the main reaction area 22. A cavity is provided on the bottom surface of the cathode cooling plate 15 as a cooling chamber 25. The cooling chamber 25 is connected to the groove through the strip-shaped through-groove group. A cooling chamber cover plate 20 is installed at the bottom of the cavity for sealing.

[0037] The cooling chamber is formed by the cooling chamber cover plate 20, the porous titanium water transfer plate 14, and the cathode cooling plate 15. The porous titanium water transfer plate 14 is a porous titanium structure formed by powder sintering and is sandwiched between the cathode cooling plate 15 and the membrane electrode 7.

[0038] The cathode cooling plate 15 of the cathode composite plate 8 has oxygen inlet and outlet holes 17 on both sides. The two oxygen inlet and outlet holes 17 on both sides are used for oxygen inflow and outflow, respectively. The oxygen inlet and outlet holes 17 on both sides are connected to the groove after passing through the channel inside the cathode cooling plate 15. The cathode cooling plate 15 of the cathode composite plate 8 has cooling water inlet and outlet holes 18 on both sides. The two cooling water inlet and outlet holes 18 on both sides are used for the inflow and outflow of cooling water, respectively. The cooling water inlet and outlet holes 18 on both sides are connected to the cooling chamber after passing through the channel inside the cathode cooling plate 15.

[0039] like Figure 6 As shown, the main reaction zone 22 is composed of multiple parallel strip channels evenly distributed on the surface of the cathode cooling plate 15 along the perpendicular flow direction, with each strip channel arranged parallel to the flow direction. like Figure 3 and Figure 5 As shown, the inclined strip protrusion group of the inlet distribution area 21 and the outlet confluence area 23 is mainly composed of multiple parallel inclined strip protrusions evenly distributed at intervals along the perpendicular flow direction on the surface of the cathode cooling plate 15, and each inclined strip protrusion is inclined at an angle along a direction that is not parallel to the flow direction. like Figure 2 As shown, the bottom surface of the porous titanium water transfer plate 14 is a plane, and the top surface is fixedly provided with a strip protrusion group. The strip protrusion group is mainly composed of multiple parallel strip protrusions evenly distributed along the perpendicular flow direction. Each strip protrusion is arranged parallel to the flow direction. The gap between all adjacent strip protrusions forms a parallel flow channel toward the membrane electrode 7. All parallel flow channels form the main reaction zone 22.

[0040] like Figure 2 and Figure 3 As shown, a cathode flow field 24 with parallel flow channels is formed on the side surface of the porous titanium water transport plate 14 facing the membrane electrode 7. It mainly consists of three parts: the inlet distribution area 21, the main reaction area 22, and the outlet confluence area 23. The overall layout is symmetrical to achieve uniform distribution and efficient discharge of the reaction gas.

[0041] like Figure 5 As shown, parallel flow channels are arranged on the surface of the anode plate 5 facing the membrane electrode 7 to form the anode flow field 26. Since the heat and water production of the fuel cell are concentrated on the cathode side, no cooling plate is provided. The layout of the anode flow field 26 is consistent with that of the cathode flow field 24, which is also composed of three parts: the inlet distribution area 21, the main reaction area 22, and the outlet confluence area 23. The rib / strip protrusion array distribution design of the inlet distribution area 21 and the outlet confluence area 23 is optimized according to the hydrogen flow distribution.

[0042] Hydrogen inlet and outlet holes are provided on both sides of the anode plate 5. The two hydrogen inlet and outlet holes on both sides are used for the inflow and outflow of hydrogen, respectively. The hydrogen inlet and outlet holes on both sides are connected to the anode flow field 26.

[0043] The inlet distribution area 21 is directly connected to the oxygen inlet / outlet port 17 on the inlet side of the cathode cooling plate 15, forming a horizontally extending trench.

[0044] The inlet distribution area 21 adopts a comb-shaped microstructure design with ribs arranged in an array. This design can initially divert and homogenize the concentrated airflow at the oxygen inlet / outlet port 17, avoiding excessively high or low local flow velocities and ensuring uniform gas flow into the parallel flow channel below.

[0045] The main reaction zone 22 is located in the center and consists of multiple parallel direct current channels with equal spacing. The channels are separated by strip-shaped protrusions of equal width acting as ribs. The width, depth, and rib width of the channels are optimized to balance pressure drop and mass transfer efficiency. The reactant gas enters each channel uniformly from the inlet distribution zone 21 and undergoes a full electrochemical reaction with the membrane electrode 7.

[0046] The outlet confluence area 23 is symmetrical to the inlet distribution area 21 and is connected to the oxygen inlet / outlet hole 17 on the outlet side of the cathode cooling plate 15. Its function is to converge the gas in each parallel flow channel and smoothly discharge it to avoid the formation of dead zones or liquid accumulation at the end of the flow channel.

[0047] The porous titanium water transfer plate 14 is made of hydrophilic porous titanium sheet formed by powder sintering. Under operating conditions where the pores are completely saturated with liquid water and the transmembrane pressure difference is lower than its bubble point, this structure only allows liquid water to pass through and be discharged, while effectively preventing gas penetration and ensuring airtightness.

[0048] like Figure 2 As shown, a cathode sealing ring 13, a cooling chamber sealing ring 16, and a cooling chamber cover sealing ring 19 are also provided. The cathode cooling plate 15 has a cathode sealing ring 13 on the outer edge of the groove for sealing connection with the bottom surface of the membrane electrode 7. The bottom surface of the porous titanium water transfer plate 14 and the bottom of the groove of the main reaction area 22 of the cathode cooling plate 15 are sealed and connected by the cooling chamber sealing ring 16, so that the cooling chamber 25 is not directly connected to the groove, but is connected to the groove through the porous titanium water transfer plate 14. The cooling chamber cover 20 and the surrounding wall of the cooling water cavity are sealed and connected by the cooling chamber cover sealing ring 19.

[0049] The anode plate 5 is tightly attached to the anode side end face of the membrane electrode 7 through the anode sealing ring. The cathode cooling plate 15 is tightly attached to the cathode side end face of the membrane electrode 7 through the cathode sealing ring 13. The porous titanium water transport plate 14 is embedded in the groove of the cathode cooling plate 15 facing the membrane electrode 7 and is sealed with the cathode cooling plate 15 through the cooling chamber sealing ring 16. The cooling chamber cover plate 20 is tightly attached to the other end face of the cathode cooling plate 15 through the cooling chamber cover plate sealing ring 19. Together with the porous titanium water transport plate 14 and the cathode cooling plate 15, they form a closed cooling chamber.

[0050] The anode plate 5 and the cathode composite plate 8 serve the functions of structural support, current conduction and reaction gas distribution. The porous titanium water transfer plate 14, the cathode cooling plate 15 and the cooling chamber cover plate 20 are integrated into an integrated structure to realize the bidirectional water management function of passive drainage of the cathode and autonomous humidification of the membrane electrode.

[0051] A continuous sealing groove surrounds the outer periphery of the cathode flow field 24, which is used to embed the rubber sealing ring of the cooling chamber sealing ring 16. It forms a surface seal with the adjacent porous titanium water transport plate 14 and cathode cooling plate 15, and also forms a surface seal between the adjacent membrane electrode 7 and cathode cooling plate 15, to prevent gas leakage and hydrogen-oxygen cross-contamination, and to ensure the airtightness of the single cell.

[0052] The membrane electrode uses a composite membrane electrode with a PET frame.

[0053] like Figure 7 As shown, the membrane electrode is mainly composed of an anode diffusion layer 27, an anode PET frame 28, a catalyst-coated proton exchange membrane 29, a cathode PET membrane 31, and a cathode diffusion layer 32 connected sequentially from top to bottom. The anode PET frame 28, the cathode PET film 31, and the cathode diffusion layer 32 are all annular shapes with a hollowed-out slot in the middle. The size of the anode diffusion layer 27 and the cathode diffusion layer 32 are larger than the hollowed-out slot in the anode PET frame 28 and the hollowed-out slot in the cathode PET film 31, respectively. The catalyst loading area of ​​the catalyst-coated proton exchange membrane 29 is smaller than the inner frame of the anode PET frame 28; thermosetting adhesive 30 is provided on the edges of the catalyst-coated proton exchange membrane 29, the anode PET frame 28 and the cathode PET membrane 31.

[0054] S1. Initially, cooling water is introduced into the cooling chamber 25 of the cathode composite plate 8 from the cooling water inlet / outlet 18 on one side and flows out from the cooling water inlet / outlet 18 on the other side. The cooling water circulates through the cooling chamber 25, and the porous titanium water transfer plate 14 of the cathode composite plate 8 originally contains water. S2. Hydrogen gas is introduced into the anode flow field 26 of the anode plate 5 through the hydrogen inlet / outlet hole on one side and flows out through the hydrogen inlet / outlet hole on the other side. The hydrogen gas is distributed through the anode flow field 26 to reach the anode catalyst layer and undergoes an oxidation reaction to generate hydrogen ions (protons). The hydrogen ions migrate through the proton exchange membrane in the membrane electrode 7 to the cathode catalyst layer and react with oxygen to generate liquid water. S3. At the same time, oxygen is introduced into the groove of the cathode composite plate 8 from the oxygen inlet / outlet hole 17 on one side and flows out from the oxygen inlet / outlet hole 17 on the other side. Hydrogen ions and oxygen are fully mixed under the action of the cathode flow field 24 in the groove to generate oxygen reaction to produce liquid water and generate heat. The liquid water is adsorbed by the pores of the hydrophilic porous titanium water transport plate 14 under capillary action. S4. The liquid water generated by the cathode flow field 24 is directionally transported to the cooling chamber 25 through the pores of the porous titanium water transfer plate 14 under the pressure difference between the cathode flow field 24 and the cooling chamber 25, thereby continuously draining the cathode-generated water. Under low humidity operating conditions, some of the water in the cooling water vaporizes to form water vapor. Driven by the concentration gradient, the water vapor diffuses in the opposite direction to the cathode flow field 24 through the pores of the water transfer plate, thereby achieving effective humidification of the membrane electrode 7.

[0055] After water is generated, part of the excess water can flow out through the oxygen inlet / outlet hole 17, and the other part can flow out through the porous titanium water transfer plate 14 and the coolant together from the cooling water inlet / outlet hole 18 of the cooling chamber 25.

[0056] The working pressure difference between the cooling chamber 7 and the cathode flow field 24 is controlled at <0.3 bar, the bubble point of the porous titanium water transfer plate 14 must be ≥0.5 bar, and a safety margin of at least 0.2 bar is reserved to prevent oxygen from leaking into the cooling chamber 25 through the pores of the porous titanium water transfer plate 14.

[0057] Example: In this embodiment, the anode plate 5 is made of high-purity graphite plate material. The side facing the membrane electrode 7 is processed to form the anode flow field. There is no additional cooling plate structure. Since the main heat and water production of the proton exchange membrane fuel cell are concentrated on the cathode side, only the hydrogen oxidation reaction occurs on the anode side. The heat release is much lower than that on the cathode side. In addition, the graphite plate itself has excellent thermal conductivity, which can indirectly achieve temperature balance on the anode side through thermal conduction with the cathode side cooling structure. A hydrogen inlet is opened on one side of the anode plate 5, and a hydrogen outlet is opened on the other side. A heating hole 2 is also opened on the side. A heating rod can be installed in the heating hole 2 to introduce a heat source during the low-temperature start-up stage of the fuel cell, improve the start-up efficiency of the single cell, and ensure the working stability under low-temperature conditions.

[0058] The cathode cooling plate 15 also uses high-purity graphite electrode material. Parallel flow channels are processed on the side facing the porous titanium water transport plate 14, which together with the parallel flow channels on the side facing the membrane electrode 7 of the porous titanium water transport plate 14 form the cathode flow field. An oxygen outlet 17 is opened on one side of the cathode cooling plate 15, which is located on the same side of the single cell as the hydrogen inlet of the anode plate 5. An oxygen inlet is opened on the other side. Cooling water inlet and outlet holes 18 are opened at intervals between the oxygen inlet and outlet holes. The cooling water inlet and outlet holes 18 are connected to the cooling chamber to provide a channel for the circulation of coolant. A temperature measuring hole 6 is also opened on the side of the cathode cooling plate 15. A temperature sensor can be installed in the temperature measuring hole 6 to monitor the working temperature of the cathode side of the single cell in real time and achieve precise temperature control.

[0059] In this embodiment, the membrane electrode 7 is a composite membrane electrode with a PET frame. It is formed by stacking and hot-pressing the anode diffusion layer, the anode PET frame, the catalyst-coated proton exchange membrane, the cathode PET frame, and the cathode diffusion layer from top to bottom. The dimensions of the anode diffusion layer and the cathode diffusion layer are larger than the inner frame dimensions of the anode PET frame and the cathode PET frame, respectively. The catalyst loading area of ​​the catalyst-coated proton exchange membrane is smaller than the inner frame dimension of the PET frame. Thermosetting adhesive is provided at the edges of the catalyst-coated proton exchange membrane and the anode and cathode PET frames. After hot pressing, the thermosetting adhesive achieves sealing and reinforcement between the layers, effectively preventing hydrogen and oxygen leakage and improving the airtightness and structural stability of the membrane electrode 7.

[0060] The porous titanium water transport plate 14 is a porous titanium sheet formed by powder sintering. After ultrasonic hydrophilic treatment with ethanol, its contact angle is controlled at 49.4°~50.9° and its electronic conductivity is 8.40×10⁻⁶. 5 S・m -1 The thermal conductivity is 26.94 W·m. -1 ・K -1 The contact resistance with the gas diffusion layer under a clamping pressure of 1.4 MPa is 16.04 mΩ·cm. 2 The porous titanium water transfer plate 14 has a bubble point ≥0.5 bar, and the working pressure difference between the cooling chamber and the cathode reaction chamber is controlled at <0.3 bar, with a safety margin of at least 0.2 bar reserved. This effectively prevents oxygen from leaking into the cooling chamber through the pores of the porous titanium water transfer plate 14, ensuring the working safety of the single cell.

[0061] The working process of this invention is as follows: Hydrogen gas enters the anode flow field through the hydrogen inlet of the anode plate 5 and diffuses uniformly to the anode side of the membrane electrode 7 to undergo an oxidation reaction; oxygen gas enters the cathode flow field through the oxygen inlet of the cathode cooling plate 15 and diffuses uniformly to the cathode side of the membrane electrode 7 through the flow channel of the porous titanium water transfer plate 14 to undergo a reduction reaction; the liquid water generated in the cathode reaction chamber is driven by the pressure difference between the cathode and the cooling chamber and is directionally transported to the cooling chamber along the pores of the porous titanium water transfer plate 14 to achieve passive drainage of the cathode and alleviate the flooding problem; the water vapor in the cooling chamber can diffuse back to the cathode reaction chamber through the pores of the porous titanium water transfer plate 14 to achieve autonomous humidification of the membrane electrode 7 and avoid membrane drying and performance degradation under low humidity conditions.

[0062] The coolant flows into the cooling chamber through the cooling water inlet of the cathode cooling plate 15 and flows along the flow channel inside the cooling chamber. It carries away the excess heat generated during the operation of the single cell through heat conduction, maintaining the single cell's operating temperature within the optimal range of 60~80℃. At the same time, the liquid water collected in the cooling chamber mixes with the coolant and is discharged from the single cell together through the cooling water outlet, achieving the synchronous discharge of heat and liquid water. The hydrogen gas at the anode and the oxygen gas at the cathode flow in opposite directions at a cross-diagonal pattern within the single cell. The coolant flows from left to right along the parallel flow channel of the cathode cooling plate 15. This flow pattern can improve the mass transfer efficiency of the reactant gas and the heat exchange efficiency of the coolant, further optimizing the working performance of the single cell.

[0063] In this embodiment, the cathode flow field consists of three parts: an inlet distribution area, a main reaction area, and an outlet confluence area, arranged in a symmetrical layout. The inlet distribution area is a transversely expanding trench connected to the oxygen inlet, employing a comb-like rib array microstructure design to initially divert and homogenize the concentrated oxygen flow, ensuring uniform gas flow into the main reaction area. The main reaction area consists of multiple equally spaced parallel direct current channels. The channel width, depth, and rib width are optimized to balance the gas flow pressure drop and mass transfer efficiency. Oxygen fully contacts the membrane electrode 7 in this area and undergoes an electrochemical reaction. The outlet confluence area is symmetrically arranged with the inlet distribution area and connected to the oxygen outlet, converging and smoothly discharging the reacted gas from each parallel channel, avoiding dead zones or liquid accumulation at the end of the channels, and improving the gas utilization efficiency of the cathode flow field.

[0064] In addition, continuous sealing grooves are opened around the outer periphery of the anode flow field and the cathode flow field. Rubber sealing rings are embedded in the grooves, forming a reliable surface seal with the adjacent membrane electrode 7, porous titanium water transport plate 14, and cathode cooling plate 15. This effectively prevents the leakage of reaction gas and hydrogen-oxygen cross-contamination, ensuring the high airtightness requirements of the single cell in the underwater closed environment.

[0065] The individual cells of this invention can be stacked according to actual power requirements to form a battery stack. The individual cells are connected in series through gas holes and coolant holes on the plates. The battery stack as a whole is also assembled and fixed by positioning pins and clamping devices to maintain the assembly consistency of each individual cell and ensure the overall working performance and stability of the battery stack.

Claims

1. A liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate, characterized in that: It includes an anode plate (1), an anode plate (5), a membrane electrode (7), a cathode composite plate (8), and a cathode plate (12) stacked tightly from top to bottom; an anode insulating sheet (3) and an anode current collector (4) are stacked between the anode plate (1) and the anode plate (5) from top to bottom, and a cathode current collector (9) and a cathode insulating sheet (10) are stacked between the cathode composite plate (8) and the cathode plate (12) from top to bottom. The cathode composite plate (8) is provided with a porous titanium water transport plate (14) for water transport, and the porous titanium water transport plate (14) is provided with a symmetrically arranged cathode flow field (24) for uniform distribution and discharge of reaction gas.

2. The liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 1, characterized in that: Heating holes (2) are provided on the sides of both the anode plate (1) and the cathode plate (12), and heating rods are installed in the heating holes (2). Temperature measuring holes (6) are provided on the sides of both the anode plate (5) and the cathode composite plate (8), and thermocouples are installed in the temperature measuring holes (6).

3. The liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 1, characterized in that: The cathode composite plate (8) is mainly composed of a porous titanium water transport plate (14), a cathode cooling plate (15), and a cooling chamber cover plate (20). The top surface of the cathode cooling plate (15) is provided with a groove, which is arranged in three parts along the flow direction: an inlet distribution area (21), a main reaction area (22), and an outlet confluence area (23). The bottom of the groove where the main reaction area (22) is located is provided with a strip-shaped through groove group, and the bottom surface of the groove where the inlet distribution area (21) and the outlet confluence area (23) are provided with a set of oblique strip protrusions. The porous titanium water transport plate (14) is placed on the groove of the cathode cooling plate (15) and covers the main reaction area (22). The bottom surface of the cathode cooling plate (15) is provided with a cavity as a cooling chamber (25), which is connected to the groove through the strip-shaped through groove group. The bottom of the cavity is sealed with a cooling chamber cover plate (20).

4. A liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 1, characterized in that: The cathode composite plate (8) has oxygen inlet and outlet holes (17) on both sides of the cathode cooling plate (15). The oxygen inlet and outlet holes (17) on both sides are connected to the groove through the channel inside the cathode cooling plate (15). The cathode composite plate (8) has cooling water inlet and outlet holes (18) on both sides of the cathode cooling plate (15). The cooling water inlet and outlet holes (18) on both sides are connected to the cooling chamber through the channel inside the cathode cooling plate (15).

5. A liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 1, characterized in that: The main reaction zone (22) is composed of multiple parallel strip channels evenly distributed on the surface of the cathode cooling plate (15) perpendicular to the flow direction, with each strip channel arranged along the flow direction. The inclined strip protrusion group of the inlet distribution area (21) and the outlet confluence area (23) is mainly composed of multiple parallel inclined strip protrusions evenly distributed on the surface of the cathode cooling plate (15) perpendicular to the flow direction. Each inclined strip protrusion is arranged at an angle that is not parallel to the flow direction. The bottom surface of the porous titanium water transport plate (14) is a plane, and the top surface is provided with a strip protrusion group. The strip protrusion group is mainly composed of multiple parallel strip protrusions evenly distributed along the perpendicular flow direction. Each strip protrusion is arranged along the flow direction. The gap between all adjacent strip protrusions forms a parallel flow channel toward the membrane electrode (7). All parallel flow channels form the main reaction zone (22).

6. A hydrogen-oxygen proton exchange membrane fuel cell single-cell stack with an integrated porous titanium water transport plate according to claim 1, characterized in that: The anode plate (5) is provided with parallel flow channels on the side facing the membrane electrode (7) to form an anode flow field (26). The layout of the anode flow field (26) is consistent with that of the cathode flow field (24), and it is also composed of three parts: the inlet distribution area (21), the main reaction area (22), and the outlet confluence area (23). Hydrogen inlet and outlet holes are provided on both sides of the anode plate (5), and the hydrogen inlet and outlet holes on both sides are connected to the anode flow field (26).

7. A hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 1, characterized in that: The porous titanium water transport plate (14) is a hydrophilic porous titanium sheet formed by powder sintering.

8. A hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 2, characterized in that: The cathode cooling plate (15) is provided with a cathode sealing ring (13) on the outer edge of the groove for sealing connection with the bottom surface of the membrane electrode (7). The bottom surface of the porous titanium water transfer plate (14) and the main reaction area (22) of the cathode cooling plate (15) are sealed and connected by a cooling chamber sealing ring (16), so that the cooling chamber (25) is not directly connected to the groove, but is connected to the groove through the porous titanium water transfer plate (14); the cooling chamber cover plate (20) and the surrounding wall of the cooling water cavity are sealed and connected by a cooling chamber cover plate sealing ring (19).

9. A hydrogen-oxygen proton exchange membrane fuel cell with an integrated porous titanium water transport plate according to claim 1, characterized in that: The membrane electrode is mainly composed of an anode diffusion layer (27), an anode PET frame (28), a catalyst-coated proton exchange membrane (29), a cathode PET membrane (31), and a cathode diffusion layer (32) connected sequentially from top to bottom; The anode PET frame (28), cathode PET film (31) and cathode diffusion layer (32) are all annular shapes with a hollowed-out slot in the middle. The size of the anode diffusion layer (27) and cathode diffusion layer (32) is larger than the hollowed-out slot in the anode PET frame (28) and the hollowed-out slot in the cathode PET film (31), respectively. The catalyst loading area of ​​the catalyst-coated proton exchange membrane (29) is smaller than the inner frame of the anode PET frame (28); thermosetting adhesive (30) is provided on the edges of the catalyst-coated proton exchange membrane (29), the anode PET frame (28) and the cathode PET membrane (31).

10. A liquid-cooled hydrogen-oxygen proton exchange method applied to a liquid-cooled hydrogen-oxygen proton exchange membrane fuel cell according to any one of claims 1-9, characterized in that: The method includes: S1. Initially, cooling water is introduced into the cooling chamber (25) of the cathode composite plate (8), and the cooling water circulates through the cooling chamber (25). The porous titanium water transport plate (14) of the cathode composite plate (8) originally contains water. S2. Hydrogen gas is introduced into the anode flow field (26) of the anode plate (5). The hydrogen gas is distributed through the anode flow field (26) to the anode catalyst layer and undergoes an oxidation reaction to generate hydrogen ions. The hydrogen ions migrate through the proton exchange membrane in the membrane electrode (7) to the cathode catalyst layer and react with oxygen to generate liquid water. S3. At the same time, oxygen is introduced into the groove of the cathode composite plate (8). Under the action of the cathode flow field (24) in the groove, hydrogen ions and oxygen are fully mixed to generate oxygen reaction to produce liquid water and generate heat. The liquid water is adsorbed by the pores of the hydrophilic porous titanium water transport plate (14) under capillary action. S4. The generated liquid water is directionally transported to the cooling chamber (25) through the pores of the porous titanium water transfer plate (14) under the pressure difference between the cathode flow field (24) and the cooling chamber (25), thereby continuously draining the cathode-generated water. The water in the cooling water partially vaporizes to form water vapor. Driven by the concentration gradient, the water vapor diffuses in the opposite direction to the cathode flow field (24) through the pores of the water transfer plate, thereby achieving effective humidification of the membrane electrode (7).

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