A fuel cell water-thermal management system based on cooperation of functional film and cooling flow channel

Abstract

This invention discloses a fuel cell hydrothermal management system based on the synergy of functional membranes and cooling channels. It includes an anode hydrothermal regulation functional membrane disposed on the anode side of the fuel cell, a cathode hydrothermal regulation functional membrane disposed on the cathode side of the fuel cell, a cooling channel disposed inside the bipolar plate of the fuel cell, and a cooling circulation system connected to the cooling channel. Both the anode and cathode hydrothermal regulation functional membranes are multilayer gradient structure composite membranes, respectively disposed on the inner wall surfaces of the anode and cathode gas channels. This invention integrates the anode, cathode, and cooling channels into a single system to form a hydrothermal regulation system, coupling moisture migration and temperature distribution, thereby solving the problem of hydrothermal imbalance in fuel cells, improving the stability and power density of the fuel cell under high current density operating conditions, and extending the service life of the fuel cell system.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically to a fuel cell hydrothermal management system based on the synergy of functional membranes and cooling channels. Background Technology

[0002] As a core technology for the efficient utilization of hydrogen energy, fuel cells have irreplaceable application value in transportation, distributed energy supply, and other fields due to their advantages such as zero emissions, rapid start-up, and high energy density. However, the large-scale application of fuel cells still faces bottlenecks such as high cost and size / weight limitations, making increasing power density a key path to overcome these technological constraints.

[0003] Currently, the core challenge in improving power density lies in the multi-field coupling imbalance caused by high current density operation. As current density increases, voltage drop exhibits a non-linear deterioration trend. The root cause can be attributed to the imbalance of water-heat-mass multi-field coupling, specifically manifested as: 1) dehydration of the membrane electrode leading to a sharp drop in proton conduction efficiency; 2) accumulation of liquid water at the cathode hindering oxygen mass transfer; and 3) localized hot spots (>85 ℃) accelerating material performance degradation. Therefore, achieving coordinated management of water and heat is a key path to overcoming the bottleneck of high power density operation.

[0004] As a mainstream technology, proton exchange membrane fuel cells (PEMFCs) face typical technical challenges under high current density conditions: the coexistence of cathode pore water blockage and anode membrane dehydration. Existing thermal management systems are unable to balance heat dissipation and humidity control, thus forming a vicious cycle of "performance-lifetime" dual degradation.

[0005] Compared to existing technologies, current fuel cell thermal management solutions mainly focus on heat conduction and dissipation, lacking coordinated control over moisture distribution. For example, existing technologies such as CN114784322B achieve heat extraction and storage by embedding an ultra-thin heat spreader in the bipolar plates and combining it with a water-cooling module and phase change materials; this is essentially a combined thermal management approach of conduction-convection-storage. Another example is CN220358139U, which uses an air-cooled structure, achieving heat dissipation solely through air convection; and CN105161727A primarily optimizes the stack structure and gas distribution. None of these technologies address the active control of moisture behavior at the electrode interface.

[0006] However, under high current density operating conditions, the fundamental reason for the performance degradation of fuel cells lies in the imbalance of multi-field coupling between water, heat, and mass. A single thermal management method is insufficient to simultaneously solve the problems of anode membrane dehydration and cathode flooding. Existing technologies generally only regulate the temperature field through external cooling or thermal conductive structures, without achieving synergistic regulation of moisture and heat at the reaction interface level. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a fuel cell hydrothermal management system based on the synergy of functional membranes and cooling channels, which addresses the shortcomings of the prior art. The anode hydrothermal regulation functional membrane, the cathode hydrothermal regulation functional membrane, and the cooling channels together constitute a hydrothermal regulation system in the same system, so that moisture migration and temperature distribution are coupled with each other, thereby solving the problem of hydrothermal imbalance in fuel cells, improving the stability and power density of fuel cells under high current density operating conditions, and extending the service life of fuel cell systems.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel, including an anode hydrothermal regulation functional membrane disposed on the anode side of the fuel cell, a cathode hydrothermal regulation functional membrane disposed on the cathode side of the fuel cell, a cooling channel disposed inside the bipolar plate of the fuel cell, and a cooling circulation system connected to the cooling channel.

[0009] Both the anode hydrothermal regulation functional membrane and the cathode hydrothermal regulation functional membrane are multi-layer gradient structure composite membranes. The anode hydrothermal regulation functional membrane and the cathode hydrothermal regulation functional membrane are respectively disposed on the inner wall surface of the anode gas flow channel and the inner wall surface of the cathode gas flow channel.

[0010] The anode hydrothermal regulation functional membrane is used to maintain the hydration state of the fuel cell membrane electrode assembly through a cycle of water adsorption, storage, and desorption release; the cathode hydrothermal regulation functional membrane is used to adsorb liquid water generated at the cathode and absorb the heat of reaction through the dissolution and endothermic process of water and endothermic working medium; the cooling channel is used to remove the heat of reaction generated during fuel cell operation through the circulation of cooling medium; the anode hydrothermal regulation functional membrane, the cathode hydrothermal regulation functional membrane, and the cooling channel together constitute a hydrothermal regulation system in which water migration and temperature distribution are coupled.

[0011] This invention integrates an anode hydrothermal regulation membrane, a cathode hydrothermal regulation membrane, and a cooling channel into a single system. The functional membranes regulate water migration behavior, while the cooling channel regulates temperature field distribution, achieving hydrothermal coupling regulation. Specifically, the anode functional membrane maintains the hydration state of the fuel cell membrane electrode assembly through a cyclic process of adsorption, storage, and desorption / release of water generated or migrated during the reaction, preventing anode dehydration. It also absorbs and releases heat during this cycle, thus achieving dynamic regulation of moisture and temperature on the anode side. The cathode hydrothermal regulation membrane adsorbs liquid water generated at the cathode and absorbs reaction heat through a dissolution endothermic process. Driven by capillary action and concentration gradients, it regulates the migration path of water within the cathode hydrothermal regulation membrane, redistributing locally accumulated liquid water to the gas channel or evaporation area, effectively suppressing cathode flooding and regulating local temperature. The cooling channel removes the reaction heat generated during the fuel cell reaction through cooling medium circulation, achieving a uniform temperature field distribution within the fuel cell. These three elements together form a hydrothermal regulation system within the same system, which couples moisture migration with temperature distribution, thereby solving the problem of hydrothermal imbalance in fuel cells, improving the stability and power density of fuel cells under high current density operating conditions, and extending the service life of fuel cell systems.

[0012] Preferably, the anode hydrothermal regulation functional membrane comprises a porous anode material layer, an adsorption regulation layer, and an anode selective mass transfer layer stacked sequentially. The porous anode material layer is disposed on the inner wall surface of the anode gas flow channel and is composed of porous carbon materials or metal-based porous materials. The adsorption regulation layer is composed of molecular sieve materials (including zeolite materials), metal-organic frameworks (MOFs), or composite materials thereof. The anode selective mass transfer layer is a hydrophilic polymer membrane or an inorganic composite membrane. The anode selective mass transfer layer is used to allow preferential permeation of water molecules and inhibit non-selective permeation of anode gas (hydrogen). In the above-mentioned anode hydrothermal regulation functional membrane, the porous anode material layer provides structural support, the adsorption regulation layer is responsible for the adsorption and release of water, and the anode selective mass transfer layer allows preferential permeation of water molecules while inhibiting hydrogen permeation. The synergistic effect of the three layers enables the anode functional membrane to maintain the hydration state of the fuel cell membrane electrode assembly while avoiding the safety hazards caused by non-selective permeation of hydrogen into the membrane layer.

[0013] As a further preferred embodiment, an anode phase change buffer layer is disposed on the surface of the porous anode material layer. This buffer layer is located between the porous anode material layer and the inner wall surface of the anode gas flow channel. The phase change temperature of the buffer layer is 60-80 °C, and its thickness is 5-50 μm. The anode phase change buffer layer absorbs localized heat during the phase change process, buffering temperature fluctuations and further enhancing the thermal regulation capability of the anode side, thus preventing damage to the fuel cell membrane electrode assembly from instantaneous overheating. Preferably, the anode phase change buffer layer is composed of one or more of paraffin-based organic phase change materials, fatty acid-based phase change materials, inorganic hydrated salt-based phase change materials, or composite materials thereof.

[0014] As a further preferred embodiment, the total thickness of the anode hydrothermal regulation functional membrane is 50-450 μm, the thickness of the anode porous material layer is 10-150 μm, the thickness of the adsorption regulation layer is 20-200 μm, and the thickness of the anode selective mass transfer layer is 5-50 μm. Within the above thickness range, the anode hydrothermal regulation functional membrane can obtain sufficient water adsorption and storage capacity while maintaining reasonable gas mass transfer resistance, so as to effectively maintain the hydration state of the fuel cell membrane electrode assembly.

[0015] Preferably, the cathode hydrothermal regulation functional membrane includes a cathode porous material layer disposed on the inner wall surface of the cathode gas flow channel. The pores of the cathode porous material layer are loaded with an endothermic working fluid. The cathode porous material layer is composed of one or more of metal-organic framework materials, molecular sieve materials, or porous carbon materials. The endothermic working fluid is an inorganic salt system or its composite system that is soluble in water and generates an endothermic effect during dissolution. In the above-mentioned cathode hydrothermal regulation functional membrane, the cathode porous material layer guides water into the endothermic working fluid through adsorption and enrichment of liquid water, causing the endothermic working fluid to undergo a dissolution and endothermic process, thereby achieving localized cooling. Simultaneously, the cathode porous material layer provides confined space, enhancing the contact efficiency between water and the endothermic working fluid. Through carrier confinement and structural constraint, it inhibits the loss of the endothermic working fluid and improves cycle stability. The inorganic salt system or its composite system is preferably NH4NO3, NH4Cl, NaNO3, KNO3, or a combination thereof.

[0016] As a further preferred embodiment, a cathode selective mass transfer layer is disposed on the surface of the porous cathode material layer. This selective mass transfer layer is a hydrophilic polymer membrane or an inorganic composite membrane, and its thickness is 5-50 μm. The selective mass transfer layer allows preferential permeation of water molecules and inhibits non-selective permeation of cathode gases (air or oxygen). The function of the selective mass transfer layer is to regulate the transfer efficiency of water to the endothermic working fluid and inhibit the migration of the endothermic working fluid into the gas flow channel, reducing the penetration of air or oxygen into the cathode hydrothermal regulation functional membrane and avoiding efficiency loss due to air or oxygen permeation.

[0017] As a further preferred embodiment, a cathode phase change buffer layer is disposed on the surface of the porous cathode material layer. This buffer layer is located between the porous cathode material layer and the inner wall surface of the cathode gas flow channel. The phase change temperature of the cathode phase change buffer layer is 60-80 °C, and its thickness is 5-50 μm. The cathode phase change buffer layer absorbs localized heat through latent heat of phase change, buffering temperature fluctuations on the cathode side. This complements the endothermic dissolution of the heat-absorbing working fluid, further enhancing the thermal regulation capability on the cathode side. Preferably, the cathode phase change buffer layer is composed of one or more of paraffin-based organic phase change materials, fatty acid-based phase change materials, inorganic hydrated salt-based phase change materials, or composite materials thereof.

[0018] As a further preferred embodiment, the total thickness of the cathode hydrothermal regulation functional membrane is 30~300μm, and the thickness of the cathode porous material layer is 20~200μm. Within the above thickness range, the cathode hydrothermal regulation functional membrane can adsorb a sufficient amount of liquid water and carry a sufficient amount of endothermic working fluid, while maintaining a reasonable oxygen mass transfer channel, effectively suppressing cathode flooding.

[0019] Preferably, the cooling channels are disposed inside the bipolar plates of the fuel cell, forming a serpentine, parallel, or mesh channel structure, with a channel width or equivalent hydraulic diameter of 0.5–3 mm. The cooling medium is deionized water, nanofluid, or phase change fluid. The nanofluid is a suspension system formed by dispersing thermally conductive nanoparticles in deionized water. The thermally conductive nanoparticles are selected from one or more of alumina, copper oxide, carbon nanotubes, graphene, and silicon carbide. The phase change fluid is a suspension system or emulsion system containing a phase change material, and the phase change temperature of the phase change material is 30–90 °C. The optimized cooling channel structure ensures uniform distribution of the cooling medium, achieving a uniform temperature field distribution in the fuel cell and avoiding local overheating. Nanofluids have a higher thermal conductivity than ordinary deionized water, and phase change fluids absorb reaction heat through latent heat of phase change within the operating temperature range, improving the system's thermal buffering capacity and suppressing temperature fluctuations; both can improve heat dissipation efficiency.

[0020] Preferably, the anode hydrothermal regulation functional membrane is formed on the inner wall surface of the anode gas flow channel by coating or in-situ construction, forming an integrated structure with the inner wall of the anode gas flow channel; the cathode hydrothermal regulation functional membrane is formed on the inner wall surface of the cathode gas flow channel by coating or in-situ construction, forming an integrated structure with the inner wall of the cathode gas flow channel. This integrated structure simplifies the system assembly process and shortens the transfer path of moisture and heat between the functional membrane and the gas flow channel, thereby improving the response speed of hydrothermal regulation.

[0021] Compared with existing technologies, this invention has the following advantages: This invention integrates the anode hydrothermal regulation functional membrane, the cathode hydrothermal regulation functional membrane, and the cooling channel into the same system. The functional membrane regulates moisture migration behavior, and the cooling channel regulates the temperature field distribution, achieving coupled hydrothermal regulation. The anode hydrothermal regulation functional membrane, the cathode hydrothermal regulation functional membrane, and the cooling channel together constitute a hydrothermal regulation system, coupling moisture migration and temperature distribution, thereby solving the problem of hydrothermal imbalance in fuel cells, improving the stability and power density of fuel cells under high current density operating conditions, and extending the service life of the fuel cell system. Attached Figure Description

[0022] Figure 1 This is a schematic diagram showing the composition and connection of the fuel cell system in the embodiment;

[0023] Figure 2 This is a schematic diagram of the structure of a single fuel cell in the embodiment;

[0024] Figure 3 This is a schematic diagram illustrating the effect of the anode hydrothermal regulation functional membrane on the anode side in the embodiment;

[0025] Figure 4 This is a schematic diagram illustrating the effect of the anode hydrothermal regulation functional membrane on the inner wall of the anode gas flow channel in the embodiment;

[0026] Figure 5 This is a schematic diagram illustrating the effect of the cathode hydrothermal regulation functional membrane on the inner wall of the cathode gas flow channel in the embodiment.

[0027] Figures 1-5 The specific reference numerals in the attached figures are as follows:

[0028] 1-Fuel cell; 2-Proton exchange membrane; 3-Catalyst layer; 4-Gas diffusion layer; 5-Bipolar plate; 6-Coolant tank; 7-Heat exchanger; 8-Circulation pump; 9-Gas flow channel; 10-Cooling flow channel; 11-Hydrogen; 12-Air or oxygen; 13-Anode hydrothermal regulation functional membrane; 14-Cathode hydrothermal regulation functional membrane; 15-Inner wall of anode gas flow channel; 16-Anode porous material layer; 17-Adsorption regulation layer; 18-Anode selective mass transfer layer; 19-Inner wall of cathode gas flow channel; 20-Cathode porous material layer; 21-Cathode selective mass transfer layer; 22-Cooling medium. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to the following embodiments. Components or structures not limited thereto in the present invention all employ existing technology in the art.

[0030] Example: To achieve coordinated water and heat control of a fuel cell system, in Figure 1 The hydrothermal management system of the present invention is installed on the fuel cell membrane electrode assembly of the fuel cell system shown. Figure 1 The fuel cell system shown is a loop consisting of multiple fuel cells 1, a coolant tank 6, a heat exchanger 7, and a circulation pump 8. Figure 1 and Figure 2 As shown, a single fuel cell 1 includes a proton exchange membrane 2, a catalyst layer 3, a gas diffusion layer 4, and a bipolar plate 5.

[0031] like Figure 2 and Figure 3 As shown, the hydrothermal management system includes an anode hydrothermal regulation functional membrane 13 disposed on the anode side of the fuel cell, a cathode hydrothermal regulation functional membrane 14 disposed on the cathode side of the fuel cell, a cooling channel 10 disposed inside the bipolar plate 5 of the fuel cell, and a cooling circulation system connected to the cooling channel 10.

[0032] The anode hydrothermal regulation functional membrane 13 and the cathode hydrothermal regulation functional membrane 14 are respectively disposed on the surface of the inner wall 15 of the anode gas flow channel and the surface of the inner wall 19 of the cathode gas flow channel. Specifically, the anode hydrothermal regulation functional membrane 13 is formed on the surface of the inner wall 15 of the anode gas flow channel by coating or in-situ construction, forming an integrated structure with the inner wall 15 of the anode gas flow channel; the cathode hydrothermal regulation functional membrane 14 is formed on the surface of the inner wall 19 of the cathode gas flow channel by coating or in-situ construction, forming an integrated structure with the inner wall 19 of the cathode gas flow channel.

[0033] like Figure 4As shown, the anode hydrothermal regulation functional membrane 13 includes a porous anode material layer 16, an adsorption regulation layer 17, and an anode selective mass transfer layer 18 stacked sequentially. The porous anode material layer 16 is disposed on the surface of the inner wall 15 of the anode gas flow channel and is composed of porous carbon material or metal-based porous material. The adsorption regulation layer 17 is composed of molecular sieve material, metal-organic framework material, or a composite material thereof. The anode selective mass transfer layer 18 is a hydrophilic polymer membrane or an inorganic composite membrane. The anode selective mass transfer layer 18 is used to achieve preferential permeation of water molecules and inhibit non-selective permeation of anode gas. The total thickness of the anode hydrothermal regulation functional membrane 13 is 50~450μm, the thickness of the porous anode material layer 16 is 10~150μm, the thickness of the adsorption regulation layer 17 is 20~200μm, and the thickness of the anode selective mass transfer layer 18 is 5~50μm. Furthermore, an anode phase change buffer layer can be provided on the surface of the anode porous material layer 16. The anode phase change buffer layer is located between the anode porous material layer 16 and the surface of the inner wall 15 of the anode gas flow channel. The phase change temperature of the anode phase change buffer layer is 60~80 ℃, and the thickness of the anode phase change buffer layer is 5~50 μm.

[0034] like Figure 5 As shown, the cathode hydrothermal regulation functional membrane 14 includes a cathode porous material layer 20, which is disposed on the surface of the inner wall 19 of the cathode gas flow channel. The pores of the cathode porous material layer 20 are loaded with an endothermic working fluid. The cathode porous material layer 20 is composed of one or more of metal-organic framework materials, molecular sieve materials, or porous carbon materials. The endothermic working fluid is an inorganic salt system or its composite system that is soluble in water and generates an endothermic effect during dissolution. The total thickness of the cathode hydrothermal regulation functional membrane 14 is 30~300μm, and the thickness of the cathode porous material layer 20 is 20~200μm. A cathode selective mass transfer layer 21 is disposed on the surface of the cathode porous material layer 20. The cathode selective mass transfer layer 21 is a hydrophilic polymer membrane or an inorganic composite membrane, and its thickness is 5~50μm. The cathode selective mass transfer layer 21 is used to achieve preferential permeation of water molecules and inhibit non-selective permeation of cathode gas. Furthermore, a cathode phase change buffer layer can be provided on the surface of the cathode porous material layer 20. The cathode phase change buffer layer is located between the cathode porous material layer 20 and the surface of the cathode gas flow channel inner wall 19. The phase change temperature of the cathode phase change buffer layer is 60~80 ℃, and the thickness of the cathode phase change buffer layer is 5~50 μm.

[0035] The anode hydrothermal regulation functional membrane 13 is used to maintain the hydration state of the fuel cell membrane electrode assembly through the cycle of water adsorption, storage and desorption release; the cathode hydrothermal regulation functional membrane 14 is used to adsorb liquid water generated at the cathode and absorb the heat of reaction through the dissolution and heat absorption process of water and endothermic working medium; the cooling channel 10 is used to remove the heat of reaction generated during the operation of the fuel cell 1 through the cooling medium 22; the anode hydrothermal regulation functional membrane 13, the cathode hydrothermal regulation functional membrane 14 and the cooling channel 10 together constitute a hydrothermal regulation system in which water migration and temperature distribution are coupled.

[0036] The cooling channel 10 forms a serpentine channel, parallel channel, or mesh channel structure, with a channel width or equivalent hydraulic diameter of 0.5~3 mm; the cooling medium 22 is deionized water, nanofluid, or phase change fluid. The nanofluid is a suspension system formed by dispersing thermally conductive nanoparticles in deionized water. The thermally conductive nanoparticles are selected from one or more of alumina, copper oxide, carbon nanotubes, graphene, and silicon carbide. The phase change fluid is a suspension system or emulsion system containing phase change material, and the phase change temperature of the phase change material is 30~90 ℃.

[0037] The working process of the above-mentioned fuel cell water-thermal management system is as follows:

[0038] When fuel cell 1 is running, hydrogen gas 11 is introduced into the anode side and air or oxygen gas 12 is introduced into the cathode side. Under high current density operating conditions, fuel cell 1 generates a large amount of heat of reaction during the electrochemical reaction process, and liquid water is generated on the cathode side. Some of the water diffuses back from the cathode side to the anode side.

[0039] On the anode side, when the fuel cell membrane electrode assembly shows a tendency to dehydrate, the water that diffuses back to the anode side passes through the anode selective mass transfer layer 18 and the adsorption control layer 17 in sequence, is adsorbed by the adsorption control layer 17, and stored in its pore structure. The adsorption control layer 17 is composed of molecular sieve materials or metal-organic framework materials and has a strong water adsorption capacity. When the local water content on the anode side is insufficient, the adsorption control layer 17 releases the stored water, allowing the water to re-enter the interface between the gas diffusion layer 4 and the fuel cell membrane electrode assembly, maintaining the hydration state of the fuel cell membrane electrode assembly. During the above adsorption and desorption cycle, the phase change of water is accompanied by the absorption and release of heat, which buffers the temperature fluctuations on the anode side. If an anode phase change buffer layer is provided between the anode porous material layer 16 and the inner wall 15 of the anode gas flow channel, the anode phase change buffer layer can further absorb local heat through the latent heat of phase change, stabilizing the anode side temperature.

[0040] On the cathode side, the liquid water generated by the cathode reaction enters the pores of the cathode porous material layer 20 under capillary action, contacting the endothermic working fluid loaded in the pores. The endothermic working fluid is a water-soluble inorganic salt system that dissolves upon contact with water and absorbs heat, thereby reducing the local temperature. The cathode porous material layer 20 forms a confined area for the endothermic working fluid, inhibiting its loss and improving cycle stability. At the same time, the cathode porous material layer 20 guides and redistributes the water, causing some water to migrate along the pores to the gas flow channel 9 or the evaporation area, preventing local accumulation of liquid water in the electrode pores and reducing gas transport resistance. The cathode selective mass transfer layer 21 is used to regulate the transfer efficiency of water to the endothermic working fluid and reduce the non-selective infiltration of air or oxygen 12 into the cathode functional membrane. If a cathode phase change buffer layer is added between the cathode porous material layer 20 and the inner wall 19 of the cathode gas flow channel, the cathode phase change buffer layer can further absorb the heat of reaction through the latent heat of phase change, complementing the heat absorption of the endothermic working fluid by dissolution.

[0041] On the cooling channel side, the cooling medium 22 flows through the cooling channel 10 inside the bipolar plate 5 under the drive of the circulating pump 8. The cooling channel 10 adopts a serpentine, parallel, or mesh structure to ensure uniform distribution of the cooling medium 22. The cooling medium 22 continuously removes the heat of reaction through convective heat transfer. If a nanofluid is used, the thermally conductive nanoparticles in it increase the thermal conductivity of the medium and enhance the heat transfer efficiency. If a phase change fluid is used, the phase change material undergoes a phase change within the operating temperature range and absorbs latent heat, improving the system's thermal buffering capacity.

[0042] Through the synergistic cooperation of the above processes, the anode hydrothermal regulation functional membrane 13 maintains the hydration state of the fuel cell membrane electrode assembly through adsorption, storage, and desorption; the cathode hydrothermal regulation functional membrane 14 inhibits flooding and absorbs heat through dissolution endothermic reaction and water redistribution; and the cooling channel 10 removes residual reaction heat through convective heat transfer or phase change heat transfer. The anode hydrothermal regulation functional membrane 13, the cathode hydrothermal regulation functional membrane 14, and the cooling channel 10 together constitute a hydrothermal regulation system in the same system, coupling water migration and temperature distribution to solve the hydrothermal imbalance problem of the fuel cell 1, improve the stability and power density of the fuel cell 1 under high current density operating conditions, and extend the service life of the fuel cell system.

Claims

1. A fuel cell hydrothermal management system based on the synergy of functional membranes and cooling channels, characterized in that, It includes an anode hydrothermal regulation functional membrane disposed on the anode side of the fuel cell, a cathode hydrothermal regulation functional membrane disposed on the cathode side of the fuel cell, a cooling channel disposed inside the bipolar plate of the fuel cell, and a cooling circulation system connected to the cooling channel. Both the anode hydrothermal regulation functional membrane and the cathode hydrothermal regulation functional membrane are multi-layer gradient structure composite membranes. The anode hydrothermal regulation functional membrane and the cathode hydrothermal regulation functional membrane are respectively disposed on the inner wall surface of the anode gas flow channel and the inner wall surface of the cathode gas flow channel. The anode hydrothermal regulation functional membrane comprises a porous anode material layer, an adsorption regulation layer, and a selective anode mass transfer layer stacked sequentially. The porous anode material layer is disposed on the inner wall surface of the anode gas flow channel and is composed of porous carbon material or metal-based porous material. The adsorption regulation layer is composed of molecular sieve material, metal-organic framework material, or their composite materials. The selective anode mass transfer layer is a hydrophilic polymer membrane or an inorganic composite membrane. The selective anode mass transfer layer is used to achieve preferential permeation of water molecules and inhibit non-selective permeation of anode gas. The cathode hydrothermal regulation functional membrane includes a cathode porous material layer. A cathode selective mass transfer layer and a cathode phase change buffer layer are disposed on the surface of the cathode porous material layer. The cathode porous material layer is disposed on the inner wall surface of the cathode gas flow channel. An endothermic working fluid is loaded inside the pores of the cathode porous material layer. The cathode porous material layer is composed of one or more of metal-organic framework materials, molecular sieve materials, or porous carbon materials. The endothermic working fluid is an inorganic salt system or its composite system that is soluble in water and generates an endothermic effect during the dissolution process. The anode hydrothermal regulation functional membrane is used to maintain the hydration state of the fuel cell membrane electrode assembly through a cycle of water adsorption, storage, and desorption release; the cathode hydrothermal regulation functional membrane is used to adsorb liquid water generated at the cathode and absorb the heat of reaction through the dissolution and endothermic process of water and endothermic working medium; the cooling channel is used to remove the heat of reaction generated during fuel cell operation through the circulation of cooling medium; the anode hydrothermal regulation functional membrane, the cathode hydrothermal regulation functional membrane, and the cooling channel together constitute a hydrothermal regulation system in which water migration and temperature distribution are coupled.

2. The fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1, characterized in that, An anode phase change buffer layer is disposed on the surface of the anode porous material layer. The anode phase change buffer layer is located between the anode porous material layer and the inner wall surface of the anode gas flow channel. The phase change temperature of the anode phase change buffer layer is 60~80 ℃, and the thickness of the anode phase change buffer layer is 5~50 μm.

3. A fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1 or 2, characterized in that, The total thickness of the anode hydrothermal regulation functional membrane is 50~450μm, the thickness of the anode porous material layer is 10~150μm, the thickness of the adsorption regulation layer is 20~200μm, and the thickness of the anode selective mass transfer layer is 5~50μm.

4. The fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1, characterized in that, The cathode selective mass transfer layer is a hydrophilic polymer membrane or an inorganic composite membrane, and the thickness of the cathode selective mass transfer layer is 5~50μm. The cathode selective mass transfer layer is used to enable preferential permeation of water molecules and inhibit non-selective permeation of cathode gases.

5. A fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1 or 4, characterized in that, The cathode phase change buffer layer is located between the cathode porous material layer and the inner wall surface of the cathode gas flow channel. The phase change temperature of the cathode phase change buffer layer is 60~80 ℃, and the thickness of the cathode phase change buffer layer is 5~50 μm.

6. A fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1 or 4, characterized in that, The total thickness of the cathode hydrothermal regulation functional membrane is 30~300μm, and the thickness of the cathode porous material layer is 20~200μm.

7. A fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1, characterized in that, The cooling channels are disposed inside the bipolar plates of the fuel cell, forming a serpentine, parallel, or mesh channel structure, with a channel width or equivalent hydraulic diameter of 0.5–3 mm. The cooling medium is deionized water, nanofluid, or phase change fluid. The nanofluid is a suspension system formed by dispersing thermally conductive nanoparticles in deionized water. The thermally conductive nanoparticles are selected from one or more of alumina, copper oxide, carbon nanotubes, graphene, and silicon carbide. The phase change fluid is a suspension system or emulsion system containing a phase change material, and the phase change temperature of the phase change material is 30–90 °C.

8. The fuel cell hydrothermal management system based on the synergy of functional membrane and cooling channel as described in claim 1, characterized in that, The anode hydrothermal regulation functional membrane is formed on the inner wall surface of the anode gas flow channel by coating or in-situ construction, forming an integrated structure with the inner wall of the anode gas flow channel; the cathode hydrothermal regulation functional membrane is formed on the inner wall surface of the cathode gas flow channel by coating or in-situ construction, forming an integrated structure with the inner wall of the cathode gas flow channel.

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