Fuel cell membrane electrode interface working condition x-ray fluorescence detection device and characterization method

Abstract

The application discloses a kind of fuel cell membrane electrode interface working condition X-ray fluorescence detection device and characterization method, it is related to battery in-situ detection technical field, detection device includes the cathode assembly, membrane electrode and anode assembly that are sequentially arranged and sealingly connected;Detection passage is provided on cathode assembly or anode assembly, window film is sealingly provided in detection passage, and detection passage and window film can make detection ray pass and reach to membrane electrode, and can be excited to generate fluorescence signal by membrane electrode.The fuel cell membrane electrode interface working condition X-ray fluorescence detection device and method provided by the application can realize in-situ detection for the internal interface working condition of fuel cell, and provide accurate data support for reaction mechanism research and performance optimization.

Description

Technical Field

[0001] This invention relates to the field of in-situ battery testing technology, and in particular to an X-ray fluorescence detection device and characterization method for the working condition of a fuel cell membrane electrode interface. Background Technology

[0002] To build a green, low-carbon, and efficient energy system, developing new energy storage and conversion devices is a key path to achieving the sustainable use of green energy. Among them, proton exchange membrane fuel cells (PEMFCs), as a highly efficient and environmentally friendly energy conversion device, can directly convert the chemical energy in hydrogen into electrical energy and are considered an important component of future energy supply. However, their commercialization is limited by the high cost of the platinum (Pt)-based cathode catalyst and its performance degradation under operating conditions (such as Pt dissolution / deposition, agglomeration, migration / desorption, and transition metal leaching).

[0003] To monitor the dynamic changes in performance degradation and develop high-performance, high-durability catalysts, there is an urgent need for characterization methods that can directly, in real-time, and quantitatively analyze the elements inside the membrane electrode under operating conditions. X-ray fluorescence spectroscopy (XRF), as a rapid and non-destructive elemental analysis technique, can accurately determine the elemental composition of battery electrode materials and plays a key role in battery quality assessment and performance change analysis. However, traditional XRF analysis requires disassembling the battery and cannot provide real-time dynamic elemental evolution information under actual operating conditions such as working potential, humidity, atmosphere, and current, nor can it establish a correlation between elemental behavior and performance degradation. Summary of the Invention

[0004] The purpose of this invention is to provide an X-ray fluorescence detection device and characterization method for the working condition of the membrane electrode interface of a fuel cell, so as to solve the problems existing in the prior art. It can realize in-situ detection of the working condition of the internal interface of the fuel cell, and provide accurate data support for reaction mechanism research and performance optimization.

[0005] To achieve the above objectives, the present invention provides the following solution: The present invention provides an X-ray fluorescence detection device for the working condition of a fuel cell membrane electrode interface, comprising a cathode assembly, a membrane electrode, and an anode assembly arranged in sequence and sealed together; a detection path is provided on the cathode assembly or the anode assembly, and a window membrane is sealed in the detection path, and the detection path and the window membrane enable the detection rays to pass through and reach the membrane electrode, and enable the fluorescence signal generated by the membrane electrode to pass through.

[0006] Preferably, both the cathode assembly and the anode assembly include a sealing gasket, a gas diffusion layer, a flow field plate, a conductive plate, an insulating gasket, and an end plate that are sequentially and sealed together along the direction away from the membrane electrode; the cathode assembly further includes a hollow gasket disposed outside the end plate; the end plate, the insulating gasket, the conductive plate, and the flow field plate included in the cathode assembly or the anode assembly are provided with opposing and communicating through holes, and the window membrane is sealed in the through holes of the flow field plate, and each through hole constitutes the detection path.

[0007] Preferably, both the cathode assembly and the anode assembly are provided with inlet and outlet pipes, which are used for gas intake and product discharge.

[0008] Preferably, the cathode assembly and / or the anode assembly are provided with heating holes for accommodating heating components.

[0009] Preferably, the cathode assembly and / or the anode assembly are provided with a temperature measuring hole for accommodating the temperature measuring component.

[0010] Preferably, both the cathode assembly and the anode assembly are provided with protruding tabs, which are used for electrical connection to an external workstation.

[0011] Preferably, the window film is made of polyethylene terephthalate, polyimide, or polyethylene, and the thickness of the window film is 100μm-200μm.

[0012] Preferably, the thickness of the flow field plate is 5mm to 10mm, and the thickness of the flow field plate with the through hole is less than the thickness of the flow field plate without the through hole.

[0013] Preferably, the cathode assembly, the membrane electrode, and the anode assembly are detachably connected.

[0014] The present invention also provides an X-ray fluorescence characterization method for the operating conditions of a fuel cell membrane electrode interface, based on the X-ray fluorescence detection device for the operating conditions of a fuel cell membrane electrode interface as described above, comprising the following steps: A cathode assembly, membrane electrode assembly, and anode assembly are assembled into a fuel cell. The fuel cell is placed on the workbench of a test device, with an insulation pad between the fuel cell and the workbench. Reaction gases are introduced into the cathode assembly and the anode assembly, and the fuel cell is electrically connected to an external workstation. The membrane electrode assembly is then tested in situ using the test device.

[0015] The present invention achieves the following technical effects compared to the prior art: The X-ray fluorescence detection device and characterization method for the interface condition of the fuel cell membrane electrode provided by this invention, by setting a detection path on the cathode assembly or anode assembly and sealing a window membrane on the detection path, allows detection rays, namely X-rays and fluorescence signals, to pass through while maintaining the sealing of the reaction chamber where the membrane electrode is located, so as to realize in-situ monitoring of the interface condition of the membrane electrode. Under the actual operating conditions of the battery, the internal reaction process of the fuel cell can be observed in real time, and the reaction dynamics can be accurately captured, which can provide data support for reaction mechanism research and performance optimization. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an exploded schematic diagram of the X-ray fluorescence detection device for the membrane electrode interface of a fuel cell provided in Embodiment 1 of the present invention. Figure 2 This is a comparison chart of the polarization curves and power density curves of Embodiment 1 and Comparative Example 1 of the present invention; Figure 3 This is a comparison chart of cyclic voltammetry (CV) curves for Embodiment 1 and Comparative Example 1 of the present invention; Figure 4 These are the X-ray fluorescence (XRF) spectra of Examples 1, 3, and 4 of the present invention; Figure 5 These are the X-ray fluorescence (XRF) spectra of Examples 1, 6, and 7 of the present invention; Figure 6 These are the X-ray fluorescence (XRF) spectra of Examples 1 and 8 of the present invention; Figure 7 These are the X-ray fluorescence (XRF) spectra of Examples 1 and 9 of the present invention; Figure 8 The images show the X-ray fluorescence (XRF) spectra of Examples 1 and 10 of this invention.

[0018] In the diagram: 1-Cathode assembly; 2-Membrane electrode; 3-Anode assembly; 4-Window membrane; 5-Sealing gasket; 6-Gas diffusion layer; 7-Flow field plate; 8-Conductive plate; 9-Insulating gasket; 10-End plate; 11-Pan plate; 12-Through hole; 13-Inlet / outlet pipeline; 14-Heating hole; 15-Temperature measuring hole; 16-Electrode tab; 17-Connecting hole. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide an X-ray fluorescence detection device and characterization method for the working condition of the membrane electrode interface of a fuel cell, so as to solve the problems existing in the prior art. It can realize in-situ detection of the working condition of the internal interface of the fuel cell, and provide accurate data support for reaction mechanism research and performance optimization.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1 This embodiment provides an X-ray fluorescence detection device for the working condition of a fuel cell membrane electrode interface. Please refer to [link to relevant documentation]. Figure 1 It includes a cathode assembly 1, a membrane electrode 2, and an anode assembly 3 arranged in sequence and sealed together; the anode assembly 3 is provided with a detection path, and a window membrane 4 is sealed in the detection path, and the detection path and the window membrane 4 enable the detection rays to pass through and reach the membrane electrode 2, and enable the fluorescence signal generated by the excitation of the membrane electrode 2 to pass through.

[0023] By setting a detection path on the anode assembly 3 and sealing a window membrane 4 on the detection path, the detection rays, namely X-rays and fluorescence signals, can be transmitted to achieve in-situ monitoring of the interface conditions of the membrane electrode 2 while maintaining the sealing of the reaction chamber where the membrane electrode 2 is located. This allows for real-time observation of the internal reaction process of the fuel cell under actual battery operation conditions, accurately capturing reaction dynamics, and providing data support for reaction mechanism research and performance optimization.

[0024] In the optional embodiments of this example, more preferably, both the cathode assembly 1 and the anode assembly 3 include a sealing gasket 5, a gas diffusion layer 6, a flow field plate 7, a conductive plate 8, an insulating gasket 9, and an end plate 10 that are sequentially and sealed together along the direction away from the membrane electrode 2; the cathode assembly 1 also includes a hollow gasket 11 disposed outside the end plate 10; the end plate 10, the insulating gasket 9, the conductive plate 8, and the flow field plate 7 included in the anode assembly 3 are provided with opposite and interconnected through holes 12, and a window membrane 4 is sealed in the through holes 12 of the flow field plate 7, and each through hole 12 constitutes a detection path.

[0025] The through holes 12 are designed to facilitate X-ray penetration and fluorescence signal transmission. Specifically, each through hole 12 is circular. The flow field plate 7 of the anode assembly 3 is provided with a circular groove corresponding to the position of the through hole 12. The center of the groove has a circular through hole 12 to provide a path for X-rays to the membrane electrode 2. A window membrane 4 that fits the size of the groove is provided in the groove. The circular groove acts as a support bracket for the window membrane 4. The window membrane 4 can be bonded to the groove with high-temperature and water-resistant adhesive. Each through hole 12 can be set at any position on the corresponding end plate 10, insulating gasket 9, conductive plate 8 or flow field plate 7 according to actual needs, as long as it can meet the requirements for X-ray detection of the membrane electrode 2. Preferably, each through hole 12 is set at the center of the corresponding end plate 10, insulating gasket 9, conductive plate 8 or flow field plate 7.

[0026] More preferably, the pad 11 of the cathode assembly 1 is made of insulating bakelite board, which serves as insulation and support; the end plate 10 is made of aluminum alloy, which serves as heat conduction and insulation; the conductive plate 8 is made of gold-plated copper plate; the insulating gasket 9 is placed between the conductive plate 8 and the end plate 10 to serve as insulation; the flow field plate 7 of both the cathode assembly 1 and the anode assembly 3 is made of graphite plate, titanium plate or stainless steel plate, and a gas flow field is provided on the flow field plate 7; the gas diffusion layer 6 is cut from carbon paper; the membrane electrode 2 is composed of a proton exchange membrane coated with catalyst; a sealing gasket 5 is provided between the membrane electrode 2 and the flow field plate 7 to prevent the leakage of reaction gas.

[0027] In the optional scheme of this embodiment, it is more preferred that both the cathode assembly 1 and the anode assembly 3 are provided with inlet and outlet pipes 13, which are used for gas intake and product discharge.

[0028] The flow field plate 7 of the cathode assembly 1 and the peripheral side of the end plate 10 of the anode assembly 3 are provided with through holes. The inlet and outlet pipes 13 are connected at the through holes. The inlet and outlet pipes 13 on the flow field plate 7 of the cathode assembly 1 are directly connected to the flow field on the flow field plate 7 through the through holes. The inlet and outlet pipes 13 on the end plate 10 of the anode assembly 3 are connected to the gas flow field on the flow field plate 7 through the through holes and the connecting holes 17 on the conductive plate 8 and the insulating gasket 9 of the anode assembly 3. The connecting holes 17 on the conductive plate 8 and the insulating gasket 9 are arranged diagonally, and the gas is connected between the opposite connecting holes 17.

[0029] In the optional scheme of this embodiment, more preferably, the cathode assembly 1 and / or the anode assembly 3 are provided with heating holes 14 for accommodating heating components; in this embodiment, the heating holes 14 are provided on the end plate 10 of the cathode assembly 1, and two are provided for placing heating rods to achieve temperature control.

[0030] In the optional scheme of this embodiment, more preferably, the cathode assembly 1 and / or the anode assembly 3 are provided with a temperature measuring hole 15 for accommodating the temperature measuring component; in this embodiment, the temperature measuring hole 15 is provided on the flow field plate 7 of the cathode assembly 1 for placing the temperature measuring component and realizing real-time monitoring of temperature.

[0031] In the optional scheme of this embodiment, more preferably, both the cathode assembly 1 and the anode assembly 3 are provided with protruding tabs 16, which are used for electrical connection to an external workstation; wherein, both the cathode assembly 1 and the anode assembly 3 are provided with protruding tabs 16 on the conductive plate 8, and the two tabs 16 are connected to the electrochemical workstation and distinguished between the cathode and the anode by connecting alligator clips.

[0032] In the optional embodiments of this example, it is more preferred that the window membrane 4 is made of polyethylene terephthalate, polyimide, or polyethylene, and the thickness of the window membrane 4 is 100μm-200μm. The window membrane 4 can meet the requirements of high transmittance for X-rays and fluorescence signals, while also meeting the sealing requirements of the fuel cell's own reaction. In this example, it is preferred that the window membrane 4 is made of polyethylene terephthalate, i.e., PET, and the thickness is 150μm.

[0033] In the optional scheme of this embodiment, more preferably, the thickness of the flow field plate 7 is 5mm~10mm, and the thickness of the flow field plate 7 with through holes 12 is less than the thickness of the flow field plate 7 without through holes 12; further, in this embodiment, the flow field plate 7 of the anode assembly 3 is set to 5mm, and the flow field plate 7 of the cathode assembly 1 is set to 10mm. By designing a thinner structure for the flow field plate 7 of the anode assembly 3, the reduction in thickness can effectively shorten the path of X-rays to the membrane electrode.

[0034] In the optional scheme of this embodiment, more preferably, the cathode assembly 1, the membrane electrode 2 and the anode assembly 3 can be detachably connected; specifically, the cathode assembly 1 and the anode assembly 3 are fixed together with bolts, and a fixing torque is applied to the bolts to ensure the sealing and stability of the reaction inside the fuel cell.

[0035] As described above, the X-ray fluorescence detection device for the fuel cell membrane electrode interface provided in this embodiment has the following beneficial effects: the window membrane 4 can ensure efficient X-ray penetration while achieving sealed protection of the internal chamber of the battery device, balancing detection penetration and device sealing; the flow field plate 7 of the anode assembly 3 adopts a thin design, effectively shortening the X-ray path and improving the XRF detection effect; it can observe the internal reaction process of the fuel cell in real time under the actual operating conditions of the battery, accurately capture the reaction dynamics, and provide data support for reaction mechanism research and performance optimization; the whole device is characterized by small size, light weight, and convenient disassembly and assembly, making it easy to use and batch assembly, which is beneficial to practical applications and mass production; it has a wide range of applications and can be widely used in the field of in-situ detection of various electrochemical devices.

[0036] Example 2 This embodiment provides a characterization method based on the X-ray fluorescence detection device for the membrane electrode interface of a fuel cell provided in Embodiment 1, including the following steps: assembling a cathode assembly 1, a membrane electrode 2, and an anode assembly 3 into a fuel cell; placing the fuel cell on the workbench of the test equipment, with an insulation pad between the fuel cell and the workbench; introducing reaction gases into the cathode assembly 1 and the anode assembly 3 respectively; electrically connecting the fuel cell to an external workstation; and performing in-situ testing of the membrane electrode 2 through the test equipment.

[0037] Specifically, the cathode assembly 1, membrane electrode 2, and anode assembly 3 are assembled and fastened with bolts to form a proton exchange membrane fuel cell (PEMFC), resulting in an X-ray fluorescence detection device for the membrane electrode interface of the fuel cell (the window membrane material of the flow field plate 7 of the anode is PET with a thickness of 150μm), abbreviated as XRF-PET150-PEMFC; the flow field plate 7 of the cathode and the end plate 10 of the anode are respectively connected to gas inlet and outlet pipelines, and the gas inlet end is connected to a mass flow meter and a humidification device to introduce the reaction gas.

[0038] Before in-situ XRF testing, the anode side of the fuel cell device with the light-transmitting hole is placed downwards, and the incident path of the X-rays is from bottom to top. A heat insulation pad is placed between the battery and the XRF equipment stage to prevent the stage from being damaged when the battery is operating at the operating temperature. An obstruction hole is opened in the middle of the heat insulation pad to avoid blocking the passage of X-rays and fluorescence signals.

[0039] The battery temperature is controlled at 80°C using a heating rod and a temperature controller. Nitrogen and hydrogen are introduced into the cathode assembly 1 and anode assembly 3 of the battery, respectively. An electrochemical workstation is connected, and an EDX600PLUS X-ray fluorescence spectrometer is used as the testing instrument. The working platform of the spectrometer is moved to locate the test point, and in-situ XRF testing is carried out to monitor the elemental changes of the fuel cell membrane electrode.

[0040] Comparative Example 1 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in Example 1 is that the flow field plate 7, conductive plate 8, insulating gasket 9 and end plate 10 of the anode assembly 3 are not provided with through holes 12 for X-rays to pass through, and the window membrane 4 is not provided in the center of the flow field plate 7. The resulting fuel cell device is referred to as S-PEMFC.

[0041] To verify the performance difference between the battery device (XRF-PET150-PEMFC) with a detection pathway and window membrane 4 in Example 1 and the complete standard fuel cell (S-PEMFC) without a detection pathway and window membrane 4 in Comparative Example 1, electrochemical tests were performed.

[0042] The (hydrogen) H2 / (air) performance was tested using a Scribner 850G fuel cell test system. The PEMFC temperature was 80℃, the back pressure was 50 kPa, the relative humidity was 100%, and the anode H2 flow rate was set to 0.5 L / min, while the cathode air flow rate was set to 2.5 L / min. Before polarization curve testing, the PEMFC was activated using a constant-pressure step method. Polarization curves were acquired using a multi-stage constant-current method, with each current stage maintained for 5 minutes. The average current for the last minute was collected, and the polarization and power density curves were plotted accordingly. Figure 2 Cyclic voltammetry was performed by applying a linearly scanning triangular wave potential to the working electrode. The H2 flow rate at the anode was set to 0.1 L / min, the N2 flow rate at the cathode to 0.3 L / min, and the battery temperature to 80 °C. The curves of electrode current versus potential were obtained, i.e., the cyclic voltammetry plot. Figure 3 ).

[0043] Depend on Figure 2 , 3 It can be seen that the main electrochemical performance of XRF-PET150-PEMFC is not significantly different from that of S-PEMFC. The polarization characteristics, maximum power density, and electrochemical active area of ​​XRF-PET150-PEMFC in Example 1 are comparable to those of a complete standard cell. This indicates that the detection pathway and window membrane 4 structure designed in Example 1, while achieving in-situ XRF testing, did not substantially affect the intrinsic reactions, mass transfer process, or overall output performance of the fuel cell, thus demonstrating the effectiveness of the detection pathway and window membrane 4 structure constructed in Example 1 in maintaining the stability and reliability of the cell operation.

[0044] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0045] Example 3 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the window membrane 4 is changed to Kapton (polyimide) material, and the resulting fuel cell device is referred to as XRF-Kapton150-PEMFC.

[0046] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0047] Example 4 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the window membrane 4 is changed to PE (polyethylene) material, and the resulting fuel cell device is referred to as XRF-PE150-PEMFC.

[0048] Figure 4 These are the X-ray fluorescence (XRF) spectra of Examples 1, 3, and 4. Figure 4 It can be seen that, under the same test conditions, when the window film material is polyethylene terephthalate (PET), the intensity of its characteristic X-ray fluorescence signal is the highest, indicating that this material has the best transmittance performance for incident X-rays and emitted fluorescence. In contrast, the Kapton and PE window films 4 used in Examples 3 and 4 both showed different degrees of signal attenuation at the same thickness.

[0049] The above results demonstrate that PET material has better X-ray transmission characteristics when used in X-ray window membrane 4, which is beneficial for achieving highly sensitive in-situ monitoring of the migration process of elements inside the fuel cell.

[0050] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0051] Example 5 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the thickness of the window membrane 4 is changed to 100μm, and the resulting fuel cell device is referred to as XRF-PET100-PEMFC.

[0052] In-situ XRF testing revealed that when a 100μm thick PET film was used as the X-ray window membrane 4, significant bulging and deformation occurred under rated operating pressure, eventually leading to rupture and failure of the battery's airtightness. This result indicates that at this thickness, the mechanical strength of the PET window membrane 4 is insufficient to withstand pressure changes within the fuel cell, and therefore it is unsuitable for long-term stable in-situ testing.

[0053] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0054] Example 6 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the thickness of the window membrane 4 is changed to 200μm, and the resulting fuel cell device is referred to as XRF-PET200-PEMFC.

[0055] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0056] Example 7 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the thickness of the window membrane 4 is changed to 250 μm, and the resulting fuel cell device is referred to as XRF-PET250-PEMFC.

[0057] Figure 5 The X-ray fluorescence (XRF) spectra of Examples 1, 6, and 7 are shown. As can be seen from the figures, Example 1 exhibits the highest peak intensity, Example 6 shows a decrease in peak intensity, and Example 7 shows the weakest peak intensity. This trend indicates that as the thickness of the PET window film 4 increases, the attenuation of the incident X-ray beam and the emitted fluorescence signal significantly increases, leading to a decrease in detection sensitivity.

[0058] A comprehensive comparison of Examples 1, 5, 6, and 7 shows that when the window film thickness 4 is too thin (as in Example 5), although it is beneficial for X-ray transmission, the mechanical strength is insufficient, making it difficult to guarantee the long-term stability and airtightness of the battery under operating pressure; when the window film thickness 4 is too thick (as in Examples 6 and 7), the mechanical strength is improved, but the X-ray transmittance decreases significantly.

[0059] Therefore, the preferred thickness range of the PET window film 4 in this invention is between 100 μm and 200 μm, and more preferably around 150 μm. This thickness range, while ensuring sufficient mechanical strength and operational stability, can achieve high X-ray transmittance, thus balancing the durability and detection sensitivity of the in-situ testing device.

[0060] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0061] Example 8 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the thickness of the flow field plate 7 of the anode assembly 3 is changed from 5mm to 10mm, and the resulting fuel cell device is referred to as XRF-Anode10-PEMFC.

[0062] Figure 6The figures show the X-ray fluorescence (XRF) spectra of Example 1 (the thickness of the flow field plate 7 of the anode assembly 3 is 5 mm) and Example 8 (the thickness of the flow field plate 7 of the anode assembly 3 is 10 mm). As shown in the figure, the intensity of the characteristic X-ray fluorescence peak in Example 1 is significantly higher than that in Example 8. This difference indicates that Example 1, by thinning the flow field plate 7 of the anode assembly 3, effectively shortens the path of X-rays to the membrane electrode 2, thereby significantly reducing X-ray scattering loss and improving the excitation efficiency and signal acquisition intensity of X-ray fluorescence.

[0063] The other mechanisms provided in this embodiment are the same as those in Embodiment 1, and will not be described in detail here.

[0064] Example 9 The difference between the X-ray fluorescence characterization method for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 2 is that air and hydrogen are introduced into the cathode assembly 1 and the anode assembly 3 respectively, and the resulting fuel cell device is referred to as XRF-Air / H2-PEMFC.

[0065] Figure 7 The images show the X-ray fluorescence (XRF) spectra of Examples 1 and 9. In Example 1, nitrogen gas was introduced into the cathode and hydrogen gas into the anode during the test; in Example 9, air was introduced into the cathode and hydrogen gas into the anode.

[0066] from Figure 7 As can be seen, the two XRF curves did not show significant differences in the position, intensity, and shape of the characteristic peaks. This indicates that the change in the cathode-side inlet gas composition (nitrogen or air) did not cause any observable interference in the in-situ X-ray fluorescence test.

[0067] Therefore, the in-situ testing method has stable signal reproducibility under different cathode atmosphere conditions, and can be further used to simulate element migration and distribution studies under real working conditions, with good working condition adaptability and testing reliability.

[0068] Example 10 The difference between the X-ray fluorescence detection device for the membrane electrode interface of the fuel cell provided in this embodiment and that in Embodiment 1 is that the detection path and window membrane 4 are set on the cathode assembly 1, and the detection path and window membrane 4 are not set on the anode assembly 3; the thickness of the flow field plate 7 of the cathode assembly 1 is changed to 5mm, and the resulting fuel cell device is referred to as XRF-Cathode-PEMFC.

[0069] Figure 8 These are the X-ray fluorescence (XRF) spectra of Examples 1 and 10. Figure 8It can be seen that the two XRF curves do not show significant differences in the position, intensity, and shape of the characteristic peaks. This indicates that, under the condition of using the same material and thickness of window membrane 4, designing the X-ray window membrane 4 structure on the anode side or the cathode side does not have a systematic impact on in-situ X-ray fluorescence testing. Therefore, the implementation scheme of the detection pathway and window membrane 4 is universal, and its structure and material selection are also applicable to the construction on the cathode side of fuel cells.

[0070] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An X-ray fluorescence detection device for the working condition of a fuel cell membrane electrode interface, characterized in that: It includes a cathode assembly (1), a membrane electrode (2), and an anode assembly (3) that are arranged in sequence and sealed together. The cathode assembly (1) or the anode assembly (3) is provided with a detection path, and a window membrane (4) is sealed in the detection path. The detection path and the window membrane (4) enable the detection rays to pass through and reach the membrane electrode (2), and enable the fluorescence signal generated by the excitation of the membrane electrode (2) to pass through.

2. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: Both the cathode assembly (1) and the anode assembly (3) include a sealing gasket (5), a gas diffusion layer (6), a flow field plate (7), a conductive plate (8), an insulating gasket (9), and an end plate (10) that are sequentially and sealed together in a direction away from the membrane electrode (2); the cathode assembly (1) also includes a hollow gasket (11) disposed on the outside of the end plate (10). The cathode assembly (1) or the anode assembly (3) includes an end plate (10), an insulating gasket (9), a conductive plate (8), and a flow field plate (7) with opposite and interconnected through holes (12). The flow field plate (7) has a window membrane (4) sealed in the through hole (12). Each through hole (12) constitutes the detection path.

3. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: Both the cathode assembly (1) and the anode assembly (3) are provided with inlet and outlet pipes (13), which are used for gas intake and product discharge.

4. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: The cathode assembly (1) and / or the anode assembly (3) are provided with heating holes (14) for accommodating heating components.

5. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: The cathode assembly (1) and / or the anode assembly (3) are provided with a temperature measuring hole (15) for accommodating the temperature measuring component.

6. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: Both the cathode assembly (1) and the anode assembly (3) are provided with protruding tabs (16), which are used for electrical connection to an external workstation.

7. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: The window film (4) is made of polyethylene terephthalate, polyimide or polyethylene, and the thickness of the window film (4) is 100μm-200μm.

8. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 2, characterized in that: The thickness of the flow field plate (7) is 5mm to 10mm, and the thickness of the flow field plate (7) with the through hole (12) is less than the thickness of the flow field plate (7) without the through hole (12).

9. The X-ray fluorescence detection device for the working condition of the fuel cell membrane electrode interface according to claim 1, characterized in that: The cathode assembly (1), the membrane electrode (2), and the anode assembly (3) are detachable and connectable.

10. A method for characterizing the working condition of a fuel cell membrane electrode interface using X-ray fluorescence, characterized in that: The X-ray fluorescence detection device for the operating conditions of the fuel cell membrane electrode interface as described in any one of claims 1-9 includes the following steps: The cathode assembly (1), membrane electrode (2) and anode assembly (3) are assembled into a fuel cell. The fuel cell is placed on the workbench of the test equipment, and an insulation pad is provided between the fuel cell and the workbench. Reaction gases are introduced into the cathode assembly (1) and the anode assembly (3) respectively, and the fuel cell is electrically connected to an external workstation. The membrane electrode (2) is tested in situ through the test equipment.

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