Regulation Method and System for Dynamic Dispersion of Ionomer in Hydrogen Fuel Cell Catalyst Slurry

Abstract

The present invention relates to a method and system for regulating the dynamic dispersion of ionomers in a hydrogen fuel cell catalyst slurry, including: placing the catalyst slurry containing ionomers in a shear field, controlling the shear force to decrease step by step from an initial preset value to zero, so that the molecular chains of the ionomers are disentangled without breaking under the continuously weakening shear action; for the slurry after shear treatment, in the temperature range of 40-60 °C, at least one heating and cooling thermal cycle treatment is carried out, and the number of times of the thermal cycle is the same as the number of times of the step-by-step decrease in the shear force; laminar flow treatment is carried out on the treated slurry, controlling the flow velocity so that the Reynolds number is less than 10, and maintaining its flow state for at least 30 s, and three-dimensional disordered network structures of ionomer fibers are formed through the viscous resistance of the fluid. Through three mutually cooperative action stages of the shear force field, thermal cycle and laminar flow stabilization, the present invention realizes the precise regulation of the whole process from the macroscopic disentanglement of ionomer fibers to the microscopic network construction.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen fuel cell preparation, and in particular to a method and system for regulating the dynamic dispersion of ionomers in a hydrogen fuel cell catalyst slurry. Background Art

[0002] As a clean energy conversion device, the performance of the catalyst layer, which is the core component of a hydrogen fuel cell, directly determines the output power and durability of the battery. During the preparation process of the catalyst slurry, the dispersion state of the ionomer is a key factor affecting the electrode performance. It needs to form a continuous proton conduction channel and maintain sufficient gas diffusion pores.

[0003] Currently, mechanical stirring or ultrasonic treatment is generally used in the industry to achieve ionomer dispersion. Although these methods can achieve a basic dispersion effect, there is a fundamental problem: it is impossible to ensure both the full disentanglement of ionomer fibers and the stability of the network structure at the same time; the high shear force generated by mechanical stirring can break up ionomer aggregates, but it will cause molecular chain breakage and local overheating; while ultrasonic treatment can achieve microscopic dispersion, it is difficult to control the final arrangement form of the ionomers.

[0004] More seriously, the random turbulence generated during the processing of the prior art will cause the ionomer fibers to be oriented, and this anisotropic structure is prone to structural collapse in the humid and hot environment during the operation of the electrode, resulting in the interruption of the proton conduction channel. Summary of the Invention

[0005] Therefore, the present invention provides a method and system for regulating the dynamic dispersion of ionomers in a hydrogen fuel cell catalyst slurry, which solves the problems of uneven dispersion, fiber orientation, and poor structural stability existing in the traditional methods, and provides an effective method guarantee for the preparation of a high-performance fuel cell catalyst layer.

[0006] To solve the above technical problems, the present invention provides a method for regulating the dynamic dispersion of ionomers in a hydrogen fuel cell catalyst slurry, including:

[0007] Placing the catalyst slurry containing ionomers in a shear field, and controlling the shear force to decrease step by step from an initial preset value to zero, so that the ionomers achieve molecular chain disentanglement without breakage under the continuously weakening shear action;

[0008] Performing at least one heating and cooling thermal cycle treatment on the slurry after shear treatment in a temperature range of 40 - 60 °C, and the number of times of the thermal cycle is the same as the number of times of the step-by-step decrease of the shear force;

[0009] The processed slurry is subjected to laminar flow treatment, controlling the flow velocity to make the Reynolds number less than 10, and maintaining its flow state for at least 30 s, so that the ionomer fibers form a three-dimensional disordered network structure through fluid viscous resistance.

[0010] In one embodiment of the present invention, during the process of gradually decreasing shear force, the change of slurry viscosity is monitored in real time through an on-line viscometer, and the gradient of gradually decreasing shear force is controlled to be dynamically adjusted according to the viscosity-shear force correlation curve, so that the disentanglement rate of ionomer molecular chains matches the shear force decay rate.

[0011] In one embodiment of the present invention, during the process of gradually decreasing shear force, the slurry temperature is synchronously adjusted. The slurry temperature is monitored in real time through a temperature sensor, and the heating power is dynamically adjusted according to the preset shear field strength-temperature correlation model. When the shear field strength decreases, the slurry temperature is correspondingly decreased to maintain a constant ionomer disentanglement kinetic condition.

[0012] In one embodiment of the present invention, during the process of gradually decreasing shear force, an inert gas is synchronously injected to form a microbubble buffer layer inside the slurry, and the gas injection flow rate is positively correlated with the decrease of shear force.

[0013] In one embodiment of the present invention, the thermal cycle treatment includes first heating to the upper limit of the target temperature at a fixed rate, maintaining a constant temperature, and then cooling to the lower limit of the initial temperature at the same rate, and multiple thermal cycle treatments are continuously completed.

[0014] In one embodiment of the present invention, during the thermal cycle treatment process, a positive and a reverse centrifugal force field are alternately applied, and the direction switching frequency is synchronized with the temperature change rate.

[0015] In one embodiment of the present invention, during the laminar flow treatment stage, the flow velocity control is realized through a multi-stage tapered flow channel. The cross-sectional area of the flow channel is contracted in multiple stages in proportion, and an equal-cross-section stable section is set after each contraction.

[0016] In one embodiment of the present invention, during the laminar flow treatment stage, a periodic pulsating disturbance is introduced. The disturbance frequency is 1-5 Hz, the pulsating amplitude does not exceed 20% of the average flow velocity, and each disturbance period includes a flow velocity fluctuation of 0.5-2 s and a stable recovery period of 3-5 s.

[0017] In one embodiment of the present invention, after the laminar flow treatment, the slurry is transferred to a vacuum environment and left standing before subsequent process treatment.

[0018] To solve the above technical problems, the present invention also provides a regulation system for dynamic dispersion of ionomers in a hydrogen fuel cell catalyst slurry, including:

[0019] A shear force regulation module, which is used to apply a shear force field to the catalyst slurry containing ionomer and control the shear force to decrease step by step from an initial preset value to zero, so that the ionomer can achieve molecular chain disentanglement without breaking under the continuously weakening shear action;

[0020] A thermal cycling treatment module, which is connected to the shear force regulation module and is used to perform at least one heating and cooling thermal cycling treatment on the slurry after shear treatment in a temperature range of 40 - 60 °C. The number of thermal cycles is the same as the number of times the shear force decreases step by step;

[0021] A laminar flow stabilization module, which is connected to the thermal cycling treatment module and is used to perform laminar flow treatment on the treated slurry, control the flow velocity so that the Reynolds number is less than 10, and maintain its flow state for at least 30 seconds, so that the ionomer fibers form a three-dimensional disordered network structure through fluid viscous resistance;

[0022] A control unit, which is communicatively connected to the shear force regulation module, the thermal cycling treatment module and the laminar flow stabilization module respectively, and is used to coordinate the operating parameters and timing relationships of each module.

[0023] The above technical solution of the present invention has the following advantages compared with the prior art:

[0024] In the method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry of the present invention, gentle disentanglement of the ionomer is achieved through a step-by-step decreasing shear force field, avoiding molecular chain damage caused by traditional high shear. The design of the shear force decreasing in stages from the initial value enables the ionomer bundles to gradually unfold under the continuously weakening mechanical action without breaking due to sudden stress changes.

[0025] The subsequent thermal cycling treatment utilizes the material expansion difference caused by temperature changes. When the slurry alternates between 40 - 60 °C, the periodic stress generated at the interface between the ionomer fibers and the solvent can effectively peel off the binding between the fibers. This non-mechanical separation method avoids the damage to the molecular structure caused by external shear force. Notably, the corresponding relationship between the number of thermal cycles and the number of times the shear force decreases step by step ensures that each disentanglement stage can obtain appropriate thermodynamic compensation, forming a synergistic effect of mechanical energy and thermal energy.

[0026] In the final laminar flow stabilization stage, by strictly controlling the flow conditions (Reynolds number less than 10), an ideal self-assembly environment is provided for the ionomer fibers. Under such low-disturbance conditions, the fluid viscous force can gently guide the movement of the fibers, enabling them to have enough time (at least 30 seconds) to explore the most stable configuration through Brownian motion and finally spontaneously form a three-dimensional network with an ideal pore distribution.

[0027] This structure not only maintains the continuity required for proton conduction but also has good mechanical stability. Through the orderly cooperation of three stages, the entire technical solution realizes the full-process optimization from macroscopic dispersion to microscopic structure regulation, fundamentally solving the contradiction that it is difficult for traditional methods to balance dispersion quality and structural stability. Ultimately, the uniform dispersion of the ionomer fibers and the construction of an ideal network are achieved, solving problems such as uneven dispersion, fiber orientation arrangement, and poor structural stability in traditional methods, providing an effective method guarantee for the preparation of high-performance fuel cell catalyst layers. Brief Description of the Drawings

[0028] To make the content of the present invention easier to understand clearly, the following further details the present invention according to specific embodiments of the present invention in combination with the accompanying drawings, where:

[0029] Figure 1 is a flowchart of the steps of the method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry of the present invention;

[0030] Figure 2 is a structural framework diagram of the system for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry of the present invention. Detailed Embodiments

[0031] The following further illustrates the present invention in combination with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0032] Referring to Figure 1 As shown, the present invention discloses a method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry, including the following steps executed sequentially:

[0033] S10. Place the catalyst slurry containing the ionomer in a shear field, and control the shear force to gradually decrease from an initial preset value to zero in stages, so that the ionomer realizes molecular chain disentanglement without breaking under the continuously weakening shear action.

[0034] First, in the stage of the shear force field decreasing in stages, the method of gradually reducing the shear force can avoid the problem of molecular chain breakage caused by traditional high-speed shearing. By gradually reducing the shear force from the initial value to zero, the ionomer bundles realize progressive disentanglement under the continuously weakening shear action. This control scheme can ensure that the molecular chains are always in a suitable stress state during the disentanglement process, avoiding both breakage caused by stress concentration and secondary entanglement caused by a sudden drop in shear force.

[0035] S20. For the slurry after shear treatment, perform at least one heating and cooling thermal cycle treatment in a temperature range of 40 - 60 °C, and the number of times of the thermal cycle is the same as the number of times of the shear force decreasing in stages.

[0036] Secondly, in the thermal cycling stage, the slurry is heated and cooled in the temperature range of 40 - 60 °C. The microscopic peeling effect is generated by the difference in the coefficient of thermal expansion between the ionomer fiber and the solvent. Specifically, the temperature range of 40 - 60 °C not only ensures sufficient thermal perturbation intensity but also avoids the degradation of the ionomer caused by high temperature. At the same time, it is required that the number of thermal cycles is the same as the number of shear force gradings decreasing. This corresponding relationship ensures that the molecular chain relaxation generated in each shear force decreasing stage can obtain corresponding thermodynamic compensation, forming a synergistic mechanism of mechanical - thermal energy.

[0037] S30. The treated slurry is subjected to laminar flow treatment. The flow velocity is controlled so that the Reynolds number is less than 10, and its flow state is maintained for at least 30 s. The ionomer fibers form a three - dimensional disordered network structure through the viscous resistance of the fluid.

[0038] Finally, in the laminar flow stabilization stage, the Reynolds number is controlled to be less than 10, so that the fluid is in a strict laminar flow state. At this time, the viscous force of the fluid is much greater than the inertial force, and the flow presents a highly ordered layered structure. This low - perturbation environment provides ideal conditions for the self - assembly of ionomer fibers. Specifically, in the laminar flow state, the shear stress generated by the fluid velocity gradient can overcome the van der Waals force between the ionomer fibers but will not destroy the formed network structure; controlling the flow state to be maintained for at least 30 seconds is based on the relaxation characteristics of the ionomer fibers. Experiments show that the conformational rearrangement time constant of the ionomer fibers treated at 40 - 60 °C is about 15 - 25 seconds, and a 30 - second duration can ensure that more than 99% of the fibers complete orientation relaxation;

[0039] In the laminar flow state, the uniform velocity field makes the fibers receive a consistent viscous resistance, avoiding local stress concentration caused by turbulence. Setting a sufficient duration ensures that the fibers can fully explore their conformational space. Finally, through the synergistic action of Brownian motion and fluid shear force, a three - dimensional disordered network structure with an ideal porosity is spontaneously formed.

[0040] Specifically, through three mutually synergistic action stages of shear force field, thermal cycling, and laminar flow stabilization, the whole process of precise regulation from macroscopic disentanglement to microscopic network construction of ionomer fibers is realized. Among them: the decreasing shear force gradings provide the action object and triggering timing for thermal cycling, the thermal cycling treatment provides thermodynamic stability conditions for the molecular chains after shear disentanglement, and the laminar flow stabilization completes the final shaping of the microscopic structure on the basis of the first two steps; this multi - stage synergistic mechanism finally realizes the uniform dispersion and ideal network construction of ionomer fibers, solving the problems of uneven dispersion, poor fiber orientation arrangement, and poor structural stability in traditional methods, and providing an effective method guarantee for the preparation of high - performance fuel cell catalyst layers.

[0041] Specifically, in order to further illustrate the characteristics of the catalyst slurry prepared by using the regulation method in this embodiment, the inventors also used the catalyst slurry prepared according to the technical solution of the present invention as an example, the catalyst slurry prepared by mechanical stirring as Comparative Example 1, and the catalyst slurry prepared by ultrasonic treatment as Comparative Example 2 to detect the performance of the catalyst slurry. The comparison results are shown in Table 1:

[0042] Table 1

[0043]

[0044] Analysis of the above test results: In the example, through the synergistic effect of hierarchical shearing and thermal cycling, the ionomer fibers are maintained at a moderate length (1.2 ± 0.3 μm), while mechanical stirring causes fiber breakage due to high shear (0.5 - 4.8 μm), and ultrasonic treatment results in uneven fiber length due to local overheating caused by the cavitation effect (0.8 - 2.5 μm).

[0045] The mild treatment conditions in the example result in a molecular weight retention rate ≥ 97%, significantly higher than that of mechanical stirring (82 - 85%) and ultrasonic treatment (88 - 92%). This is due to: the shear force decreasing gradually to avoid stress concentration, and controlling the thermal cycling temperature window of 40 - 60 °C can prevent thermal degradation.

[0046] The three-dimensional disordered network (porosity of 68 - 72%) formed in the laminar flow stable stage in the example is more conducive to gas transmission than that of mechanical stirring (45 - 55%) and ultrasonic treatment (60 - 65%). Moreover, the continuous ionomer network reduces the surface resistance to 0.18 - 0.22 Ω·cm², improving by more than 40% compared with Comparative Example 1 and Comparative Example 2. The three-dimensional disordered network enables the maximum power density to reach 1.15 - 1.25 W / cm², increasing by 30 - 50% compared with Comparative Example 1 and Comparative Example 2.

[0047] The slurry in the example shows no stratification after standing for 72 hours, far superior to the 12 - 24 hour stability of Comparative Example 1 and Comparative Example 2. This is attributed to: the laminar flow stage (Re < 10) eliminates fiber aggregation caused by turbulence, and the 30-second duration ensures sufficient structural relaxation.

[0048] Specifically, in this embodiment, the method of gradually decreasing shear force is adopted. Its core lies in realizing the progressive disentanglement of ionomer molecular chains through a precisely controlled shear field. In this process, the change in slurry viscosity directly reflects the disentanglement state of ionomer molecular chains and the evolution of the network structure. Therefore, the inventors want to introduce an on-line viscosity monitoring and dynamic adjustment mechanism to establish a real-time feedback relationship between shear force regulation and ionomer structure evolution, making the entire disentanglement process more controllable and efficient.

[0049] During the implementation process, the viscosity of the slurry is continuously monitored by an online viscometer. When the shear force starts to decrease from the initial preset value, the ionomer molecular chains gradually change from a highly oriented state to a partially disentangled state. This transformation causes the slurry viscosity to exhibit a specific variation pattern: initially, as the shear force decreases, the previously stretched molecular chains begin to retract, and the intermolecular interactions increase, manifested as a slow increase in viscosity. When the shear force drops to a certain critical value, the ionomer molecular chains gain sufficient space for movement and start to form a transient network structure, at which point the viscosity will show a significant jump. By establishing a viscosity-shear force correlation curve, this transition point can be accurately captured, providing a scientific basis for the hierarchical adjustment of the shear force.

[0050] Based on the viscosity change data monitored in real time, the system dynamically adjusts the gradient of the shear force decrease. When it is detected that the viscosity increase rate exceeds the expected range, it indicates a mismatch between the disentanglement process of the ionomer molecular chains and the decrease rate of the shear force. At this time, the next-level shear force decrease needs to be postponed and continued after the viscosity change tends to be stable.

[0051] This feedback regulation mechanism ensures that the ionomer molecular chains can be gradually disentangled while maintaining the structural integrity, avoiding the molecular chain breakage or excessive aggregation caused by a sudden drop in shear force. Through this precise control, the ionomer molecular chains can release the stored elastic potential energy at an optimal rate and finally form an ideal dispersion state.

[0052] In the preparation process of the hydrogen fuel cell catalyst slurry, the disentanglement process of the ionomer molecular chains is essentially a kinetic process closely related to temperature. Therefore, on the basis of the above embodiments, a temperature synchronous regulation mechanism is further introduced to solve the problem of the mismatch of the molecular motion ability of the ionomer when the shear field changes, so that the entire disentanglement process is always under the optimal thermodynamic conditions.

[0053] During the implementation process, the temperature sensor continuously collects the slurry temperature data, which together with the shear field strength information obtained by the shear force sensor constitutes the input signal of the closed-loop control system. When the system detects that the shear force starts to decrease hierarchically, according to the pre-established shear field strength-temperature correlation model, the temperature value required for the ionomer molecular chains to maintain the optimal disentanglement rate at the current shear field strength is calculated. The core physical basis of this correlation model is that the shear field strength directly affects the orientation degree and stress state of the molecular chains, while the temperature determines the movement ability of the molecular segments. By adjusting the heating power, the slurry temperature can be made to decrease correspondingly as the shear force decreases, compensating for the increase in the molecular chain movement ability caused by the weakening of the shear force, thus maintaining a constant disentanglement kinetic condition.

[0054] Under a higher shear field, the molecular chains are strongly stretched. At this time, a higher temperature is required to provide sufficient segmental mobility to achieve disentanglement. As the shear force decreases, the stress state of the molecular chains gradually relaxes. At this time, appropriately reducing the temperature can avoid random entanglement caused by excessive movement of the molecular chains. Through this dynamic balance, the ionic polymer molecular chains can release internal stress at the most stable rate and achieve a uniform and controllable disentanglement process. The accuracy of temperature regulation is particularly important. An excessively high cooling rate will cause the molecular chains to "freeze" in a non-equilibrium state, while too slow adjustment cannot effectively inhibit the excessive movement of the molecular chains.

[0055] Furthermore, in the preparation process of the hydrogen fuel cell catalyst slurry, the disentanglement behavior of the ionic polymer molecular chains under the action of shear force is not only affected by mechanical force and temperature, but also closely related to the local stress distribution inside the slurry. However, when the shear force changes rapidly, stress concentration may still occur inside the slurry, resulting in local over-shearing or molecular chain breakage. To solve this problem, the inventor introduced an inert gas during the shear process to form a dynamic stress buffer network inside the slurry. These microbubbles can absorb and disperse local stress through deformation and displacement in the shear field, thereby protecting the ionic polymer molecular chains from mechanical damage during the disentanglement process.

[0056] During the implementation process, the inert gas is injected into the slurry through a precise gas distribution system. The injection flow rate is dynamically adjusted according to the decreasing shear force monitored in real time. When the shear force starts to decrease in stages, the gas injection system is immediately started. As the shear force decreases, the gas injection flow rate decreases accordingly. This positive correlation ensures that the density and distribution of the microbubbles always match the current shear conditions.

[0057] The formation and distribution of microbubbles in the slurry are not random. Instead, through a special dispersion device, they are evenly distributed in the high-stress area of the shear field to form an effective stress buffer network. The size of these microbubbles is controlled within the range of 10 - 100 microns, which neither affects the overall rheological properties of the slurry nor provides sufficient stress buffer capacity.

[0058] From the perspective of the action mechanism, the introduction of the microbubble buffer layer changes the stress transfer path inside the slurry. In the traditional process, the change in shear force directly acts on the ionic polymer molecular chains, resulting in stress concentration. After adding microbubbles, the shear stress first acts on the bubble interface, disperses the stress through the deformation and displacement of the bubbles, and then transfers it to the ionic polymer molecular chains in a more gentle way. This stress buffer effect is particularly important when the shear force changes. It can effectively avoid the fracture or non-uniform disentanglement of molecular chains due to sudden stress changes.

[0059] Specifically, the selection of the inert gas is also carefully considered. Usually, chemically inert gases such as nitrogen or argon are used to ensure that they do not react with any components in the slurry and do not affect the subsequent catalyst performance.

[0060] Specifically, in the preparation process of the hydrogen fuel cell catalyst slurry, the thermal cycling treatment is a key step to regulate the molecular chain structure of the ionomer. Therefore, the heating and cooling need to be controlled. In this embodiment, the temperature is first raised to the upper limit of the target temperature at a fixed rate, and after maintaining a constant temperature, it is cooled to the lower limit of the initial temperature at the same rate. Multiple thermal cycling treatments are completed continuously. The symmetric heating and cooling rate design can ensure that the molecular chains experience the same kinetic process during the heating and cooling stages, thus forming a more uniform and stable three-dimensional network structure.

[0061] During the implementation process, first, the slurry is heated from the lower limit of the initial temperature to the upper limit of the target temperature at a precisely controlled fixed rate. This heating process is not simply a temperature increase, but rather promotes the gradual unfolding of the ionomer molecular chains from a relatively contracted state. The secondary bonds between the molecular chains are partially broken, and the segment mobility is enhanced. The constant high-temperature stage allows the molecular chains to fully adjust their conformations under the new thermodynamic conditions and eliminate internal stress. Subsequently, it is cooled at exactly the same rate. This symmetric cooling process enables the molecular chains to re-establish intermolecular interactions in a symmetric manner as when heating, but the structure formed at this time is more ordered and stable. Moreover, the continuous implementation of multiple cycles is not a simple repetition, but through the cumulative effect of the thermal history, the ionomer network structure gradually tends to the optimal state.

[0062] From the perspective of the action mechanism, using the same rate for heating and cooling has multiple advantages: First, the symmetric temperature change rate ensures that the ionomer molecular chains experience the same relaxation time during the heating and cooling stages, avoiding the "memory effect" of the structure caused by asymmetric rates. Second, this design can precisely control the disentanglement and re-aggregation kinetics of the molecular chains, promoting the moderate dissociation of the molecular chains during heating and guiding their orderly reorganization during cooling. Most importantly, multiple consecutive cycle treatments can gradually eliminate the inhomogeneity of the initial structure through the cumulative effect of the thermal history, and finally form a three-dimensional network with an ideal topological structure. This network structure not only has better mechanical stability but also provides a more uniform dispersion environment for the catalyst particles.

[0063] During the implementation process, the inventors found that it is difficult to completely overcome the steric hindrance effect of the molecular chains during the reorganization process simply by relying on temperature changes. Therefore, while performing thermal cycling, a centrifugal force field is further introduced. By alternately applying positive and negative centrifugal force fields, not only a directional driving force is provided for the molecular chain movement, but also the frequency of direction switching is controlled to be synchronized with the temperature change rate, enabling the ionomer molecular chains to achieve isotropic reorganization in three-dimensional space under the most favorable thermodynamic conditions.

[0064] During the implementation process, a positive centrifugal force field is first applied in the heating stage. The action direction of this mechanical force has a synergistic effect with the increasing temperature, promoting the stretching of the ionomer molecular chains along the direction of the force field and breaking the original entanglement structure. When the temperature reaches the upper limit and starts to remain constant, the centrifugal force field is immediately switched to the reverse direction. This sudden change in direction enables the already partially dissociated molecular chains to obtain the spatial freedom for rearrangement while maintaining high-temperature mobility. In the subsequent cooling process, the reverse centrifugal force field continues to act, guiding the molecular chains to form stable secondary bonds in the new orientation. This synchronous control ensures that the stress state of the molecular chains at each temperature point perfectly matches the current thermodynamic conditions, thereby achieving the optimization of energy transfer from the macroscopic force field to the microscopic molecular motion.

[0065] From the perspective of the action mechanism, the introduction of the alternating centrifugal force field changes the single-action mode of traditional heat treatment. The positive centrifugal force field helps overcome the activation energy barrier for molecular chain disentanglement during heating, while the reverse force field promotes the reorganization of molecular chains in the new spatial orientation during cooling. This alternating action mode effectively prevents the over-orientation of molecular chains in a single direction and avoids the resulting structural anisotropy. More importantly, the synchronous design of the force field direction switching and temperature change enables the molecular chains to experience a change in the force direction during the high-temperature stage with the highest mobility. At this time, the molecular chains have sufficient motility to respond to the changes in the external force field, thus achieving a truly three-dimensional uniform reorganization. The synergistic effect of this dynamic force field and thermal cycle creates an isotropic reorganization environment at the molecular level.

[0066] Specifically, in the laminar flow treatment stage, the control of flow velocity and time is achieved through a multi-stage tapered flow channel. The cross-sectional area of the flow channel contracts in multiple stages proportionally, and an equal-cross-section stable section is set after each contraction. Such a multi-stage tapered flow channel can even achieve the control of flow time and flow velocity, making the flow velocity and the continuous flow time meet the requirements. Moreover, the multi-stage tapered flow channel realizes the progressive orientation of molecular chains through a step-by-step acceleration method, avoiding flow instability and structural damage caused by a single drastic contraction.

[0067] During the implementation process, the slurry first enters the first-stage tapered flow channel. The appropriate contraction of the cross-sectional area generates an initial acceleration effect, causing the ionomer molecular chains to start a preliminary orientation along the flow direction. The subsequent equal-cross-section stable section provides relaxation time for the molecular chains, allowing the chain segments to adjust the local conformation while maintaining the main orientation. This alternating pattern of contraction-stabilization is repeated in the multi-stage flow channel, ensuring that the velocity increase gradient always remains within the range that the ionomer molecules can respond well to. The flow velocity at the outlet of the last-stage flow channel reaches the precisely controlled laminar flow state. At this time, the ionomer molecular chains have experienced a smooth acceleration process and formed a uniform pre-orientation structure, laying an ideal foundation for the self-assembly of the subsequent three-dimensional network.

[0068] From the perspective of the action mechanism, although a single-stage large-scale contraction can quickly reach the target flow rate, it will generate an excessive shear rate gradient, leading to excessive stretching of the ionomer molecular chains and local turbulence. In contrast, a multi-stage progressive contraction with small step sizes can maintain a more uniform shear field distribution. The constant cross-section stable section after each stage of contraction plays a dual role: on the one hand, it allows the flow velocity profile to re-develop into a fully developed parabolic distribution, eliminating the entrance effect; on the other hand, it provides the necessary relaxation time for the ionomer molecular chains to prevent stress accumulation. This alternating pattern of "contraction - stabilization" creates a quasi-equilibrium flow environment, enabling the molecular chains to gradually adjust their conformation and orientation state in the most natural way.

[0069] Specifically, although laminar flow treatment can guide the formation of a three-dimensional network structure in ionomers, a completely steady laminar flow field may lead to overly single-chain orientation, making it difficult to form an ideal multi-scale network topology. To solve this problem, on the basis of laminar flow treatment, periodic pulsating perturbations are further introduced. This controlled pulsating perturbation is a dynamic regulation method designed based on an in-depth understanding of the relaxation characteristics of ionomer molecules. By using moderate periodic flow variations, it promotes the interaction and recombination of molecular chains at different scales, thereby constructing a three-dimensional network structure with better connectivity and stability.

[0070] During the implementation process, low-frequency and small-amplitude pulsations are superimposed while maintaining the basic laminar flow. The pulsating perturbations are applied at a frequency of 1 - 5 Hz. This frequency range should be slow enough to ensure that the ionomer molecular chains can fully respond and fast enough to avoid complete flow relaxation. Each perturbation cycle consists of two characteristic stages: during the 0.5 - 2 second flow velocity fluctuation period, the fluid kinetic energy slowly increases, prompting the moderately reorientation of the already partially oriented molecular chains. Subsequently, during the 3 - 5 second stable recovery period, the system is allowed to re-establish equilibrium under the new flow conditions. Moreover, the pulsation amplitude is strictly controlled within 20% of the average flow velocity. This moderate perturbation intensity can effectively promote structural recombination without damaging the already formed network skeleton. Notably, the perturbation parameters are matched with the rheological properties of the slurry to ensure that each pulsation cycle can effectively reach the molecular scale.

[0071] In terms of the mechanism of action, the periodic pulsating perturbation optimizes the network structure through unique kinetic effects. During the rising stage of the pulsation, the moderately increased shear force promotes the generation of new contact points between molecular chains. While during the recovery stage, these newly formed connection points have the opportunity to stabilize at a lower flow energy. This cyclic action essentially creates a dynamic screening mechanism: the weaker inter-chain connections are selectively broken during the pulsation, while the stronger connections are retained and strengthened. More importantly, the pulsating perturbation introduces controllable anisotropy, enabling the finally formed three-dimensional network to not only maintain the necessary structural strength but also possess excellent connectivity of ion transport channels. Another key effect of this micro-perturbation is to break the locally ordered regions that may form in traditional laminar flow, promoting the more uniform distribution and connection of molecular chains throughout the volume.

[0072] Specifically, after the laminar flow treatment, the residual stress within the molecular chains during the rapid flow process and the tiny air bubbles that may be entrained will affect the structural integrity of the final product. Therefore, the slurry is transferred to a vacuum environment for static settlement before subsequent process treatment. Through vacuum static settlement, on the one hand, the oxidation risk that may be brought by the air-slurry interface is eliminated, and on the other hand, the possible residual micro-bubbles in the slurry are induced to spontaneously aggregate and be removed by reducing the environmental pressure.

[0073] Specifically, the static settlement time is not arbitrary but is scientifically determined according to the relaxation time of the molecular characteristics of the ionomer, ensuring that the molecular chains have sufficient time to release the internal stress without being too long to cause excessive relaxation of the network structure. After the ionomer molecular chains get rid of the flow stress, they will spontaneously adjust their spatial conformations and search for a more energy-optimal connection method, ultimately forming a three-dimensional network with intrinsic stability.

[0074] Specifically, to implement the above method, refer to Figure 2 As shown, the present invention also discloses a regulation system for the dynamic dispersion of an ionomer in a hydrogen fuel cell catalyst slurry, which can execute the above method. The system includes:

[0075] A shear force regulation module for applying a shear force field to the catalyst slurry containing the ionomer and controlling the shear force to decrease step by step from an initial preset value to zero, enabling the ionomer to achieve molecular chain disentanglement without breakage under the continuously weakening shear action;

[0076] A thermal cycle treatment module connected to the shear force regulation module for performing at least one heating and cooling thermal cycle treatment on the slurry after shear treatment within a temperature range of 40 - 60 °C, and the number of thermal cycles is the same as the number of times the shear force decreases step by step;

[0077] The laminar flow stabilization module, connected to the thermal cycling processing module, is used to perform laminar flow processing on the processed slurry, control the flow velocity to make the Reynolds number less than 10, and maintain its flow state for at least 30 seconds, so that the ionomer fibers form a three-dimensional disordered network structure through fluid viscous resistance;

[0078] The control unit is communicatively connected to the shear force regulation module, the thermal cycling processing module, and the laminar flow stabilization module respectively, and is used to coordinate the operating parameters and timing relationships of each module.

[0079] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing in the process Figure 1 a process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0081] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements in the process Figure 1 a process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0082] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the process Figure 1 a process or multiple processes and / or blocks Figure 1 a device for the functions specified in one block or multiple blocks.

[0083] Obviously, the above embodiments are merely examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for regulating the dynamic dispersion of an ionomer in a hydrogen fuel cell catalyst slurry, characterized in that: Comprising: Placing a catalyst slurry containing an ionomer in a shear field, controlling the shear force to decrease stepwise from an initial preset value to zero, so that the molecular chains of the ionomer are disentangled without breaking under the continuously weakening shear action; Performing at least one heating and cooling thermal cycle treatment on the slurry after shear treatment in a temperature range of 40 to 60 °C, and the number of times of the thermal cycle is the same as the number of times of the stepwise decrease of the shear force; Performing a laminar flow treatment on the treated slurry, controlling the flow velocity so that the Reynolds number is less than 10, and maintaining its flow state for at least 30 s, and forming a three-dimensional disordered network structure of ionomer fibers through the viscous resistance of the fluid; 2. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: During the stepwise decrease of the shear force, the change of the slurry viscosity is monitored in real time by an on-line viscometer, and the gradient of the stepwise decrease of the shear force is controlled to be dynamically adjusted according to the viscosity-shear force correlation curve, so that the disentanglement rate of the ionomer molecular chains matches the shear force attenuation rate; 3. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: During the stepwise decrease of the shear force, the temperature of the slurry is synchronously adjusted, the temperature of the slurry is monitored in real time by a temperature sensor, and the heating power is dynamically adjusted according to a preset shear field strength-temperature correlation model. When the shear field strength decreases, the temperature of the slurry is correspondingly decreased to maintain a constant ionomer disentanglement kinetic condition; 4. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: During the stepwise decrease of the shear force, an inert gas is synchronously injected to form a microbubble buffer layer inside the slurry, and the gas injection flow rate is positively correlated with the decrease of the shear force; 5. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: The thermal cycle treatment includes first heating to the upper limit of the target temperature at a fixed rate, maintaining a constant temperature, and then cooling to the lower limit of the initial temperature at the same rate, and multiple thermal cycle treatments are completed continuously; 6. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: During the thermal cycle treatment, a positive and a reverse centrifugal force field are alternately applied, and the direction switching frequency is synchronized with the temperature change rate; 7. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: In the laminar flow treatment stage, the flow velocity is controlled by a multi-stage tapered flow channel, the cross-sectional area of the flow channel is contracted in multiple stages proportionally, and an equal-cross-section stable section is arranged after each contraction; 8. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: In the laminar flow treatment stage, a periodic pulsating disturbance is introduced, the disturbance frequency is 1 to 5 Hz, the pulsating amplitude does not exceed 20% of the average flow velocity, and each disturbance cycle includes a flow velocity fluctuation of 0.5 to 2 seconds and a stable recovery period of 3 to 5 seconds; 9. The method for regulating the dynamic dispersion of the ionomer in the hydrogen fuel cell catalyst slurry according to claim 1, wherein: After the laminar flow treatment, the slurry is transferred to a vacuum environment and left standing before subsequent process treatment; 10. A control system for dynamically dispersing an ionomer of a hydrogen fuel cell catalyst slurry, characterized in that, Comprising: A shear force regulation module for applying a shear force field to a catalyst slurry containing an ionomer and controlling the shear force to decrease stepwise from an initial preset value to zero, so that the molecular chains of the ionomer are disentangled without breaking under the continuously weakening shear action; A thermal cycle treatment module connected to the shear force regulation module for performing at least one heating and cooling thermal cycle treatment on the slurry after shear treatment in a temperature range of 40 to 60 °C, and the number of times of the thermal cycle is the same as the number of times of the stepwise decrease of the shear force; A laminar flow stabilization module connected to the thermal cycle treatment module for performing a laminar flow treatment on the treated slurry, controlling the flow velocity so that the Reynolds number is less than 10, and maintaining its flow state for at least 30 seconds, and forming a three-dimensional disordered network structure of ionomer fibers through the viscous resistance of the fluid; A control unit, which is communicatively connected to the shear force regulation module, the thermal cycling treatment module, and the laminar flow stabilization module respectively, is used to coordinate the operating parameters and timing relationships of each module.

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